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<CFRDOC xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="CFRMergedXML.xsd">
    <AMDDATE>Mar. 28, 2025</AMDDATE>
    <FMTR>
        <TITLEPG>
            <CODE/>
            <PRTPAGE P="1"/>
            <TITLENUM>Title 40</TITLENUM>
            <SUBJECT>Protection of Environment</SUBJECT>
            <PARTS>Parts 136 to 149</PARTS>
            <REVISED>Revised as of July 1, 2025</REVISED>
            <CONTAINS>Containing a codification of documents of general applicability and future effect</CONTAINS>
            <DATE>As of July 1, 2025</DATE>
            <PUB>
                <P>Published by the Office of the Federal Register National Archives and Records Administration as a Special Edition of the Federal Register</P>
            </PUB>
        </TITLEPG>
        <BTITLE>
            <OENOTICE>
                <PRTPAGE P="?ii"/>
                <HD SOURCE="HED">U.S. GOVERNMENT OFFICIAL EDITION NOTICE</HD>
                <HD SOURCE="HED">Legal Status and Use of Seals and Logos</HD>
                <GPH SPAN="1" DEEP="54" HTYPE="LEFT">
                    <GID>archives.ai</GID>
                </GPH>
                <P>The seal of the National Archives and Records Administration (NARA) authenticates the Code of Federal Regulations (CFR) as the official codification of Federal regulations established under the Federal Register Act. Under the provisions of 44 U.S.C. 1507, the contents of the CFR, a special edition of the Federal Register, shall be judicially noticed. The CFR is prima facie evidence of the original documents published in the Federal Register (44 U.S.C. 1510).</P>
                <P>It is prohibited to use NARA's official seal and the stylized Code of Federal Regulations logo on any republication of this material without the express, written permission of the Archivist of the United States or the Archivist's designee. Any person using NARA's official seals and logos in a manner inconsistent with the provisions of 36 CFR part 1200 is subject to the penalties specified in 18 U.S.C. 506, 701, and 1017.</P>
                <HD SOURCE="HED">Use of ISBN Prefix</HD>
                <P>This is the Official U.S. Government edition of this publication and is herein identified to certify its authenticity. Use of the 0-16 ISBN prefix is for U.S. Government Publishing Office Official Editions only. The Superintendent of Documents of the U.S. Government Publishing Office requests that any reprinted edition clearly be labeled as a copy of the authentic work with a new ISBN.</P>
            </OENOTICE>
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                    <GID>e:\seals\gpologo2.eps</GID>
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                <P>U . S . G O V E R N M E N T P U B L I S H I N G O F F I C E</P>
            </GPO>
            <SUDOCS>
                <P>U.S. Superintendent of Documents • Washington, DC 20402-0001</P>
                <P>http://bookstore.gpo.gov</P>
                <P>Phone: toll-free (866) 512-1800; DC area (202) 512-1800</P>
            </SUDOCS>
        </BTITLE>
        <TOC>
            <PRTPAGE P="iii"/>
            <HD SOURCE="HED">Table of Contents</HD>
            <PGHD>Page</PGHD>
            <EXPL>
                <SUBJECT>Explanation</SUBJECT>
                <PG>v</PG>
            </EXPL>
            <TITLENO>
                <HD SOURCE="HED">Title 40:</HD>
                <CHAPTI>
                    <SUBJECT>Chapter I—Environmental Protection Agency (Continued)</SUBJECT>
                    <PG>3</PG>
                </CHAPTI>
            </TITLENO>
            <FAIDS>
                <HD SOURCE="HED">Finding Aids:</HD>
                <SUBJECT>Table of CFR Titles and Chapters</SUBJECT>
                <PG>1177</PG>
                <SUBJECT>Alphabetical List of Agencies Appearing in the CFR</SUBJECT>
                <PG>1197</PG>
                <SUBJECT>List of CFR Sections Affected</SUBJECT>
                <PG>1207</PG>
            </FAIDS>
        </TOC>
        <CITE>
            <PRTPAGE P="iv"/>
            <P>
                Cite this Code: 
                <E T="01">CFR</E>
            </P>
            <CITEP>
                To cite the regulations in this volume use title, part and section number. Thus, 
                <E T="01">40 CFR 136.1</E>
                 refers to title 40, part 136, section 1.
            </CITEP>
        </CITE>
        <EXPLA>
            <PRTPAGE P="v"/>
            <HD SOURCE="HED">Explanation</HD>
            <P>The Code of Federal Regulations is a codification of the general and permanent rules published in the Federal Register by the Executive departments and agencies of the Federal Government. The Code is divided into 50 titles which represent broad areas subject to Federal regulation. Each title is divided into chapters which usually bear the name of the issuing agency. Each chapter is further subdivided into parts covering specific regulatory areas.</P>
            <P>Each volume of the Code is revised at least once each calendar year and issued on a quarterly basis approximately as follows:</P>
            <IPAR>
                <P SOURCE="P1">Title 1 through Title 16 </P>
                <STUB>as of January 1</STUB>
                <P SOURCE="P1">Title 17 through Title 27 </P>
                <STUB>as of April 1</STUB>
                <P SOURCE="P1">Title 28 through Title 41 </P>
                <STUB>as of July 1</STUB>
                <P SOURCE="P1">Title 42 through Title 50 </P>
                <STUB>as of October 1</STUB>
            </IPAR>
            <P>The appropriate revision date is printed on the cover of each volume.</P>
            <SIDEHED>
                <HD SOURCE="HED">LEGAL STATUS</HD>
                <P>The contents of the Federal Register are required to be judicially noticed (44 U.S.C. 1507). The Code of Federal Regulations is prima facie evidence of the text of the original documents (44 U.S.C. 1510).</P>
            </SIDEHED>
            <SIDEHED>
                <HD SOURCE="HED">HOW TO USE THE CODE OF FEDERAL REGULATIONS</HD>
                <P>The Code of Federal Regulations is kept up to date by the individual issues of the Federal Register. These two publications must be used together to determine the latest version of any given rule.</P>
                <P>To determine whether a Code volume has been amended since its revision date (in this case, July 1, 2025), consult the “List of CFR Sections Affected (LSA),” which is issued monthly, and the “Cumulative List of Parts Affected,” which appears in the Reader Aids section of the daily Federal Register. These two lists will identify the Federal Register page number of the latest amendment of any given rule.</P>
            </SIDEHED>
            <SIDEHED>
                <HD SOURCE="HED">EFFECTIVE AND EXPIRATION DATES</HD>
                <P>Each volume of the Code contains amendments published in the Federal Register since the last revision of that volume of the Code. Source citations for the regulations are referred to by volume number and page number of the Federal Register and date of publication. Publication dates and effective dates are usually not the same and care must be exercised by the user in determining the actual effective date. In instances where the effective date is beyond the cut-off date for the Code a note has been inserted to reflect the future effective date. In those instances where a regulation published in the Federal Register states a date certain for expiration, an appropriate note will be inserted following the text.</P>
            </SIDEHED>
            <SIDEHED>
                <HD SOURCE="HED">OMB CONTROL NUMBERS</HD>
                <P>
                    The Paperwork Reduction Act of 1980 (Pub. L. 96-511) requires Federal agencies to display an OMB control number with their information collection request. 
                    <PRTPAGE P="vi"/>
                    Many agencies have begun publishing numerous OMB control numbers as amendments to existing regulations in the CFR. These OMB numbers are placed as close as possible to the applicable recordkeeping or reporting requirements.
                </P>
            </SIDEHED>
            <SIDEHED>
                <HD SOURCE="HED">PAST PROVISIONS OF THE CODE</HD>
                <P>Provisions of the Code that are no longer in force and effect as of the revision date stated on the cover of each volume are not carried. Code users may find the text of provisions in effect on any given date in the past by using the appropriate List of CFR Sections Affected (LSA). For the convenience of the reader, a “List of CFR Sections Affected” is published at the end of each CFR volume. For changes to the Code prior to the LSA listings at the end of the volume, consult previous annual editions of the LSA. For changes to the Code prior to 2001, consult the List of CFR Sections Affected compilations, published for 1949-1963, 1964-1972, 1973-1985, and 1986-2000.</P>
            </SIDEHED>
            <SIDEHED>
                <HD SOURCE="HED">“[RESERVED]” TERMINOLOGY</HD>
                <P>The term “[Reserved]” is used as a place holder within the Code of Federal Regulations. An agency may add regulatory information at a “[Reserved]” location at any time. Occasionally “[Reserved]” is used editorially to indicate that a portion of the CFR was left vacant and not dropped in error.</P>
            </SIDEHED>
            <SIDEHED>
                <HD SOURCE="HED">INCORPORATION BY REFERENCE</HD>
                <P>
                    <E T="03">What is incorporation by reference?</E>
                     Incorporation by reference was established by statute and allows Federal agencies to meet the requirement to publish regulations in the Federal Register by referring to materials already published elsewhere. For an incorporation to be valid, the Director of the Federal Register must approve it. The legal effect of incorporation by reference is that the material is treated as if it were published in full in the Federal Register (5 U.S.C. 552(a)). This material, like any other properly issued regulation, has the force of law.
                </P>
                <P>
                    <E T="03">What is a proper incorporation by reference?</E>
                     The Director of the Federal Register will approve an incorporation by reference only when the requirements of 1 CFR part 51 are met. Some of the elements on which approval is based are:
                </P>
                <P>(a) The incorporation will substantially reduce the volume of material published in the Federal Register.</P>
                <P>(b) The matter incorporated is adequately summarized in the preamble of the final rule and is available to the extent necessary to afford fairness and uniformity in the administrative process.</P>
                <P>(c) The incorporating document is drafted and submitted for publication in accordance with 1 CFR part 51.</P>
                <P>
                    <E T="03">What if the material incorporated by reference cannot be found?</E>
                     If you have any problem locating or obtaining a copy of material listed as an approved incorporation by reference, please contact the agency that issued the regulation containing that incorporation. If, after contacting the agency, you find the material is not available, please notify the Director of the Federal Register, National Archives and Records Administration, 8601 Adelphi Road, College Park, MD 20740-6001, or email fr.inspection@nara.gov.
                </P>
            </SIDEHED>
            <SIDEHED>
                <HD SOURCE="HED">CFR INDEXES AND TABULAR GUIDES</HD>
                <P>
                    A subject index to the Code of Federal Regulations is contained in a separate volume, revised annually as of January 1, entitled CFR 
                    <E T="04">Index and Finding Aids.</E>
                     This volume contains the Parallel Table of Authorities and Rules. A list of CFR titles, chapters, subchapters, and parts and an alphabetical list of agencies publishing in the CFR are also included in this volume.
                    <PRTPAGE P="vii"/>
                </P>
                <P>An index to the text of “Title 3—The President” is carried within that volume.</P>
                <P>The Federal Register Index is issued monthly in cumulative form. This index is based on a consolidation of the “Contents” entries in the daily Federal Register.</P>
                <P>A List of CFR Sections Affected (LSA) is published monthly, keyed to the revision dates of the 50 CFR titles.</P>
            </SIDEHED>
            <SIDEHED>
                <HD SOURCE="HED">REPUBLICATION OF MATERIAL</HD>
                <P>There are no restrictions on the republication of material appearing in the Code of Federal Regulations.</P>
            </SIDEHED>
            <SIDEHED>
                <HD SOURCE="HED">INQUIRIES</HD>
                <P>For a legal interpretation or explanation of any regulation in this volume, contact the issuing agency. The issuing agency's name appears at the top of odd-numbered pages.</P>
                <P>
                    For inquiries concerning CFR reference assistance, call 202-741-6000 or write to the Director, Office of the Federal Register, National Archives and Records Administration, 8601 Adelphi Road, College Park, MD 20740-6001 or e-mail 
                    <E T="03">fedreg.info@nara.gov.</E>
                </P>
            </SIDEHED>
            <SIDEHED>
                <HD SOURCE="HED">SALES</HD>
                <P>The Government Publishing Office (GPO) processes all sales and distribution of the CFR. For payment by credit card, call toll-free, 866-512-1800, or DC area, 202-512-1800, M-F 8 a.m. to 4 p.m. e.s.t. or fax your order to 202-512-2104, 24 hours a day. For payment by check, write to: U.S. Government Publishing Office Superintendent of Documents, P.O. Box 37082, Washington, DC 20013-7082.</P>
            </SIDEHED>
            <SIDEHED>
                <HD SOURCE="HED">ELECTRONIC SERVICES</HD>
                <P>
                    The full text of the Code of Federal Regulations, the LSA (List of CFR Sections Affected), The United States Government Manual, the Federal Register, Public Laws, Compilation of Presidential Documents and the Privacy Act Compilation are available in electronic format via 
                    <E T="03">www.govinfo.gov.</E>
                     For more information, contact the GPO Customer Contact Center, U.S. Government Publishing Office. Phone 202-512-1800, or 866-512-1800 (toll-free). E-mail, 
                    <E T="03">ContactCenter@gpo.gov.</E>
                </P>
                <P>
                    The Office of the Federal Register also offers a free service on the National Archives and Records Administration's (NARA) website for public law numbers, Federal Register finding aids, and related information. Connect to NARA's website at 
                    <E T="03">www.archives.gov/federal-register.</E>
                </P>
                <P>
                    The eCFR is a regularly updated, unofficial editorial compilation of CFR material and Federal Register amendments, produced by the Office of the Federal Register and the Government Publishing Office. It is available at 
                    <E T="03">www.ecfr.gov.</E>
                </P>
                <P>
                    <E T="04">Oliver A. Potts,</E>
                </P>
                <P>
                    <E T="03">Director,</E>
                </P>
                <P>
                    <E T="03">Office of the Federal Register</E>
                </P>
                <P>
                    <E T="03">July 1, 2025</E>
                </P>
            </SIDEHED>
            <SIG>
                <NAME> </NAME>
                <POSITION> </POSITION>
                <OFFICE> </OFFICE>
            </SIG>
            <DATE> </DATE>
        </EXPLA>
        <THISTITL>
            <PRTPAGE P="ix"/>
            <HD SOURCE="HED">THIS TITLE</HD>
            <P>
                Title 40—
                <E T="04">Protection of Environment</E>
                 is composed of thirty-seven volumes. The parts in these volumes are arranged in the following order: Parts 1-49, parts 50-51, part 52 (52.01-52.1018), part 52 (52.1019-52.2019), part 52 (52.2020-end of part 52), parts 53-59, part 60 (60.1-60.499), part 60 (60.500-end of part 60, sections), part 60 (Appendices), parts 61-62, part 63 (63.1-63.599), part 63 (63.600-63.1199), part 63 (63.1200-63.1439), part 63 (63.1440-63.6175), part 63 (63.6580-63.8830), part 63 (63.8980-end of part 63), parts 64-71, parts 72-79, part 80, part 81, parts 82-84, parts 85-96, parts 97-99, parts 100-135, parts 136-149, parts 150-189, parts 190-259, parts 260-265, parts 266-299, parts 300-399, parts 400-424, parts 425-699, parts 700-722, parts 723-789, parts 790-999, parts 1000-1059, and part 1060 to end. The contents of these volumes represent all current regulations codified under this title of the CFR as of July 1, 2025.
            </P>
            <P>Chapter I—Environmental Protection Agency appears in all thirty-seven volumes. OMB control numbers for title 40 appear in § 9.1 of this chapter.</P>
            <P>Chapters IV-IX—Regulations issued by the Environmental Protection Agency and Department of Justice, Council on Environmental Quality, Chemical Safety and Hazard Investigation Board, Environmental Protection Agency and Department of Defense; Uniform National Discharge Standards for Vessels of the Armed Forces, Gulf Coast Ecosystem Restoration Council, and the Federal Permitting Improvement Steering Council appear in volume thirty-seven.</P>
            <P>For this volume, Cheryl E. Sirofchuck was Chief Editor. The Code of Federal Regulations publication program is under the direction of John Hyrum Martinez, assisted by Stephen J. Frattini.</P>
        </THISTITL>
    </FMTR>
    <TITLE>
        <LRH>40 CFR Ch. I (7-1-25 Edition)</LRH>
        <RRH>Environmental Protection Agency</RRH>
        <CFRTITLE>
            <TITLEHD>
                <PRTPAGE P="1"/>
                <HD SOURCE="HED">Title 40—Protection of Environment</HD>
                <P>(This book contains parts 136 to 149)</P>
            </TITLEHD>
            <CFRTOC>
                <PTHD>Part</PTHD>
                <CHAPTI>
                    <SUBJECT>
                        <E T="04">chapter i</E>
                        —Environmental Protection Agency (Continued)
                    </SUBJECT>
                    <PG>136</PG>
                </CHAPTI>
            </CFRTOC>
        </CFRTITLE>
        <CHAPTER>
            <TOC>
                <TOCHD>
                    <PRTPAGE P="3"/>
                    <HD SOURCE="HED">CHAPTER I—ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)</HD>
                </TOCHD>
                <EDNOTE>
                    <HD SOURCE="HED">Editorial Note:</HD>
                    <P>Nomenclature changes to chapter I appear at 65 FR 47324, 47325, Aug. 2, 2000, and at 66 FR 34375, 34376, June 28, 2001.</P>
                </EDNOTE>
                <SUBCHAP>
                    <HD SOURCE="HED">SUBCHAPTER D—WATER PROGRAMS (CONTINUED)</HD>
                </SUBCHAP>
                <PTHD>Part</PTHD>
                <PGHD>Page</PGHD>
                <CHAPTI>
                    <PT>136</PT>
                    <SUBJECT>Guidelines establishing test procedures for the analysis of pollutants</SUBJECT>
                    <PG>5</PG>
                    <PT>139</PT>
                    <SUBJECT>Discharges incidental to the normal operation of vessels</SUBJECT>
                    <PG>420</PG>
                    <PT>140</PT>
                    <SUBJECT>Marine sanitation device standard</SUBJECT>
                    <PG>467</PG>
                    <PT>141</PT>
                    <SUBJECT>National primary drinking water regulations</SUBJECT>
                    <PG>471</PG>
                    <PT>142</PT>
                    <SUBJECT>National primary drinking water regulations implementation</SUBJECT>
                    <PG>840</PG>
                    <PT>143</PT>
                    <SUBJECT>Other safe drinking water regulations</SUBJECT>
                    <PG>904</PG>
                    <PT>144</PT>
                    <SUBJECT>Underground injection control program</SUBJECT>
                    <PG>912</PG>
                    <PT>145</PT>
                    <SUBJECT>State UIC program requirements</SUBJECT>
                    <PG>982</PG>
                    <PT>146</PT>
                    <SUBJECT>Underground injection control program: Criteria and standards</SUBJECT>
                    <PG>995</PG>
                    <PT>147</PT>
                    <SUBJECT>State, tribal, and EPA-administered underground injection control programs</SUBJECT>
                    <PG>1048</PG>
                    <PT>148</PT>
                    <SUBJECT>Hazardous waste injection restrictions</SUBJECT>
                    <PG>1161</PG>
                    <PT>149</PT>
                    <SUBJECT>Sole source aquifers</SUBJECT>
                    <PG>1170</PG>
                </CHAPTI>
            </TOC>
            <SUBCHAP TYPE="N">
                <PRTPAGE P="5"/>
                <HD SOURCE="HED">SUBCHAPTER D—WATER PROGRAMS (CONTINUED)</HD>
                <PART>
                    <EAR>Pt. 136</EAR>
                    <HD SOURCE="HED">PART 136—GUIDELINES ESTABLISHING TEST PROCEDURES FOR THE ANALYSIS OF POLLUTANTS</HD>
                    <CONTENTS>
                        <SECHD>Sec.</SECHD>
                        <SECTNO>136.1</SECTNO>
                        <SUBJECT>Applicability.</SUBJECT>
                        <SECTNO>136.2</SECTNO>
                        <SUBJECT>Definitions.</SUBJECT>
                        <SECTNO>136.3</SECTNO>
                        <SUBJECT>Identification of test procedures.</SUBJECT>
                        <SECTNO>136.4</SECTNO>
                        <SUBJECT>Application for and approval of alternate test procedures for nationwide use.</SUBJECT>
                        <SECTNO>136.5</SECTNO>
                        <SUBJECT>Approval of alternate test procedures for limited use.</SUBJECT>
                        <SECTNO>136.6</SECTNO>
                        <SUBJECT>Method modifications and analytical requirements.</SUBJECT>
                        <SECTNO>136.7</SECTNO>
                        <SUBJECT>Quality assurance and quality control.</SUBJECT>
                        <APP>Appendix A to Part 136—Methods for Organic Chemical Analysis of Municipal and Industrial Wastewater</APP>
                        <APP>Appendix B to Part 136—Definition and Procedure for the Determination of the Method Detection Limit—Revision 1.11</APP>
                        <APP>Appendix C to Part 136—Determination of Metals and Trace Elements in Water and Wastes by Inductively Coupled Plasma-Atomic Emission Spectrometry Method 200.7</APP>
                        <APP>Appendix D to Part 136—Precision and Recovery Statements for Methods for Measuring Metals</APP>
                    </CONTENTS>
                    <AUTH>
                        <HD SOURCE="HED">Authority:</HD>
                        <P>
                            Secs. 301, 304(h), 307 and 501(a), Pub. L. 95-217, 91 Stat. 1566, 
                            <E T="03">et seq.</E>
                             (33 U.S.C. 1251, 
                            <E T="03">et seq.</E>
                            ) (the Federal Water Pollution Control Act Amendments of 1972 as amended by the Clean Water Act of 1977).
                        </P>
                    </AUTH>
                    <SECTION>
                        <SECTNO>§ 136.1</SECTNO>
                        <SUBJECT>Applicability.</SUBJECT>
                        <P>(a) The procedures prescribed herein shall, except as noted in §§ 136.4, 136.5, and 136.6, be used to perform the measurements indicated whenever the waste constituent specified is required to be measured for:</P>
                        <P>(1) An application submitted to the Director and/or reports required to be submitted under NPDES permits or other requests for quantitative or qualitative effluent data under parts 122 through 125 of this chapter; and</P>
                        <P>(2) Reports required to be submitted by dischargers under the NPDES established by parts 124 and 125 of this chapter; and</P>
                        <P>(3) Certifications issued by States pursuant to section 401 of the Clean Water Act (CWA), as amended.</P>
                        <P>(b) The procedure prescribed herein and in part 503 of title 40 shall be used to perform the measurements required for an application submitted to the Administrator or to a State for a sewage sludge permit under section 405(f) of the Clean Water Act and for recordkeeping and reporting requirements under part 503 of title 40.</P>
                        <P>(c) For the purposes of the NPDES program, when more than one test procedure is approved under this part for the analysis of a pollutant or pollutant parameter, the test procedure must be sufficiently sensitive as defined at 40 CFR 122.21(e)(3) and 122.44(i)(1)(iv).</P>
                        <CITA>[72 FR 14224, Mar. 26, 2007, as amended at 77 FR 29771, May 18, 2012; 79 FR 49013, Aug. 19, 2014; 82 FR 40846, Aug. 28, 2017]</CITA>
                    </SECTION>
                    <SECTION>
                        <SECTNO>§ 136.2</SECTNO>
                        <SUBJECT>Definitions.</SUBJECT>
                        <P>As used in this part, the term:</P>
                        <P>
                            (a) 
                            <E T="03">Act</E>
                             means the Clean Water Act of 1977, Pub. L. 95-217, 91 Stat. 1566, 
                            <E T="03">et seq.</E>
                             (33 U.S.C. 1251 
                            <E T="03">et seq.</E>
                            ) (The Federal Water Pollution Control Act Amendments of 1972 as amended by the Clean Water Act of 1977).
                        </P>
                        <P>
                            (b) 
                            <E T="03">Administrator</E>
                             means the Administrator of the U.S. Environmental Protection Agency.
                        </P>
                        <P>
                            (c) 
                            <E T="03">Regional Administrator</E>
                             means one of the EPA Regional Administrators.
                        </P>
                        <P>
                            (d) 
                            <E T="03">Director</E>
                             means the director as defined in 40 CFR 122.2.
                        </P>
                        <P>
                            (e) 
                            <E T="03">National Pollutant Discharge Elimination System (NPDES)</E>
                             means the national system for the issuance of permits under section 402 of the Act and includes any State or interstate program which has been approved by the Administrator, in whole or in part, pursuant to section 402 of the Act.
                        </P>
                        <P>
                            (f) 
                            <E T="03">Detection limit</E>
                             means the minimum concentration of an analyte (substance) that can be measured and reported with a 99% confidence that the analyte concentration is distinguishable from the method blank results as determined by the procedure set forth at appendix B of this part.
                        </P>
                        <CITA>[38 FR 28758, Oct. 16, 1973, as amended at 49 FR 43250, Oct. 26, 1984; 82 FR 40846, Aug. 28, 2017]</CITA>
                    </SECTION>
                    <SECTION>
                        <PRTPAGE P="6"/>
                        <SECTNO>§ 136.3</SECTNO>
                        <SUBJECT>Identification of test procedures.</SUBJECT>
                        <P>
                            (a) Parameters or pollutants, for which methods are approved, are listed together with test procedure descriptions and references in Tables IA, IB, IC, ID, IE, IF, IG, and IH of this section. The methods listed in Tables IA, IB, IC, ID, IE, IF, IG, and IH are incorporated by reference, see paragraph (b) of this section, with the exception of EPA Methods 200.7, 601-613, 624.1, 625.1, 1613, 1624, and 1625. The full texts of Methods 601-613, 624.1, 625.1, 1613, 1624, and 1625 are printed in appendix A of this part, and the full text of Method 200.7 is printed in appendix C of this part. The full text for determining the method detection limit when using the test procedures is given in appendix B of this part. In the event of a conflict between the reporting requirements of 40 CFR parts 122 and 125 and any reporting requirements associated with the methods listed in these tables, the provisions of 40 CFR parts 122 and 125 are controlling and will determine a permittee's reporting requirements. The full texts of the referenced test procedures are incorporated by reference into Tables IA, IB, IC, ID, IE, IF, IG, and IH. The date after the method number indicates the latest editorial change of the method. The discharge parameter values for which reports are required must be determined by one of the standard analytical test procedures incorporated by reference and described in Tables IA, IB, IC, ID, IE, IF, IG, and IH or by any alternate test procedure which has been approved by the Administrator under the provisions of paragraph (d) of this section and §§ 136.4 and 136.5. Under certain circumstances (paragraph (c) of this section, § 136.5(a) through (d) or 40 CFR 401.13,) other additional or alternate test procedures may be used.
                            <PRTPAGE P="7"/>
                        </P>
                        <GPOTABLE COLS="6" OPTS="L2,nj,p7,7/8" CDEF="s100,r100,r50,r60,r50,r50">
                            <TTITLE>Table IA—List of Approved Biological Methods for Wastewater and Sewage Sludge</TTITLE>
                            <BOXHD>
                                <CHED H="1">Parameter and units</CHED>
                                <CHED H="1">
                                    Method 
                                    <SU>1</SU>
                                </CHED>
                                <CHED H="1">EPA</CHED>
                                <CHED H="1">Standard methods</CHED>
                                <CHED H="1">AOAC, ASTM, USGS</CHED>
                                <CHED H="1">Other</CHED>
                            </BOXHD>
                            <ROW EXPSTB="05" RUL="s">
                                <ENT I="21">
                                    <E T="02">Bacteria</E>
                                </ENT>
                            </ROW>
                            <ROW EXPSTB="00">
                                <ENT I="01">1. Coliform (fecal), number per gram dry weight</ENT>
                                <ENT>Most Probable Number (MPN), 5 tube, 3 dilution, or</ENT>
                                <ENT O="xl">
                                    p. 132 
                                    <SU>3</SU>
                                    , 1680 
                                    <SU>11</SU>
                                     
                                    <SU>15</SU>
                                    , 1681.
                                    <SU>11</SU>
                                     
                                    <SU>20</SU>
                                </ENT>
                                <ENT O="xl">9221 E-2014.</ENT>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    Membrane filter (MF) 
                                    <SU>2</SU>
                                     
                                    <SU>5</SU>
                                    , single step
                                </ENT>
                                <ENT>
                                    p. 124 
                                    <SU>3</SU>
                                </ENT>
                                <ENT O="xl">
                                    9222 D-2015.
                                    <SU>29</SU>
                                </ENT>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                            </ROW>
                            <ROW>
                                <ENT I="01">2. Coliform (fecal), number per 100 mL</ENT>
                                <ENT>MPN, 5 tube, 3 dilution, or</ENT>
                                <ENT>
                                    p. 132 
                                    <SU>3</SU>
                                </ENT>
                                <ENT O="xl">
                                    9221 E-2014, 9221 F-2014.
                                    <SU>33</SU>
                                </ENT>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Multiple tube/multiple well, or</ENT>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                                <ENT>
                                    Colilert-18®.
                                    <SU>13</SU>
                                     
                                    <SU>18</SU>
                                     
                                    <SU>28</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    MF 
                                    <SU>2</SU>
                                     
                                    <SU>5</SU>
                                    , single step 
                                    <SU>5</SU>
                                </ENT>
                                <ENT>
                                    p. 124 
                                    <SU>3</SU>
                                </ENT>
                                <ENT>
                                    9222 D-2015. 
                                    <SU>29</SU>
                                </ENT>
                                <ENT O="xl">
                                    B-0050-85. 
                                    <SU>4</SU>
                                </ENT>
                                <ENT O="xl"/>
                            </ROW>
                            <ROW>
                                <ENT I="01">3. Coliform (total), number per 100 mL</ENT>
                                <ENT>MPN, 5 tube, 3 dilution, or</ENT>
                                <ENT>
                                    p. 114 
                                    <SU>3</SU>
                                </ENT>
                                <ENT O="xl">9221 B-2014.</ENT>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    MF 
                                    <SU>2</SU>
                                     
                                    <SU>5</SU>
                                    , single step or
                                </ENT>
                                <ENT>
                                    p. 108 
                                    <SU>3</SU>
                                </ENT>
                                <ENT O="xl">
                                    9222 B-2015. 
                                    <SU>30</SU>
                                </ENT>
                                <ENT O="xl">
                                    B-0025-85.
                                    <SU>4</SU>
                                </ENT>
                                <ENT O="xl"/>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    MF 
                                    <SU>2</SU>
                                     
                                    <SU>5</SU>
                                    , two step with enrichment
                                </ENT>
                                <ENT>
                                    p. 111 
                                    <SU>3</SU>
                                </ENT>
                                <ENT>
                                    9222 B-2015.
                                    <SU>30</SU>
                                </ENT>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    4. 
                                    <E T="03">E. coli,</E>
                                     number per 100 mL
                                </ENT>
                                <ENT>
                                    MPN 
                                    <SU>6</SU>
                                     
                                    <SU>8</SU>
                                     
                                    <SU>16</SU>
                                     multiple tube, or
                                </ENT>
                                <ENT O="xl"/>
                                <ENT O="xl">
                                    9221 B2014/9221 F-2014.
                                    <SU>12</SU>
                                     
                                    <SU>14</SU>
                                     
                                    <SU>33</SU>
                                </ENT>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>multiple tube/multiple well, or</ENT>
                                <ENT/>
                                <ENT>
                                    9223 B-2016. 
                                    <SU>13</SU>
                                </ENT>
                                <ENT>
                                    991.15 
                                    <SU>10</SU>
                                </ENT>
                                <ENT>
                                    Colilert®.
                                    <SU>13</SU>
                                     
                                    <SU>18</SU>
                                    <LI>
                                        Colilert-18®.
                                        <SU>13</SU>
                                         
                                        <SU>17</SU>
                                         
                                        <SU>18</SU>
                                    </LI>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    MF 
                                    <SU>2</SU>
                                     
                                    <SU>5</SU>
                                     
                                    <SU>6</SU>
                                     
                                    <SU>7</SU>
                                     
                                    <SU>8</SU>
                                    , two step, or
                                </ENT>
                                <ENT/>
                                <ENT O="xl">
                                    9222 B-2015/9222 I-2015.
                                    <SU>31</SU>
                                </ENT>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Single step</ENT>
                                <ENT>
                                    1603.1 
                                    <SU>21</SU>
                                </ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    m-ColiBlue24®.
                                    <SU>19</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">5. Fecal streptococci, number per 100 mL</ENT>
                                <ENT>MPN, 5 tube, 3 dilution, or</ENT>
                                <ENT>
                                    p. 139 
                                    <SU>3</SU>
                                </ENT>
                                <ENT O="xl">9230 B-2013.</ENT>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    MF 
                                    <SU>2</SU>
                                    , or
                                </ENT>
                                <ENT>
                                    p. 136 
                                    <SU>3</SU>
                                </ENT>
                                <ENT>
                                    9230 C-2013 
                                    <SU>32</SU>
                                </ENT>
                                <ENT O="xl">
                                    B-0055-85.
                                    <SU>4</SU>
                                </ENT>
                                <ENT O="xl"/>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Plate count</ENT>
                                <ENT>
                                    p. 143 
                                    <SU>3</SU>
                                </ENT>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                            </ROW>
                            <ROW>
                                <ENT I="01">6. Enterococci, number per 100 mL</ENT>
                                <ENT>MPN, 5 tube, 3 dilution, or</ENT>
                                <ENT>
                                    p. 139 
                                    <SU>3</SU>
                                </ENT>
                                <ENT O="xl">9230 B-2013.</ENT>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    MPN 
                                    <SU>6</SU>
                                     
                                    <SU>8</SU>
                                    , multiple tube/multiple well, or
                                </ENT>
                                <ENT O="xl"/>
                                <ENT>9230 D-2013</ENT>
                                <ENT>
                                    D6503-99 
                                    <SU>9</SU>
                                </ENT>
                                <ENT>
                                    Enterolert®.
                                    <SU>13</SU>
                                     
                                    <SU>23</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    MF 
                                    <SU>2</SU>
                                     
                                    <SU>5</SU>
                                     
                                    <SU>6</SU>
                                     
                                    <SU>7</SU>
                                     
                                    <SU>8</SU>
                                     single step or
                                </ENT>
                                <ENT>
                                    1600.1 
                                    <SU>24</SU>
                                </ENT>
                                <ENT O="xl">
                                    9230 C-2013.
                                    <SU>32</SU>
                                </ENT>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Plate count</ENT>
                                <ENT O="xl">
                                    p. 143.
                                    <SU>3</SU>
                                </ENT>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                            </ROW>
                            <ROW RUL="s">
                                <ENT I="01">
                                    7. 
                                    <E T="03">Salmonella</E>
                                    , number per gram dry weight 
                                    <SU>11</SU>
                                </ENT>
                                <ENT>MPN multiple tube</ENT>
                                <ENT>
                                    1682 
                                    <SU>22</SU>
                                </ENT>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                            </ROW>
                            <ROW EXPSTB="05" RUL="s">
                                <ENT I="21">
                                    <E T="02">Aquatic Toxicity</E>
                                </ENT>
                            </ROW>
                            <ROW EXPSTB="00">
                                <ENT I="01">
                                    8. Toxicity, acute, fresh water organisms, LC
                                    <E T="0732">50</E>
                                    , percent effluent
                                </ENT>
                                <ENT>
                                    Water flea, 
                                    <E T="03">Cladoceran, Ceriodaphnia dubia</E>
                                     acute
                                </ENT>
                                <ENT O="xl">
                                    2002.0.
                                    <SU>25</SU>
                                </ENT>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="8"/>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    Water flea, 
                                    <E T="03">Cladocerans, Daphnia pulex</E>
                                     and 
                                    <E T="03">Daphnia magna</E>
                                     acute
                                </ENT>
                                <ENT O="xl">
                                    2021.0.
                                    <SU>25</SU>
                                </ENT>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    Fish, Fathead minnow, 
                                    <E T="03">Pimephales promelas,</E>
                                     and Bannerfin shiner, 
                                    <E T="03">Cyprinella leedsi,</E>
                                     acute
                                </ENT>
                                <ENT O="xl">
                                    2000.0.
                                    <SU>25</SU>
                                </ENT>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    Fish, Rainbow trout, 
                                    <E T="03">Oncorhynchus mykiss,</E>
                                     and brook trout, 
                                    <E T="03">Salvelinus fontinalis,</E>
                                     acute
                                </ENT>
                                <ENT O="xl">
                                    2019.0.
                                    <SU>25</SU>
                                </ENT>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    9. Toxicity, acute, estuarine and marine organisms of the Atlantic Ocean and Gulf of Mexico, LC
                                    <E T="0732">50</E>
                                    , percent effluent
                                </ENT>
                                <ENT>
                                    Mysid, 
                                    <E T="03">Mysidopsis bahia,</E>
                                     acute
                                </ENT>
                                <ENT O="xl">
                                    2007.0.
                                    <SU>25</SU>
                                </ENT>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    Fish, Sheepshead minnow, 
                                    <E T="03">Cyprinodon variegatus,</E>
                                     acute
                                </ENT>
                                <ENT O="xl">
                                    2004.0.
                                    <SU>25</SU>
                                </ENT>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    Fish, Silverside, 
                                    <E T="03">Menidia beryllina, Menidia menidia,</E>
                                     and 
                                    <E T="03">Menidia peninsulae,</E>
                                     acute
                                </ENT>
                                <ENT O="xl">
                                    2006.0.
                                    <SU>25</SU>
                                </ENT>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    10. Toxicity, chronic, fresh water organisms, NOEC or IC
                                    <E T="0732">25</E>
                                    , percent effluent
                                </ENT>
                                <ENT>
                                    Fish, Fathead minnow, 
                                    <E T="03">Pimephales promelas,</E>
                                     larval survival and growth
                                </ENT>
                                <ENT O="xl">
                                    1000.0.
                                    <SU>26</SU>
                                </ENT>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    Fish, Fathead minnow, 
                                    <E T="03">Pimephales promelas,</E>
                                     embryo-larval survival and teratogenicity
                                </ENT>
                                <ENT O="xl">
                                    1001.0.
                                    <SU>26</SU>
                                </ENT>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    Water flea, Cladoceran, 
                                    <E T="03">Ceriodaphnia dubia,</E>
                                     survival and reproduction
                                </ENT>
                                <ENT O="xl">
                                    1002.0.
                                    <SU>26</SU>
                                </ENT>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    Green alga, 
                                    <E T="03">Selenastrum capricornutum,</E>
                                     growth
                                </ENT>
                                <ENT O="xl">
                                    1003.0.
                                    <SU>26</SU>
                                </ENT>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    11. Toxicity, chronic, estuarine and marine organisms of the Atlantic Ocean and Gulf of Mexico, NOEC or IC
                                    <E T="0732">25</E>
                                    , percent effluent
                                </ENT>
                                <ENT>
                                    Fish, Sheepshead minnow, 
                                    <E T="03">Cyprinodon variegatus,</E>
                                     larval survival and growth
                                </ENT>
                                <ENT O="xl">
                                    1004.0.
                                    <SU>27</SU>
                                </ENT>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    Fish, Sheepshead minnow, 
                                    <E T="03">Cyprinodon variegatus,</E>
                                     embryo-larval survival and teratogenicity
                                </ENT>
                                <ENT O="xl">
                                    1005.0.
                                    <SU>27</SU>
                                </ENT>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    Fish, Inland silverside, 
                                    <E T="03">Menidia beryllina,</E>
                                     larval survival and growth
                                </ENT>
                                <ENT O="xl">
                                    1006.0.
                                    <SU>27</SU>
                                </ENT>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="9"/>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    Mysid, 
                                    <E T="03">Mysidopsis bahia,</E>
                                     survival, growth, and fecundity
                                </ENT>
                                <ENT O="xl">
                                    1007.0.
                                    <SU>27</SU>
                                </ENT>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    Sea urchin, 
                                    <E T="03">Arbacia punctulata,</E>
                                     fertilization
                                </ENT>
                                <ENT O="xl">
                                    1008.0.
                                    <SU>27</SU>
                                </ENT>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                            </ROW>
                            <TNOTE>
                                <E T="02">Table IA notes:</E>
                            </TNOTE>
                            <TNOTE>
                                <SU>1</SU>
                                 The method must be specified when results are reported.
                            </TNOTE>
                            <TNOTE>
                                <SU>2</SU>
                                 A 0.45-µm membrane filter (MF) or other pore size certified by the manufacturer to fully retain organisms to be cultivated and to be free of extractables which could interfere with their growth.
                            </TNOTE>
                            <TNOTE>
                                <SU>3</SU>
                                 Microbiological Methods for Monitoring the Environment, Water and Wastes, EPA/600/8-78/017. 1978. US EPA.
                            </TNOTE>
                            <TNOTE>
                                <SU>4</SU>
                                 U.S. Geological Survey Techniques of Water-Resource Investigations, Book 5, Laboratory Analysis, Chapter A4, Methods for Collection and Analysis of Aquatic Biological and Microbiological Samples. 1989. USGS.
                            </TNOTE>
                            <TNOTE>
                                <SU>5</SU>
                                 Because the MF technique usually yields low and variable recovery from chlorinated wastewaters, the Most Probable Number method will be required to resolve any controversies.
                            </TNOTE>
                            <TNOTE>
                                <SU>6</SU>
                                 Tests must be conducted to provide organism enumeration (density). Select the appropriate configuration of tubes/filtrations and dilutions/volumes to account for the quality, character, consistency, and anticipated organism density of the water sample.
                            </TNOTE>
                            <TNOTE>
                                <SU>7</SU>
                                 When the MF method has been used previously to test waters with high turbidity, large numbers of noncoliform bacteria, or samples that may contain organisms stressed by chlorine, a parallel test should be conducted with a multiple-tube technique to demonstrate applicability and comparability of results.
                            </TNOTE>
                            <TNOTE>
                                <SU>8</SU>
                                 To assess the comparability of results obtained with individual methods, it is suggested that side-by-side tests be conducted across seasons of the year with the water samples routinely tested in accordance with the most current 
                                <E T="03">Standard Methods for the Examination of Water and Wastewater</E>
                                 or EPA alternate test procedure (ATP) guidelines.
                            </TNOTE>
                            <TNOTE>
                                <SU>9</SU>
                                 Annual Book of ASTM Standards—Water and Environmental Technology, Section 11.02. 2000, 1999, 1996. ASTM International.
                            </TNOTE>
                            <TNOTE>
                                <SU>10</SU>
                                 Official Methods of Analysis of AOAC International. 16th Edition, 4th Revision, 1998. AOAC International.
                            </TNOTE>
                            <TNOTE>
                                <SU>11</SU>
                                 Recommended for enumeration of target organism in sewage sludge.
                            </TNOTE>
                            <TNOTE>
                                <SU>12</SU>
                                 The multiple-tube fermentation test is used in 9221B.2-2014. Lactose broth may be used in lieu of lauryl tryptose broth (LTB), if at least 25 parallel tests are conducted between this broth and LTB using the water samples normally tested, and this comparison demonstrates that the false-positive rate and false-negative rate for total coliform using lactose broth is less than 10 percent. No requirement exists to run the completed phase on 10 percent of all total coliform-positive tubes on a seasonal basis.
                            </TNOTE>
                            <TNOTE>
                                <SU>13</SU>
                                 These tests are collectively known as defined enzyme substrate tests.
                            </TNOTE>
                            <TNOTE>
                                <SU>14</SU>
                                 After prior enrichment in a presumptive medium for total coliform using 9221B.2-2014, all presumptive tubes or bottles showing any amount of gas, growth or acidity within 48 h ± 3 h of incubation shall be submitted to 9221F-2014. Commercially available EC-MUG media or EC media supplemented in the laboratory with 50 µg/mL of MUG may be used.
                            </TNOTE>
                            <TNOTE>
                                <SU>15</SU>
                                 Method 1680: Fecal Coliforms in Sewage Sludge (Biosolids) by Multiple-Tube Fermentation Using Lauryl-Tryptose Broth (LTB) and EC Medium, EPA-821-R-14-009. September 2014. U.S. EPA.
                            </TNOTE>
                            <TNOTE>
                                <SU>16</SU>
                                 Samples shall be enumerated by the multiple-tube or multiple-well procedure. Using multiple-tube procedures, employ an appropriate tube and dilution configuration of the sample as needed and report the Most Probable Number (MPN). Samples tested with Colilert® may be enumerated with the multiple-well procedures, Quanti-Tray® or Quanti-Tray®/2000 and the MPN calculated from the table provided by the manufacturer.
                            </TNOTE>
                            <TNOTE>
                                <SU>17</SU>
                                 Colilert-18® is an optimized formulation of the Colilert® for the determination of total coliforms and 
                                <E T="03">E. coli</E>
                                 that provides results within 18 h of incubation at 35 °C rather than the 24 h required for the Colilert® test and is recommended for marine water samples.
                            </TNOTE>
                            <TNOTE>
                                <SU>18</SU>
                                 Descriptions of the Colilert®, Colilert-18®, Quanti-Tray®, and Quanti-Tray®/2000 may be obtained from IDEXX Laboratories, Inc.
                            </TNOTE>
                            <TNOTE>
                                <SU>19</SU>
                                 A description of the mColiBlue24® test is available from Hach Company.
                            </TNOTE>
                            <TNOTE>
                                <SU>20</SU>
                                 Method 1681: Fecal Coliforms in Sewage Sludge (Biosolids) by Multiple-Tube Fermentation Using A-1 Medium, EPA-821-R-06-013. July 2006. U.S. EPA.
                            </TNOTE>
                            <TNOTE>
                                <SU>21</SU>
                                 Method 1603.1: 
                                <E T="03">Escherichia coli</E>
                                 (
                                <E T="03">E. coli</E>
                                ) in Water by Membrane Filtration Using Modified membrane-Thermotolerant 
                                <E T="03">Escherichia coli</E>
                                 Agar (Modified mTEC), EPA-821-R-23-008. September 2023. U.S. EPA.
                            </TNOTE>
                            <TNOTE>
                                <SU>22</SU>
                                 Method 1682: 
                                <E T="03">Salmonella</E>
                                 in Sewage Sludge (Biosolids) by Modified Semisolid Rappaport-Vassiliadis (MSRV) Medium, EPA-821-R-14-012. September 2014. U.S. EPA.
                            </TNOTE>
                            <TNOTE>
                                <SU>23</SU>
                                 A description of the Enterolert® test may be obtained from IDEXX Laboratories Inc.
                            </TNOTE>
                            <TNOTE>
                                <SU>24</SU>
                                 Method 1600.1: Enterococci in Water by Membrane Filtration Using Membrane-Enterococcus Indoxyl-β-D-Glucoside Agar (mEI), EPA-821-R-23-006. September 2023. U.S. EPA.
                                <PRTPAGE P="10"/>
                            </TNOTE>
                            <TNOTE>
                                <SU>25</SU>
                                 Methods for Measuring the Acute Toxicity of Effluents and Receiving Waters to Freshwater and Marine Organisms, EPA-821-R-02-012. Fifth Edition, October 2002. U.S. EPA; and U.S. EPA Whole Effluent Toxicity Methods Errata Sheet, EPA 821-R-02-012-ES. December 2016.
                            </TNOTE>
                            <TNOTE>
                                <SU>26</SU>
                                 Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms, EPA-821-R-02-013. Fourth Edition, October 2002. U.S. EPA; and U.S. EPA Whole Effluent Toxicity Methods Errata Sheet, EPA 821-R-02-012-ES. December 2016.
                            </TNOTE>
                            <TNOTE>
                                <SU>27</SU>
                                 Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Marine and Estuarine Organisms, EPA-821-R-02-014. Third Edition, October 2002. U.S. EPA; and U.S. EPA Whole Effluent Toxicity Methods Errata Sheet, EPA 821-R-02-012-ES. December 2016.
                            </TNOTE>
                            <TNOTE>
                                <SU>28</SU>
                                 To use Colilert-18® to assay for fecal coliforms, the incubation temperature is 44.5 ± 0.2 °C, and a water bath incubator is used.
                            </TNOTE>
                            <TNOTE>
                                <SU>29</SU>
                                 On a monthly basis, at least ten blue colonies from positive samples must be verified using Lauryl Tryptose Broth and EC broth, followed by count adjustment based on these results; and representative non-blue colonies should be verified using Lauryl Tryptose Broth. Where possible, verifications should be done from randomized sample sources.
                            </TNOTE>
                            <TNOTE>
                                <SU>30</SU>
                                 On a monthly basis, at least ten sheen colonies from positive samples must be verified using lauryl tryptose broth and brilliant green lactose bile broth, followed by count adjustment based on these results; and representative non-sheen colonies should be verified using lauryl tryptose broth. Where possible, verifications should be done from randomized sample sources.
                            </TNOTE>
                            <TNOTE>
                                <SU>31</SU>
                                 Subject coliform positive samples determined by 9222 B-2015 or other membrane filter procedure to 9222 I-2015 using NA-MUG media.
                            </TNOTE>
                            <TNOTE>
                                <SU>32</SU>
                                 Verification of colonies by incubation of BHI agar at 10 ± 0.5 °C for 48 ± 3 h is optional. As per the Errata to the 23rd Edition of 
                                <E T="03">Standard Methods for the Examination of Water and Wastewater</E>
                                 “Growth on a BHI agar plate incubated at 10 ± 0.5 °C for 48 ± 3 h is further verification that the colony belongs to the genus 
                                <E T="03">Enterococcus.”</E>
                            </TNOTE>
                            <TNOTE>
                                <SU>33</SU>
                                 9221F. 2-2014 allows for simultaneous detection of 
                                <E T="03">E. coli</E>
                                 and thermotolerant fecal coliforms by adding inverted vials to EC-MUG; the inverted vials collect gas produced by thermotolerant fecal coliforms.
                            </TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="6" OPTS="L2,nj,p7,7/8" CDEF="s50,r100,r50,r50,r50,r50">
                            <TTITLE>Table IB—List of Approved Inorganic Test Procedures</TTITLE>
                            <BOXHD>
                                <CHED H="1">Parameter</CHED>
                                <CHED H="1">
                                    Methodology 
                                    <SU>58</SU>
                                </CHED>
                                <CHED H="1">
                                    EPA 
                                    <SU>52</SU>
                                </CHED>
                                <CHED H="1">
                                    Standard methods 
                                    <SU>84</SU>
                                </CHED>
                                <CHED H="1">ASTM</CHED>
                                <CHED H="1">USGS/AOAC/Other</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">
                                    1. Acidity (as CaCO
                                    <E T="0732">3</E>
                                    ), mg/L
                                </ENT>
                                <ENT>Electrometric endpoint or phenolphthalein endpoint</ENT>
                                <ENT/>
                                <ENT>2310 B-2020</ENT>
                                <ENT>D1067-16</ENT>
                                <ENT>
                                    I-1020-85.
                                    <SU>2</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    2. Alkalinity (as CaCO
                                    <E T="0732">3</E>
                                    ), mg/L
                                </ENT>
                                <ENT>Electrometric or Colorimetric titration to pH 4.5, Manual</ENT>
                                <ENT/>
                                <ENT>2320 B-2021</ENT>
                                <ENT>D1067-16</ENT>
                                <ENT>
                                    973.43 
                                    <SU>3</SU>
                                    , I-1030-85.
                                    <SU>2</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Automatic</ENT>
                                <ENT>
                                    310.2 (Rev. 1974) 
                                    <SU>1</SU>
                                </ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    I-2030-85.
                                    <SU>2</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    3. Aluminum—Total,
                                    <SU>4</SU>
                                     mg/L
                                </ENT>
                                <ENT O="xl">
                                    Digestion,
                                    <SU>4</SU>
                                     followed by any of the following:
                                </ENT>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    AA direct aspiration 
                                    <SU>36</SU>
                                </ENT>
                                <ENT/>
                                <ENT>3111 D-2019 or 3111 E-2019</ENT>
                                <ENT/>
                                <ENT>
                                    I-3051-85.
                                    <SU>2</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>AA furnace</ENT>
                                <ENT/>
                                <ENT O="xl">3113 B-2020.</ENT>
                                <ENT O="xl"/>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>STGFAA</ENT>
                                <ENT O="xl">200.9 Rev. 2.2 (1994).</ENT>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    ICP/AES 
                                    <SU>36</SU>
                                </ENT>
                                <ENT>
                                    200.5 Rev 4.2 (2003) 
                                    <SU>68</SU>
                                    , 200.7 Rev. 4.4 (1994)
                                </ENT>
                                <ENT>3120 B-2020</ENT>
                                <ENT>D1976-20</ENT>
                                <ENT>
                                    I-4471-97.
                                    <SU>50</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>ICP/MS</ENT>
                                <ENT>200.8, Rev. 5.4 (1994)</ENT>
                                <ENT>3125 B-2020</ENT>
                                <ENT>D5673-16</ENT>
                                <ENT>
                                    993.14 
                                    <SU>3</SU>
                                    , I-4472-97.
                                    <SU>81</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    Direct Current Plasma (DCP) 
                                    <SU>36</SU>
                                </ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>D4190-15</ENT>
                                <ENT>
                                    See footnote.
                                    <SU>34</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Colorimetric (Eriochrome cyanine R)</ENT>
                                <ENT/>
                                <ENT O="xl">3500-Al B-2020.</ENT>
                                <ENT O="xl"/>
                            </ROW>
                            <ROW>
                                <ENT I="01">4. Ammonia (as N), mg/L</ENT>
                                <ENT O="xl">
                                    Manual distillation 
                                    <SU>6</SU>
                                     or gas diffusion (pH &gt; 11), followed by any of the following:
                                </ENT>
                                <ENT>350.1 Rev. 2.0 (1993)</ENT>
                                <ENT>
                                    4500-NH
                                    <E T="0732">3</E>
                                     B-2021
                                </ENT>
                                <ENT/>
                                <ENT>
                                    973.49.
                                    <SU>3</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="11"/>
                                <ENT I="22"> </ENT>
                                <ENT>Nesslerization</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>D1426-15 (A)</ENT>
                                <ENT>
                                    973.49 
                                    <SU>3</SU>
                                    , I-3520-85.
                                    <SU>2</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Titration</ENT>
                                <ENT/>
                                <ENT O="xl">
                                    4500-NH
                                    <E T="0732">3</E>
                                     C-2021.
                                </ENT>
                                <ENT O="xl"/>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Electrode</ENT>
                                <ENT/>
                                <ENT>
                                    4500-NH
                                    <E T="0732">3</E>
                                     D-2021 or E-2021
                                </ENT>
                                <ENT>D1426-15 (B)</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Manual phenate, salicylate, or other substituted phenols in Berthelot reaction-based methods</ENT>
                                <ENT/>
                                <ENT>
                                    4500-NH
                                    <E T="0732">3</E>
                                     F-2021
                                </ENT>
                                <ENT/>
                                <ENT>
                                    See footnote.
                                    <SU>60</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Automated phenate, salicylate, or other substituted phenols in Berthelot reaction-based methods</ENT>
                                <ENT>
                                    350.1
                                    <SU>30</SU>
                                     Rev. 2.0 (1993)
                                </ENT>
                                <ENT>
                                    4500-NH
                                    <E T="0732">3</E>
                                     G-2021, 4500-NH
                                    <E T="0732">3</E>
                                     H-2021
                                </ENT>
                                <ENT/>
                                <ENT>
                                    I-4523-85 
                                    <SU>2</SU>
                                    , I-2522-90.
                                    <SU>80</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Automated electrode</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote.
                                    <SU>7</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Ion Chromatography</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT O="xl">D6919-17</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Automated gas diffusion, followed by conductivity cell analysis</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    Timberline Ammonia-001.
                                    <SU>74</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Automated gas diffusion followed by fluorescence detector analysis</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    FIAlab100.
                                    <SU>82</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    5. Antimony—Total,
                                    <SU>4</SU>
                                     mg/L
                                </ENT>
                                <ENT O="xl">
                                    Digestion,
                                    <SU>4</SU>
                                     followed by any of the following:
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    AA direct aspiration 
                                    <SU>36</SU>
                                </ENT>
                                <ENT/>
                                <ENT O="xl">3111 B-2019.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>AA furnace</ENT>
                                <ENT/>
                                <ENT O="xl">3113 B-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>STGFAA</ENT>
                                <ENT O="xl">200.9 Rev. 2.2 (1994).</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    ICP/AES 
                                    <SU>36</SU>
                                </ENT>
                                <ENT>
                                    200.5 Rev 4.2 (2003) 
                                    <SU>68</SU>
                                    , 200.7 Rev. 4.4 (1994)
                                </ENT>
                                <ENT>3120 B-2020</ENT>
                                <ENT O="xl">D1976-20.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>ICP/MS</ENT>
                                <ENT>200.8, Rev. 5.4 (1994)</ENT>
                                <ENT>3125 B-2020</ENT>
                                <ENT>D5673-16</ENT>
                                <ENT>
                                    993.14 
                                    <SU>3</SU>
                                    , I-4472-97.
                                    <SU>81</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    6. Arsenic—Total,
                                    <SU>4</SU>
                                     mg/L
                                </ENT>
                                <ENT O="xl">
                                    Digestion,
                                    <SU>4</SU>
                                     followed by any of the following:
                                </ENT>
                                <ENT O="xl">
                                    206.5 (Issued 1978).
                                    <SU>1</SU>
                                </ENT>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>AA gaseous hydride</ENT>
                                <ENT/>
                                <ENT>3114 B-2020 or 3114 C-2020</ENT>
                                <ENT>D2972-15 (B)</ENT>
                                <ENT>
                                    I-3062-85.
                                    <SU>2</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>AA furnace</ENT>
                                <ENT/>
                                <ENT>3113 B-2020</ENT>
                                <ENT>D2972-15 (C)</ENT>
                                <ENT>
                                    I-4063-98.
                                    <SU>49</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>STGFAA</ENT>
                                <ENT O="xl">200.9 Rev. 2.2 (1994).</ENT>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    ICP/AES 
                                    <SU>36</SU>
                                </ENT>
                                <ENT>
                                    200.5, Rev 4.2 (2003) 
                                    <SU>68</SU>
                                    , 200.7 Rev. 4.4 (1994)
                                </ENT>
                                <ENT>3120 B-2020</ENT>
                                <ENT O="xl">D1976-20.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>ICP/MS</ENT>
                                <ENT>200.8, Rev. 5.4 (1994)</ENT>
                                <ENT>3125 B-2020</ENT>
                                <ENT>D5673-16</ENT>
                                <ENT>
                                    993.14 
                                    <SU>3</SU>
                                    , I-4020-05.
                                    <SU>70</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Colorimetric (SDDC)</ENT>
                                <ENT/>
                                <ENT>3500-As B-2020</ENT>
                                <ENT>D2972-15 (A)</ENT>
                                <ENT>
                                    I-3060-85.
                                    <SU>2</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    7. Barium—Total,
                                    <SU>4</SU>
                                     mg/L
                                </ENT>
                                <ENT O="xl">
                                    Digestion,
                                    <SU>4</SU>
                                     followed by any of the following:
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    AA direct aspiration 
                                    <SU>36</SU>
                                </ENT>
                                <ENT/>
                                <ENT>3111 D-2019</ENT>
                                <ENT/>
                                <ENT>
                                    I-3084-85.
                                    <SU>2</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="12"/>
                                <ENT I="22"> </ENT>
                                <ENT>AA furnace</ENT>
                                <ENT O="xl"/>
                                <ENT>3113 B-2020</ENT>
                                <ENT O="xl">D4382-18.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    ICP/AES 
                                    <SU>36</SU>
                                </ENT>
                                <ENT>
                                    200.5, Rev 4.2 (2003) 
                                    <SU>68</SU>
                                    , 200.7 Rev. 4.4 (1994)
                                </ENT>
                                <ENT>3120 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    I-4471-97.
                                    <SU>50</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>ICP/MS</ENT>
                                <ENT>200.8 Rev. 5.4 (1994)</ENT>
                                <ENT>3125 B-2020</ENT>
                                <ENT>D5673-16</ENT>
                                <ENT>
                                    993.14 
                                    <SU>3</SU>
                                    , I-4472-97.
                                    <SU>81</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    DCP 
                                    <SU>36</SU>
                                </ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote.
                                    <SU>34</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    8. Beryllium—Total,
                                    <SU>4</SU>
                                     mg/L
                                </ENT>
                                <ENT O="xl">
                                    Digestion,
                                    <SU>4</SU>
                                     followed by any of the following:
                                </ENT>
                                <ENT/>
                                <ENT/>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>AA direct aspiration</ENT>
                                <ENT/>
                                <ENT>3111 D-2019 or 3111 E-2019</ENT>
                                <ENT>D3645-15 (A)</ENT>
                                <ENT>
                                    I-3095-85.
                                    <SU>2</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>AA furnace</ENT>
                                <ENT/>
                                <ENT O="xl">3113 B-2020</ENT>
                                <ENT O="xl">D3645-15 (B).</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>STGFAA</ENT>
                                <ENT O="xl">200.9, Rev. 2.2 (1994).</ENT>
                                <ENT O="xl"/>
                                <ENT O="xl"/>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>ICP/AES</ENT>
                                <ENT>
                                    200.5 Rev 4.2 (2003) 
                                    <SU>68</SU>
                                    , 200.7 Rev. 4.4 (1994)
                                </ENT>
                                <ENT>3120 B-2020</ENT>
                                <ENT>D1976-20</ENT>
                                <ENT>
                                    I-4471-97.
                                    <SU>50</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>ICP/MS</ENT>
                                <ENT>200.8 Rev. 5.4 (1994)</ENT>
                                <ENT>3125 B-2020</ENT>
                                <ENT>D5673-16</ENT>
                                <ENT>
                                    993.14 
                                    <SU>3</SU>
                                    , I-4472-97.
                                    <SU>81</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>DCP</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>D4190-15</ENT>
                                <ENT>
                                    See footnote.
                                    <SU>34</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Colorimetric (aluminon)</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>61</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    9. Biochemical oxygen demand (BOD
                                    <E T="0732">5</E>
                                    ), mg/L
                                </ENT>
                                <ENT>Dissolved Oxygen Depletion</ENT>
                                <ENT/>
                                <ENT>
                                    5210 B-2016 
                                    <SU>85</SU>
                                </ENT>
                                <ENT/>
                                <ENT>
                                    973.44 
                                    <SU>3</SU>
                                     p. 17 
                                    <SU>9</SU>
                                    , I-1578-78 
                                    <SU>8</SU>
                                    , see footnote.
                                    <SU>10</SU>
                                     
                                    <SU>63</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    10. Boron—Total,
                                    <SU>37</SU>
                                     mg/L
                                </ENT>
                                <ENT>Colorimetric (curcumin)</ENT>
                                <ENT/>
                                <ENT>4500-B B-2011</ENT>
                                <ENT/>
                                <ENT>
                                    I-3112-85.
                                    <SU>2</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>ICP/AES</ENT>
                                <ENT>
                                    200.5 Rev 4.2 (2003) 
                                    <SU>68</SU>
                                    , 200.7 Rev. 4.4 (1994)
                                </ENT>
                                <ENT>3120 B-2020</ENT>
                                <ENT>D1976-20</ENT>
                                <ENT>
                                    I-4471-97.
                                    <SU>50</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>ICP/MS</ENT>
                                <ENT>200.8 Rev. 5.4 (1994)</ENT>
                                <ENT>3125 B-2020</ENT>
                                <ENT>D5673-16</ENT>
                                <ENT>
                                    993.14.
                                    <SU>3</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>DCP</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>D4190-15</ENT>
                                <ENT>
                                    See footnote.
                                    <SU>34</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">11. Bromide, mg/L</ENT>
                                <ENT>Electrode</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>D1246-16</ENT>
                                <ENT>
                                    I-1125-85.
                                    <SU>2</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Ion Chromatography</ENT>
                                <ENT>300.0 Rev 2.1 (1993), and 300.1 Rev 1.0 (1997)</ENT>
                                <ENT>4110 B-2020, C-2020 or D-2020</ENT>
                                <ENT>D4327-17</ENT>
                                <ENT>
                                    993.30 
                                    <SU>3</SU>
                                    , I-2057-85.
                                    <SU>79</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>CIE/UV</ENT>
                                <ENT/>
                                <ENT>4140 B-2020</ENT>
                                <ENT>D6508-15</ENT>
                                <ENT>
                                    D6508 Rev. 2.
                                    <SU>54</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    12. Cadmium—Total,
                                    <SU>4</SU>
                                     mg/L
                                </ENT>
                                <ENT O="xl">
                                    Digestion,
                                    <SU>4</SU>
                                     followed by any of the following:
                                </ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="13"/>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    AA direct aspiration 
                                    <SU>36</SU>
                                </ENT>
                                <ENT/>
                                <ENT>3111 B-2019 or 3111 C-2019</ENT>
                                <ENT>D3557-17 (A or B)</ENT>
                                <ENT>
                                    974.27 
                                    <SU>3</SU>
                                     p. 37 
                                    <SU>9</SU>
                                    , I-3135-85 
                                    <SU>2</SU>
                                     or I-3136-85.
                                    <SU>2</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>AA furnace</ENT>
                                <ENT/>
                                <ENT>3113 B-2020</ENT>
                                <ENT>D3557-17 (D)</ENT>
                                <ENT>
                                    I-4138-89.
                                    <SU>51</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>STGFAA</ENT>
                                <ENT>200.9 Rev. 2.2 (1994)</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    ICP/AES 
                                    <SU>36</SU>
                                </ENT>
                                <ENT>
                                    200.5 Rev 4.2 (2003) 
                                    <SU>68</SU>
                                    , 200.7 Rev. 4.4 (1994)
                                </ENT>
                                <ENT>3120 B-2020</ENT>
                                <ENT>D1976-20</ENT>
                                <ENT>
                                    I-1472-85 
                                    <SU>2</SU>
                                     or I-4471-97.
                                    <SU>50</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>ICP/MS</ENT>
                                <ENT>200.8, Rev. 5.4 (1994)</ENT>
                                <ENT>3125 B-2020</ENT>
                                <ENT>D5673-16</ENT>
                                <ENT>
                                    993.14 
                                    <SU>3</SU>
                                    , I-4472-97.
                                    <SU>81</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    DCP 
                                    <SU>36</SU>
                                </ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>D4190-15</ENT>
                                <ENT>
                                    See footnote.
                                    <SU>34</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    Voltammetry 
                                    <SU>11</SU>
                                </ENT>
                                <ENT/>
                                <ENT/>
                                <ENT O="xl">D3557-17 (C).</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Colorimetric (Dithizone)</ENT>
                                <ENT/>
                                <ENT O="xl">3500-Cd D-1990.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    13. Calcium—Total,
                                    <SU>4</SU>
                                     mg/L
                                </ENT>
                                <ENT O="xl">
                                    Digestion 
                                    <SU>4</SU>
                                     followed by any of the following:
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>AA direct aspiration</ENT>
                                <ENT/>
                                <ENT>3111 B-2019 or 3111 D-2019</ENT>
                                <ENT>D511-14 (B)</ENT>
                                <ENT>
                                    I-3152-85.
                                    <SU>2</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>ICP/AES</ENT>
                                <ENT>
                                    200.5 Rev 4.2 (2003)
                                    <SU>68</SU>
                                    , 200.7 Rev. 4.4 (1994)
                                </ENT>
                                <ENT>3120 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    I-4471-97.
                                    <SU>50</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>ICP/MS</ENT>
                                <ENT>200.8, Rev. 5.4 (1994)</ENT>
                                <ENT>3125 B-2020</ENT>
                                <ENT>D5673-16</ENT>
                                <ENT>
                                    993.14.
                                    <SU>3</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>DCP</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote.
                                    <SU>34</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Titrimetric (EDTA)</ENT>
                                <ENT/>
                                <ENT>3500-Ca B-2020</ENT>
                                <ENT O="xl">D511-14 (A).</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Ion Chromatography</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT O="xl">D6919-17.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    14. Carbonaceous biochemical oxygen demand (CBOD
                                    <E T="0732">5</E>
                                    ), mg/L
                                    <SU>12</SU>
                                </ENT>
                                <ENT>Dissolved Oxygen Depletion with nitrification inhibitor</ENT>
                                <ENT/>
                                <ENT>
                                    5210 B-2016 
                                    <SU>85</SU>
                                </ENT>
                                <ENT/>
                                <ENT>
                                    See footnotes.
                                    <SU>35 63</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">15. Chemical oxygen demand (COD), mg/L</ENT>
                                <ENT>Titrimetric</ENT>
                                <ENT>
                                    410.3 (Rev. 1978) 
                                    <SU>1</SU>
                                </ENT>
                                <ENT>5220 B-2011 or C-2011</ENT>
                                <ENT>D1252-06(12) (A)</ENT>
                                <ENT>
                                    973.46 
                                    <SU>3</SU>
                                     p. 17 
                                    <SU>9</SU>
                                    , I-3560-85.
                                    <SU>2</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Spectrophotometric, manual or automatic</ENT>
                                <ENT>410.4 Rev. 2.0 (1993)</ENT>
                                <ENT>5220 D-2011</ENT>
                                <ENT>D1252-06(12) (B)</ENT>
                                <ENT>
                                    See footnotes 
                                    <SU>13</SU>
                                     
                                    <SU>14</SU>
                                     
                                    <SU>83</SU>
                                    , I-3561-85.
                                    <SU>2</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">16. Chloride, mg/L</ENT>
                                <ENT>Titrimetric: (silver nitrate)</ENT>
                                <ENT/>
                                <ENT>
                                    4500-Cl
                                    <E T="0731">−</E>
                                     B-2021
                                </ENT>
                                <ENT>D512-12 (B)</ENT>
                                <ENT>
                                    I-1183-85.
                                    <SU>2</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>(Mercuric nitrate)</ENT>
                                <ENT/>
                                <ENT>
                                    4500-Cl
                                    <E T="0731">−</E>
                                     C-2021
                                </ENT>
                                <ENT>D512-12 (A)</ENT>
                                <ENT>
                                    973.51 
                                    <SU>3</SU>
                                    , I-1184-85.
                                    <SU>2</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Colorimetric: manual</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    I-1187-85.
                                    <SU>2</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Automated (ferricyanide)</ENT>
                                <ENT/>
                                <ENT>
                                    4500-Cl
                                    <E T="0731">−</E>
                                     E-2021
                                </ENT>
                                <ENT/>
                                <ENT>
                                    I-2187-85.
                                    <SU>2</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT O="xl">Potentiometric Titration</ENT>
                                <ENT/>
                                <ENT O="xl">
                                    4500-Cl
                                    <E T="0731">−</E>
                                     D-2021.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Ion Selective Electrode</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT O="xl">D512-12 (C).</ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="14"/>
                                <ENT I="22"> </ENT>
                                <ENT>Ion Chromatography</ENT>
                                <ENT>300.0 Rev 2.1 (1993), and 300.1 Rev 1.0 (1997)</ENT>
                                <ENT>4110 B-2020 or 4110 C-2020</ENT>
                                <ENT>D4327-17</ENT>
                                <ENT>
                                    993.30 
                                    <SU>3</SU>
                                    , I-2057-90.
                                    <SU>51</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>CIE/UV</ENT>
                                <ENT/>
                                <ENT>4140 B-2020</ENT>
                                <ENT>D6508-15</ENT>
                                <ENT>
                                    D6508, Rev. 2.
                                    <SU>54</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">17. Chlorine—Total residual, mg/L</ENT>
                                <ENT>Amperometric direct</ENT>
                                <ENT/>
                                <ENT>4500-Cl D-2011</ENT>
                                <ENT O="xl">D1253-14.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Amperometric direct (low level)</ENT>
                                <ENT/>
                                <ENT O="xl">4500-Cl E-2011.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Iodometric direct</ENT>
                                <ENT/>
                                <ENT O="xl">4500-Cl B-2011.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    Back titration ether end-point 
                                    <SU>15</SU>
                                </ENT>
                                <ENT/>
                                <ENT O="xl">4500-Cl C-2011.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>DPD-FAS</ENT>
                                <ENT/>
                                <ENT O="xl">4500-Cl F-2011.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Spectrophotometric, DPD</ENT>
                                <ENT/>
                                <ENT O="xl">4500-Cl G-2011.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Electrode</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote.
                                    <SU>16</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">17A. Chlorine—Free Available, mg/L</ENT>
                                <ENT>Amperometric direct</ENT>
                                <ENT/>
                                <ENT>4500-Cl D-2011</ENT>
                                <ENT>D1253-14</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Amperometric direct (low level)</ENT>
                                <ENT/>
                                <ENT O="xl">4500-Cl E-2011.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>DPD-FAS</ENT>
                                <ENT/>
                                <ENT O="xl">4500-Cl F-2011.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Spectrophotometric, DPD</ENT>
                                <ENT/>
                                <ENT O="xl">4500-Cl G-2011.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">18. Chromium VI dissolved, mg/L</ENT>
                                <ENT O="xl">0.45-micron filtration followed by any of the following:</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>AA chelation-extraction</ENT>
                                <ENT/>
                                <ENT>3111 C-2019</ENT>
                                <ENT/>
                                <ENT>
                                    I-1232-85.
                                    <SU>2</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Ion Chromatography</ENT>
                                <ENT>218.6 Rev. 3.3 (1994)</ENT>
                                <ENT>3500-Cr C-2020</ENT>
                                <ENT>D5257-17</ENT>
                                <ENT>
                                    993.23.
                                    <SU>3</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Colorimetric (diphenyl-carbazide)</ENT>
                                <ENT/>
                                <ENT>3500-Cr B-2020</ENT>
                                <ENT>D1687-17 (A)</ENT>
                                <ENT>
                                    I-1230-85.
                                    <SU>2</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    19. Chromium—Total,
                                    <SU>4</SU>
                                     mg/L
                                </ENT>
                                <ENT O="xl">
                                    Digestion,
                                    <SU>4</SU>
                                     followed by any of the following:
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    AA direct aspiration 
                                    <SU>36</SU>
                                </ENT>
                                <ENT/>
                                <ENT>3111 B-2019</ENT>
                                <ENT>D1687-17 (B)</ENT>
                                <ENT>
                                    974.27 
                                    <SU>3</SU>
                                    , I-3236-85.
                                    <SU>2</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>AA chelation-extraction</ENT>
                                <ENT/>
                                <ENT O="xl">3111 C-2019.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>AA furnace</ENT>
                                <ENT/>
                                <ENT>3113 B-2020</ENT>
                                <ENT>D1687-17 (C)</ENT>
                                <ENT>
                                    I-3233-93.
                                    <SU>46</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>STGFAA</ENT>
                                <ENT O="xl">200.9 Rev. 2.2 (1994).</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    ICP/AES 
                                    <SU>36</SU>
                                </ENT>
                                <ENT>
                                    200.5 Rev 4.2 (2003) 
                                    <SU>68</SU>
                                    , 200.7 Rev. 4.4 (1994)
                                </ENT>
                                <ENT>3120 B-2020</ENT>
                                <ENT O="xl">D1976-20.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>ICP/MS</ENT>
                                <ENT>200.8 Rev. 5.4 (1994)</ENT>
                                <ENT>3125 B-2020</ENT>
                                <ENT>D5673-16</ENT>
                                <ENT>
                                    993.14 
                                    <SU>3</SU>
                                    , I-4020-05 
                                    <SU>70</SU>
                                     I-4472-97.
                                    <SU>81</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    DCP 
                                    <SU>36</SU>
                                </ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>D4190-15</ENT>
                                <ENT>
                                    See footnote.
                                    <SU>34</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Colorimetric (diphenyl-carbazide)</ENT>
                                <ENT/>
                                <ENT O="xl">3500-Cr B-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    20. Cobalt—Total,
                                    <SU>4</SU>
                                     mg/L
                                </ENT>
                                <ENT O="xl">
                                    Digestion,
                                    <SU>4</SU>
                                     followed by any of the following:
                                </ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="15"/>
                                <ENT I="22"> </ENT>
                                <ENT>AA direct aspiration</ENT>
                                <ENT/>
                                <ENT>3111 B-2019 or 3111 C-2019</ENT>
                                <ENT>D3558-15 (A or B)</ENT>
                                <ENT>
                                    p. 37 
                                    <SU>9</SU>
                                    , I-323985.
                                    <SU>2</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>AA furnace</ENT>
                                <ENT/>
                                <ENT>3113 B-2020</ENT>
                                <ENT>D3558-15 (C)</ENT>
                                <ENT>
                                    I-4243-89.
                                    <SU>51</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>STGFAA</ENT>
                                <ENT O="xl">200.9 Rev. 2.2 (1994).</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>ICP/AES</ENT>
                                <ENT>200.7 Rev. 4.4 (1994)</ENT>
                                <ENT>3120 B-2020</ENT>
                                <ENT>D1976-20</ENT>
                                <ENT>
                                    I-4471-97.
                                    <SU>50</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>ICP/MS</ENT>
                                <ENT>200.8 Rev. 5.4 (1994)</ENT>
                                <ENT>3125 B-2020</ENT>
                                <ENT>D5673-16</ENT>
                                <ENT>
                                    993.14 
                                    <SU>3</SU>
                                    , I-4020-05 
                                    <SU>70</SU>
                                     I-4472-97.
                                    <SU>81</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>DCP</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>D4190-15</ENT>
                                <ENT>
                                    See footnote.
                                    <SU>34</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">21. Color, platinum cobalt units or dominant wavelength, hue, luminance purity</ENT>
                                <ENT>Colorimetric (ADMI)</ENT>
                                <ENT/>
                                <ENT O="xl">
                                    2120 F-2021.
                                    <SU>78</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Platinum cobalt visual comparison</ENT>
                                <ENT/>
                                <ENT>2120 B-2021</ENT>
                                <ENT/>
                                <ENT>
                                    I-1250-85.
                                    <SU>2</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Spectrophotometric</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote.
                                    <SU>18</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    22. Copper—Total,
                                    <SU>4</SU>
                                     mg/L
                                </ENT>
                                <ENT O="xl">
                                    Digestion,
                                    <SU>4</SU>
                                     followed by any of the following:
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    AA direct aspiration 
                                    <SU>36</SU>
                                </ENT>
                                <ENT/>
                                <ENT>3111 B-2019 or 3111 C-2019</ENT>
                                <ENT>D1688-17 (A or B)</ENT>
                                <ENT>
                                    974.27 
                                    <SU>3</SU>
                                     p. 37 
                                    <SU>9</SU>
                                    , I-3270-85 
                                    <SU>2</SU>
                                     or I-3271-85.
                                    <SU>2</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>AA furnace</ENT>
                                <ENT/>
                                <ENT>3113 B-2020</ENT>
                                <ENT>D1688-17 (C)</ENT>
                                <ENT>
                                    I-4274-89.
                                    <SU>51</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>STGFAA</ENT>
                                <ENT O="xl">200.9 Rev. 2.2 (1994).</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    ICP/AES 
                                    <SU>36</SU>
                                </ENT>
                                <ENT>
                                    200.5 Rev 4.2 (2003),
                                    <SU>68</SU>
                                     200.7 Rev. 4.4 (1994)
                                </ENT>
                                <ENT>3120 B-2020</ENT>
                                <ENT>D1976-20</ENT>
                                <ENT>
                                    I-4471-97.
                                    <SU>50</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>ICP/MS</ENT>
                                <ENT>200.8 Rev. 5.4 (1994)</ENT>
                                <ENT>3125 B-2020</ENT>
                                <ENT>D5673-16</ENT>
                                <ENT>
                                    993.14 
                                    <SU>3</SU>
                                    , I-4020-05 
                                    <SU>70</SU>
                                    , I-4472-97.
                                    <SU>81</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    DCP 
                                    <SU>36</SU>
                                </ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>D4190-15</ENT>
                                <ENT>
                                    See footnote.
                                    <SU>34</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Colorimetric (Neocuproine)</ENT>
                                <ENT/>
                                <ENT O="xl">3500-Cu B-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Colorimetric (Bathocuproine)</ENT>
                                <ENT/>
                                <ENT>3500-Cu C-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote.
                                    <SU>19</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">23. Cyanide—Total, mg/L</ENT>
                                <ENT>Automated UV digestion/distillation and Colorimetry</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    Kelada-01.
                                    <SU>55</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Segmented Flow Injection, In-Line Ultraviolet Digestion, followed by gas diffusion amperometry</ENT>
                                <ENT/>
                                <ENT>
                                    4500-CN
                                    <E T="0731">−</E>
                                     P-2021
                                </ENT>
                                <ENT>D7511-12 (17).</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT O="xl">
                                    Manual distillation with MgCl
                                    <E T="0732">2</E>
                                    , followed by any of the following:
                                </ENT>
                                <ENT>
                                    335.4 Rev. 1.0 (1993) 
                                    <SU>57</SU>
                                </ENT>
                                <ENT>
                                    4500-CN
                                    <E T="0731">−</E>
                                     B-2021 and C-2021
                                </ENT>
                                <ENT>D2036-09(15)(A), D7284-20</ENT>
                                <ENT>
                                    10-204-00-1-X.
                                    <SU>56</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Flow Injection, gas diffusion amperometry</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT O="xl">D2036-09(15)(A) D7284-20.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Titrimetric</ENT>
                                <ENT/>
                                <ENT>
                                    4500-CN
                                    <E T="0731">−</E>
                                     D-2021
                                </ENT>
                                <ENT>D2036-09(15)(A)</ENT>
                                <ENT>
                                    See footnote 
                                    <SU>9</SU>
                                     p. 22.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Spectrophotometric, manual</ENT>
                                <ENT/>
                                <ENT>
                                    4500-CN
                                    <E T="0731">−</E>
                                     E-2021
                                </ENT>
                                <ENT>D2036-09(15)(A)</ENT>
                                <ENT>
                                    I-3300-85.
                                    <SU>2</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="16"/>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    Semi-Automated 
                                    <SU>20</SU>
                                </ENT>
                                <ENT>
                                    335.4 Rev. 1.0 (1993) 
                                    <SU>57</SU>
                                </ENT>
                                <ENT>
                                    4500-CN
                                    <E T="0731">−</E>
                                     N-2021
                                </ENT>
                                <ENT/>
                                <ENT>
                                    10-204-00-1-X 
                                    <SU>56</SU>
                                    , I-4302-85.
                                    <SU>2</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Ion Chromatography</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT O="xl">D2036-09(15)(A).</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Ion Selective Electrode</ENT>
                                <ENT/>
                                <ENT>
                                    4500-CN
                                    <E T="0731">−</E>
                                     F-2021
                                </ENT>
                                <ENT O="xl">D2036-09(15)(A).</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">24. Cyanide—Available, mg/L</ENT>
                                <ENT>
                                    Cyanide Amenable to Chlorination (CATC); Manual distillation with MgCl
                                    <E T="0732">2</E>
                                    , followed by Titrimetric or Spectrophotometric
                                </ENT>
                                <ENT/>
                                <ENT>
                                    4500-CN
                                    <E T="0731">−</E>
                                     G-2021
                                </ENT>
                                <ENT O="xl">D2036-09(15)(B).</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    Flow injection and ligand exchange, followed by gas diffusion amperometry 
                                    <SU>59</SU>
                                </ENT>
                                <ENT/>
                                <ENT>
                                    4500-CN
                                    <E T="0731">−</E>
                                     Q-2021
                                </ENT>
                                <ENT>D6888-16</ENT>
                                <ENT>
                                    OIA-1677-09.
                                    <SU>44</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Automated Distillation and Colorimetry (no UV digestion)</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    Kelada-01.
                                    <SU>55</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">24A. Cyanide—Free, mg/L</ENT>
                                <ENT>Flow Injection, followed by gas diffusion amperometry</ENT>
                                <ENT/>
                                <ENT>
                                    4500-CN
                                    <E T="0731">−</E>
                                     R-2021
                                </ENT>
                                <ENT>D7237-18 (A)</ENT>
                                <ENT>
                                    OIA-1677-09.
                                    <SU>44</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Manual micro-diffusion and colorimetry</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT O="xl">D4282-15.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">25. Fluoride—Total, mg/L</ENT>
                                <ENT>
                                    Manual distillation,
                                    <SU>6</SU>
                                     followed by any of the following:
                                </ENT>
                                <ENT/>
                                <ENT>
                                    4500-F
                                    <E T="0731">−</E>
                                     B-2021
                                </ENT>
                                <ENT O="xl">D1179-16 (A).</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Electrode, manual</ENT>
                                <ENT/>
                                <ENT>
                                    4500-F
                                    <E T="0731">−</E>
                                     C-2021
                                </ENT>
                                <ENT O="xl">D1179-16 (B).</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Electrode, automated</ENT>
                                <ENT/>
                                <ENT>
                                    4500-F
                                    <E T="0731">−</E>
                                     G-2021
                                </ENT>
                                <ENT/>
                                <ENT>
                                    I-4327-85.
                                    <SU>2</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Colorimetric, (SPADNS)</ENT>
                                <ENT/>
                                <ENT O="xl">
                                    4500-F
                                    <E T="0731">−</E>
                                     D-2021.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Automated complexone</ENT>
                                <ENT/>
                                <ENT O="xl">
                                    4500-F
                                    <E T="0731">−</E>
                                     E-2021.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Ion Chromatography</ENT>
                                <ENT>300.0 Rev 2.1 (1993) and 300.1 Rev 1.0 (1997)</ENT>
                                <ENT>4110 B-2020 or C-2020</ENT>
                                <ENT>D4327-17</ENT>
                                <ENT>
                                    993.30.
                                    <SU>3</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>CIE/UV</ENT>
                                <ENT/>
                                <ENT>4140 B-2020</ENT>
                                <ENT>D6508-15</ENT>
                                <ENT>
                                    D6508, Rev. 2.
                                    <SU>54</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    26. Gold—Total,
                                    <SU>4</SU>
                                     mg/L
                                </ENT>
                                <ENT O="xl">
                                    Digestion,
                                    <SU>4</SU>
                                     followed by any of the following:
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>AA direct aspiration</ENT>
                                <ENT/>
                                <ENT O="xl">3111 B-2019.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>AA furnace</ENT>
                                <ENT>
                                    231.2 (Issued 1978) 
                                    <SU>1</SU>
                                </ENT>
                                <ENT O="xl">3113 B-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>ICP/MS</ENT>
                                <ENT>200.8, Rev. 5.4 (1994)</ENT>
                                <ENT>3125 B-2020</ENT>
                                <ENT>D5673-16</ENT>
                                <ENT>
                                    993.14.
                                    <SU>3</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>DCP</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote.
                                    <SU>34</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    27. Hardness—Total (as CaCO
                                    <E T="0732">(3)</E>
                                    , mg/L
                                </ENT>
                                <ENT>Automated colorimetric</ENT>
                                <ENT O="xl">
                                    130.1 (Issued 1971).
                                    <SU>1</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Titrimetric (EDTA)</ENT>
                                <ENT/>
                                <ENT>2340 C-2021</ENT>
                                <ENT>D1126-17</ENT>
                                <ENT>
                                    973.52B 
                                    <SU>3</SU>
                                    , I-1338-85.
                                    <SU>2</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="17"/>
                                <ENT I="22"> </ENT>
                                <ENT>Ca plus Mg as their carbonates, by any approved method for Ca and Mg (See Parameters 13 and 33), provided that the sum of the lowest point of quantitation for Ca and Mg is below the NPDES permit requirement for Hardness.</ENT>
                                <ENT/>
                                <ENT O="xl">2340 B-2021.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">28. Hydrogen ion (pH), pH units</ENT>
                                <ENT>Electrometric measurement</ENT>
                                <ENT/>
                                <ENT>
                                    4500-H
                                    <SU>+</SU>
                                     B-2021
                                </ENT>
                                <ENT>D1293-18 (A or B)</ENT>
                                <ENT>
                                    973.41 
                                    <SU>3</SU>
                                    , I-1586-85.
                                    <SU>2</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Automated electrode</ENT>
                                <ENT>
                                    150.2 (Dec. 1982) 
                                    <SU>1</SU>
                                </ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>21</SU>
                                     I-2587-85.
                                    <SU>2</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    29. Iridium—Total,
                                    <SU>4</SU>
                                     mg/L
                                </ENT>
                                <ENT>
                                    Digestion,
                                    <SU>4</SU>
                                     followed by any of the following:
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>AA direct aspiration</ENT>
                                <ENT/>
                                <ENT O="xl">3111 B-2019.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>AA furnace</ENT>
                                <ENT O="xl">
                                    235.2 (Issued 1978).
                                    <SU>1</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>ICP/MS</ENT>
                                <ENT/>
                                <ENT O="xl">3125 B-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    30. Iron—Total,
                                    <SU>4</SU>
                                     mg/L
                                </ENT>
                                <ENT O="xl">
                                    Digestion,
                                    <SU>4</SU>
                                     followed by any of the following:
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    AA direct aspiration 
                                    <SU>36</SU>
                                </ENT>
                                <ENT/>
                                <ENT>3111 B-2019 or 3111 C-2019</ENT>
                                <ENT>D1068-15 (A)</ENT>
                                <ENT>
                                    974.27 
                                    <SU>3</SU>
                                    , I-3381-85.
                                    <SU>2</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>AA furnace</ENT>
                                <ENT/>
                                <ENT>3113 B-2020</ENT>
                                <ENT O="xl">D1068-15 (B).</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>STGFAA</ENT>
                                <ENT O="xl">200.9, Rev. 2.2 (1994).</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    ICP/AES 
                                    <SU>36</SU>
                                </ENT>
                                <ENT>
                                    200.5 Rev. 4.2 (2003) 
                                    <SU>68</SU>
                                    , 200.7 Rev. 4.4 (1994)
                                </ENT>
                                <ENT>3120 B-2020</ENT>
                                <ENT>D1976-20</ENT>
                                <ENT>
                                    I-4471-97.
                                    <SU>50</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>ICP/MS</ENT>
                                <ENT>200.8, Rev. 5.4 (1994)</ENT>
                                <ENT>3125 B-2020</ENT>
                                <ENT>D5673-16</ENT>
                                <ENT>
                                    993.14.
                                    <SU>3</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    DCP 
                                    <SU>36</SU>
                                </ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>D4190-15</ENT>
                                <ENT>
                                    See footnote.
                                    <SU>34</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Colorimetric (Phenanthroline)</ENT>
                                <ENT/>
                                <ENT>3500-Fe B-2011</ENT>
                                <ENT>D1068-15 (C)</ENT>
                                <ENT>
                                    See footnote.
                                    <SU>22</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    31. Kjeldahl Nitrogen 
                                    <SU>5</SU>
                                    —Total (as N), mg/L
                                </ENT>
                                <ENT O="xl">
                                    Manual digestion 
                                    <SU>20</SU>
                                     and distillation or gas diffusion, followed by any of the following:
                                </ENT>
                                <ENT/>
                                <ENT>
                                    4500-N
                                    <E T="0732">org</E>
                                     B-2021 or C-2021 and 4500-NH
                                    <E T="0732">3</E>
                                     B-2021
                                </ENT>
                                <ENT>D3590-17 (A)</ENT>
                                <ENT>
                                    I-4515-91.
                                    <SU>45</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Titration</ENT>
                                <ENT/>
                                <ENT>
                                    4500-NH
                                    <E T="0732">3</E>
                                     C-2021
                                </ENT>
                                <ENT/>
                                <ENT>
                                    973.48.
                                    <SU>3</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Nesslerization</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT O="xl">D1426-15 (A).</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Electrode</ENT>
                                <ENT/>
                                <ENT>
                                    4500-NH
                                    <E T="0732">3</E>
                                     D-2021 or E-2021
                                </ENT>
                                <ENT O="xl">D1426-15 (B).</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Semi-automated phenate</ENT>
                                <ENT>350.1 Rev. 2.0 (1993)</ENT>
                                <ENT O="xl">
                                    4500-NH
                                    <E T="0732">3</E>
                                     G-2021 or 4500-NH
                                    <E T="0732">3</E>
                                     H-2021.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Manual phenate, salicylate, or other substituted phenols in Berthelot reaction based methods</ENT>
                                <ENT/>
                                <ENT>
                                    4500-NH
                                    <E T="0732">3</E>
                                     F-2021
                                </ENT>
                                <ENT/>
                                <ENT>
                                    See footnote.
                                    <SU>60</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="18"/>
                                <ENT I="22"> </ENT>
                                <ENT>Automated gas diffusion, followed by conductivity cell analysis</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    Timberline Ammonia-001.
                                    <SU>74</SU>
                                </ENT>
                            </ROW>
                            <ROW RUL="s">
                                <ENT I="22"> </ENT>
                                <ENT>Automated gas diffusion followed by fluorescence detector analysis</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    FIAlab 100.
                                    <SU>82</SU>
                                </ENT>
                            </ROW>
                            <ROW EXPSTB="05" RUL="s">
                                <ENT I="22"> </ENT>
                                <ENT I="21">Automated Methods for TKN that do not require manual distillation</ENT>
                            </ROW>
                            <ROW EXPSTB="00">
                                <ENT I="22"> </ENT>
                                <ENT I="22"> </ENT>
                                <ENT O="xl">Automated phenate, salicylate, or other substituted phenols in Berthelot reaction-based methods colorimetric (auto digestion and distillation)</ENT>
                                <ENT>
                                    351.1 (Rev. 1978) 
                                    <SU>1</SU>
                                </ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    I-4551-78.
                                    <SU>8</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Semi-automated block digestor colorimetric (distillation not required)</ENT>
                                <ENT>351.2 Rev. 2.0 (1993)</ENT>
                                <ENT>
                                    4500-N
                                    <E T="0732">org</E>
                                     D-2021
                                </ENT>
                                <ENT>D3590-17 (B)</ENT>
                                <ENT>
                                    I-4515-91.
                                    <SU>45</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Block digester, followed by Auto distillation and Titration</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote.
                                    <SU>39</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Block digester, followed by Auto distillation and Nesslerization</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote.
                                    <SU>40</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Block Digester, followed by Flow injection gas diffusion (distillation not required)</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote.
                                    <SU>41</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Digestion with peroxdisulfate, followed by Spectrophotometric (2,6-dimethyl phenol)</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    Hach 10242.
                                    <SU>76</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Digestion with persulfate, followed by Colorimetric</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    NCASI TNTP W10900.
                                    <SU>77</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    32. Lead—Total,
                                    <SU>4</SU>
                                     mg/L
                                </ENT>
                                <ENT O="xl">
                                    Digestion,
                                    <SU>4</SU>
                                     followed by any of the following:
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    AA direct aspiration 
                                    <SU>36</SU>
                                </ENT>
                                <ENT/>
                                <ENT>3111 B-2019 or 3111 C-2019</ENT>
                                <ENT>D3559-15 (A or B)</ENT>
                                <ENT>
                                    974.27 
                                    <SU>3</SU>
                                    , I-3399-85.
                                    <SU>2</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>AA furnace</ENT>
                                <ENT/>
                                <ENT>3113 B-2020</ENT>
                                <ENT>D3559-15 (D)</ENT>
                                <ENT>
                                    I-4403-89.
                                    <SU>51</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>STGFAA</ENT>
                                <ENT O="xl">200.9 Rev. 2.2 (1994).</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    ICP/AES 
                                    <SU>36</SU>
                                </ENT>
                                <ENT>
                                    200.5 Rev. 4.2 (2003) 
                                    <SU>68</SU>
                                    , 200.7 Rev. 4.4 (1994)
                                </ENT>
                                <ENT>3120 B-2020</ENT>
                                <ENT>D1976-20</ENT>
                                <ENT>
                                    I-4471-97.
                                    <SU>50</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>ICP/MS</ENT>
                                <ENT>200.8 Rev. 5.4 (1994)</ENT>
                                <ENT>3125 B-2020</ENT>
                                <ENT>D5673-16</ENT>
                                <ENT>
                                    993.14 
                                    <SU>3</SU>
                                    , I-4472-97.
                                    <SU>81</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    DCP 
                                    <SU>36</SU>
                                </ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>D4190-15</ENT>
                                <ENT>
                                    See footnote.
                                    <SU>34</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="19"/>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    Voltammetry 
                                    <SU>11</SU>
                                </ENT>
                                <ENT/>
                                <ENT/>
                                <ENT O="xl">D3559-15 (C).</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Colorimetric (Dithizone)</ENT>
                                <ENT/>
                                <ENT O="xl">3500-Pb B-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    33. Magnesium—Total,
                                    <SU>4</SU>
                                     mg/L
                                </ENT>
                                <ENT O="xl">
                                    Digestion,
                                    <SU>4</SU>
                                     followed by any of the following:
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>AA direct aspiration</ENT>
                                <ENT/>
                                <ENT>3111 B-2019</ENT>
                                <ENT>D511-14 (B)</ENT>
                                <ENT>
                                    974.27 
                                    <SU>3</SU>
                                    , I-3447-85.
                                    <SU>2</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>ICP/AES</ENT>
                                <ENT>
                                    200.5 Rev. 4.2 (2003) 
                                    <SU>68</SU>
                                    , 200.7 Rev. 4.4 (1994)
                                </ENT>
                                <ENT>3120 B-2020</ENT>
                                <ENT>D1976-20</ENT>
                                <ENT>
                                    I-4471-97.
                                    <SU>50</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>ICP/MS</ENT>
                                <ENT>200.8 Rev. 5.4 (1994)</ENT>
                                <ENT>3125 B-2020</ENT>
                                <ENT>D5673-16</ENT>
                                <ENT>
                                    993.14.
                                    <SU>3</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>DCP</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote.
                                    <SU>34</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Ion Chromatography</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT O="xl">D6919-17.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    34. Manganese—Total,
                                    <SU>4</SU>
                                     mg/L
                                </ENT>
                                <ENT O="xl">
                                    Digestion,
                                    <SU>4</SU>
                                     followed by any of the following:
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    AA direct aspiration 
                                    <SU>36</SU>
                                </ENT>
                                <ENT/>
                                <ENT>3111 B-2019 or 3111 C-2019</ENT>
                                <ENT>D858-17 (A or B)</ENT>
                                <ENT>
                                    974.27 
                                    <SU>3</SU>
                                    , I-3454-85.
                                    <SU>2</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>AA furnace</ENT>
                                <ENT/>
                                <ENT>3113 B-2020</ENT>
                                <ENT O="xl">D858-17 (C).</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>STGFAA</ENT>
                                <ENT O="xl">200.9 Rev. 2.2 (1994).</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    ICP/AES 
                                    <SU>36</SU>
                                </ENT>
                                <ENT>
                                    200.5, Rev. 4.2 (2003) 
                                    <SU>68</SU>
                                    ; 200.7, Rev. 4.4 (1994)
                                </ENT>
                                <ENT>3120 B-2020</ENT>
                                <ENT>D1976-20</ENT>
                                <ENT>
                                    I-4471-97.
                                    <SU>50</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>ICP/MS</ENT>
                                <ENT>200.8 Rev. 5.4 (1994)</ENT>
                                <ENT>3125 B-2020</ENT>
                                <ENT>D5673-16</ENT>
                                <ENT>
                                    993.14 
                                    <SU>3</SU>
                                    , I-4472-97.
                                    <SU>81</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    DCP 
                                    <SU>36</SU>
                                </ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>D4190-15</ENT>
                                <ENT>
                                    See footnote.
                                    <SU>34</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Colorimetric (Persulfate)</ENT>
                                <ENT/>
                                <ENT>3500-Mn B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    920.203.
                                    <SU>3</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Colorimetric (Periodate)</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote.
                                    <SU>23</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">35. Mercury—Total, mg/L</ENT>
                                <ENT>Cold vapor, Manual</ENT>
                                <ENT>245.1 Rev. 3.0 (1994)</ENT>
                                <ENT>3112 B-2020</ENT>
                                <ENT>D3223-17</ENT>
                                <ENT>
                                    977.22 
                                    <SU>3</SU>
                                    , I-3462-85.
                                    <SU>2</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Cold vapor, Automated</ENT>
                                <ENT O="xl">
                                    245.2 (Issued 1974).
                                    <SU>1</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Cold vapor atomic fluorescence spectrometry (CVAFS)</ENT>
                                <ENT>
                                    245.7 Rev. 2.0 (2005) 
                                    <SU>17</SU>
                                </ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    I-4464-01.
                                    <SU>71</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Purge and Trap CVAFS</ENT>
                                <ENT O="xl">
                                    1631E.
                                    <SU>43</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    36. Molybdenum—Total,
                                    <SU>4</SU>
                                     mg/L
                                </ENT>
                                <ENT O="xl">
                                    Digestion,
                                    <SU>4</SU>
                                     followed by any of the following:
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>AA direct aspiration</ENT>
                                <ENT/>
                                <ENT>3111 D-2019</ENT>
                                <ENT/>
                                <ENT>
                                    I-3490-85.
                                    <SU>2</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>AA furnace</ENT>
                                <ENT/>
                                <ENT>3113 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    I-3492-96.
                                    <SU>47</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>ICP/AES</ENT>
                                <ENT>200.7 Rev. 4.4 (1994)</ENT>
                                <ENT>3120 B-2020</ENT>
                                <ENT>D1976-20</ENT>
                                <ENT>
                                    I-4471-97.
                                    <SU>50</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>ICP/MS</ENT>
                                <ENT>200.8 Rev. 5.4 (1994)</ENT>
                                <ENT>3125 B-2020</ENT>
                                <ENT>D5673-16</ENT>
                                <ENT>
                                    993.14 
                                    <SU>3</SU>
                                    , I-4472-97.
                                    <SU>81</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>DCP</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote.
                                    <SU>34</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="20"/>
                                <ENT I="01">
                                    37. Nickel—Total,
                                    <SU>4</SU>
                                     mg/L
                                </ENT>
                                <ENT O="xl">
                                    Digestion,
                                    <SU>4</SU>
                                     followed by any of the following:
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    AA direct aspiration 
                                    <SU>36</SU>
                                </ENT>
                                <ENT/>
                                <ENT>3111 B-2019 or 3111 C-2019</ENT>
                                <ENT>D1886-14 (A or B)</ENT>
                                <ENT>
                                    I-3499-85.
                                    <SU>2</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>AA furnace</ENT>
                                <ENT/>
                                <ENT>3113 B-2020</ENT>
                                <ENT>D1886-14 (C)</ENT>
                                <ENT>
                                    I-4503-89.
                                    <SU>51</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>STGFAA</ENT>
                                <ENT O="xl">200.9 Rev. 2.2 (1994).</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    ICP/AES 
                                    <SU>36</SU>
                                </ENT>
                                <ENT>
                                    200.5 Rev. 4.2 (2003) 
                                    <SU>68</SU>
                                    , 200.7 Rev. 4.4 (1994)
                                </ENT>
                                <ENT>3120 B-2020</ENT>
                                <ENT>D1976-20</ENT>
                                <ENT>
                                    I-4471-97.
                                    <SU>50</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>ICP/MS</ENT>
                                <ENT>200.8, Rev. 5.4 (1994)</ENT>
                                <ENT>3125 B-2020</ENT>
                                <ENT>D5673-16</ENT>
                                <ENT>
                                    993.14 
                                    <SU>3</SU>
                                    , I-4020-05 
                                    <SU>70</SU>
                                    , I-4472-97.
                                    <SU>81</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    DCP 
                                    <SU>36</SU>
                                </ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>D4190-15</ENT>
                                <ENT>
                                    See footnote.
                                    <SU>34</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">38. Nitrate (as N), mg/L</ENT>
                                <ENT>Ion Chromatography</ENT>
                                <ENT>300.0 Rev. 2.1 (1993) and 300.1 Rev. 1.0 (1997)</ENT>
                                <ENT>4110 B-2020 or C-2020</ENT>
                                <ENT>D4327-17</ENT>
                                <ENT>
                                    993.30.
                                    <SU>3</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>CIE/UV</ENT>
                                <ENT/>
                                <ENT>4140 B-2020</ENT>
                                <ENT>D6508-15</ENT>
                                <ENT>
                                    D6508, Rev. 2.
                                    <SU>54</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Ion Selective Electrode</ENT>
                                <ENT/>
                                <ENT>
                                    4500-NO
                                    <E T="0732">3</E>
                                    <E T="0731">−</E>
                                     D-2019.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Colorimetric (Brucine sulfate)</ENT>
                                <ENT>
                                    352.1 (Issued 1971) 
                                    <SU>1</SU>
                                </ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    973.50 
                                    <SU>3</SU>
                                    , 419D 
                                    <SU>86</SU>
                                    , p. 28.
                                    <SU>9</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Spectrophotometric (2,6-dimethylphenol)</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    Hach 10206.
                                    <SU>75</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT O="xl">Nitrate-nitrite N minus Nitrite N (see parameters 39 and 40).</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">39. Nitrate-nitrite (as N), mg/L</ENT>
                                <ENT>Cadmium reduction, Manual</ENT>
                                <ENT/>
                                <ENT>
                                    4500-NO
                                    <E T="0732">3</E>
                                    <E T="0731">−</E>
                                     E-2019
                                </ENT>
                                <ENT O="xl">D3867-16 (B).</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Cadmium reduction, Automated</ENT>
                                <ENT>353.2 Rev. 2.0 (1993)</ENT>
                                <ENT>
                                    4500-NO
                                    <E T="0732">3</E>
                                    <E T="0731">−</E>
                                     F-2019 or 4500-NO
                                    <E T="0732">3</E>
                                    <E T="0731">−</E>
                                     I-2019
                                </ENT>
                                <ENT>D3867-16 (A)</ENT>
                                <ENT>
                                    I-2545-90.
                                    <SU>51</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Automated hydrazine</ENT>
                                <ENT/>
                                <ENT O="xl">
                                    4500-NO
                                    <E T="0732">3</E>
                                    <E T="0731">−</E>
                                     H-2019.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Reduction/Colorimetric</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote.
                                    <SU>62</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Ion Chromatography</ENT>
                                <ENT>300.0 Rev. 2.1 (1993) and 300.1 Rev. 1.0 (1997)</ENT>
                                <ENT>4110 B-2020 or C-2020</ENT>
                                <ENT>D4327-17</ENT>
                                <ENT>
                                    993.30.
                                    <SU>3</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>CIE/UV</ENT>
                                <ENT/>
                                <ENT>4140 B-2020</ENT>
                                <ENT>D6508-15</ENT>
                                <ENT>
                                    D6508, Rev. 2.
                                    <SU>54</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Enzymatic reduction, followed by automated colorimetric determination</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>D7781-14</ENT>
                                <ENT>
                                    I-2547-11 
                                    <SU>72</SU>
                                    , I-2548-11 
                                    <SU>72</SU>
                                    , N07-0003.
                                    <SU>73</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Enzymatic reduction, followed by manual colorimetric determination</ENT>
                                <ENT/>
                                <ENT O="xl">
                                    4500-NO
                                    <E T="0732">3</E>
                                    <E T="0731">−</E>
                                     J-2018.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Spectrophotometric (2,6-dimethylphenol)</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    Hach 10206.
                                    <SU>75</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="21"/>
                                <ENT I="01">40. Nitrite (as N), mg/L</ENT>
                                <ENT>Spectrophotometric: Manual</ENT>
                                <ENT/>
                                <ENT>
                                    4500-NO
                                    <E T="0732">2</E>
                                    <E T="0731">−</E>
                                     B-2021
                                </ENT>
                                <ENT/>
                                <ENT>
                                    See footnote.
                                    <SU>25</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Automated (Diazotization)</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    I-4540-85 
                                    <SU>2</SU>
                                     see footnote 
                                    <SU>62</SU>
                                    , I-2540-90.
                                    <SU>80</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Automated (*bypass cadmium reduction)</ENT>
                                <ENT>353.2 Rev. 2.0 (1993)</ENT>
                                <ENT>
                                    4500-NO
                                    <E T="0732">3</E>
                                    <E T="0731">−</E>
                                     F-2019, 4500-NO
                                    <E T="0732">3</E>
                                    <E T="0731">−</E>
                                     I-2019
                                </ENT>
                                <ENT>D3867-16 (A)</ENT>
                                <ENT>
                                    I-4545-85.
                                    <SU>2</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Manual (*bypass cadmium or enzymatic reduction)</ENT>
                                <ENT/>
                                <ENT>
                                    4500-NO
                                    <E T="0732">3</E>
                                    <E T="0731">−</E>
                                     E-2019, 4500-NO
                                    <E T="0732">3</E>
                                    <E T="0731">−</E>
                                     J-2018
                                </ENT>
                                <ENT O="xl">D3867-16 (B).</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Ion Chromatography</ENT>
                                <ENT>300.0 Rev. 2.1 (1993) and 300.1 Rev. 1.0 (1997)</ENT>
                                <ENT>4110 B-2020 or C-2020</ENT>
                                <ENT>D4327-17</ENT>
                                <ENT>
                                    993.30.
                                    <SU>3</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>CIE/UV</ENT>
                                <ENT/>
                                <ENT>4140 B-2020</ENT>
                                <ENT>D6508-15</ENT>
                                <ENT>
                                    D6508, Rev. 2.
                                    <SU>54</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Automated (*bypass Enzymatic reduction)</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>D7781-14</ENT>
                                <ENT>
                                    I-2547-11 
                                    <SU>72</SU>
                                    , I-2548-11 
                                    <SU>72</SU>
                                    , N07-0003.
                                    <SU>73</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">41. Oil and grease—Total recoverable, mg/L</ENT>
                                <ENT>
                                    Hexane extractable material (HEM): 
                                    <E T="03">n</E>
                                    -Hexane extraction and gravimetry
                                </ENT>
                                <ENT>
                                    1664 Rev. A 1664 Rev. B 
                                    <SU>42</SU>
                                </ENT>
                                <ENT>
                                    5520 B or G-2021.
                                    <SU>38</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Silica gel treated HEM (SGT-HEM): Silica gel treatment and gravimetry</ENT>
                                <ENT>
                                    1664 Rev. A, 1664 Rev. B 
                                    <SU>42</SU>
                                </ENT>
                                <ENT O="xl">
                                    5520 B or G-2021 
                                    <SU>38</SU>
                                     and 5520 F-2021.
                                    <SU>38</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">42. Organic carbon—Total (TOC), mg/L</ENT>
                                <ENT>Combustion</ENT>
                                <ENT/>
                                <ENT>5310 B-2014</ENT>
                                <ENT>
                                    D7573-18a
                                    <SU>e1</SU>
                                </ENT>
                                <ENT>
                                    973.47 
                                    <SU>3</SU>
                                    , p. 14 
                                    <SU>24</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Heated persulfate or UV persulfate oxidation</ENT>
                                <ENT/>
                                <ENT>5310 C-2014, 5310 D-2011</ENT>
                                <ENT>D4839-03(17)</ENT>
                                <ENT>
                                    973.47 
                                    <SU>3</SU>
                                    , p. 14 
                                    <SU>24</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">43. Organic nitrogen (as N), mg/L</ENT>
                                <ENT O="xl">Total Kjeldahl N (Parameter 31) minus ammonia N (Parameter 4).</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">44. Ortho-phosphate (as P), mg/L</ENT>
                                <ENT O="xl">Ascorbic acid method:</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Automated</ENT>
                                <ENT>365.1 Rev. 2.0 (1993)</ENT>
                                <ENT>4500-P F-2021 or G-2021</ENT>
                                <ENT/>
                                <ENT>
                                    973.56 
                                    <SU>3</SU>
                                    , I-4601-85 
                                    <SU>2</SU>
                                    , I-2601-90.
                                    <SU>80</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Manual, single-reagent</ENT>
                                <ENT/>
                                <ENT>4500-P E-2021</ENT>
                                <ENT>D515-88 (A)</ENT>
                                <ENT>
                                    973.55.
                                    <SU>3</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Manual, two-reagent</ENT>
                                <ENT O="xl">
                                    365.3 (Issued 1978).
                                    <SU>1</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Ion Chromatography</ENT>
                                <ENT>300.0 Rev. 2.1 (1993) and 300.1 Rev. 1.0 (1997)</ENT>
                                <ENT>4110 B-2020 or C-2020</ENT>
                                <ENT>D4327-17</ENT>
                                <ENT>
                                    993.30.
                                    <SU>3</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>CIE/UV</ENT>
                                <ENT/>
                                <ENT>4140 B-2020</ENT>
                                <ENT>D6508-15</ENT>
                                <ENT>
                                    D6508, Rev. 2.
                                    <SU>54</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    45. Osmium—Total
                                    <SU>4</SU>
                                    , mg/L
                                </ENT>
                                <ENT O="xl">
                                    Digestion,
                                    <SU>4</SU>
                                     followed by any of the following:
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>AA direct aspiration</ENT>
                                <ENT/>
                                <ENT O="xl">3111 D-2019.</ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="22"/>
                                <ENT I="22"> </ENT>
                                <ENT>AA furnace</ENT>
                                <ENT O="xl">
                                    252.2 (Issued 1978).
                                    <SU>1</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">46. Oxygen, dissolved, mg/L</ENT>
                                <ENT>Winkler (Azide modification)</ENT>
                                <ENT/>
                                <ENT>4500-O (B-F)-2021</ENT>
                                <ENT>D888-18 (A)</ENT>
                                <ENT>
                                    973.45B 
                                    <SU>3</SU>
                                    , I-1575-78.
                                    <SU>8</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Electrode</ENT>
                                <ENT/>
                                <ENT>4500-O G-2021</ENT>
                                <ENT>D888-18 (B)</ENT>
                                <ENT>
                                    I-1576-78.
                                    <SU>8</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Luminescence-Based Sensor</ENT>
                                <ENT/>
                                <ENT>4500-O H-2021</ENT>
                                <ENT>D888-18 (C)</ENT>
                                <ENT>
                                    See footnotes. 
                                    <E T="0731">63, 64</E>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    47. Palladium—Total,
                                    <SU>4</SU>
                                     mg/L
                                </ENT>
                                <ENT O="xl">
                                    Digestion,
                                    <SU>4</SU>
                                     followed by any of the following:
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>AA direct aspiration</ENT>
                                <ENT/>
                                <ENT O="xl">3111 B-2019.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>AA furnace</ENT>
                                <ENT O="xl">
                                    253.2 (Issued 1978).
                                    <SU>1</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>ICP/MS</ENT>
                                <ENT/>
                                <ENT O="xl">3125 B-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>DCP</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote.
                                    <SU>34</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">48. Phenols, mg/L</ENT>
                                <ENT>
                                    Manual distillation,
                                    <SU>26</SU>
                                     followed by any of the following:
                                </ENT>
                                <ENT>
                                    420.1 (Rev. 1978) 
                                    <SU>1</SU>
                                </ENT>
                                <ENT>5530 B-2021</ENT>
                                <ENT>D1783-01(12)</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Colorimetric (4AAP) manual</ENT>
                                <ENT>
                                    420.1 (Rev. 1978) 
                                    <SU>1</SU>
                                </ENT>
                                <ENT>
                                    5530 D-2021 
                                    <SU>27</SU>
                                </ENT>
                                <ENT O="xl">D1783-01(12) (A or B).</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Automated colorimetric (4AAP)</ENT>
                                <ENT O="xl">420.4 Rev. 1.0 (1993).</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">49. Phosphorus (elemental), mg/L</ENT>
                                <ENT>Gas-liquid chromatography</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote.
                                    <SU>28</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">50. Phosphorus—Total, mg/L</ENT>
                                <ENT>
                                    Digestion,
                                    <SU>20</SU>
                                     followed by any of the following:
                                </ENT>
                                <ENT/>
                                <ENT>4500-P B (5)-2021</ENT>
                                <ENT/>
                                <ENT>
                                    973.55.
                                    <SU>3</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Manual</ENT>
                                <ENT>
                                    365.3 (Issued 1978) 
                                    <SU>1</SU>
                                </ENT>
                                <ENT>4500-P E-2021</ENT>
                                <ENT O="xl">D515-88 (A).</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Automated ascorbic acid reduction</ENT>
                                <ENT>365.1 Rev. 2.0 (1993)</ENT>
                                <ENT>4500-P (F-H)-2021</ENT>
                                <ENT/>
                                <ENT>
                                    973.56 
                                    <SU>3</SU>
                                    , I-4600-85.
                                    <SU>2</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    ICP/AES 
                                    <SU>4</SU>
                                     
                                    <SU>36</SU>
                                </ENT>
                                <ENT>200.7 Rev. 4.4 (1994)</ENT>
                                <ENT>3120 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    I-4471-97.
                                    <SU>50</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Semi-automated block digestor (TKP digestion)</ENT>
                                <ENT>
                                    365.4 (Issued 1974) 
                                    <SU>1</SU>
                                </ENT>
                                <ENT/>
                                <ENT>D515-88 (B)</ENT>
                                <ENT>
                                    I-4610-91.
                                    <SU>48</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Digestion with persulfate, followed by Colorimetric</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    NCASI TNTP W10900.
                                    <SU>77</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    51. Platinum—Total,
                                    <SU>4</SU>
                                     mg/L
                                </ENT>
                                <ENT O="xl">
                                    Digestion,
                                    <SU>4</SU>
                                     followed by any of the following:
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>AA direct aspiration</ENT>
                                <ENT/>
                                <ENT O="xl">3111 B-2019.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>AA furnace</ENT>
                                <ENT O="xl">
                                    255.2 (Issued 1978).
                                    <SU>1</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>ICP/MS</ENT>
                                <ENT/>
                                <ENT O="xl">3125 B-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>DCP</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote.
                                    <SU>34</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="23"/>
                                <ENT I="01">
                                    52. Potassium—Total,
                                    <SU>4</SU>
                                     mg/L
                                </ENT>
                                <ENT O="xl">
                                    Digestion,
                                    <SU>4</SU>
                                     followed by any of the following:
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>AA direct aspiration</ENT>
                                <ENT/>
                                <ENT>3111 B-2019</ENT>
                                <ENT/>
                                <ENT>
                                    973.5 
                                    <SU>3</SU>
                                    , I-3630-85.
                                    <SU>2</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>ICP/AES</ENT>
                                <ENT>200.7 Rev. 4.4 (1994)</ENT>
                                <ENT O="xl">3120 B-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>ICP/MS</ENT>
                                <ENT>200.8, Rev. 5.4 (1994)</ENT>
                                <ENT>3125 B-2020</ENT>
                                <ENT>D5673-16</ENT>
                                <ENT>
                                    993.14.
                                    <SU>3</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Flame photometric</ENT>
                                <ENT/>
                                <ENT O="xl">3500-K B-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Electrode</ENT>
                                <ENT/>
                                <ENT O="xl">3500-K C-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Ion Chromatography</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT O="xl">D6919-17.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">53. Residue—Total, mg/L</ENT>
                                <ENT>Gravimetric, 103-105°</ENT>
                                <ENT/>
                                <ENT>2540 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    I-3750-85.
                                    <SU>2</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">54. Residue—filterable, mg/L</ENT>
                                <ENT>Gravimetric, 180°</ENT>
                                <ENT/>
                                <ENT>2540 C-2020</ENT>
                                <ENT>D5907-18 (B)</ENT>
                                <ENT>
                                    I-1750-85.
                                    <SU>2</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">55. Residue—non-filterable (TSS), mg/L</ENT>
                                <ENT>Gravimetric, 103-105° post-washing of residue</ENT>
                                <ENT/>
                                <ENT>2540 D-2020</ENT>
                                <ENT>D5907-18 (A)</ENT>
                                <ENT>
                                    I-3765-85.
                                    <SU>2</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">56. Residue—settleable, mg/L</ENT>
                                <ENT>Volumetric (Imhoff cone), or gravimetric</ENT>
                                <ENT/>
                                <ENT O="xl">2540 F-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">57. Residue—Volatile, mg/L</ENT>
                                <ENT>Gravimetric, 550°</ENT>
                                <ENT>
                                    160.4 (Issued 1971) 
                                    <SU>1</SU>
                                </ENT>
                                <ENT>2540 E-2020</ENT>
                                <ENT/>
                                <ENT>
                                    I-3753-85.
                                    <SU>2</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    58. Rhodium—Total,
                                    <SU>4</SU>
                                     mg/L
                                </ENT>
                                <ENT O="xl">
                                    Digestion,
                                    <SU>4</SU>
                                     followed by any of the following:
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>AA direct aspiration, or</ENT>
                                <ENT/>
                                <ENT O="xl">3111 B-2019.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>AA furnace</ENT>
                                <ENT O="xl">
                                    265.2 (Issued 1978).
                                    <SU>1</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>ICP/MS</ENT>
                                <ENT/>
                                <ENT O="xl">3125 B-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    59. Ruthenium—Total,
                                    <SU>4</SU>
                                     mg/L
                                </ENT>
                                <ENT O="xl">
                                    Digestion,
                                    <SU>4</SU>
                                     followed by any of the following:
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>AA direct aspiration, or</ENT>
                                <ENT/>
                                <ENT O="xl">3111 B-2019.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>AA furnace</ENT>
                                <ENT O="xl">
                                    267.2.
                                    <SU>1</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>ICP/MS</ENT>
                                <ENT/>
                                <ENT O="xl">3125 B-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    60. Selenium—Total,
                                    <SU>4</SU>
                                     mg/L
                                </ENT>
                                <ENT O="xl">
                                    Digestion,
                                    <SU>4</SU>
                                     followed by any of the following:
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>AA furnace</ENT>
                                <ENT/>
                                <ENT>3113 B-2020</ENT>
                                <ENT>D3859-15 (B)</ENT>
                                <ENT>
                                    I-4668-98.
                                    <SU>49</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>STGFAA</ENT>
                                <ENT O="xl">200.9 Rev. 2.2 (1994).</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    ICP/AES 
                                    <SU>36</SU>
                                </ENT>
                                <ENT>
                                    200.5 Rev 4.2 (2003) 
                                    <SU>68</SU>
                                    , 200.7 Rev. 4.4 (1994)
                                </ENT>
                                <ENT>3120 B-2020</ENT>
                                <ENT O="xl">D1976-20.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>ICP/MS</ENT>
                                <ENT>200.8 Rev. 5.4 (1994)</ENT>
                                <ENT>3125 B-2020</ENT>
                                <ENT>D5673-16</ENT>
                                <ENT>
                                    993.14 
                                    <SU>3</SU>
                                    , I-4020-05 
                                    <SU>70</SU>
                                     I-4472-97.
                                    <SU>81</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>AA gaseous hydride</ENT>
                                <ENT/>
                                <ENT>3114 B-2020, or 3114 C-2020</ENT>
                                <ENT>D3859-15 (A)</ENT>
                                <ENT>
                                    I-3667-85.
                                    <SU>2</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="24"/>
                                <ENT I="01">
                                    61. Silica—Dissolved,
                                    <SU>37</SU>
                                     mg/L
                                </ENT>
                                <ENT O="xl">0.45-micron filtration followed by any of the following:</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Colorimetric, Manual</ENT>
                                <ENT/>
                                <ENT>
                                    4500-SiO
                                    <E T="0732">2</E>
                                     C-2021
                                </ENT>
                                <ENT>D859-16</ENT>
                                <ENT>
                                    I-1700-85.
                                    <SU>2</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Automated (Molybdosilicate)</ENT>
                                <ENT/>
                                <ENT>
                                    4500-SiO
                                    <E T="0732">2</E>
                                     E-2021 or F-2021
                                </ENT>
                                <ENT/>
                                <ENT>
                                    I-2700-85.
                                    <SU>2</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>ICP/AES</ENT>
                                <ENT>
                                    200.5 Rev. 4.2 (2003),
                                    <SU>68</SU>
                                     200.7 Rev. 4.4 (1994)
                                </ENT>
                                <ENT>3120 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    I-4471-97.
                                    <SU>50</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>ICP/MS</ENT>
                                <ENT>200.8 Rev. 5.4 (1994)</ENT>
                                <ENT>3125 B-2020</ENT>
                                <ENT>D5673-16</ENT>
                                <ENT>
                                    993.14.
                                    <SU>3</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    62. Silver—Total,
                                    <SU>4 31</SU>
                                     mg/L
                                </ENT>
                                <ENT O="xl">
                                    Digestion,
                                    <SU>4 29</SU>
                                     followed by any of the following:
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>AA direct aspiration</ENT>
                                <ENT/>
                                <ENT>3111 B-2019 or 3111 C-2019</ENT>
                                <ENT/>
                                <ENT>
                                    974.27 
                                    <SU>3</SU>
                                    , p. 37 
                                    <SU>9</SU>
                                    , I-3720-85.
                                    <SU>2</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>AA furnace</ENT>
                                <ENT/>
                                <ENT>3113 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    I-4724-89.
                                    <SU>51</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>STGFAA</ENT>
                                <ENT O="xl">200.9 Rev. 2.2 (1994).</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>ICP/AES</ENT>
                                <ENT>
                                    200.5 Rev. 4.2 (2003) 
                                    <SU>68</SU>
                                    , 200.7 Rev. 4.4 (1994)
                                </ENT>
                                <ENT>3120 B-2020</ENT>
                                <ENT>D1976-20</ENT>
                                <ENT>
                                    I-4471-97.
                                    <SU>50</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>ICP/MS</ENT>
                                <ENT>200.8 Rev. 5.4 (1994)</ENT>
                                <ENT>3125 B-2020</ENT>
                                <ENT>D5673-16</ENT>
                                <ENT>
                                    993.14 
                                    <SU>3</SU>
                                    , I-4472-97.
                                    <SU>81</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>DCP</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote.
                                    <SU>34</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    63. Sodium—Total,
                                    <SU>4</SU>
                                     mg/L
                                </ENT>
                                <ENT O="xl">
                                    Digestion,
                                    <SU>4</SU>
                                     followed by any of the following:
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>AA direct aspiration</ENT>
                                <ENT/>
                                <ENT>3111 B-2019</ENT>
                                <ENT/>
                                <ENT>
                                    973.54 
                                    <SU>3</SU>
                                    , I-3735-85.
                                    <SU>2</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>ICP/AES</ENT>
                                <ENT>
                                    200.5 Rev. 4.2 (2003) 
                                    <SU>68</SU>
                                    , 200.7 Rev. 4.4 (1994)
                                </ENT>
                                <ENT>3120 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    I-4471-97.
                                    <SU>50</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>ICP/MS</ENT>
                                <ENT>200.8 Rev. 5.4 (1994)</ENT>
                                <ENT>3125 B-2020</ENT>
                                <ENT>D5673-16</ENT>
                                <ENT>
                                    993.14.
                                    <SU>3</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>DCP</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote.
                                    <SU>34</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Flame photometric</ENT>
                                <ENT/>
                                <ENT O="xl">3500-Na B-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Ion Chromatography</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT O="xl">D6919-17.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">64. Specific conductance, micromhos/cm at 25 °C</ENT>
                                <ENT>Wheatstone bridge</ENT>
                                <ENT>
                                    120.1 (Rev. 1982) 
                                    <SU>1</SU>
                                </ENT>
                                <ENT>2510 B-2021</ENT>
                                <ENT>D1125-95(99) (A)</ENT>
                                <ENT>
                                    973.40 
                                    <SU>3</SU>
                                    , I-2781-85.
                                    <SU>2</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    65. Sulfate (as SO
                                    <E T="0732">4</E>
                                    ), mg/L
                                </ENT>
                                <ENT>Automated colorimetric</ENT>
                                <ENT>375.2 Rev. 2.0 (1993)</ENT>
                                <ENT O="xl">
                                    4500-SO
                                    <E T="0732">4</E>
                                    <SU>2</SU>
                                    <E T="0731">−</E>
                                     F-2021 or G-2021.
                                </ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="25"/>
                                <ENT I="22"> </ENT>
                                <ENT>Gravimetric</ENT>
                                <ENT/>
                                <ENT>
                                    4500-SO
                                    <E T="0732">4</E>
                                    <SU>2</SU>
                                    <E T="0731">−</E>
                                     C-2021 or D-2021
                                </ENT>
                                <ENT/>
                                <ENT>
                                    925.54.
                                    <SU>3</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Turbidimetric</ENT>
                                <ENT/>
                                <ENT>
                                    4500-SO
                                    <E T="0732">4</E>
                                    <SU>2</SU>
                                    <E T="0731">−</E>
                                     E-2021
                                </ENT>
                                <ENT O="xl">D516-16.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Ion Chromatography</ENT>
                                <ENT>300.0 Rev. 2.1 (1993) and 300.1 Rev. 1.0 (1997)</ENT>
                                <ENT>4110 B-2020 or C-2020</ENT>
                                <ENT>D4327-17</ENT>
                                <ENT>
                                    993.30 
                                    <SU>3</SU>
                                    , I-4020-05.
                                    <SU>70</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>CIE/UV</ENT>
                                <ENT/>
                                <ENT>4140 B-2020</ENT>
                                <ENT>D6508-15</ENT>
                                <ENT>
                                    D6508 Rev. 2.
                                    <SU>54</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">66. Sulfide (as S), mg/L</ENT>
                                <ENT>Sample Pretreatment</ENT>
                                <ENT/>
                                <ENT O="xl">
                                    4500-S
                                    <SU>2</SU>
                                    <E T="0731">−</E>
                                     B, C-2021.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Titrimetric (iodine)</ENT>
                                <ENT/>
                                <ENT>
                                    4500-S
                                    <SU>2</SU>
                                    <E T="0731">−</E>
                                     F-2021
                                </ENT>
                                <ENT/>
                                <ENT>
                                    I-3840-85.
                                    <SU>2</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Colorimetric (methylene blue)</ENT>
                                <ENT/>
                                <ENT O="xl">
                                    4500-S
                                    <SU>2</SU>
                                    <E T="0731">−</E>
                                     D-2021.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Ion Selective Electrode</ENT>
                                <ENT/>
                                <ENT>
                                    4500-S
                                    <SU>2</SU>
                                    <E T="0731">−</E>
                                     G-2021
                                </ENT>
                                <ENT O="xl">D4658-15.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    67. Sulfite (as SO
                                    <E T="0732">3</E>
                                    ), mg/L
                                </ENT>
                                <ENT>Titrimetric (iodine-iodate)</ENT>
                                <ENT/>
                                <ENT O="xl">
                                    4500-SO
                                    <E T="0732">3</E>
                                    <SU>2</SU>
                                    <E T="0731">−</E>
                                     B-2021.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">68. Surfactants, mg/L</ENT>
                                <ENT>Colorimetric (methylene blue)</ENT>
                                <ENT/>
                                <ENT>5540 C-2021</ENT>
                                <ENT O="xl">D2330-20.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">69. Temperature, °C</ENT>
                                <ENT>Thermometric</ENT>
                                <ENT/>
                                <ENT>2550 B-2010</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote.
                                    <SU>32</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    70. Thallium-Total,
                                    <SU>4</SU>
                                     mg/L
                                </ENT>
                                <ENT O="xl">
                                    Digestion,
                                    <SU>4</SU>
                                     followed by any of the following:
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>AA direct aspiration</ENT>
                                <ENT/>
                                <ENT O="xl">3111 B-2019.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>AA furnace</ENT>
                                <ENT>
                                    279.2 (Issued 1978) 
                                    <SU>1</SU>
                                </ENT>
                                <ENT O="xl">3113 B-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>STGFAA</ENT>
                                <ENT O="xl">200.9 Rev. 2.2 (1994).</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>ICP/AES</ENT>
                                <ENT>200.7 Rev. 4.4 (1994)</ENT>
                                <ENT>3120 B-2020</ENT>
                                <ENT O="xl">D1976-20.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>ICP/MS</ENT>
                                <ENT>200.8, Rev. 5.4 (1994)</ENT>
                                <ENT>3125 B-2020</ENT>
                                <ENT>D5673-16</ENT>
                                <ENT>
                                    993.14 
                                    <SU>3</SU>
                                    , I-4471-97 
                                    <SU>50</SU>
                                     I-4472-97.
                                    <SU>81</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    71. Tin—Total,
                                    <SU>4</SU>
                                     mg/L
                                </ENT>
                                <ENT O="xl">
                                    Digestion,
                                    <SU>4</SU>
                                     followed by any of the following:
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>AA direct aspiration</ENT>
                                <ENT/>
                                <ENT>3111 B-2019</ENT>
                                <ENT/>
                                <ENT>
                                    I-3850-78.
                                    <SU>8</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>AA furnace</ENT>
                                <ENT/>
                                <ENT O="xl">3113 B-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>STGFAA</ENT>
                                <ENT O="xl">200.9 Rev. 2.2 (1994).</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>ICP/AES</ENT>
                                <ENT O="xl">
                                    200.5 Rev. 4.2 (2003) 
                                    <SU>68</SU>
                                    , 200.7 Rev. 4.4 (1994).
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>ICP/MS</ENT>
                                <ENT>200.8 Rev. 5.4 (1994)</ENT>
                                <ENT>3125 B-2020</ENT>
                                <ENT>D5673-16</ENT>
                                <ENT>
                                    993.14.
                                    <SU>3</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    72. Titanium—Total,
                                    <SU>4</SU>
                                     mg/L
                                </ENT>
                                <ENT O="xl">
                                    Digestion,
                                    <SU>4</SU>
                                     followed by any of the following:
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>AA direct aspiration</ENT>
                                <ENT/>
                                <ENT O="xl">3111 D-2019.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>AA furnace</ENT>
                                <ENT O="xl">
                                    283.2 (Issued 1978).
                                    <SU>1</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>ICP/AES</ENT>
                                <ENT O="xl">200.7 Rev. 4.4 (1994).</ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="26"/>
                                <ENT I="22"> </ENT>
                                <ENT>ICP/MS</ENT>
                                <ENT>200.8 Rev. 5.4 (1994)</ENT>
                                <ENT>3125 B-2020</ENT>
                                <ENT>D5673-16</ENT>
                                <ENT>
                                    993.14.
                                    <SU>3</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>DCP</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote.
                                    <SU>34</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    73. Turbidity, NTU 
                                    <SU>53</SU>
                                </ENT>
                                <ENT>Nephelometric</ENT>
                                <ENT>180.1, Rev. 2.0 (1993)</ENT>
                                <ENT>2130 B-2020</ENT>
                                <ENT>D1889-00</ENT>
                                <ENT>
                                    I-3860-85 
                                    <SU>2</SU>
                                    , see footnotes.
                                    <SU>65</SU>
                                     
                                    <SU>66</SU>
                                     
                                    <SU>67</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    74. Vanadium—Total,
                                    <SU>4</SU>
                                     mg/L
                                </ENT>
                                <ENT O="xl">
                                    Digestion,
                                    <SU>4</SU>
                                     followed by any of the following:
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>AA direct aspiration</ENT>
                                <ENT/>
                                <ENT O="xl">3111 D-2019.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>AA furnace</ENT>
                                <ENT/>
                                <ENT>3113 B-2020</ENT>
                                <ENT O="xl">D3373-17.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>ICP/AES</ENT>
                                <ENT>
                                    200.5 Rev. 4.2 (2003) 
                                    <SU>68</SU>
                                    , 200.7 Rev. 4.4 (1994)
                                </ENT>
                                <ENT>3120 B-2020</ENT>
                                <ENT>D1976-20</ENT>
                                <ENT>
                                    I-4471-97.
                                    <SU>50</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>ICP/MS</ENT>
                                <ENT>200.8 Rev. 5.4 (1994)</ENT>
                                <ENT>3125 B-2020</ENT>
                                <ENT>D5673-16</ENT>
                                <ENT>
                                    993.14 
                                    <SU>3</SU>
                                    , I-4020-05.
                                    <SU>70</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>DCP</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>D4190-15</ENT>
                                <ENT>
                                    See footnote.
                                    <SU>34</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Colorimetric (Gallic Acid)</ENT>
                                <ENT/>
                                <ENT O="xl">3500-V B-2011.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    75. Zinc—Total,
                                    <SU>4</SU>
                                     mg/L
                                </ENT>
                                <ENT O="xl">
                                    Digestion,
                                    <SU>4</SU>
                                     followed by any of the following:
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    AA direct aspiration 
                                    <SU>36</SU>
                                </ENT>
                                <ENT/>
                                <ENT>3111 B-2019 or 3111 C-2019</ENT>
                                <ENT>D1691-17 (A or B)</ENT>
                                <ENT>
                                    974.27 
                                    <SU>3</SU>
                                     p. 37
                                    <SU>9</SU>
                                    , I-3900-85.
                                    <SU>2</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>AA furnace</ENT>
                                <ENT O="xl">
                                    289.2 (Issued 1978).
                                    <SU>1</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    ICP/AES 
                                    <SU>36</SU>
                                </ENT>
                                <ENT>
                                    200.5 Rev. 4.2 (2003),
                                    <SU>68</SU>
                                     200.7, Rev. 4.4 (1994)
                                </ENT>
                                <ENT>3120 B-2020</ENT>
                                <ENT>D1976-20</ENT>
                                <ENT>
                                    I-4471-97.
                                    <SU>50</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>ICP/MS</ENT>
                                <ENT>200.8 Rev. 5.4 (1994)</ENT>
                                <ENT>3125 B-2020</ENT>
                                <ENT>D5673-16</ENT>
                                <ENT>
                                    993.14
                                    <SU>3</SU>
                                    , I-4020-05 
                                    <SU>70</SU>
                                    , I-4472-97.
                                    <SU>81</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    DCP 
                                    <SU>36</SU>
                                </ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>D4190-15</ENT>
                                <ENT>
                                    See footnote.
                                    <SU>34</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Colorimetric (Zincon)</ENT>
                                <ENT/>
                                <ENT>3500 Zn B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote.
                                    <SU>33</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">76. Acid Mine Drainage</ENT>
                                <ENT/>
                                <ENT O="xl">
                                    1627.
                                    <SU>69</SU>
                                </ENT>
                            </ROW>
                            <TNOTE>
                                <E T="02">Table IB Notes:</E>
                            </TNOTE>
                            <TNOTE>
                                <SU>1</SU>
                                 Methods for Chemical Analysis of Water and Wastes, EPA-600/4-79-020. Revised March 1983 and 1979, where applicable. U.S. EPA.
                            </TNOTE>
                            <TNOTE>
                                <SU>2</SU>
                                 Methods for Analysis of Inorganic Substances in Water and Fluvial Sediments, Techniques of Water-Resource Investigations of the U.S. Geological Survey, Book 5, Chapter A1., unless otherwise stated. 1989. USGS.
                            </TNOTE>
                            <TNOTE>
                                <SU>3</SU>
                                 Official Methods of Analysis of the Association of Official Analytical Chemists, Methods Manual, Sixteenth Edition, 4th Revision, 1998. AOAC International.
                                <PRTPAGE P="27"/>
                            </TNOTE>
                            <TNOTE>
                                <SU>4</SU>
                                 For the determination of total metals (which are equivalent to total recoverable metals) the sample is not filtered before processing. A digestion procedure is required to solubilize analytes in suspended material and to break down organic-metal complexes (to convert the analyte to a detectable form for colorimetric analysis). For non-platform graphite furnace atomic absorption determinations, a digestion using nitric acid (as specified in Section 4.1.3 of Methods for Chemical Analysis of Water and Wastes) is required prior to analysis. The procedure used should subject the sample to gentle acid refluxing, and at no time should the sample be taken to dryness. For direct aspiration flame atomic absorption (FLAA) determinations, a combination acid (nitric and hydrochloric acids) digestion is preferred, prior to analysis. The approved total recoverable digestion is described as Method 200.2 in Supplement I of “Methods for the Determination of Metals in Environmental Samples” EPA/600R-94/111, May 1994, and is reproduced in EPA Methods 200.7, 200.8, and 200.9 from the same Supplement. However, when using the gaseous hydride technique or for the determination of certain elements such as antimony, arsenic, selenium, silver, and tin by non-EPA graphite furnace atomic absorption methods, mercury by cold vapor atomic absorption, the noble metals and titanium by FLAA, a specific or modified sample digestion procedure may be required, and, in all cases the referenced method write-up should be consulted for specific instruction and/or cautions. For analyses using inductively coupled plasma-atomic emission spectrometry (ICP-AES), the direct current plasma (DCP) technique or EPA spectrochemical techniques (platform furnace AA, ICP-AES, and ICP-MS), use EPA Method 200.2 or an approved alternate procedure (e.g., CEM microwave digestion, which may be used with certain analytes as indicated in this table IB); the total recoverable digestion procedures in EPA Methods 200.7, 200.8, and 200.9 may be used for those respective methods. Regardless of the digestion procedure, the results of the analysis after digestion procedure are reported as “total” metals.
                            </TNOTE>
                            <TNOTE>
                                <SU>5</SU>
                                 Copper sulfate or other catalysts that have been found suitable may be used in place of mercuric sulfate.
                            </TNOTE>
                            <TNOTE>
                                <SU>6</SU>
                                 Manual distillation is not required if comparability data on representative effluent samples are on file to show that this preliminary distillation step is not necessary; however, manual distillation will be required to resolve any controversies. In general, the analytical method should be consulted regarding the need for distillation. If the method is not clear, the laboratory may compare a minimum of 9 different sample matrices to evaluate the need for distillation. For each matrix, a matrix spike and matrix spike duplicate are analyzed both with and without the distillation step (for a total of 36 samples, assuming 9 matrices). If results are comparable, the laboratory may dispense with the distillation step for future analysis. Comparable is defined as &lt;20% RPD for all tested matrices). Alternatively, the two populations of spike recovery percentages may be compared using a recognized statistical test.
                            </TNOTE>
                            <TNOTE>
                                <SU>7</SU>
                                 Industrial Method Number 379-75 WE Ammonia, Automated Electrode Method, Technicon Auto Analyzer II. February 19, 1976. Bran &amp; Luebbe Analyzing Technologies Inc.
                            </TNOTE>
                            <TNOTE>
                                <SU>8</SU>
                                 The approved method is that cited in Methods for Determination of Inorganic Substances in Water and Fluvial Sediments, Techniques of Water-Resources Investigations of the U.S. Geological Survey, Book 5, Chapter A1. 1979. USGS.
                            </TNOTE>
                            <TNOTE>
                                <SU>9</SU>
                                 American National Standard on Photographic Processing Effluents. April 2, 1975. American National Standards Institute.
                            </TNOTE>
                            <TNOTE>
                                <SU>10</SU>
                                 In-Situ Method 1003-8-2009, Biochemical Oxygen Demand (BOD) Measurement by Optical Probe. 2009. In-Situ Incorporated.
                            </TNOTE>
                            <TNOTE>
                                <SU>11</SU>
                                 The use of normal and differential pulse voltage ramps to increase sensitivity and resolution is acceptable.
                            </TNOTE>
                            <TNOTE>
                                <SU>12</SU>
                                 Carbonaceous biochemical oxygen demand (CBOD
                                <E T="0732">5</E>
                                ) must not be confused with the traditional BOD
                                <E T="0732">5</E>
                                 test method which measures “total 5-day BOD.” The addition of the nitrification inhibitor is not a procedural option but must be included to report the CBOD
                                <E T="0732">5</E>
                                 parameter. A discharger whose permit requires reporting the traditional BOD
                                <E T="0732">5</E>
                                 may not use a nitrification inhibitor in the procedure for reporting the results. Only when a discharger's permit specifically states CBOD
                                <E T="0732">5</E>
                                 is required can the permittee report data using a nitrification inhibitor.
                            </TNOTE>
                            <TNOTE>
                                <SU>13</SU>
                                 OIC Chemical Oxygen Demand Method. 1978. Oceanography International Corporation.
                            </TNOTE>
                            <TNOTE>
                                <SU>14</SU>
                                 Method 8000, Chemical Oxygen Demand, Hach Handbook of Water Analysis, 1979. Hach Company.
                            </TNOTE>
                            <TNOTE>
                                <SU>15</SU>
                                 The back-titration method will be used to resolve controversy.
                            </TNOTE>
                            <TNOTE>
                                <SU>16</SU>
                                 Orion Research Instruction Manual, Residual Chlorine Electrode Model 97-70. 1977. Orion Research Incorporated. The calibration graph for the Orion residual chlorine method must be derived using a reagent blank and three standard solutions, containing 0.2, 1.0, and 5.0 mL 0.00281 N potassium iodate/100 mL solution, respectively.
                            </TNOTE>
                            <TNOTE>
                                <SU>17</SU>
                                 Method 245.7, Mercury in Water by Cold Vapor Atomic Fluorescence Spectrometry, EPA-821-R-05-001. Revision 2.0, February 2005. US EPA.
                            </TNOTE>
                            <TNOTE>
                                <SU>18</SU>
                                 National Council of the Paper Industry for Air and Stream Improvement (NCASI) Technical Bulletin 253 (1971) and Technical Bulletin 803, May 2000.
                            </TNOTE>
                            <TNOTE>
                                <SU>19</SU>
                                 Method 8506, Bicinchoninate Method for Copper, Hach Handbook of Water Analysis. 1979. Hach Company.
                            </TNOTE>
                            <TNOTE>
                                <SU>20</SU>
                                 When using a method with block digestion, this treatment is not required.
                            </TNOTE>
                            <TNOTE>
                                <SU>21</SU>
                                 Industrial Method Number 378-75WA, Hydrogen ion (pH) Automated Electrode Method, Bran &amp; Luebbe (Technicon) Autoanalyzer II. October 1976. Bran &amp; Luebbe Analyzing Technologies.
                            </TNOTE>
                            <TNOTE>
                                <SU>22</SU>
                                 Method 8008, 1,10-Phenanthroline Method using FerroVer Iron Reagent for Water. 1980. Hach Company.
                            </TNOTE>
                            <TNOTE>
                                <SU>23</SU>
                                 Method 8034, Periodate Oxidation Method for Manganese, Hach Handbook of Wastewater Analysis. 1979. Hach Company.
                            </TNOTE>
                            <TNOTE>
                                <SU>24</SU>
                                 Methods for Analysis of Organic Substances in Water and Fluvial Sediments, Techniques of Water-Resources Investigations of the U.S. Geological Survey, Book 5, Chapter A3, (1972 Revised 1987). 1987. USGS.
                            </TNOTE>
                            <TNOTE>
                                <SU>25</SU>
                                 Method 8507, Nitrogen, Nitrite-Low Range, Diazotization Method for Water and Wastewater. 1979. Hach Company.
                            </TNOTE>
                            <TNOTE>
                                <SU>26</SU>
                                 Just prior to distillation, adjust the sulfuric-acid-preserved sample to pH 4 with 1 + 9 NaOH.
                                <PRTPAGE P="28"/>
                            </TNOTE>
                            <TNOTE>
                                <SU>27</SU>
                                 The colorimetric reaction must be conducted at a pH of 10.0 ± 0.2.
                            </TNOTE>
                            <TNOTE>
                                <SU>28</SU>
                                 Addison, R.F., and R.G. Ackman. 1970. Direct Determination of Elemental Phosphorus by Gas-Liquid Chromatography, 
                                <E T="03">Journal of Chromatograph</E>
                                y, 47(3):421-426.
                            </TNOTE>
                            <TNOTE>
                                <SU>29</SU>
                                 Approved methods for the analysis of silver in industrial wastewaters at concentrations of 1 mg/L and above are inadequate where silver exists as an inorganic halide. Silver halides such as the bromide and chloride are relatively insoluble in reagents such as nitric acid but are readily soluble in an aqueous buffer of sodium thiosulfate and sodium hydroxide to pH of 12. Therefore, for levels of silver above 1 mg/L, 20 mL of sample should be diluted to 100 mL by adding 40 mL each of 2 M Na
                                <E T="0732">2</E>
                                S
                                <E T="0732">2</E>
                                O
                                <E T="0732">3</E>
                                 and NaOH. Standards should be prepared in the same manner. For levels of silver below 1 mg/L the approved method is satisfactory.
                            </TNOTE>
                            <TNOTE>
                                <SU>30</SU>
                                 The use of EDTA decreases method sensitivity. Analysts may omit EDTA or replace with another suitable complexing reagent provided that all method-specified quality control acceptance criteria are met.
                            </TNOTE>
                            <TNOTE>
                                <SU>31</SU>
                                 For samples known or suspected to contain high levels of silver (e.g., in excess of 4 mg/L), cyanogen iodide should be used to keep the silver in solution for analysis. Prepare a cyanogen iodide solution by adding 4.0 mL of concentrated NH
                                <E T="0732">4</E>
                                OH, 6.5 g of KCN, and 5.0 mL of a 1.0 N solution of I
                                <E T="0732">2</E>
                                 to 50 mL of reagent water in a volumetric flask and dilute to 100.0 mL. After digestion of the sample, adjust the pH of the digestate to &lt;7 to prevent the formation of HCN under acidic conditions. Add 1 mL of the cyanogen iodide solution to the sample digestate and adjust the volume to 100 mL with reagent water (NOT acid). If cyanogen iodide is added to sample digestates, then silver standards must be prepared that contain cyanogen iodide as well. Prepare working standards by diluting a small volume of a silver stock solution with water and adjusting the pH&gt;7 with NH
                                <E T="0732">4</E>
                                OH. Add 1 mL of the cyanogen iodide solution and let stand 1 hour. Transfer to a 100-mL volumetric flask and dilute to volume with water.
                            </TNOTE>
                            <TNOTE>
                                <SU>32</SU>
                                 “Water Temperature-Influential Factors, Field Measurement and Data Presentation,” Techniques of Water-Resources Investigations of the U.S. Geological Survey, Book 1, Chapter D1. 1975. USGS.
                            </TNOTE>
                            <TNOTE>
                                <SU>33</SU>
                                 Method 8009, Zincon Method for Zinc, Hach Handbook of Water Analysis, 1979. Hach Company.
                            </TNOTE>
                            <TNOTE>
                                <SU>34</SU>
                                 Method AES0029, Direct Current Plasma (DCP) Optical Emission Spectrometric Method for Trace Elemental Analysis of Water and Wastes. 1986—Revised 1991. Thermo Jarrell Ash Corporation.
                            </TNOTE>
                            <TNOTE>
                                <SU>35</SU>
                                 In-Situ Method 1004-8-2009, Carbonaceous Biochemical Oxygen Demand (CBOD) Measurement by Optical Probe. 2009. In-Situ Incorporated.
                            </TNOTE>
                            <TNOTE>
                                <SU>36</SU>
                                 Microwave-assisted digestion may be employed for this metal, when analyzed by this methodology. Closed Vessel Microwave Digestion of Wastewater Samples for Determination of Metals. April 16, 1992. CEM Corporation.
                            </TNOTE>
                            <TNOTE>
                                <SU>37</SU>
                                 When determining boron and silica, only plastic, PTFE, or quartz laboratory ware may be used from start until completion of analysis.
                            </TNOTE>
                            <TNOTE>
                                <SU>38</SU>
                                 Only use 
                                <E T="03">n</E>
                                -hexane (
                                <E T="03">n</E>
                                -Hexane—85% minimum purity, 99.0% min. saturated C6 isomers, residue less than 1 mg/L) extraction solvent when determining Oil and Grease parameters—Hexane Extractable Material (HEM), or Silica Gel Treated HEM (analogous to EPA Methods 1664 Rev. A and 1664 Rev. B). Use of other extraction solvents is prohibited.
                            </TNOTE>
                            <TNOTE>
                                <SU>39</SU>
                                 Method PAI-DK01, Nitrogen, Total Kjeldahl, Block Digestion, Steam Distillation, Titrimetric Detection. Revised December 22, 1994. OI Analytical.
                            </TNOTE>
                            <TNOTE>
                                <SU>40</SU>
                                 Method PAI-DK02, Nitrogen, Total Kjeldahl, Block Digestion, Steam Distillation, Colorimetric Detection. Revised December 22, 1994. OI Analytical.
                            </TNOTE>
                            <TNOTE>
                                <SU>41</SU>
                                 Method PAI-DK03, Nitrogen, Total Kjeldahl, Block Digestion, Automated FIA Gas Diffusion. Revised December 22, 1994. OI Analytical.
                            </TNOTE>
                            <TNOTE>
                                <SU>42</SU>
                                 Method 1664 Rev. B is the revised version of EPA Method 1664 Rev. A. U.S. EPA. February 1999, Revision A. Method 1664, 
                                <E T="03">n</E>
                                -Hexane Extractable Material (HEM; Oil and Grease) and Silica Gel Treated 
                                <E T="03">n</E>
                                -Hexane Extractable Material (SGT-HEM; Non-polar Material) by Extraction and Gravimetry. EPA-821-R-98-002. U.S. EPA. February 2010, Revision B. Method 1664, 
                                <E T="03">n</E>
                                -Hexane Extractable Material (HEM; Oil and Grease) and Silica Gel Treated 
                                <E T="03">n</E>
                                -Hexane Extractable Material (SGT-HEM; Non-polar Material) by Extraction and Gravimetry. EPA-821-R-10-001.
                            </TNOTE>
                            <TNOTE>
                                <SU>43</SU>
                                 Method 1631, Revision E, Mercury in Water by Oxidation, Purge and Trap, and Cold Vapor Atomic Fluorescence Spectrometry, EPA-821-R-02-019. Revision E. August 2002, U.S. EPA. The application of clean techniques described in EPA's Method 1669: 
                                <E T="03">Sampling Ambient Water for Trace Metals at EPA Water Quality Criteria Levels,</E>
                                 EPA-821-R-96-011, are recommended to preclude contamination at low-level, trace metal determinations.
                            </TNOTE>
                            <TNOTE>
                                <SU>44</SU>
                                 Method OIA-1677-09, Available Cyanide by Ligand Exchange and Flow Injection Analysis (FIA). 2010. OI Analytical.
                            </TNOTE>
                            <TNOTE>
                                <SU>45</SU>
                                 Open File Report 00-170, Methods of Analysis by the U.S. Geological Survey National Water Quality Laboratory—Determination of Ammonium Plus Organic Nitrogen by a Kjeldahl Digestion Method and an Automated Photometric Finish that Includes Digest Cleanup by Gas Diffusion. 2000. USGS.
                            </TNOTE>
                            <TNOTE>
                                <SU>46</SU>
                                 Open File Report 93-449, Methods of Analysis by the U.S. Geological Survey National Water Quality Laboratory—Determination of Chromium in Water by Graphite Furnace Atomic Absorption Spectrophotometry. 1993. USGS.
                            </TNOTE>
                            <TNOTE>
                                <SU>47</SU>
                                 Open File Report 97-198, Methods of Analysis by the U.S. Geological Survey National Water Quality Laboratory—Determination of Molybdenum by Graphite Furnace Atomic Absorption Spectrophotometry. 1997. USGS.
                            </TNOTE>
                            <TNOTE>
                                <SU>48</SU>
                                 Open File Report 92-146, Methods of Analysis by the U.S. Geological Survey National Water Quality Laboratory—Determination of Total Phosphorus by Kjeldahl Digestion Method and an Automated Colorimetric Finish That Includes Dialysis. 1992. USGS.
                            </TNOTE>
                            <TNOTE>
                                <SU>49</SU>
                                 Open File Report 98-639, Methods of Analysis by the U.S. Geological Survey National Water Quality Laboratory—Determination of Arsenic and Selenium in Water and Sediment by Graphite Furnace-Atomic Absorption Spectrometry. 1999. USGS.
                                <PRTPAGE P="29"/>
                            </TNOTE>
                            <TNOTE>
                                <SU>50</SU>
                                 Open File Report 98-165, Methods of Analysis by the U.S. Geological Survey National Water Quality Laboratory—Determination of Elements in Whole-water Digests Using Inductively Coupled Plasma-Optical Emission Spectrometry and Inductively Coupled Plasma-Mass Spectrometry. 1998. USGS.
                            </TNOTE>
                            <TNOTE>
                                <SU>51</SU>
                                 Open File Report 93-125, Methods of Analysis by the U.S. Geological Survey National Water Quality Laboratory—Determination of Inorganic and Organic Constituents in Water and Fluvial Sediments. 1993. USGS.
                            </TNOTE>
                            <TNOTE>
                                <SU>52</SU>
                                 Unless otherwise indicated, all EPA methods, excluding EPA Method 300.1, are published in U.S. EPA. May 1994. Methods for the Determination of Metals in Environmental Samples, Supplement I, EPA/600/R-94/111; or U.S. EPA. August 1993. Methods for the Determination of Inorganic Substances in Environmental Samples, EPA/600/R-93/100. EPA Method 300.1 is U.S. EPA. Revision 1.0, 1997, including errata cover sheet April 27, 1999. Determination of Inorganic Ions in Drinking Water by Ion Chromatography.
                            </TNOTE>
                            <TNOTE>
                                <SU>53</SU>
                                 Styrene divinyl benzene beads (e.g., AMCO-AEPA-1 or equivalent) and stabilized formazin (e.g., Hach StablCal
                                <SU>TM</SU>
                                 or equivalent) are acceptable substitutes for formazin.
                            </TNOTE>
                            <TNOTE>
                                <SU>54</SU>
                                 Waters Corp. Now included in ASTM D6508-15, Test Method for Determination of Dissolved Inorganic Anions in Aqueous Matrices Using Capillary Ion Electrophoresis and Chromate Electrolyte. 2015.
                            </TNOTE>
                            <TNOTE>
                                <SU>55</SU>
                                 Kelada-01, Kelada Automated Test Methods for Total Cyanide, Acid Dissociable Cyanide, and Thiocyanate, EPA 821-B-01-009, Revision 1.2, August 2001. US EPA. Note: A 450-W UV lamp may be used in this method instead of the 550-W lamp specified if it provides performance within the quality control (QC) acceptance criteria of the method in a given instrument. Similarly, modified flow cell configurations and flow conditions may be used in the method, provided that the QC acceptance criteria are met.
                            </TNOTE>
                            <TNOTE>
                                <SU>56</SU>
                                 QuikChem Method 10-204-00-1-X, Digestion and Distillation of Total Cyanide in Drinking and Wastewaters using MICRO DIST and Determination of Cyanide by Flow Injection Analysis. Revision 2.2, March 2005. Lachat Instruments.
                            </TNOTE>
                            <TNOTE>
                                <SU>57</SU>
                                 When using sulfide removal test procedures described in EPA Method 335.4, reconstitute particulate that is filtered with the sample prior to distillation.
                            </TNOTE>
                            <TNOTE>
                                <SU>58</SU>
                                 Unless otherwise stated, if the language of this table specifies a sample digestion and/or distillation “followed by” analysis with a method, approved digestion and/or distillation are required prior to analysis.
                            </TNOTE>
                            <TNOTE>
                                <SU>59</SU>
                                 Samples analyzed for available cyanide using OI Analytical method OIA-1677-09 or ASTM method D6888-16 that contain particulate matter may be filtered only after the ligand exchange reagents have been added to the samples, because the ligand exchange process converts complexes containing available cyanide to free cyanide, which is not removed by filtration. Analysts are further cautioned to limit the time between the addition of the ligand exchange reagents and sample filtration to no more than 30 minutes to preclude settling of materials in samples.
                            </TNOTE>
                            <TNOTE>
                                <SU>60</SU>
                                 Analysts should be aware that pH optima and chromophore absorption maxima might differ when phenol is replaced by a substituted phenol as the color reagent in Berthelot Reaction (“phenol-hypochlorite reaction”) colorimetric ammonium determination methods. For example, when phenol is used as the color reagent, pH optimum and wavelength of maximum absorbance are about 11.5 and 635 nm, respectively—see, Patton, C.J. and S.R. Crouch. March 1977. 
                                <E T="03">Anal. Chem.</E>
                                 49:464-469. These reaction parameters increase to pH &gt; 12.6 and 665 nm when salicylate is used as the color reagent—see, Krom, M.D. April 1980. 
                                <E T="03">The Analyst</E>
                                 105:305-316.
                            </TNOTE>
                            <TNOTE>
                                <SU>61</SU>
                                 If atomic absorption or ICP instrumentation is not available, the aluminon colorimetric method detailed in the 19th Edition of 
                                <E T="03">Standard Methods for the Examination of Water and Wastewater</E>
                                 may be used. This method has poorer precision and bias than the methods of choice.
                            </TNOTE>
                            <TNOTE>
                                <SU>62</SU>
                                 Easy (1-Reagent) Nitrate Method, Revision November 12, 2011. Craig Chinchilla.
                            </TNOTE>
                            <TNOTE>
                                <SU>63</SU>
                                 Hach Method 10360, Luminescence Measurement of Dissolved Oxygen in Water and Wastewater and for Use in the Determination of BOD
                                <E T="0732">5</E>
                                 and CBOD
                                <E T="0732">5</E>
                                . Revision 1.2, October 2011. Hach Company. This method may be used to measure dissolved oxygen when performing the methods approved in this table IB for measurement of biochemical oxygen demand (BOD) and carbonaceous biochemical oxygen demand (CBOD).
                            </TNOTE>
                            <TNOTE>
                                <SU>64</SU>
                                 In-Situ Method 1002-8-2009, Dissolved Oxygen (DO) Measurement by Optical Probe. 2009. In-Situ Incorporated.
                            </TNOTE>
                            <TNOTE>
                                <SU>65</SU>
                                 Mitchell Method M5331, Determination of Turbidity by Nephelometry. Revision 1.0, July 31, 2008. Leck Mitchell.
                            </TNOTE>
                            <TNOTE>
                                <SU>66</SU>
                                 Mitchell Method M5271, Determination of Turbidity by Nephelometry. Revision 1.0, July 31, 2008. Leck Mitchell.
                            </TNOTE>
                            <TNOTE>
                                <SU>67</SU>
                                 Orion Method AQ4500, Determination of Turbidity by Nephelometry. Revision 5, March 12, 2009. Thermo Scientific.
                            </TNOTE>
                            <TNOTE>
                                <SU>68</SU>
                                 EPA Method 200.5, Determination of Trace Elements in Drinking Water by Axially Viewed Inductively Coupled Plasma-Atomic Emission Spectrometry, EPA/600/R-06/115. Revision 4.2, October 2003. US EPA.
                            </TNOTE>
                            <TNOTE>
                                <SU>69</SU>
                                 Method 1627, Kinetic Test Method for the Prediction of Mine Drainage Quality, EPA-821-R-09-002. December 2011. US EPA.
                            </TNOTE>
                            <TNOTE>
                                <SU>70</SU>
                                 Techniques and Methods Book 5-B1, Determination of Elements in Natural-Water, Biota, Sediment and Soil Samples Using Collision/Reaction Cell Inductively Coupled Plasma-Mass Spectrometry, Chapter 1, Section B, Methods of the National Water Quality Laboratory, Book 5, Laboratory Analysis, 2006. USGS.
                            </TNOTE>
                            <TNOTE>
                                <SU>71</SU>
                                 Water-Resources Investigations Report 01-4132, Methods of Analysis by the U.S. Geological Survey National Water Quality Laboratory—Determination of Organic Plus Inorganic Mercury in Filtered and Unfiltered Natural Water with Cold Vapor-Atomic Fluorescence Spectrometry, 2001. USGS.
                            </TNOTE>
                            <TNOTE>
                                <SU>72</SU>
                                 USGS Techniques and Methods 5-B8, Chapter 8, Section B, Methods of the National Water Quality Laboratory Book 5, Laboratory Analysis, 2011 USGS.
                            </TNOTE>
                            <TNOTE>
                                <SU>73</SU>
                                 NECi Method N07-0003, “Nitrate Reductase Nitrate-Nitrogen Analysis,” Revision 9.0, March 2014, The Nitrate Elimination Co., Inc.
                                <PRTPAGE P="30"/>
                            </TNOTE>
                            <TNOTE>
                                <SU>74</SU>
                                 Timberline Instruments, LLC Method Ammonia-001, “Determination of Inorganic Ammonia by Continuous Flow Gas Diffusion and Conductivity Cell Analysis,” June 2011, Timberline Instruments, LLC.
                            </TNOTE>
                            <TNOTE>
                                <SU>75</SU>
                                 Hach Company Method 10206, “Spectrophotometric Measurement of Nitrate in Water and Wastewater,” Revision 2.1, January 2013, Hach Company.
                            </TNOTE>
                            <TNOTE>
                                <SU>76</SU>
                                 Hach Company Method 10242, “Simplified Spectrophotometric Measurement of Total Kjeldahl Nitrogen in Water and Wastewater,” Revision 1.1, January 2013, Hach Company.
                            </TNOTE>
                            <TNOTE>
                                <SU>77</SU>
                                 National Council for Air and Stream Improvement (NCASI) Method TNTP-W10900, “Total (Kjeldahl) Nitrogen and Total Phosphorus in Pulp and Paper Biologically Treated Effluent by Alkaline Persulfate Digestion,” June 2011, National Council for Air and Stream Improvement, Inc.
                            </TNOTE>
                            <TNOTE>
                                <SU>78</SU>
                                 The pH adjusted sample is to be adjusted to 7.6 for NPDES reporting purposes.
                            </TNOTE>
                            <TNOTE>
                                <SU>79</SU>
                                 I-2057-85 in U.S. Geological Survey Techniques of Water-Resources Investigations, Book 5, Chap. A1, Methods for Determination of Inorganic Substances in Water and Fluvial Sediments, 1989.
                            </TNOTE>
                            <TNOTE>
                                <SU>80</SU>
                                 Methods I-2522-90, I-2540-90, and I-2601-90 in U.S. Geological Survey Open-File Report 93-125, Methods of Analysis by the U.S. Geological Survey National Water Quality Laboratory—Determination of Inorganic and Organic Constituents in Water and Fluvial Sediments, 1993.
                            </TNOTE>
                            <TNOTE>
                                <SU>81</SU>
                                 Method I-4472-97 in U.S. Geological Survey Open-File Report 98-165, Methods of Analysis by the U.S. Geological Survey National Water Quality Laboratory—Determination of Inorganic and Organic Constituents in Water and Fluvial Sediments, 1998.
                            </TNOTE>
                            <TNOTE>
                                <SU>82</SU>
                                 FIAlab 100, “Determination of Inorganic Ammonia by Continuous Flow Gas Diffusion and Fluorescence Detector Analysis”, April 4, 2018, FIAlab Instruments, Inc.
                            </TNOTE>
                            <TNOTE>
                                <SU>83</SU>
                                 MACHEREY-NAGEL GmbH and Co. Method 036/038 NANOCOLOR® COD LR/HR, “Spectrophotometric Measurement of Chemical Oxygen Demand in Water and Wastewater”, Revision 1.5, May 2018, MACHEREY-NAGEL GmbH and Co. KG.
                            </TNOTE>
                            <TNOTE>
                                <SU>84</SU>
                                 Please refer to the following applicable Quality Control Sections: Part 2000 Methods, Physical and Aggregate Properties 2020 (2021); Part 3000 Methods, Metals, 3020 (2021); Part 4000 Methods, Inorganic Nonmetallic Constituents, 4020 (2022); Part 5000 Methods, and Aggregate Organic Constituents, 5020 (2022). These Quality Control Standards are available for download at 
                                <E T="03">www.standardmethods.org</E>
                                 at no charge.
                            </TNOTE>
                            <TNOTE>
                                <SU>85</SU>
                                 Each laboratory may establish its own control limits by performing at least 25 glucose-glutamic acid (GGA) checks over several weeks or months and calculating the mean and standard deviation. The laboratory may then use the mean ± 3 standard deviations as the control limit for future GGA checks. However, GGA acceptance criteria can be no wider than 198 ± 30.5 mg/L for BOD
                                <E T="0732">5</E>
                                . GGA acceptance criteria for CBOD must be either 198 ± 30.5 mg/L, or the lab may develop control charts under the following conditions: dissolved oxygen uptake from the seed contribution is between 0.6-1.0 mg/L; control charts are performed on at least 25 GGA checks with three standard deviations from the derived mean; the RSD must not exceed 7.5%; and any single GGA value cannot be less than 150 mg/L or higher than 250 mg/L.
                            </TNOTE>
                            <TNOTE>
                                <SU>86</SU>
                                 The approved method is that cited in 
                                <E T="03">Standard Methods for the Examination of Water and Wastewater,</E>
                                 14th Edition, 1976.
                            </TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="6" OPTS="L2,nj,p7,7/8" CDEF="s50,xs60,xs60,xs60,xs60,r50">
                            <TTITLE>Table IC—List of Approved Test Procedures for Non-Pesticide Organic Compounds</TTITLE>
                            <BOXHD>
                                <CHED H="1">
                                    Parameter 
                                    <SU>1</SU>
                                </CHED>
                                <CHED H="1">Method</CHED>
                                <CHED H="1">
                                    EPA 
                                    <SU>2</SU>
                                     
                                    <SU>7</SU>
                                </CHED>
                                <CHED H="1">
                                    Standard
                                    <LI>
                                        methods 
                                        <SU>17</SU>
                                    </LI>
                                </CHED>
                                <CHED H="1">ASTM</CHED>
                                <CHED H="1">Other</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">1. Acenaphthene</ENT>
                                <ENT>GC</ENT>
                                <ENT>610</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1, 1625B</ENT>
                                <ENT>6410 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>9</SU>
                                     p. 27.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>HPLC</ENT>
                                <ENT>610</ENT>
                                <ENT>6440 B-2021</ENT>
                                <ENT O="xl">D4657-92 (98).</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2. Acenaphthylene</ENT>
                                <ENT>GC</ENT>
                                <ENT>610</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1, 1625B</ENT>
                                <ENT>6410 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>9</SU>
                                     p. 27.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>HPLC</ENT>
                                <ENT>610</ENT>
                                <ENT>6440 B-2021</ENT>
                                <ENT O="xl">D4657-92 (98).</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">3. Acrolein</ENT>
                                <ENT>GC</ENT>
                                <ENT>603</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT O="xl">
                                    624.1 
                                    <SU>4</SU>
                                    , 1624B.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4. Acrylonitrile</ENT>
                                <ENT>GC</ENT>
                                <ENT>603</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>
                                    624.1 
                                    <SU>4</SU>
                                    , 1624B
                                </ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    O-4127-96.
                                    <SU>13</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">5. Anthracene</ENT>
                                <ENT>GC</ENT>
                                <ENT>610</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1, 1625B</ENT>
                                <ENT>6410 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>9</SU>
                                     p. 27.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>HPLC</ENT>
                                <ENT>610</ENT>
                                <ENT>6440 B-2021</ENT>
                                <ENT O="xl">D4657-92 (98).</ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="31"/>
                                <ENT I="01">6. Benzene</ENT>
                                <ENT>GC</ENT>
                                <ENT>602</ENT>
                                <ENT O="xl">6200 C-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>624.1, 1624B</ENT>
                                <ENT>6200 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    O-4127-96 
                                    <SU>13</SU>
                                    , O-4436-16.
                                    <SU>14</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">7. Benzidine</ENT>
                                <ENT>Spectro-photometric</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p.1.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>
                                    625.1 
                                    <SU>5</SU>
                                    , 1625B
                                </ENT>
                                <ENT O="xl">6410 B-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>HPLC</ENT>
                                <ENT>605</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">8. Benzo(a)anthracene</ENT>
                                <ENT>GC</ENT>
                                <ENT>610</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1, 1625B</ENT>
                                <ENT>6410 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>9</SU>
                                     p. 27.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>HPLC</ENT>
                                <ENT>610</ENT>
                                <ENT>6440 B-2021</ENT>
                                <ENT O="xl">D4657-92 (98).</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">9. Benzo(a)pyrene</ENT>
                                <ENT>GC</ENT>
                                <ENT>610</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1, 1625B</ENT>
                                <ENT>6410 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>9</SU>
                                     p. 27.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>HPLC</ENT>
                                <ENT>610</ENT>
                                <ENT>6440 B-2021</ENT>
                                <ENT O="xl">D4657-92 (98).</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">10. Benzo(b)fluoranthene</ENT>
                                <ENT>GC</ENT>
                                <ENT>610</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1, 1625B</ENT>
                                <ENT>6410 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>9</SU>
                                     p. 27.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>HPLC</ENT>
                                <ENT>610</ENT>
                                <ENT>6440 B-2021</ENT>
                                <ENT O="xl">D4657-92 (98).</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">11. Benzo(g,h,i)perylene</ENT>
                                <ENT>GC</ENT>
                                <ENT>610</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1, 1625B</ENT>
                                <ENT>6410 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>9</SU>
                                     p. 27.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>HPLC</ENT>
                                <ENT>610</ENT>
                                <ENT>6440 B-2021</ENT>
                                <ENT O="xl">D4657-92 (98).</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">12. Benzo(k)fluoranthene</ENT>
                                <ENT>GC</ENT>
                                <ENT>610</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1, 1625B</ENT>
                                <ENT>6410 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>9</SU>
                                     p. 27.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>HPLC</ENT>
                                <ENT>610</ENT>
                                <ENT>6440 B-2021</ENT>
                                <ENT O="xl">D4657-92 (98).</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">13. Benzyl chloride</ENT>
                                <ENT>GC</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 130.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>6</SU>
                                     p. S102.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">14. Butyl benzyl phthalate</ENT>
                                <ENT>GC</ENT>
                                <ENT>606</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1, 1625B</ENT>
                                <ENT>6410 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>9</SU>
                                     p. 27.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">15. bis(2-Chloroethoxy) methane</ENT>
                                <ENT>GC</ENT>
                                <ENT>611</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1, 1625B</ENT>
                                <ENT>6410 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>9</SU>
                                     p. 27.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">16. bis(2-Chloroethyl) ether</ENT>
                                <ENT>GC</ENT>
                                <ENT>611</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1, 1625B</ENT>
                                <ENT>6410 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>9</SU>
                                     p. 27.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">17. bis(2-Ethylhexyl) phthalate</ENT>
                                <ENT>GC</ENT>
                                <ENT>606</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1, 1625B</ENT>
                                <ENT>6410 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>9</SU>
                                     p. 27.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">18. Bromodichloromethane</ENT>
                                <ENT>GC</ENT>
                                <ENT>601</ENT>
                                <ENT O="xl">6200 C-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>624.1, 1624B</ENT>
                                <ENT>6200 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    O-4127-96 
                                    <SU>13</SU>
                                    , O-4436-16.
                                    <SU>14</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">19. Bromoform</ENT>
                                <ENT>GC</ENT>
                                <ENT>601</ENT>
                                <ENT O="xl">6200 C-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>624.1, 1624B</ENT>
                                <ENT>6200 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    O-4127-96 
                                    <SU>13</SU>
                                    , O-4436-16.
                                    <SU>14</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">20. Bromomethane</ENT>
                                <ENT>GC</ENT>
                                <ENT>601</ENT>
                                <ENT O="xl">6200 C-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>624.1, 1624B</ENT>
                                <ENT>6200 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    O-4127-96 
                                    <SU>13</SU>
                                    , O-4436-16.
                                    <SU>14</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">21. 4-Bromophenyl phenyl ether</ENT>
                                <ENT>GC</ENT>
                                <ENT>611</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1, 1625B</ENT>
                                <ENT>6410 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>9</SU>
                                     p. 27.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">22. Carbon tetrachloride</ENT>
                                <ENT>GC</ENT>
                                <ENT>601</ENT>
                                <ENT>6200 C-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 130.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>624.1, 1624B</ENT>
                                <ENT>6200 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    O-4127-96 
                                    <SU>13</SU>
                                    , O-4436-16.
                                    <SU>14</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">23. 4-Chloro-3-methyl phenol</ENT>
                                <ENT>GC</ENT>
                                <ENT>604</ENT>
                                <ENT O="xl">6420 B-2021.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1, 1625B</ENT>
                                <ENT>6410 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>9</SU>
                                     p. 27.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">24. Chlorobenzene</ENT>
                                <ENT>GC</ENT>
                                <ENT>601, 602</ENT>
                                <ENT>6200 C-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 130.
                                </ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="32"/>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>624.1, 1624B</ENT>
                                <ENT>6200 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    O-4127-96 
                                    <SU>13</SU>
                                     O-4436-16.
                                    <SU>14</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">25. Chloroethane</ENT>
                                <ENT>GC</ENT>
                                <ENT>601</ENT>
                                <ENT O="xl">6200 C-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>624.1, 1624B</ENT>
                                <ENT>6200 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    O-4127-96.
                                    <SU>13</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">26. 2-Chloroethylvinyl ether</ENT>
                                <ENT>GC</ENT>
                                <ENT>601</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT O="xl">624.1, 1624B.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">27. Chloroform</ENT>
                                <ENT>GC</ENT>
                                <ENT>601</ENT>
                                <ENT>6200 C-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 130.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>624.1, 1624B</ENT>
                                <ENT>6200 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    O-4127-96 
                                    <SU>13</SU>
                                    , O-4436-16.
                                    <SU>14</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">28. Chloromethane</ENT>
                                <ENT>GC</ENT>
                                <ENT>601</ENT>
                                <ENT O="xl">6200 C-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>624.1, 1624B</ENT>
                                <ENT>6200 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    O-4127-96 
                                    <SU>13</SU>
                                    , O-4436-16.
                                    <SU>14</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">29. 2-Chloronaphthalene</ENT>
                                <ENT>GC</ENT>
                                <ENT>612</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1, 1625B</ENT>
                                <ENT>6410 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>9</SU>
                                     p. 27.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">30. 2-Chlorophenol</ENT>
                                <ENT>GC</ENT>
                                <ENT>604</ENT>
                                <ENT O="xl">6420 B-2021.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1, 1625B</ENT>
                                <ENT>6410 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>9</SU>
                                     p. 27.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">31. 4-Chlorophenyl phenyl ether</ENT>
                                <ENT>GC</ENT>
                                <ENT>611</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1, 1625B</ENT>
                                <ENT>6410 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>9</SU>
                                     p. 27.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">32. Chrysene</ENT>
                                <ENT>GC</ENT>
                                <ENT>610</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1, 1625B</ENT>
                                <ENT>6410 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>9</SU>
                                     p. 27.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>HPLC</ENT>
                                <ENT>610</ENT>
                                <ENT>6440 B-2021</ENT>
                                <ENT O="xl">D4657-92 (98).</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">33. Dibenzo(a,h)anthracene</ENT>
                                <ENT>GC</ENT>
                                <ENT>610</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1, 1625B</ENT>
                                <ENT>6410 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>9</SU>
                                     p. 27.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>HPLC</ENT>
                                <ENT>610</ENT>
                                <ENT>6440 B-2021</ENT>
                                <ENT O="xl">D4657-92 (98).</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">34. Dibromochloromethane</ENT>
                                <ENT>GC</ENT>
                                <ENT>601</ENT>
                                <ENT O="xl">6200 C-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>624.1, 1624B</ENT>
                                <ENT>6200 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    O-4127-96 
                                    <SU>13</SU>
                                    , O-4436-16.
                                    <SU>14</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">35. 1,2-Dichlorobenzene</ENT>
                                <ENT>GC</ENT>
                                <ENT>601, 602</ENT>
                                <ENT O="xl">6200 C-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>624.1, 1625B</ENT>
                                <ENT>6200 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>9</SU>
                                     p. 27, O-4127-96 
                                    <SU>13</SU>
                                    , O-4436-16.
                                    <SU>14</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">36. 1,3-Dichlorobenzene</ENT>
                                <ENT>GC</ENT>
                                <ENT>601, 602</ENT>
                                <ENT O="xl">6200 C-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>624.1, 1625B</ENT>
                                <ENT>6200 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>9</SU>
                                     p. 27, O-4127-96.
                                    <SU>13</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">37. 1,4-Dichlorobenzene</ENT>
                                <ENT>GC</ENT>
                                <ENT>601, 602</ENT>
                                <ENT O="xl">6200 C-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>624.1, 1625B</ENT>
                                <ENT>6200 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>9</SU>
                                     p. 27, O-4127-96 
                                    <SU>13</SU>
                                    , O-4436-16.
                                    <SU>14</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">38. 3,3′-Dichlorobenzidine</ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1, 1625B</ENT>
                                <ENT O="xl">6410 B-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>HPLC</ENT>
                                <ENT O="xl">605.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">39. Dichlorodifluoromethane</ENT>
                                <ENT>GC</ENT>
                                <ENT O="xl">601.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT/>
                                <ENT>6200 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    O-4127-96 
                                    <SU>13</SU>
                                    , O-4436-16.
                                    <SU>14</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">40. 1,1-Dichloroethane</ENT>
                                <ENT>GC</ENT>
                                <ENT>601</ENT>
                                <ENT O="xl">6200 C-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>624.1, 1624B</ENT>
                                <ENT>6200 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    O-4127-96 
                                    <SU>13</SU>
                                    , O-4436-16.
                                    <SU>14</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">41. 1,2-Dichloroethane</ENT>
                                <ENT>GC</ENT>
                                <ENT>601</ENT>
                                <ENT O="xl">6200 C-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>624.1, 1624B</ENT>
                                <ENT>6200 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    O-4127-96 
                                    <SU>13</SU>
                                    , O-4436-16.
                                    <SU>14</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="33"/>
                                <ENT I="01">42. 1,1-Dichloroethene</ENT>
                                <ENT>GC</ENT>
                                <ENT>601</ENT>
                                <ENT O="xl">6200 C-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>624.1, 1624B</ENT>
                                <ENT>6200 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    O-4127-96 
                                    <SU>13</SU>
                                    , O-4436-16.
                                    <SU>14</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    43. 
                                    <E T="03">trans</E>
                                    -1,2-Dichloroethene
                                </ENT>
                                <ENT>GC</ENT>
                                <ENT>601</ENT>
                                <ENT O="xl">6200 C-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>624.1, 1624B</ENT>
                                <ENT>6200 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    O-4127-96 
                                    <SU>13</SU>
                                    , O-4436-16.
                                    <SU>14</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">44. 2,4-Dichlorophenol</ENT>
                                <ENT>GC</ENT>
                                <ENT>604</ENT>
                                <ENT O="xl">6420 B-2021.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1, 1625B</ENT>
                                <ENT>6410 B-2020</ENT>
                                <ENT/>
                                <ENT O="xl">
                                    See footnote 
                                    <SU>9</SU>
                                     p. 27.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">45. 1,2-Dichloropropane</ENT>
                                <ENT>GC</ENT>
                                <ENT>601</ENT>
                                <ENT O="xl">6200 C-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>624.1, 1624B</ENT>
                                <ENT>6200 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    O-4127-96 
                                    <SU>13</SU>
                                     O-4436-16.
                                    <SU>14</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    46. 
                                    <E T="03">cis</E>
                                    -1,3-Dichloropropene
                                </ENT>
                                <ENT>GC</ENT>
                                <ENT>601</ENT>
                                <ENT O="xl">6200 C-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>624.1, 1624B</ENT>
                                <ENT>6200 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    O-4127-96 
                                    <SU>13</SU>
                                    , O-4436-16.
                                    <SU>14</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    47. 
                                    <E T="03">trans</E>
                                    -1,3-Dichloropropene
                                </ENT>
                                <ENT>GC</ENT>
                                <ENT>601</ENT>
                                <ENT O="xl">6200 C-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>624.1, 1624B</ENT>
                                <ENT>6200 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    O-4127-96 
                                    <SU>13</SU>
                                    , O-4436-16.
                                    <SU>14</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">48. Diethyl phthalate</ENT>
                                <ENT>GC</ENT>
                                <ENT O="xl">606.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1, 1625B</ENT>
                                <ENT>6410 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>9</SU>
                                     p. 27.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">49. 2,4-Dimethylphenol</ENT>
                                <ENT>GC</ENT>
                                <ENT>604</ENT>
                                <ENT O="xl">6420 B-2021.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1, 1625B</ENT>
                                <ENT>6410 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>9</SU>
                                     p. 27.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">50. Dimethyl phthalate</ENT>
                                <ENT>GC</ENT>
                                <ENT O="xl">606.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1, 1625B</ENT>
                                <ENT>6410 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>9</SU>
                                     p. 27.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    51. Di-
                                    <E T="03">n</E>
                                    -butyl phthalate
                                </ENT>
                                <ENT>GC</ENT>
                                <ENT O="xl">606.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1, 1625B</ENT>
                                <ENT>6410 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>9</SU>
                                     p. 27.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    52. Di-
                                    <E T="03">n</E>
                                    -octyl phthalate
                                </ENT>
                                <ENT>GC</ENT>
                                <ENT O="xl">606.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1, 1625B</ENT>
                                <ENT>6410 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>9</SU>
                                     p. 27.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">53. 2, 4-Dinitrophenol</ENT>
                                <ENT>GC</ENT>
                                <ENT>604</ENT>
                                <ENT>6420 B-2021</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>9</SU>
                                     p. 27.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1, 1625B</ENT>
                                <ENT O="xl">6410 B-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">54. 2,4-Dinitrotoluene</ENT>
                                <ENT>GC</ENT>
                                <ENT O="xl">609.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1, 1625B</ENT>
                                <ENT>6410 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>9</SU>
                                     p. 27.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">55. 2,6-Dinitrotoluene</ENT>
                                <ENT>GC</ENT>
                                <ENT O="xl">609.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1, 1625B</ENT>
                                <ENT>6410 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>9</SU>
                                     p. 27.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">56. Epichlorohydrin</ENT>
                                <ENT>GC</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 130.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>6</SU>
                                     p. S102.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">57. Ethylbenzene</ENT>
                                <ENT>GC</ENT>
                                <ENT>602</ENT>
                                <ENT O="xl">6200 C-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>624.1, 1624B</ENT>
                                <ENT>6200 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    O-4127-96 
                                    <SU>13</SU>
                                    , O-4436-16.
                                    <SU>14</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">58. Fluoranthene</ENT>
                                <ENT>GC</ENT>
                                <ENT O="xl">610.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1, 1625B</ENT>
                                <ENT>6410 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>9</SU>
                                     p. 27.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>HPLC</ENT>
                                <ENT>610</ENT>
                                <ENT>6440 B-2021</ENT>
                                <ENT>D4657-92 (98).</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">59. Fluorene</ENT>
                                <ENT>GC</ENT>
                                <ENT O="xl">610.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1, 1625B</ENT>
                                <ENT>6410 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>9</SU>
                                     p. 27.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>HPLC</ENT>
                                <ENT>610</ENT>
                                <ENT>6440 B-2021</ENT>
                                <ENT O="xl">D4657-92 (98).</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">60. 1,2,3,4,6,7,8-Heptachloro-dibenzofuran</ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>
                                    1613B 
                                    <SU>10</SU>
                                </ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    SGS AXYS 16130 
                                    <SU>15</SU>
                                    , PAM 16130-SSI.
                                    <SU>16</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">61. 1,2,3,4,7,8,9-Heptachloro-dibenzofuran</ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>
                                    1613B 
                                    <SU>10</SU>
                                </ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    SGS AXYS 16130 
                                    <SU>15</SU>
                                    , PAM 16130-SSI.
                                    <SU>16</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    62. 1,2,3,4,6,7,8- Heptachloro-dibenzo-
                                    <E T="03">p</E>
                                    -dioxin
                                </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>
                                    1613B 
                                    <SU>10</SU>
                                </ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    SGS AXYS 16130 
                                    <SU>15</SU>
                                    , PAM 16130-SSI.
                                    <SU>16</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="34"/>
                                <ENT I="01">63. Hexachlorobenzene</ENT>
                                <ENT>GC</ENT>
                                <ENT O="xl">612.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1, 1625B</ENT>
                                <ENT>6410 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>9</SU>
                                     p. 27.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">64. Hexachlorobutadiene</ENT>
                                <ENT>GC</ENT>
                                <ENT O="xl">612.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1, 1625B</ENT>
                                <ENT>6410 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>9</SU>
                                     p. 27, O-4127-96.
                                    <SU>13</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">65. Hexachlorocyclopentadiene</ENT>
                                <ENT>GC</ENT>
                                <ENT O="xl">612.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>
                                    625.1 
                                    <SU>5</SU>
                                    , 1625B
                                </ENT>
                                <ENT>6410 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>9</SU>
                                    , p. 27, O-4127-96.
                                    <SU>13</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">66. 1,2,3,4,7,8-Hexachloro-dibenzofuran</ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>
                                    1613B 
                                    <SU>10</SU>
                                </ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    SGS AXYS 16130 
                                    <SU>15</SU>
                                    , PAM 16130-SSI.
                                    <SU>16</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">67. 1,2,3,6,7,8-Hexachloro-dibenzofuran</ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>
                                    1613B 
                                    <SU>10</SU>
                                </ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    SGS AXYS 16130 
                                    <SU>15</SU>
                                    , PAM 16130-SSI.
                                    <SU>16</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">68. 1,2,3,7,8,9-Hexachloro-dibenzofuran</ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>
                                    1613B 
                                    <SU>10</SU>
                                </ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    SGS AXYS 16130 
                                    <SU>15</SU>
                                    , PAM 16130-SSI.
                                    <SU>16</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">69. 2,3,4,6,7,8-Hexachloro-dibenzofuran</ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>
                                    1613B 
                                    <SU>10</SU>
                                </ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    SGS AXYS 16130 
                                    <SU>15</SU>
                                    , PAM 16130-SSI.
                                    <SU>16</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    70. 1,2,3,4,7,8-Hexachloro-dibenzo-
                                    <E T="03">p</E>
                                    -dioxin
                                </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>
                                    1613B 
                                    <SU>10</SU>
                                </ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    SGS AXYS 16130 
                                    <SU>15</SU>
                                    , PAM 16130-SSI.
                                    <SU>16</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    71. 1,2,3,6,7,8-Hexachloro-dibenzo-
                                    <E T="03">p</E>
                                    -dioxin
                                </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>
                                    1613B 
                                    <SU>10</SU>
                                </ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    SGS AXYS 16130 
                                    <SU>15</SU>
                                    , PAM 16130-SSI.
                                    <SU>16</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    72. 1,2,3,7,8,9-Hexachloro-dibenzo-
                                    <E T="03">p</E>
                                    -dioxin
                                </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>
                                    1613B 
                                    <SU>10</SU>
                                </ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    SGS AXYS 16130 
                                    <SU>15</SU>
                                    , PAM 16130-SSI.
                                    <SU>16</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">73. Hexachloroethane</ENT>
                                <ENT>GC</ENT>
                                <ENT O="xl">612.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1, 1625B</ENT>
                                <ENT>6410 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>9</SU>
                                     p. 27, O-4127-96.
                                    <SU>13</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">74. Indeno(1,2,3-c,d) pyrene</ENT>
                                <ENT>GC</ENT>
                                <ENT O="xl">610.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1, 1625B</ENT>
                                <ENT>6410 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>9</SU>
                                     p. 27.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>HPLC</ENT>
                                <ENT>610</ENT>
                                <ENT>6440 B-2021</ENT>
                                <ENT O="xl">D4657-92 (98).</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">75. Isophorone</ENT>
                                <ENT>GC</ENT>
                                <ENT O="xl">609.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1, 1625B</ENT>
                                <ENT>6410 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>9</SU>
                                     p. 27.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">76. Methylene chloride</ENT>
                                <ENT>GC</ENT>
                                <ENT>601</ENT>
                                <ENT>6200 C-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 130.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>624.1, 1624B</ENT>
                                <ENT>6200 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    O-4127-96 
                                    <SU>13</SU>
                                    , O-4436-16.
                                    <SU>14</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">77. 2-Methyl-4,6-dinitrophenol</ENT>
                                <ENT>GC</ENT>
                                <ENT>604</ENT>
                                <ENT O="xl">6420 B-2021.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1, 1625B</ENT>
                                <ENT>6410 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>9</SU>
                                     p. 27.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">78. Naphthalene</ENT>
                                <ENT>GC</ENT>
                                <ENT O="xl">610.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1, 1625B</ENT>
                                <ENT>6410 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>9</SU>
                                     p. 27.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>HPLC</ENT>
                                <ENT>610</ENT>
                                <ENT O="xl">6440 B-2021.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">79. Nitrobenzene</ENT>
                                <ENT>GC</ENT>
                                <ENT O="xl">609.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1, 1625B</ENT>
                                <ENT>6410 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>9</SU>
                                     p. 27.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>HPLC</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT O="xl">D4657-92 (98).</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">80. 2-Nitrophenol</ENT>
                                <ENT>GC</ENT>
                                <ENT>604</ENT>
                                <ENT O="xl">6420 B-2021.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1, 1625B</ENT>
                                <ENT>6410 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>9</SU>
                                     p. 27.
                                </ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="35"/>
                                <ENT I="01">81. 4-Nitrophenol</ENT>
                                <ENT>GC</ENT>
                                <ENT>604</ENT>
                                <ENT O="xl">6420 B-2021.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1, 1625B</ENT>
                                <ENT>6410 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>9</SU>
                                     p. 27.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">82. N-Nitrosodimethylamine</ENT>
                                <ENT>GC</ENT>
                                <ENT O="xl">607.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>
                                    625.1 
                                    <SU>5</SU>
                                    , 1625B
                                </ENT>
                                <ENT>6410 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>9</SU>
                                     p. 27.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    83. N-Nitrosodi-
                                    <E T="03">n</E>
                                    -propylamine
                                </ENT>
                                <ENT>GC</ENT>
                                <ENT O="xl">607.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>
                                    625.1 
                                    <SU>5</SU>
                                    , 1625B
                                </ENT>
                                <ENT>6410 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>9</SU>
                                     p. 27.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">84. N-Nitrosodiphenylamine</ENT>
                                <ENT>GC</ENT>
                                <ENT O="xl">607.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>
                                    625.1 
                                    <SU>5</SU>
                                    , 1625B
                                </ENT>
                                <ENT>6410 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>9</SU>
                                     p. 27.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">85. Octachlorodibenzofuran</ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>
                                    1613B 
                                    <SU>10</SU>
                                </ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    SGS AXYS 16130 
                                    <SU>15</SU>
                                    , PAM 16130-SSI.
                                    <SU>16</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    86. Octachlorodibenzo-
                                    <E T="03">p</E>
                                    -dioxin
                                </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>
                                    1613B 
                                    <SU>10</SU>
                                </ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    SGS AXYS 16130 
                                    <SU>15</SU>
                                    , PAM 16130-SSI.
                                    <SU>16</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    87. 2,2′-oxybis(1-chloropropane) 
                                    <SU>12</SU>
                                     [also known as bis(2-Chloro-1-methylethyl) ether]
                                </ENT>
                                <ENT>GC</ENT>
                                <ENT O="xl">611.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1, 1625B</ENT>
                                <ENT>6410 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>9</SU>
                                     p. 27.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">88. PCB-1016</ENT>
                                <ENT>GC</ENT>
                                <ENT>608.3</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 43, see footnote.
                                    <SU>8</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1</ENT>
                                <ENT O="xl">6410 B-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">89. PCB-1221</ENT>
                                <ENT>GC</ENT>
                                <ENT>608.3</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 43, see footnote.
                                    <SU>8</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1</ENT>
                                <ENT O="xl">6410 B-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">90. PCB-1232</ENT>
                                <ENT>GC</ENT>
                                <ENT>608.3</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 43, see footnote.
                                    <SU>8</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1</ENT>
                                <ENT O="xl">6410 B-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">91. PCB-1242</ENT>
                                <ENT>GC</ENT>
                                <ENT>608.3</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 43, see footnote.
                                    <SU>8</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1</ENT>
                                <ENT O="xl">6410 B-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">92. PCB-1248</ENT>
                                <ENT>GC</ENT>
                                <ENT>608.3</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 43, see footnote.
                                    <SU>8</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1</ENT>
                                <ENT O="xl">6410 B-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">93. PCB-1254</ENT>
                                <ENT>GC</ENT>
                                <ENT>608.3</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 43, see footnote.
                                    <SU>8</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1</ENT>
                                <ENT O="xl">6410 B-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">94. PCB-1260</ENT>
                                <ENT>GC</ENT>
                                <ENT>608.3</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 43, see footnote.
                                    <SU>8</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1</ENT>
                                <ENT O="xl">6410 B-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">95. 1,2,3,7,8-Pentachloro-dibenzofuran</ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>
                                    1613B 
                                    <SU>10</SU>
                                </ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    SGS AXYS 16130 
                                    <SU>15</SU>
                                    , PAM 16130-SSI.
                                    <SU>16</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">96. 2,3,4,7,8-Pentachloro-dibenzofuran</ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>
                                    1613B 
                                    <SU>10</SU>
                                </ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    SGS AXYS 16130 
                                    <SU>15</SU>
                                    , PAM 16130-SSI.
                                    <SU>16</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    97. 1,2,3,7,8-Pentachloro-dibenzo-
                                    <E T="03">p</E>
                                    -dioxin
                                </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>
                                    1613B 
                                    <SU>10</SU>
                                </ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    SGS AXYS 16130 
                                    <SU>15</SU>
                                    , PAM 16130-SSI.
                                    <SU>16</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">98. Pentachlorophenol</ENT>
                                <ENT>GC</ENT>
                                <ENT>604</ENT>
                                <ENT>6420 B-2021</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 140.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1, 1625B</ENT>
                                <ENT>6410 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>9</SU>
                                     p. 27.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">99. Phenanthrene</ENT>
                                <ENT>GC</ENT>
                                <ENT O="xl">610.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1, 1625B</ENT>
                                <ENT>6410 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>9</SU>
                                     p. 27.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>HPLC</ENT>
                                <ENT>610</ENT>
                                <ENT>6440 B-2021</ENT>
                                <ENT O="xl">D4657-92 (98).</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">100. Phenol</ENT>
                                <ENT>GC</ENT>
                                <ENT>604</ENT>
                                <ENT O="xl">6420 B-2021.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1, 1625B</ENT>
                                <ENT>6410 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>9</SU>
                                     p. 27.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">101. Pyrene</ENT>
                                <ENT>GC</ENT>
                                <ENT O="xl">610.</ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="36"/>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1, 1625B</ENT>
                                <ENT>6410 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>9</SU>
                                     p. 27.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>HPLC</ENT>
                                <ENT>610</ENT>
                                <ENT>6440 B-2021</ENT>
                                <ENT>D4657-92 (98).</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">102. 2,3,7,8-Tetrachloro-dibenzofuran</ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>
                                    1613B 
                                    <SU>10</SU>
                                </ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    SGS AXYS 16130 
                                    <SU>15</SU>
                                    , PAM 16130-SSI.
                                    <SU>16</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    103. 2,3,7,8-Tetrachloro-dibenzo-
                                    <E T="03">p</E>
                                    -dioxin
                                </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>
                                    613, 625.1 
                                    <SU>5</SU>
                                    , 1613B
                                </ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    SGS AXYS 16130 
                                    <SU>15</SU>
                                    , PAM 16130-SSI.
                                    <SU>16</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">104. 1,1,2,2-Tetrachloroethane</ENT>
                                <ENT>GC</ENT>
                                <ENT>601</ENT>
                                <ENT>6200 C-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 130.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>624.1, 1624B</ENT>
                                <ENT>6200 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    O-4127-96.
                                    <SU>13</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">105. Tetrachloroethene</ENT>
                                <ENT>GC</ENT>
                                <ENT>601</ENT>
                                <ENT>6200 C-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 130.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>624.1, 1624B</ENT>
                                <ENT>6200 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    O-4127-96 
                                    <SU>13</SU>
                                    , O-4436-16.
                                    <SU>14</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">106. Toluene</ENT>
                                <ENT>GC</ENT>
                                <ENT>602</ENT>
                                <ENT O="xl">6200 C-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>624.1, 1624B</ENT>
                                <ENT>6200 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    O-4127-96 
                                    <SU>13</SU>
                                    , O-4436-16.
                                    <SU>14</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">107. 1,2,4-Trichlorobenzene</ENT>
                                <ENT>GC</ENT>
                                <ENT>612</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 130.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1, 1625B</ENT>
                                <ENT>6410 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>9</SU>
                                     p. 27, O-4127-96 
                                    <SU>13</SU>
                                    , O-4436-16.
                                    <SU>14</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">108. 1,1,1-Trichloroethane</ENT>
                                <ENT>GC</ENT>
                                <ENT>601</ENT>
                                <ENT O="xl">6200 C-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>624.1, 1624B</ENT>
                                <ENT>6200 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    O-4127-96 
                                    <SU>13</SU>
                                    , O-4436-16.
                                    <SU>14</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">109. 1,1,2-Trichloroethane</ENT>
                                <ENT>GC</ENT>
                                <ENT>601</ENT>
                                <ENT>6200 C-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 130.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>624.1, 1624B</ENT>
                                <ENT>6200 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    O-4127-96 
                                    <SU>13</SU>
                                    , O-4436-16.
                                    <SU>14</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">110. Trichloroethene</ENT>
                                <ENT>GC</ENT>
                                <ENT>601</ENT>
                                <ENT O="xl">6200 C-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>624.1, 1624B</ENT>
                                <ENT>6200 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    O-4127-96 
                                    <SU>13</SU>
                                    , O-4436-16.
                                    <SU>14</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">111. Trichlorofluoromethane</ENT>
                                <ENT>GC</ENT>
                                <ENT>601</ENT>
                                <ENT O="xl">6200 C-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>624.1</ENT>
                                <ENT>6200 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    O-4127-96.
                                    <SU>13</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">112. 2,4,6-Trichlorophenol</ENT>
                                <ENT>GC</ENT>
                                <ENT>604</ENT>
                                <ENT O="xl">6420 B-2021.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1, 1625B</ENT>
                                <ENT>6410 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>9</SU>
                                     p. 27.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">113. Vinyl chloride</ENT>
                                <ENT>GC</ENT>
                                <ENT>601</ENT>
                                <ENT O="xl">6200 C-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>624.1, 1624B</ENT>
                                <ENT>6200 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    O-4127-96 
                                    <SU>13</SU>
                                    , O-4436-16.
                                    <SU>14</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">114. Nonylphenol</ENT>
                                <ENT>GC/MS</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT O="xl">D7065-17.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">115. Bisphenol A (BPA)</ENT>
                                <ENT>GC/MS</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT O="xl">D7065-17.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    116. 
                                    <E T="03">p-tert</E>
                                    -Octylphenol (OP)
                                </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT O="xl">D7065-17.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">117. Nonylphenol Monoethoxylate (NP1EO)</ENT>
                                <ENT>GC/MS</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT O="xl">D7065-17.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">118. Nonylphenol Diethoxylate (NP2EO)</ENT>
                                <ENT>GC/MS</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT O="xl">D7065-17.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">119. Adsorbable Organic Halides (AOX)</ENT>
                                <ENT>Adsorption and Coulometric Titration</ENT>
                                <ENT O="xl">
                                    1650.
                                    <SU>11</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="37"/>
                                <ENT I="01">120. Chlorinated Phenolics</ENT>
                                <ENT>In Situ Acetylation and GC/MS</ENT>
                                <ENT O="xl">
                                    1653.
                                    <SU>11</SU>
                                </ENT>
                            </ROW>
                            <TNOTE>
                                <E T="02">Table IC notes:</E>
                            </TNOTE>
                            <TNOTE>
                                <SU>1</SU>
                                 All parameters are expressed in micrograms per liter (µg/L) except for Method 1613B, in which the parameters are expressed in picograms per liter (pg/L).
                            </TNOTE>
                            <TNOTE>
                                <SU>2</SU>
                                 The full text of Methods 601-613, 1613B, 1624B, and 1625B are provided at appendix A, Test Procedures for Analysis of Organic Pollutants. The standardized test procedure to be used to determine the method detection limit (MDL) for these test procedures is given at appendix B of this part, Definition and Procedure for the Determination of the Method Detection Limit. These methods are available at: 
                                <E T="03">https://www.epa.gov/cwa-methods</E>
                                 as individual PDF files.
                            </TNOTE>
                            <TNOTE>
                                <SU>3</SU>
                                 Methods for Benzidine: Chlorinated Organic Compounds, Pentachlorophenol and Pesticides in Water and Wastewater. September 1978. U.S. EPA.
                            </TNOTE>
                            <TNOTE>
                                <SU>4</SU>
                                 Method 624.1 may be used for quantitative determination of acrolein and acrylonitrile, provided that the laboratory has documentation to substantiate the ability to detect and quantify these analytes at levels necessary to comply with any associated regulations. In addition, the use of sample introduction techniques other than simple purge-and-trap may be required. QC acceptance criteria from Method 603 should be used when analyzing samples for acrolein and acrylonitrile in the absence of such criteria in Method 624.1.
                            </TNOTE>
                            <TNOTE>
                                <SU>5</SU>
                                 Method 625.1 may be extended to include benzidine, hexachlorocyclopentadiene, N-nitrosodimethylamine, N-nitrosodi-
                                <E T="03">n</E>
                                -propylamine, and N-nitrosodiphenylamine. However, when they are known to be present, Methods 605, 607, and 612, or Method 1625B, are preferred methods for these compounds. Method 625.1 may be applied to 2,3,7,8-Tetrachloro-dibenzo-
                                <E T="03">p</E>
                                -dioxin for screening purposes only.
                            </TNOTE>
                            <TNOTE>
                                <SU>6</SU>
                                 Selected Analytical Methods Approved and Cited by the United States Environmental Protection Agency, Supplement to the 15th Edition of 
                                <E T="03">Standard Methods for the Examination of Water and Wastewater.</E>
                                 1981. American Public Health Association (APHA).
                            </TNOTE>
                            <TNOTE>
                                <SU>7</SU>
                                 Each analyst must make an initial, one-time demonstration of their ability to generate acceptable precision and accuracy with Methods 601-603, 1624B, and 1625B in accordance with procedures in Section 8.2 of each of these methods. Additionally, each laboratory, on an on-going basis must spike and analyze 10% (5% for Methods 624.1 and 625.1 and 100% for methods 1624B and 1625B) of all samples to monitor and evaluate laboratory data quality in accordance with Sections 8.3 and 8.4 of these methods. When the recovery of any parameter falls outside the quality control (QC) acceptance criteria in the pertinent method, analytical results for that parameter in the unspiked sample are suspect. The results should be reported but cannot be used to demonstrate regulatory compliance. If the method does not contain QC acceptance criteria, control limits of ±three standard deviations around the mean of a minimum of five replicate measurements must be used. These quality control requirements also apply to the Standard Methods, ASTM Methods, and other methods cited.
                            </TNOTE>
                            <TNOTE>
                                <SU>8</SU>
                                 Organochlorine Pesticides and PCBs in Wastewater Using Empore
                                <SU>TM</SU>
                                 Disk. Revised October 28, 1994. 3M Corporation.
                            </TNOTE>
                            <TNOTE>
                                <SU>9</SU>
                                 Method O-3116-87 is in Open File Report 93-125, Methods of Analysis by U.S. Geological Survey National Water Quality Laboratory—Determination of Inorganic and Organic Constituents in Water and Fluvial Sediments. 1993. USGS.
                            </TNOTE>
                            <TNOTE>
                                <SU>10</SU>
                                 Analysts may use Fluid Management Systems, Inc. Power-Prep system in place of manual cleanup provided the analyst meets the requirements of Method 1613B (as specified in Section 9 of the method) and permitting authorities. Method 1613, Revision B, Tetra- through Octa-Chlorinated Dioxins and Furans by Isotope Dilution HRGC/HRMS. Revision B, 1994. U.S. EPA. The full text of this method is provided in appendix A to this part and at 
                                <E T="03">https://www.epa.gov/cwa-methods/approved-cwa-test-methods-organic-compounds.</E>
                            </TNOTE>
                            <TNOTE>
                                <SU>11</SU>
                                 Method 1650, Adsorbable Organic Halides by Adsorption and Coulometric Titration. Revision C, 1997 U.S. EPA. Method 1653, Chlorinated Phenolics in Wastewater by In Situ Acetylation and GCMS. Revision A, 1997 U.S. EPA. The full text for both of these methods is provided at appendix A in part 430 of this chapter, The Pulp, Paper, and Paperboard Point Source Category.
                            </TNOTE>
                            <TNOTE>
                                <SU>12</SU>
                                 The compound was formerly inaccurately labeled as 2,2′-oxybis(2-chloropropane) and bis(2-chloroisopropyl) ether. Some versions of Methods 611, and 1625 inaccurately list the analyte as “bis(2-chloroisopropyl) ether,” but use the correct CAS number of 108-60-1.
                            </TNOTE>
                            <TNOTE>
                                <SU>13</SU>
                                 Method O-4127-96, U.S. Geological Survey Open-File Report 97-829, Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory—Determination of 86 volatile organic compounds in water by gas chromatography/mass spectrometry, including detections less than reporting limits,1998, USGS.
                            </TNOTE>
                            <TNOTE>
                                <SU>14</SU>
                                 Method O-4436-16 U.S. Geological Survey Techniques and Methods, book 5, chap. B12, Determination of heat purgeable and ambient purgeable volatile organic compounds in water by gas chromatography/mass spectrometry, 2016, USGS.
                            </TNOTE>
                            <TNOTE>
                                <SU>15</SU>
                                 SGS AXYS Method 16130, “Determination of 2,3,7,8-Substituted Tetra- through Octa-Chlorinated Dibenzo-
                                <E T="03">p</E>
                                -Dioxins and Dibenzofurans (CDDs/CDFs) Using Waters and Agilent Gas Chromatography-Tandem-Mass Spectrometry (GC/MS/MS), Revision 1.0” is available at: 
                                <E T="03">https://www.sgsaxys.com/wp-content/uploads/2022/09/SGS-AXYS-Method-16130-Rev-1.0.pdf.</E>
                            </TNOTE>
                            <TNOTE>
                                <SU>16</SU>
                                 Pace Analytical Method PAM-16130-SSI, “Determination of 2,3,7,8-Substituted Tetra- through Octa-Chlorinated Dibenzo-
                                <E T="03">p</E>
                                -Dioxins and Dibenzofurans (CDDs/CDFs) Using Shimadzu Gas Chromatography Mass Spectrometry (GC-MS/MS), Revision 1.1,” is available at: 
                                <E T="03">pacelabs.com.</E>
                            </TNOTE>
                            <TNOTE>
                                <SU>17</SU>
                                 Please refer to the following applicable Quality Control Section: Part 6000 Individual Organic Compounds, 6020 (2019). The Quality Control Standards are available for download at standardmethods.org at no charge.
                            </TNOTE>
                        </GPOTABLE>
                        <PRTPAGE P="38"/>
                        <GPOTABLE COLS="6" OPTS="L2,nj,p7,7/8" CDEF="s50,xs60,xs60,xs60,xs60,r50">
                            <TTITLE>
                                Table ID—List of Approved Test Procedures for Pesticides 
                                <SU>1</SU>
                            </TTITLE>
                            <BOXHD>
                                <CHED H="1">Parameter</CHED>
                                <CHED H="1">Method</CHED>
                                <CHED H="1">
                                    EPA 
                                    <E T="0731">2 7 10</E>
                                </CHED>
                                <CHED H="1">
                                    Standard
                                    <LI>
                                        methods 
                                        <SU>15</SU>
                                    </LI>
                                </CHED>
                                <CHED H="1">ASTM</CHED>
                                <CHED H="1">Other</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">1. Aldrin</ENT>
                                <ENT>GC</ENT>
                                <ENT>617, 608.3</ENT>
                                <ENT>6630 B-2021 &amp; C-2021</ENT>
                                <ENT>D3086-90, D5812-96 (02)</ENT>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 7, see footnote 
                                    <SU>4</SU>
                                     O-3104-83, see footnote 
                                    <SU>8</SU>
                                     3M0222.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1</ENT>
                                <ENT O="xl">6410 B-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2. Ametryn</ENT>
                                <ENT>GC</ENT>
                                <ENT>507, 619</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 83, see footnote 
                                    <SU>9</SU>
                                     O-3106-93, see footnote 
                                    <SU>6</SU>
                                     p. S68.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>525.2, 625.1</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>14</SU>
                                     O-1121-91.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">3. Aminocarb</ENT>
                                <ENT>TLC</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 94, see footnote 
                                    <SU>6</SU>
                                     p. S60.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>HPLC</ENT>
                                <ENT O="xl">632.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4. Atraton</ENT>
                                <ENT>GC</ENT>
                                <ENT>619</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 83, see footnote 
                                    <SU>6</SU>
                                     p. S68.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT O="xl">625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">5. Atrazine</ENT>
                                <ENT>GC</ENT>
                                <ENT>507, 619, 608.3</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 83, see footnote 
                                    <SU>6</SU>
                                     p. S68, see footnote 
                                    <SU>9</SU>
                                     O-3106-93.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>HPLC/MS</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>12</SU>
                                     O-2060-01.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>525.1, 525.2, 625.1</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>11</SU>
                                     O-1126-95.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">6. Azinphos methyl</ENT>
                                <ENT>GC</ENT>
                                <ENT>614, 622, 1657</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 25, see footnote 
                                    <SU>6</SU>
                                     p. S51.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC-MS</ENT>
                                <ENT>625.1</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>11</SU>
                                     O-1126-95.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">7. Barban</ENT>
                                <ENT>TLC</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 104, see footnote 
                                    <SU>6</SU>
                                     p. S64.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>HPLC</ENT>
                                <ENT O="xl">632.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT O="xl">625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">8. α-BHC</ENT>
                                <ENT>GC</ENT>
                                <ENT>617, 608.3</ENT>
                                <ENT>6630 B-2021 &amp; C-2021</ENT>
                                <ENT>D3086-90, D5812-96(02)</ENT>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 7, see footnote 
                                    <SU>8</SU>
                                     3M0222.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>
                                    625.1 
                                    <SU>5</SU>
                                </ENT>
                                <ENT>6410 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>11</SU>
                                     O-1126-95.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">9. β-BHC</ENT>
                                <ENT>GC</ENT>
                                <ENT>617, 608.3</ENT>
                                <ENT>6630 B-2021 &amp; C-2021</ENT>
                                <ENT>D3086-90, D5812-96(02)</ENT>
                                <ENT>
                                    See footnote 
                                    <SU>8</SU>
                                     3M0222.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1</ENT>
                                <ENT O="xl">6410 B-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">10. δ-BHC</ENT>
                                <ENT>GC</ENT>
                                <ENT>617, 608.3</ENT>
                                <ENT>6630 B-2021 &amp; C-2021</ENT>
                                <ENT>D3086-90, D5812-96(02)</ENT>
                                <ENT>
                                    See footnote 
                                    <SU>8</SU>
                                     3M0222.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1</ENT>
                                <ENT>6410 B-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">11. γ-BHC (Lindane)</ENT>
                                <ENT>GC</ENT>
                                <ENT>617, 608.3</ENT>
                                <ENT>6630 B-2021 &amp; C-2021</ENT>
                                <ENT>D3086-90, D5812-96(02)</ENT>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 7, see footnote 
                                    <SU>4</SU>
                                    , O-3104-83, see footnote 
                                    <SU>8</SU>
                                     3M0222.
                                </ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="39"/>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>
                                    625.1 
                                    <SU>5</SU>
                                </ENT>
                                <ENT>6410 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>11</SU>
                                    , O-1126-95.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">12. Captan</ENT>
                                <ENT>GC</ENT>
                                <ENT>617, 608.3</ENT>
                                <ENT>6630 B-2021</ENT>
                                <ENT>D3086-90, D5812-96(02)</ENT>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 7.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">13. Carbaryl</ENT>
                                <ENT>TLC</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 94, see footnote 
                                    <SU>6</SU>
                                     p. S60.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>HPLC</ENT>
                                <ENT O="xl">531.1, 632.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>HPLC/MS</ENT>
                                <ENT>553</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>12</SU>
                                     O-2060-01.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>11</SU>
                                     O-1126-95.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">14. Carbophenothion</ENT>
                                <ENT>GC</ENT>
                                <ENT>617, 608.3</ENT>
                                <ENT>6630 B-2021</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>4</SU>
                                     page 27, see footnote 
                                    <SU>6</SU>
                                     p. S73.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT O="xl">625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">15. Chlordane</ENT>
                                <ENT>GC</ENT>
                                <ENT>617, 608.3</ENT>
                                <ENT>6630 B-2021 &amp; C-2021</ENT>
                                <ENT>D3086-90, D5812-96(02)</ENT>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 7, see footnote 
                                    <SU>4</SU>
                                     O-3104-83, see footnote 
                                    <SU>8</SU>
                                     3M0222.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1</ENT>
                                <ENT O="xl">6410 B-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">16. Chloropropham</ENT>
                                <ENT>TLC</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 104, see footnote 
                                    <SU>6</SU>
                                     p. S64.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>HPLC</ENT>
                                <ENT O="xl">632.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT O="xl">625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">17. 2,4-D</ENT>
                                <ENT>GC</ENT>
                                <ENT>615</ENT>
                                <ENT O="xl">6640 B-2021</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 115, see footnote 
                                    <SU>4</SU>
                                     O-3105-83.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>HPLC/MS</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>12</SU>
                                     O-2060-01.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">18. 4,4′-DDD</ENT>
                                <ENT>GC</ENT>
                                <ENT>617, 608.3</ENT>
                                <ENT>6630 B-2021 &amp; C-2021</ENT>
                                <ENT>D3086-90, D5812-96(02)</ENT>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 7, see footnote 
                                    <SU>4</SU>
                                     O-3105-83, see footnote 
                                    <SU>8</SU>
                                     3M0222.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1</ENT>
                                <ENT O="xl">6410 B-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">19. 4,4′-DDE</ENT>
                                <ENT>GC</ENT>
                                <ENT>617, 608.3</ENT>
                                <ENT>6630 B-2021 &amp; C-2021</ENT>
                                <ENT>D3086-90, D5812-96(02)</ENT>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 7, see footnote 
                                    <SU>4</SU>
                                    , O-3104-83, see footnote 
                                    <SU>8</SU>
                                     3M0222.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1</ENT>
                                <ENT>6410 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>11</SU>
                                     O-1126-95.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">20. 4,4′-DDT</ENT>
                                <ENT>GC</ENT>
                                <ENT>617, 608.3</ENT>
                                <ENT>6630 B-2021 &amp; C-2021</ENT>
                                <ENT>D3086-90, D5812-96(02)</ENT>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 7, see footnote 
                                    <SU>4</SU>
                                     O-3104-83, see footnote 
                                    <SU>8</SU>
                                     3M0222.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1</ENT>
                                <ENT O="xl">6410 B-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">21. Demeton-O</ENT>
                                <ENT>GC</ENT>
                                <ENT O="xl">614, 622</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 25, see footnote 
                                    <SU>6</SU>
                                     p. S51.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT O="xl">625.1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">22. Demeton-S.</ENT>
                                <ENT>GC</ENT>
                                <ENT>614, 622</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 25, see footnote 
                                    <SU>6</SU>
                                    p. S51.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT O="xl">625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">23. Diazinon</ENT>
                                <ENT>GC</ENT>
                                <ENT>507, 614, 622, 1657</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 25, see footnote 
                                    <SU>4</SU>
                                     O-3104-83, see footnote 
                                    <SU>6</SU>
                                     p. S51.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>525.2, 625.1</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>11</SU>
                                     O-1126-95.
                                </ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="40"/>
                                <ENT I="01">24. Dicamba</ENT>
                                <ENT>GC</ENT>
                                <ENT>615</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 115.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>HPLC/MS</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>12</SU>
                                     O-2060-01.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">25. Dichlofenthion</ENT>
                                <ENT>GC</ENT>
                                <ENT>622.1</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>4</SU>
                                     page 27, see footnote 
                                    <SU>6</SU>
                                     p. S73.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">26. Dichloran</ENT>
                                <ENT>GC</ENT>
                                <ENT>608.2, 617, 608.3</ENT>
                                <ENT>6630 B-2021</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 7.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">27. Dicofol</ENT>
                                <ENT>GC</ENT>
                                <ENT>617, 608.3</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>4</SU>
                                     O-3104-83.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">28. Dieldrin</ENT>
                                <ENT>GC</ENT>
                                <ENT>617, 608.3</ENT>
                                <ENT>6630 B-2021 &amp; C-2021</ENT>
                                <ENT>D3086-90, D5812-96(02)</ENT>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 7, see footnote 
                                    <SU>4</SU>
                                     O-3104-83, see footnote 
                                    <SU>8</SU>
                                     3M0222.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1</ENT>
                                <ENT>6410 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>11</SU>
                                     O-1126-95.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">29. Dioxathion</ENT>
                                <ENT>GC</ENT>
                                <ENT>614.1, 1657</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>4</SU>
                                     page 27, see footnote 
                                    <SU>6</SU>
                                     p. S73.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">30. Disulfoton</ENT>
                                <ENT>GC</ENT>
                                <ENT>507, 614, 622, 1657</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 25, see footnote 
                                    <SU>6</SU>
                                     p. S51.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>525.2, 625.1</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>11</SU>
                                     O-1126-95.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">31. Diuron</ENT>
                                <ENT>TLC</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 104, see footnote 
                                    <SU>6</SU>
                                     p. S64.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>HPLC</ENT>
                                <ENT O="xl">632.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>HPLC/MS</ENT>
                                <ENT>553</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>12</SU>
                                     O-2060-01.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">32. Endosulfan I</ENT>
                                <ENT>GC</ENT>
                                <ENT>617, 608.3</ENT>
                                <ENT>6630 B-2021 &amp; C-2021</ENT>
                                <ENT>D3086-90, D5812-96(02)</ENT>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 7, see footnote 
                                    <SU>4</SU>
                                     O-3104-83, see footnote 
                                    <SU>8</SU>
                                     3M0222.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>
                                    625.1 
                                    <SU>5</SU>
                                </ENT>
                                <ENT>6410 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>13</SU>
                                     O-2002-01.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">33. Endosulfan II</ENT>
                                <ENT>GC</ENT>
                                <ENT>617, 608.3</ENT>
                                <ENT>6630 B-2021 &amp; C-2021</ENT>
                                <ENT>D3086-90, D5812-96(02)</ENT>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 7, see footnote 
                                    <SU>8</SU>
                                     3M0222.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>
                                    625.1 
                                    <SU>5</SU>
                                </ENT>
                                <ENT>6410 B-2020</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>13</SU>
                                     O-2002-01.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">34. Endosulfan Sulfate</ENT>
                                <ENT>GC</ENT>
                                <ENT>617, 608.3</ENT>
                                <ENT>6630 C-2021</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>8</SU>
                                     3M0222.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1</ENT>
                                <ENT O="xl">6410 B-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">35. Endrin</ENT>
                                <ENT>GC</ENT>
                                <ENT>505, 508, 617, 1656, 608.3</ENT>
                                <ENT>6630 B-2021 &amp; C-2021</ENT>
                                <ENT>D3086-90, D5812-96(02)</ENT>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 7, see footnote 
                                    <SU>4</SU>
                                     O-3104-83, see footnote 
                                    <SU>8</SU>
                                     3M0222.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>
                                    525.1, 525.2, 625.1 
                                    <SU>5</SU>
                                </ENT>
                                <ENT O="xl">6410 B-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">36. Endrin aldehyde</ENT>
                                <ENT>GC</ENT>
                                <ENT>617, 608.3</ENT>
                                <ENT>6630 C-2021</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>8</SU>
                                     3M0222.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1</ENT>
                                <ENT>6410 B-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">37. Ethion</ENT>
                                <ENT>GC</ENT>
                                <ENT>614, 614.1, 1657</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>4</SU>
                                     page 27, see footnote 
                                    <SU>6</SU>
                                    , p. S73.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>13</SU>
                                     O-2002-01.
                                </ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="41"/>
                                <ENT I="01">38. Fenuron</ENT>
                                <ENT>TLC</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 104, see footnote 
                                    <SU>6</SU>
                                     p. S64.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>HPLC</ENT>
                                <ENT O="xl">632.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>HPLC/MS</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>12</SU>
                                     O-2060-01.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">39. Fenuron-TCA</ENT>
                                <ENT>TLC</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 104, see footnote 
                                    <SU>6</SU>
                                     p. S64.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>HPLC</ENT>
                                <ENT O="xl">632.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">40. Heptachlor</ENT>
                                <ENT>GC</ENT>
                                <ENT>505, 508, 617, 1656, 608.3</ENT>
                                <ENT>6630 B-2021 &amp; C-2021</ENT>
                                <ENT>D3086-90, D5812-96(02)</ENT>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 7, see footnote 
                                    <SU>4</SU>
                                     O-3104-83, see footnote 
                                    <SU>8</SU>
                                     3M0222.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>525.1, 525.2, 625.1</ENT>
                                <ENT O="xl">6410 B-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">41. Heptachlor epoxide</ENT>
                                <ENT>GC</ENT>
                                <ENT>617, 608.3</ENT>
                                <ENT>6630 B-2021 &amp; C-2021</ENT>
                                <ENT>D3086-90, D5812-96(02)</ENT>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 7, see footnote 
                                    <SU>4</SU>
                                     O-3104-83, see footnote 
                                    <SU>6</SU>
                                     p. S73, see footnote 
                                    <SU>8</SU>
                                     3M0222.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1</ENT>
                                <ENT O="xl">6410 B-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">42. Isodrin</ENT>
                                <ENT>GC</ENT>
                                <ENT>617, 608.3</ENT>
                                <ENT>6630 B-2021 &amp; C-2021</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>4</SU>
                                     O-3104-83, see footnote 
                                    <SU>6</SU>
                                     p. S73.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT O="xl">625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">43. Linuron</ENT>
                                <ENT>GC</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 104, see footnote 
                                    <SU>6</SU>
                                     p. S64.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>HPLC</ENT>
                                <ENT O="xl">632.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>HPLC/MS</ENT>
                                <ENT>553</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>12</SU>
                                     O-2060-01.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>11</SU>
                                     O-1126-95.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">44. Malathion</ENT>
                                <ENT>GC</ENT>
                                <ENT>614, 1657</ENT>
                                <ENT>6630 B-2021</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 25, see footnote 
                                    <SU>6</SU>
                                     p. S51.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>625.1</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>11</SU>
                                     O-1126-95.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">45. Methiocarb</ENT>
                                <ENT>TLC</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 94, see footnote 
                                    <SU>6</SU>
                                     p. S60.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>HPLC</ENT>
                                <ENT O="xl">632.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>HPLC/MS</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>12</SU>
                                     O-2060-01.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">46. Methoxychlor</ENT>
                                <ENT>GC</ENT>
                                <ENT>505, 508, 608.2, 617, 1656, 608.3</ENT>
                                <ENT>6630 B-2021 &amp; C-2021</ENT>
                                <ENT>D3086-90, D5812-96(02)</ENT>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 7, see footnote 
                                    <SU>4</SU>
                                     O-3104-83, see footnote 
                                    <SU>8</SU>
                                     3M0222.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>525.1, 525.2, 625.1</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>11</SU>
                                     O-1126-95.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">47. Mexacarbate</ENT>
                                <ENT>TLC</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 94, see footnote 
                                    <SU>6</SU>
                                     p. S60.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>HPLC</ENT>
                                <ENT O="xl">632.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT O="xl">625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">48. Mirex</ENT>
                                <ENT>GC</ENT>
                                <ENT>617, 608.3</ENT>
                                <ENT>6630 B-2021 &amp; C-2021</ENT>
                                <ENT>D3086-90, D5812-96(02)</ENT>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 7, see footnote 
                                    <SU>4</SU>
                                     O-3104-83.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT O="xl">625.1.</ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="42"/>
                                <ENT I="01">49. Monuron</ENT>
                                <ENT>TLC</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 104, see footnote 
                                    <SU>6</SU>
                                     p. S64.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>HPLC</ENT>
                                <ENT O="xl">632.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">50. Monuron-TCA</ENT>
                                <ENT>TLC</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 104, see footnote 
                                    <SU>6</SU>
                                     p. S64.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>HPLC</ENT>
                                <ENT O="xl">632.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">51. Neburon</ENT>
                                <ENT>TLC</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 104, see footnote 
                                    <SU>6</SU>
                                     p. S64.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>HPLC</ENT>
                                <ENT O="xl">632.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>HPLC/MS</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>12</SU>
                                     O-2060-01.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">52. Parathion methyl</ENT>
                                <ENT>GC</ENT>
                                <ENT>614, 622, 1657</ENT>
                                <ENT>6630 B-2021</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>4</SU>
                                     page 27, see footnote 
                                    <SU>3</SU>
                                     p. 25.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT O="xl">625.1</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>11</SU>
                                     O-1126-95.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">53. Parathion ethyl</ENT>
                                <ENT>GC</ENT>
                                <ENT>614</ENT>
                                <ENT>6630 B-2021</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>4</SU>
                                     page 27, see footnote 
                                    <SU>3</SU>
                                     p. 25.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>11</SU>
                                     O-1126-95.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">54. PCNB</ENT>
                                <ENT>GC</ENT>
                                <ENT>608.1, 617, 608.3</ENT>
                                <ENT>6630 B-2021 &amp; C-2021</ENT>
                                <ENT>
                                    D3086-90
                                    <E T="03">,</E>
                                     D5812-96(02)
                                </ENT>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 7.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">55. Perthane</ENT>
                                <ENT>GC</ENT>
                                <ENT>617, 608.3</ENT>
                                <ENT/>
                                <ENT>D3086-90, D5812-96(02)</ENT>
                                <ENT>
                                    See footnote 
                                    <SU>4</SU>
                                     O-3104-83.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">56. Prometon</ENT>
                                <ENT>GC</ENT>
                                <ENT>507, 619</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 83, see footnote 
                                    <SU>6</SU>
                                     p. S68, see footnote 
                                    <SU>9</SU>
                                     O-3106-93.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>525.2, 625.1</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>11</SU>
                                     O-1126-95.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">57. Prometryn</ENT>
                                <ENT>GC</ENT>
                                <ENT>507, 619</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 83, see footnote 
                                    <SU>6</SU>
                                     p. S68, see footnote 
                                    <SU>9</SU>
                                     O-3106-93.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>525.1, 525.2, 625.1</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>13</SU>
                                     O-2002-01.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">58. Propazine</ENT>
                                <ENT>GC</ENT>
                                <ENT>507, 619, 1656, 608.3</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 83, see footnote 
                                    <SU>6</SU>
                                     p. S68, see footnote 
                                    <SU>9</SU>
                                     O-3106-93.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT O="xl">525.1, 525.2, 625.1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">59. Propham</ENT>
                                <ENT>TLC</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 10, see footnote 
                                    <SU>6</SU>
                                     p. S64.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>HPLC</ENT>
                                <ENT O="xl">632.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>HPLC/MS</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>12</SU>
                                     O-2060-01.
                                </ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="43"/>
                                <ENT I="01">60. Propoxur</ENT>
                                <ENT>TLC</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 94, see footnote 
                                    <SU>6</SU>
                                    , p. S60.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>HPLC</ENT>
                                <ENT O="xl">632.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">61. Secbumeton</ENT>
                                <ENT>TLC</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 83, see footnote 
                                    <SU>6</SU>
                                     p. S68.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC</ENT>
                                <ENT O="xl">619.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">62. Siduron</ENT>
                                <ENT>TLC</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 104, see footnote 
                                    <SU>6</SU>
                                     p. S64.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>HPLC</ENT>
                                <ENT O="xl">632.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>HPLC/MS</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>12</SU>
                                     O-2060-01.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">63. Simazine</ENT>
                                <ENT>GC</ENT>
                                <ENT>505, 507, 619, 1656, 608.3</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 83, see footnote 
                                    <SU>6</SU>
                                     p. S68, see footnote 
                                    <SU>9</SU>
                                     O-3106-93.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>525.1, 525.2, 625.1</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>11</SU>
                                     O-1126-95.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">64. Strobane</ENT>
                                <ENT>GC</ENT>
                                <ENT>617, 608.3</ENT>
                                <ENT>6630 B-2021 &amp; C-2021</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 7.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">65. Swep</ENT>
                                <ENT>TLC</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 104, see footnote 
                                    <SU>6</SU>
                                     p. S64.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>HPLC</ENT>
                                <ENT O="xl">632.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">66. 2,4,5-T</ENT>
                                <ENT>GC</ENT>
                                <ENT>615</ENT>
                                <ENT>6640 B-2021</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 115, see footnote 
                                    <SU>4</SU>
                                     O-3105-83.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">67. 2,4,5-TP (Silvex)</ENT>
                                <ENT>GC</ENT>
                                <ENT>615</ENT>
                                <ENT>6640 B-2021</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 115, see footnote 
                                    <SU>4</SU>
                                     O-3105-83.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">68. Terbuthylazine</ENT>
                                <ENT>GC</ENT>
                                <ENT>619, 1656, 608.3</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 83, see footnote 
                                    <SU>6</SU>
                                     p. S68.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>13</SU>
                                     O-2002-01.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">69. Toxaphene</ENT>
                                <ENT>GC</ENT>
                                <ENT>505, 508, 617, 1656, 608.3</ENT>
                                <ENT>6630 B-2021 &amp; C-2021</ENT>
                                <ENT>D3086-90, D5812-96(02)</ENT>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 7, see footnote 
                                    <SU>8</SU>
                                    , see footnote 
                                    <SU>4</SU>
                                     O-3105-83.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>525.1, 525.2, 625.1</ENT>
                                <ENT O="xl">6410 B-2020.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">70. Trifluralin</ENT>
                                <ENT>GC</ENT>
                                <ENT>508, 617, 627, 1656, 608.3</ENT>
                                <ENT>6630 B-2021</ENT>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>3</SU>
                                     p. 7, see footnote 
                                    <SU>9</SU>
                                     O-3106-93.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>GC/MS</ENT>
                                <ENT>525.2, 625.1</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    See footnote 
                                    <SU>11</SU>
                                     O-1126-95.
                                </ENT>
                            </ROW>
                            <TNOTE>
                                <E T="02">Table ID notes:</E>
                            </TNOTE>
                            <TNOTE>
                                <SU>1</SU>
                                 Pesticides are listed in this table by common name for the convenience of the reader. Additional pesticides may be found under table IC of this section, where entries are listed by chemical name.
                            </TNOTE>
                            <TNOTE>
                                <SU>2</SU>
                                 The standardized test procedure to be used to determine the method detection limit (MDL) for these test procedures is given at appendix B to this part, Definition and Procedure for the Determination of the Method Detection Limit.
                            </TNOTE>
                            <TNOTE>
                                <SU>3</SU>
                                 Methods for Benzidine, Chlorinated Organic Compounds, Pentachlorophenol and Pesticides in Water and Wastewater. September 1978. U.S. EPA. This EPA publication includes thin-layer chromatography (TLC) methods.
                            </TNOTE>
                            <TNOTE>
                                <SU>4</SU>
                                 Methods for the Determination of Organic Substances in Water and Fluvial Sediments, Techniques of Water-Resources Investigations of the U.S. Geological Survey, Book 5, Chapter A3. 1987. USGS.
                                <PRTPAGE P="44"/>
                            </TNOTE>
                            <TNOTE>
                                <SU>5</SU>
                                 The method may be extended to include α-BHC, γ-BHC, endosulfan I, endosulfan II, and endrin. However, when they are known to exist, Method 608 is the preferred method.
                            </TNOTE>
                            <TNOTE>
                                <SU>6</SU>
                                 Selected Analytical Methods Approved and Cited by the United States Environmental Protection Agency, Supplement to the 15th Edition of 
                                <E T="03">Standard Methods for the Examination of Water and Wastewater.</E>
                                1981. American Public Health Association (APHA).
                            </TNOTE>
                            <TNOTE>
                                <SU>7</SU>
                                 Each analyst must make an initial, one-time, demonstration of their ability to generate acceptable precision and accuracy with Methods 608.3 and 625.1 in accordance with procedures given in Section 8.2 of each of these methods. Additionally, each laboratory, on an on-going basis, must spike and analyze 10% of all samples analyzed with Method 608.3 or 5% of all samples analyzed with Method 625.1 to monitor and evaluate laboratory data quality in accordance with Sections 8.3 and 8.4 of these methods. When the recovery of any parameter falls outside the warning limits, the analytical results for that parameter in the unspiked sample are suspect. The results should be reported, but cannot be used to demonstrate regulatory compliance. These quality control requirements also apply to the Standard Methods, ASTM Methods, and other methods cited.
                            </TNOTE>
                            <TNOTE>
                                <SU>8</SU>
                                 Organochlorine Pesticides and PCBs in Wastewater Using Empore 
                                <SU>TM</SU>
                                 Disk. Revised October 28, 1994. 3M Corporation.
                            </TNOTE>
                            <TNOTE>
                                <SU>9</SU>
                                 Method O-3106-93 is in Open File Report 94-37, Methods of Analysis by the U.S. Geological Survey National Water Quality Laboratory—Determination of Triazine and Other Nitrogen-Containing Compounds by Gas Chromatography with Nitrogen Phosphorus Detectors. 1994. USGS.
                            </TNOTE>
                            <TNOTE>
                                <SU>10</SU>
                                 EPA Methods 608.1, 608.2, 614, 614.1, 615, 617, 619, 622, 622.1, 627, and 632 are found in Methods for the Determination of Nonconventional Pesticides in Municipal and Industrial Wastewater, EPA 821-R-92-002, April 1992, U.S. EPA. EPA Methods 505, 507, 508, 525.1, 531.1 and 553 are in Methods for the Determination of Nonconventional Pesticides in Municipal and Industrial Wastewater, Volume II, EPA 821-R-93-010B, 1993, U.S. EPA. EPA Method 525.2 is in Determination of Organic Compounds in Drinking Water by Liquid-Solid Extraction and Capillary Column Gas Chromatography/Mass Spectrometry, Revision 2.0, 1995, U.S. EPA. EPA methods 1656 and 1657 are in Methods for The Determination of Nonconventional Pesticides In Municipal and Industrial Wastewater, Volume I, EPA 821-R-93-010A, 1993, U.S. EPA. Methods 608.3 and 625.1 are available at: cwa-methods/approved-cwa-test-methods-organic-compounds.
                            </TNOTE>
                            <TNOTE>
                                <SU>11</SU>
                                 Method O-1126-95 is in Open-File Report 95-181, Methods of Analysis by the U.S. Geological Survey National Water Quality Laboratory—Determination of pesticides in water by C-18 solid-phase extraction and capillary-column gas chromatography/mass spectrometry with selected-ion monitoring. 1995. USGS.
                            </TNOTE>
                            <TNOTE>
                                <SU>12</SU>
                                 Method O-2060-01 is in Water-Resources Investigations Report 01-4134, Methods of Analysis by the U.S. Geological Survey National Water Quality Laboratory—Determination of Pesticides in Water by Graphitized Carbon-Based Solid-Phase Extraction and High-Performance Liquid Chromatography/Mass Spectrometry. 2001. USGS.
                            </TNOTE>
                            <TNOTE>
                                <SU>13</SU>
                                 Method O-2002-01 is in Water-Resources Investigations Report 01-4098, Methods of Analysis by the U.S. Geological Survey National Water Quality Laboratory—Determination of moderate-use pesticides in water by C-18 solid-phase extraction and capillary-column gas chromatography/mass spectrometry. 2001. USGS.
                            </TNOTE>
                            <TNOTE>
                                <SU>14</SU>
                                 Method O-1121-91 is in Open-File Report 91-519, Methods of Analysis by the U.S. Geological Survey National Water Quality Laboratory—Determination of organonitrogen herbicides in water by solid-phase extraction and capillary-column gas chromatography/mass spectrometry with selected-ion monitoring. 1992. USGS.
                            </TNOTE>
                            <TNOTE>
                                <SU>15</SU>
                                 Please refer to the following applicable Quality Control Section: Part 6000 Methods, Individual Organic Compounds 6020 (2019). These Quality Control Standards are available for download at 
                                <E T="03">www.standardmethods.org</E>
                                 at no charge.
                            </TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="7" OPTS="L2" CDEF="s50,r50,xs48,xs64,xs64,xs64,xs64">
                            <TTITLE>Table IE—List of Approved Radiologic Test Test Procedures</TTITLE>
                            <BOXHD>
                                <CHED H="1">Parameter and units</CHED>
                                <CHED H="1">Method</CHED>
                                <CHED H="1">Reference (method number or page)</CHED>
                                <CHED H="2">
                                    EPA 
                                    <SU>1</SU>
                                </CHED>
                                <CHED H="2">Standard Methods 18th, 19th, 20th Ed.</CHED>
                                <CHED H="2">Standard Methods Online</CHED>
                                <CHED H="2">ASTM</CHED>
                                <CHED H="2">
                                    USGS 
                                    <SU>2</SU>
                                </CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">1. Alpha-Total, pCi per liter</ENT>
                                <ENT>Proportional or scintillation counter</ENT>
                                <ENT>900.0</ENT>
                                <ENT>7110 B</ENT>
                                <ENT>7110 B-00</ENT>
                                <ENT>D1943-90, 96</ENT>
                                <ENT>
                                    pp. 75 and 78 
                                    <SU>3</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2. Alpha-Counting error, pCi per liter</ENT>
                                <ENT>Proportional or scintillation counter</ENT>
                                <ENT>Appendix B</ENT>
                                <ENT>7110 B</ENT>
                                <ENT>7110 B-00</ENT>
                                <ENT>D1943-90, 96</ENT>
                                <ENT>p. 79</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">3. Beta-Total, pCi per liter</ENT>
                                <ENT>Proportional counter</ENT>
                                <ENT>900.0</ENT>
                                <ENT>7110 B</ENT>
                                <ENT>7110 B-00</ENT>
                                <ENT>D1890-90, 96</ENT>
                                <ENT>
                                    pp. 75 and 78 
                                    <SU>3</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4. Beta-Counting error, pCi</ENT>
                                <ENT>Proportional counter</ENT>
                                <ENT>Appendix B</ENT>
                                <ENT>7110 B</ENT>
                                <ENT>7110 B-00</ENT>
                                <ENT>D1890-90, 96</ENT>
                                <ENT>p. 79</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    5. (a) Radium Total pCi per liter
                                    <LI>(b) Ra, pCi per liter</LI>
                                </ENT>
                                <ENT>Proportional counter</ENT>
                                <ENT>903.0</ENT>
                                <ENT>7500-Ra B</ENT>
                                <ENT>7500-Ra B-01</ENT>
                                <ENT>D2460-90, 97</ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="45"/>
                                <ENT I="22"> </ENT>
                                <ENT>Scintillation counter</ENT>
                                <ENT>903.1</ENT>
                                <ENT>7500-Ra C</ENT>
                                <ENT>7500-Ra C-01</ENT>
                                <ENT>D3454-91, 97</ENT>
                                <ENT>p. 81</ENT>
                            </ROW>
                            <TNOTE>
                                <SU>1</SU>
                                 Prescribed Procedures for Measurement of Radioactivity in Drinking Water, EPA-600/4-80-032 (1980), U.S. Environmental Protection Agency, August 1980.
                            </TNOTE>
                            <TNOTE>
                                <SU>2</SU>
                                 Fishman, M. J. and Brown, Eugene, “Selected Methods of the U.S. Geological Survey of Analysis of Wastewaters,” U.S. Geological Survey, Open-File Report 76-177 (1976).
                            </TNOTE>
                            <TNOTE>
                                <SU>3</SU>
                                 The method found on p. 75 measures only the dissolved portion while the method on p. 78 measures only the suspended portion. Therefore, the two results must be added to obtain the “total.”
                            </TNOTE>
                        </GPOTABLE>
                        <PRTPAGE P="46"/>
                        <GPOTABLE COLS="3" OPTS="L2" CDEF="s100,12,xs160">
                            <TTITLE>Table IF—List of Approved Methods for Pharmaceutical Pollutants</TTITLE>
                            <BOXHD>
                                <CHED H="1">Pharmaceuticals pollutants</CHED>
                                <CHED H="1">CAS registry No.</CHED>
                                <CHED H="1">Analytical method number</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">Acetonitrile</ENT>
                                <ENT>75-05-8</ENT>
                                <ENT>1666/1671/D3371/D3695/624.1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">n-Amyl acetate</ENT>
                                <ENT>628-63-7</ENT>
                                <ENT>1666/D3695</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">n-Amyl alcohol</ENT>
                                <ENT>71-41-0</ENT>
                                <ENT>1666/D3695</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzene</ENT>
                                <ENT>71-43-2</ENT>
                                <ENT>D4763/D3695/502.2/524.2/624.1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">n-Butyl-acetate</ENT>
                                <ENT>123-86-4</ENT>
                                <ENT>1666/D3695</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">tert</E>
                                    -Butyl alcohol
                                </ENT>
                                <ENT>75-65-0</ENT>
                                <ENT>1666/624.1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chlorobenzene</ENT>
                                <ENT>108-90-7</ENT>
                                <ENT>502.2/524.2/624.1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chloroform</ENT>
                                <ENT>67-66-3</ENT>
                                <ENT>502.2/524.2/551/624.1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">o</E>
                                    -Dichlorobenzene
                                </ENT>
                                <ENT>95-50-1</ENT>
                                <ENT>1625C/502.2/524.2/624.1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2-Dichloroethane</ENT>
                                <ENT>107-06-2</ENT>
                                <ENT>D3695/502.2/524.2/624.1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Diethylamine</ENT>
                                <ENT>109-89-7</ENT>
                                <ENT>1666/1671</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dimethyl sulfoxide</ENT>
                                <ENT>67-68-5</ENT>
                                <ENT>1666/1671</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ethanol</ENT>
                                <ENT>64-17-5</ENT>
                                <ENT>1666/1671/D3695/624.1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ethyl acetate</ENT>
                                <ENT>141-78-6</ENT>
                                <ENT>1666/D3695/624.1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">n-Heptane</ENT>
                                <ENT>142-82-5</ENT>
                                <ENT>1666/D3695</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">n-Hexane</ENT>
                                <ENT>110-54-3</ENT>
                                <ENT>1666/D3695</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Isobutyraldehyde</ENT>
                                <ENT>78-84-2</ENT>
                                <ENT>1666/1667</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Isopropanol</ENT>
                                <ENT>67-63-0</ENT>
                                <ENT>1666/D3695</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Isopropyl acetate</ENT>
                                <ENT>108-21-4</ENT>
                                <ENT>1666/D3695</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Isopropyl ether</ENT>
                                <ENT>108-20-3</ENT>
                                <ENT>1666/D3695</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Methanol</ENT>
                                <ENT>67-56-1</ENT>
                                <ENT>1666/1671/D3695/624.1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Methyl Cellosolve® (2-Methoxy ethanol)</ENT>
                                <ENT>109-86-4</ENT>
                                <ENT>1666/1671</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Methylene chloride</ENT>
                                <ENT>75-09-2</ENT>
                                <ENT>502.2/524.2/624.1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Methyl formate</ENT>
                                <ENT>107-31-3</ENT>
                                <ENT>1666</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4-Methyl-2-pentanone (MIBK)</ENT>
                                <ENT>108-10-1</ENT>
                                <ENT>1624C/1666/D3695/D4763/524.2/624.1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Phenol</ENT>
                                <ENT>108-95-2</ENT>
                                <ENT>D4763</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">n-Propanol</ENT>
                                <ENT>71-23-8</ENT>
                                <ENT>1666/1671/D3695/624.1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-Propanone (Acetone)</ENT>
                                <ENT>67-64-1</ENT>
                                <ENT>D3695/D4763/524.2/624.1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Tetrahydrofuran</ENT>
                                <ENT>109-99-9</ENT>
                                <ENT>1666/524.2/624.1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Toluene</ENT>
                                <ENT>108-88-3</ENT>
                                <ENT>D3695/D4763/502.2/524.2/624.1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Triethlyamine</ENT>
                                <ENT>121-44-8</ENT>
                                <ENT>1666/1671</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Xylenes</ENT>
                                <ENT>(Note 1)</ENT>
                                <ENT>1624C/1666/624.1</ENT>
                            </ROW>
                            <TNOTE>
                                <E T="02">Table IF note:</E>
                            </TNOTE>
                            <TNOTE>
                                <SU>1</SU>
                                 1624C: 
                                <E T="03">m</E>
                                -xylene 108-38-3, 
                                <E T="03">o,p</E>
                                -xylene, E-14095 (Not a CAS number; this is the number provided in the Environmental Monitoring Methods Index [EMMI] database.); 1666: m,p-xylene 136777-61-2, 
                                <E T="03">o</E>
                                -xylene 95-47-6.
                            </TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="4" OPTS="L2,nj" CDEF="xs54,r50,12,r50">
                            <TTITLE>Table IG—Test Methods for Pesticide Active Ingredients</TTITLE>
                            <TDESC>[40 CFR part 455]</TDESC>
                            <BOXHD>
                                <CHED H="1">EPA survey code</CHED>
                                <CHED H="1">Pesticide name</CHED>
                                <CHED H="1">CAS No.</CHED>
                                <CHED H="1">
                                    EPA analytical method No.(s) 
                                    <SU>3</SU>
                                </CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">8</ENT>
                                <ENT>Triadimefon</ENT>
                                <ENT>43121-43-3</ENT>
                                <ENT>507/633/525.1/525.2/1656/625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">12</ENT>
                                <ENT>Dichlorvos</ENT>
                                <ENT>62-73-7</ENT>
                                <ENT>1657/507/622/525.1/525.2/625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">16</ENT>
                                <ENT>2,4-D; 2,4-D Salts and Esters [2,4-Dichloro-phenoxyacetic acid]</ENT>
                                <ENT>94-75-7</ENT>
                                <ENT>1658/515.1/615/515.2/555.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">17</ENT>
                                <ENT>2,4-DB; 2,4-DB Salts and Esters [2,4-Dichlorophenoxybutyric acid]</ENT>
                                <ENT>94-82-6</ENT>
                                <ENT>1658/515.1/615/515.2/555.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">22</ENT>
                                <ENT>Mevinphos</ENT>
                                <ENT>7786-34-7</ENT>
                                <ENT>1657/507/622/525.1/525.2/625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">25</ENT>
                                <ENT>Cyanazine</ENT>
                                <ENT>21725-46-2</ENT>
                                <ENT>629/507/608.3/625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">26</ENT>
                                <ENT>Propachlor</ENT>
                                <ENT>1918-16-7</ENT>
                                <ENT>1656/508/608.1/525.1/525.2/608.3/625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">27</ENT>
                                <ENT>
                                    MCPA; MCPA Salts and Esters
                                    <LI>[2-Methyl-4-chlorophenoxyacetic acid]</LI>
                                </ENT>
                                <ENT>94-74-6</ENT>
                                <ENT>1658/615/555.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">30</ENT>
                                <ENT>Dichlorprop; Dichlorprop Salts and Esters [2-(2,4-Dichlorophenoxy) propionic acid]</ENT>
                                <ENT>120-36-5</ENT>
                                <ENT>1658/515.1/615/515.2/555.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">31</ENT>
                                <ENT>MCPP; MCPP Salts and Esters [2-(2-Methyl-4-chlorophenoxy) propionic acid]</ENT>
                                <ENT>93-65-2</ENT>
                                <ENT>1658/615/555.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">35</ENT>
                                <ENT>TCMTB [2-(Thiocyanomethylthio) benzo-thiazole]</ENT>
                                <ENT>21564-17-0</ENT>
                                <ENT>637.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">39</ENT>
                                <ENT>Pronamide</ENT>
                                <ENT>23950-58-5</ENT>
                                <ENT>525.1/525.2/507/633.1/625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">41</ENT>
                                <ENT>Propanil</ENT>
                                <ENT>709-98-8</ENT>
                                <ENT>632.1/1656/608.3.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">45</ENT>
                                <ENT>Metribuzin</ENT>
                                <ENT>21087-64-9</ENT>
                                <ENT>507/633/525.1/525.2/1656/608.3/625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">52</ENT>
                                <ENT>Acephate</ENT>
                                <ENT>30560-19-1</ENT>
                                <ENT>1656/1657/608.3.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">53</ENT>
                                <ENT>Acifluorfen</ENT>
                                <ENT>50594-66-6</ENT>
                                <ENT>515.1/515.2/555.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">54</ENT>
                                <ENT>Alachlor</ENT>
                                <ENT>15972-60-8</ENT>
                                <ENT>505/507/645/525.1/525.2/1656/608.3/625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">55</ENT>
                                <ENT>Aldicarb</ENT>
                                <ENT>116-06-3</ENT>
                                <ENT>531.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">58</ENT>
                                <ENT>Ametryn</ENT>
                                <ENT>834-12-8</ENT>
                                <ENT>507/619/525.2/625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">60</ENT>
                                <ENT>Atrazine</ENT>
                                <ENT>1912-24-9</ENT>
                                <ENT>505/507/619/525.1/525.2/1656/ 608.3/625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">62</ENT>
                                <ENT>Benomyl</ENT>
                                <ENT>17804-35-2</ENT>
                                <ENT>631.</ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="47"/>
                                <ENT I="01">68</ENT>
                                <ENT>Bromacil; Bromacil Salts and Esters</ENT>
                                <ENT>314-40-9</ENT>
                                <ENT>507/633/525.1/525.2/1656/608.3/625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">69</ENT>
                                <ENT>Bromoxynil</ENT>
                                <ENT>1689-84-5</ENT>
                                <ENT>1625/1661/625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">69</ENT>
                                <ENT>Bromoxynil Octanoate</ENT>
                                <ENT>1689-99-2</ENT>
                                <ENT>1656/608.3.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">70</ENT>
                                <ENT>Butachlor</ENT>
                                <ENT>23184-66-9</ENT>
                                <ENT>507/645/525.1/525.2/1656/608.3/625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">73</ENT>
                                <ENT>Captafol</ENT>
                                <ENT>2425-06-1</ENT>
                                <ENT>1656/608.3/625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">75</ENT>
                                <ENT>Carbaryl [Sevin]</ENT>
                                <ENT>63-25-2</ENT>
                                <ENT>531.1/632/553/625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">76</ENT>
                                <ENT>Carbofuran</ENT>
                                <ENT>1563-66-2</ENT>
                                <ENT>531.1/632/625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">80</ENT>
                                <ENT>Chloroneb</ENT>
                                <ENT>2675-77-6</ENT>
                                <ENT>1656/508/608.1/525.1/525.2/608.3/625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">82</ENT>
                                <ENT>Chlorothalonil</ENT>
                                <ENT>1897-45-6</ENT>
                                <ENT>508/608.2/525.1/525.2/1656/608.3/625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">84</ENT>
                                <ENT>Stirofos</ENT>
                                <ENT>961-11-5</ENT>
                                <ENT>1657/507/622/525.1/525.2/625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">86</ENT>
                                <ENT>Chlorpyrifos</ENT>
                                <ENT>2921-88-2</ENT>
                                <ENT>1657/508/622/625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">90</ENT>
                                <ENT>Fenvalerate</ENT>
                                <ENT>51630-58-1</ENT>
                                <ENT>1660.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">103</ENT>
                                <ENT>Diazinon</ENT>
                                <ENT>333-41-5</ENT>
                                <ENT>1657/507/614/622/525.2/625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">107</ENT>
                                <ENT>Parathion methyl</ENT>
                                <ENT>298-00-0</ENT>
                                <ENT>1657/614/622/625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">110</ENT>
                                <ENT>DCPA [Dimethyl 2,3,5,6-tetrachloro-terephthalate]</ENT>
                                <ENT>1861-32-1</ENT>
                                <ENT>
                                    508/608.2/525.1/525.2/515.1 
                                    <SU>2</SU>
                                    /515.2 
                                    <SU>2</SU>
                                    /1656/608.3/625.1.
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">112</ENT>
                                <ENT>Dinoseb</ENT>
                                <ENT>88-85-7</ENT>
                                <ENT>1658/515.1/615/515.2/555/625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">113</ENT>
                                <ENT>Dioxathion</ENT>
                                <ENT>78-34-2</ENT>
                                <ENT>1657/614.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">118</ENT>
                                <ENT>Nabonate [Disodium cyanodithio-imidocarbonate]</ENT>
                                <ENT>138-93-2</ENT>
                                <ENT>630.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">119</ENT>
                                <ENT>Diuron</ENT>
                                <ENT>330-54-1</ENT>
                                <ENT>632/553.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">123</ENT>
                                <ENT>Endothall</ENT>
                                <ENT>145-73-3</ENT>
                                <ENT>548/548.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">124</ENT>
                                <ENT>Endrin</ENT>
                                <ENT>72-20-8</ENT>
                                <ENT>1656/505/508/617/525.1/525.2/608.3/625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">125</ENT>
                                <ENT>Ethalfluralin</ENT>
                                <ENT>55283-68-6</ENT>
                                <ENT>1656/627/608.3 See footnote 1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">126</ENT>
                                <ENT>Ethion</ENT>
                                <ENT>563-12-2</ENT>
                                <ENT>1657/614/614.1/625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">127</ENT>
                                <ENT>Ethoprop</ENT>
                                <ENT>13194-48-4</ENT>
                                <ENT>1657/507/622/525.1/525.2/625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">132</ENT>
                                <ENT>Fenarimol</ENT>
                                <ENT>60168-88-9</ENT>
                                <ENT>507/633.1/525.1/525.2/1656/608.3/625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">133</ENT>
                                <ENT>Fenthion</ENT>
                                <ENT>55-38-9</ENT>
                                <ENT>1657/622/625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">138</ENT>
                                <ENT>Glyphosate [N-(Phosphonomethyl) glycine]</ENT>
                                <ENT>1071-83-6</ENT>
                                <ENT>547.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">140</ENT>
                                <ENT>Heptachlor</ENT>
                                <ENT>76-44-8</ENT>
                                <ENT>1656/505/508/617/525.1/525.2/608.3/625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">144</ENT>
                                <ENT>Isopropalin</ENT>
                                <ENT>33820-53-0</ENT>
                                <ENT>1656/627/608.3.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">148</ENT>
                                <ENT>Linuron</ENT>
                                <ENT>330-55-2</ENT>
                                <ENT>553/632.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">150</ENT>
                                <ENT>Malathion</ENT>
                                <ENT>121-75-5</ENT>
                                <ENT>1657/614/625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">154</ENT>
                                <ENT>Methamidophos</ENT>
                                <ENT>10265-92-6</ENT>
                                <ENT>1657.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">156</ENT>
                                <ENT>Methomyl</ENT>
                                <ENT>16752-77-5</ENT>
                                <ENT>531.1/632.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">158</ENT>
                                <ENT>Methoxychlor</ENT>
                                <ENT>72-43-5</ENT>
                                <ENT>1656/505/508/608.2/617/525.1/525.2/608.3/625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">172</ENT>
                                <ENT>Nabam</ENT>
                                <ENT>142-59-6</ENT>
                                <ENT>630/630.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">173</ENT>
                                <ENT>Naled</ENT>
                                <ENT>300-76-5</ENT>
                                <ENT>1657/622/625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">175</ENT>
                                <ENT>Norflurazon</ENT>
                                <ENT>27314-13-2</ENT>
                                <ENT>507/645/525.1/525.2/1656/608.3/625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">178</ENT>
                                <ENT>Benfluralin</ENT>
                                <ENT>1861-40-1</ENT>
                                <ENT>1656/627/608.3 See footnote 1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">182</ENT>
                                <ENT>Fensulfothion</ENT>
                                <ENT>115-90-2</ENT>
                                <ENT>1657/622/625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">183</ENT>
                                <ENT>Disulfoton</ENT>
                                <ENT>298-04-4</ENT>
                                <ENT>1657/507/614/622/525.2/625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">185</ENT>
                                <ENT>Phosmet</ENT>
                                <ENT>732-11-6</ENT>
                                <ENT>1657/622.1/625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">186</ENT>
                                <ENT>Azinphos Methyl</ENT>
                                <ENT>86-50-0</ENT>
                                <ENT>1657/614/622/625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">192</ENT>
                                <ENT>Organo-tin pesticides</ENT>
                                <ENT>12379-54-3</ENT>
                                <ENT>Ind-01/200.7/200.9.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">197</ENT>
                                <ENT>Bolstar</ENT>
                                <ENT>35400-43-2</ENT>
                                <ENT>1657/622.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">203</ENT>
                                <ENT>Parathion</ENT>
                                <ENT>56-38-2</ENT>
                                <ENT>1657/614/625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">204</ENT>
                                <ENT>Pendimethalin</ENT>
                                <ENT>40487-42-1</ENT>
                                <ENT>1656.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">205</ENT>
                                <ENT>Pentachloronitrobenzene</ENT>
                                <ENT>82-68-8</ENT>
                                <ENT>1656/608.1/617/608.3/625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">206</ENT>
                                <ENT>Pentachlorophenol</ENT>
                                <ENT>87-86-5</ENT>
                                <ENT>1625/515.2/555/515.1/525.1/525.2/625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">208</ENT>
                                <ENT>Permethrin</ENT>
                                <ENT>52645-53-1</ENT>
                                <ENT>
                                    608.2/508/525.1/525.2/1656/1660/608.3 
                                    <SU>4</SU>
                                    /625.1 
                                    <SU>4</SU>
                                    .
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">212</ENT>
                                <ENT>Phorate</ENT>
                                <ENT>298-02-2</ENT>
                                <ENT>1657/622/625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">218</ENT>
                                <ENT>Busan 85 [Potassium dimethyldithiocarbamate]</ENT>
                                <ENT>128-03-0</ENT>
                                <ENT>630/630.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">219</ENT>
                                <ENT>Busan 40 [Potassium N-hydroxymethyl-N-methyldithiocarbamate]</ENT>
                                <ENT>51026-28-9</ENT>
                                <ENT>630/630.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">220</ENT>
                                <ENT>KN Methyl [Potassium N-methyl-dithiocarbamate]</ENT>
                                <ENT>137-41-7</ENT>
                                <ENT>630/630.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">223</ENT>
                                <ENT>Prometon</ENT>
                                <ENT>1610-18-0</ENT>
                                <ENT>507/619/525.2/625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">224</ENT>
                                <ENT>Prometryn</ENT>
                                <ENT>7287-19-6</ENT>
                                <ENT>507/619/525.1/525.2/625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">226</ENT>
                                <ENT>Propazine</ENT>
                                <ENT>139-40-2</ENT>
                                <ENT>507/619/525.1/525.2/1656/608.3/625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">230</ENT>
                                <ENT>Pyrethrin I</ENT>
                                <ENT>121-21-1</ENT>
                                <ENT>1660.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">232</ENT>
                                <ENT>Pyrethrin II</ENT>
                                <ENT>121-29-9</ENT>
                                <ENT>1660.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">236</ENT>
                                <ENT>DEF [S,S,S-Tributyl phosphorotrithioate]</ENT>
                                <ENT>78-48-8</ENT>
                                <ENT>1657.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">239</ENT>
                                <ENT>Simazine</ENT>
                                <ENT>122-34-9</ENT>
                                <ENT>505/507/619/525.1/525.2/1656/608.3/625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">241</ENT>
                                <ENT>Carbam-S [Sodium dimethyldithio-carbamate]</ENT>
                                <ENT>128-04-1</ENT>
                                <ENT>630/630.1.</ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="48"/>
                                <ENT I="01">243</ENT>
                                <ENT>Vapam [Sodium methyldithiocarbamate]</ENT>
                                <ENT>137-42-8</ENT>
                                <ENT>630/630.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">252</ENT>
                                <ENT>Tebuthiuron</ENT>
                                <ENT>34014-18-1</ENT>
                                <ENT>507/525.1/525.2/625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">254</ENT>
                                <ENT>Terbacil</ENT>
                                <ENT>5902-51-2</ENT>
                                <ENT>507/633/525.1/525.2/1656/608.3/625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">255</ENT>
                                <ENT>Terbufos</ENT>
                                <ENT>13071-79-9</ENT>
                                <ENT>1657/507/614.1/525.1/525.2/625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">256</ENT>
                                <ENT>Terbuthylazine</ENT>
                                <ENT>5915-41-3</ENT>
                                <ENT>619/1656/608.3.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">257</ENT>
                                <ENT>Terbutryn</ENT>
                                <ENT>886-50-0</ENT>
                                <ENT>507/619/525.1/525.2/625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">259</ENT>
                                <ENT>Dazomet</ENT>
                                <ENT>533-74-4</ENT>
                                <ENT>630/630.1/1659.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">262</ENT>
                                <ENT>Toxaphene</ENT>
                                <ENT>8001-35-2</ENT>
                                <ENT>1656/505/508/617/525.1/525.2/608.3/625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">263</ENT>
                                <ENT>Merphos [Tributyl phosphorotrithioate]</ENT>
                                <ENT>150-50-5</ENT>
                                <ENT>1657/507/525.1/525.2/622/625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">264</ENT>
                                <ENT>
                                    Trifluralin 
                                    <SU>1</SU>
                                </ENT>
                                <ENT>1582-09-8</ENT>
                                <ENT>1656/508/617/627/525.2/608.3/625.1.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">268</ENT>
                                <ENT>Ziram [Zinc dimethyldithiocarbamate]</ENT>
                                <ENT>137-30-4</ENT>
                                <ENT>630/630.1.</ENT>
                            </ROW>
                            <TNOTE>
                                <E T="02">Table IG notes:</E>
                            </TNOTE>
                            <TNOTE>
                                <SU>1</SU>
                                 Monitor and report as total Trifluralin.
                            </TNOTE>
                            <TNOTE>
                                <SU>2</SU>
                                 Applicable to the analysis of DCPA degradates.
                            </TNOTE>
                            <TNOTE>
                                <SU>3</SU>
                                 EPA Methods 608.1 through 645, 1645 through 1661, and Ind-01 are available in Methods for the Determination of Nonconventional Pesticides in Municipal and Industrial Wastewater, Volume I, EPA 821-R-93-010A, Revision I, August 1993, U.S. EPA. EPA Methods 200.9 and 505 through 555 are available in Methods for the Determination of Nonconventional Pesticides in Municipal and Industrial Wastewater, Volume II, EPA 821-R-93-010B, August 1993, U.S. EPA. The full text of Methods 608.3, 625.1, and 1625 are provided at appendix A of this part. The full text of Method 200.7 is provided at appendix C of this part. Methods 608.3 and 625.1 are available at 
                                <E T="03">https://www.epa.gov/cwa-methods/approved-cwa-test-methods-organic-compounds</E>
                                .
                            </TNOTE>
                            <TNOTE>
                                <SU>4</SU>
                                 Permethrin is not listed within methods 608.3 and 625.1; however, 
                                <E T="03">cis</E>
                                -permethrin and 
                                <E T="03">trans</E>
                                -permethrin are listed. Permethrin can be calculated by adding the results of 
                                <E T="03">cis-</E>
                                 and 
                                <E T="03">trans</E>
                                -permethrin.
                            </TNOTE>
                        </GPOTABLE>
                        <PRTPAGE P="49"/>
                        <GPOTABLE COLS="6" OPTS="L2,nj,p7,7/8" CDEF="s50,r100,r50,r50,r50,r50">
                            <TTITLE>Table IH—List of Approved Microbiological Methods for Ambient Water</TTITLE>
                            <BOXHD>
                                <CHED H="1">Parameter and units</CHED>
                                <CHED H="1">
                                    Method 
                                    <SU>1</SU>
                                </CHED>
                                <CHED H="1">EPA</CHED>
                                <CHED H="1">Standard methods</CHED>
                                <CHED H="1">AOAC, ASTM, USGS</CHED>
                                <CHED H="1">Other</CHED>
                            </BOXHD>
                            <ROW EXPSTB="05" RUL="s">
                                <ENT I="21">
                                    <E T="02">Bacteria</E>
                                </ENT>
                            </ROW>
                            <ROW EXPSTB="00">
                                <ENT I="01">1. Coliform (fecal), number per 100 mL</ENT>
                                <ENT>Most Probable Number (MPN), 5 tube, 3 dilution, or</ENT>
                                <ENT>
                                    p. 132 
                                    <SU>3</SU>
                                </ENT>
                                <ENT O="xl">
                                    9221 E-2014, 9221 F-2014.
                                    <SU>32</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    Membrane filter (MF) 
                                    <SU>2</SU>
                                    , single step
                                </ENT>
                                <ENT>
                                    p. 124 
                                    <SU>3</SU>
                                </ENT>
                                <ENT>
                                    9222 D-2015 
                                    <SU>26</SU>
                                </ENT>
                                <ENT O="xl">
                                    B-0050-85.
                                    <SU>4</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2. Coliform (total), number per 100 mL</ENT>
                                <ENT>MPN, 5 tube, 3 dilution, or</ENT>
                                <ENT>
                                    p. 114 
                                    <SU>3</SU>
                                </ENT>
                                <ENT O="xl">9221 B-2014.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    MF 
                                    <SU>2</SU>
                                    , single step or
                                </ENT>
                                <ENT>
                                    p. 108 
                                    <SU>3</SU>
                                </ENT>
                                <ENT>
                                    9222 B-2015 
                                    <SU>27</SU>
                                </ENT>
                                <ENT O="xl">
                                    B-0025-85.
                                    <SU>4</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    MF 
                                    <SU>2</SU>
                                    , two step with enrichment
                                </ENT>
                                <ENT>
                                    p. 111 
                                    <SU>3</SU>
                                </ENT>
                                <ENT O="xl">
                                    9222 B-2015.
                                    <SU>27</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    3. 
                                    <E T="03">E. coli,</E>
                                     number per 100 mL
                                </ENT>
                                <ENT>
                                    MPN 
                                    <SU>5</SU>
                                     
                                    <SU>7</SU>
                                     
                                    <SU>13</SU>
                                    , multiple tube, or
                                </ENT>
                                <ENT/>
                                <ENT O="xl">
                                    9221 B.3-2014/9221 F-2014.
                                    <SU>10</SU>
                                     
                                    <SU>12</SU>
                                     
                                    <SU>32</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Multiple tube/multiple well, or</ENT>
                                <ENT/>
                                <ENT>
                                    9223 B-2016 
                                    <SU>11</SU>
                                </ENT>
                                <ENT>
                                    991.15 
                                    <SU>9</SU>
                                </ENT>
                                <ENT>
                                    Colilert® 
                                    <SU>11</SU>
                                     
                                    <SU>15</SU>
                                    , Colilert-18®.
                                    <SU>11</SU>
                                     
                                    <SU>14</SU>
                                     
                                    <SU>15</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    MF 
                                    <SU>2</SU>
                                     
                                    <SU>5</SU>
                                     
                                    <SU>6</SU>
                                     
                                    <SU>7</SU>
                                    , two step, or
                                </ENT>
                                <ENT>
                                    1103.2 
                                    <SU>18</SU>
                                </ENT>
                                <ENT>
                                    9222 B-2015/9222 I-2015 
                                    <SU>17</SU>
                                    , 9213 D-2007
                                </ENT>
                                <ENT O="xl">
                                    D5392-93.
                                    <SU>8</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Single step</ENT>
                                <ENT>
                                    1603.1 
                                    <SU>19</SU>
                                    , 1604 
                                    <SU>20</SU>
                                </ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>
                                    m-ColiBlue24® 
                                    <SU>16</SU>
                                    , KwikCount
                                    <E T="0731">TM</E>
                                     EC.
                                    <SU>28</SU>
                                     
                                    <SU>29</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4. Fecal streptococci, number per 100 mL</ENT>
                                <ENT>MPN, 5 tube, 3 dilution, or</ENT>
                                <ENT>
                                    p. 139 
                                    <SU>3</SU>
                                </ENT>
                                <ENT O="xl">9230 B-2013.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    MF 
                                    <SU>2</SU>
                                    , or
                                </ENT>
                                <ENT>
                                    p. 136 
                                    <SU>3</SU>
                                </ENT>
                                <ENT>
                                    9230 C-2013 
                                    <SU>30</SU>
                                </ENT>
                                <ENT O="xl">
                                    B-0055-85.
                                    <SU>4</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Plate count</ENT>
                                <ENT O="xl">
                                    p. 143.
                                    <SU>3</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">5. Enterococci, number per 100 mL</ENT>
                                <ENT>
                                    MPN 
                                    <SU>5</SU>
                                     
                                    <SU>7</SU>
                                    , multiple tube/multiple well, or
                                </ENT>
                                <ENT/>
                                <ENT>9230 D-2013</ENT>
                                <ENT>
                                    D6503-99 
                                    <SU>8</SU>
                                </ENT>
                                <ENT>
                                    Enterolert®.
                                    <SU>11</SU>
                                     
                                    <SU>21</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>
                                    MF 
                                    <SU>2</SU>
                                     
                                    <SU>5</SU>
                                     
                                    <SU>6</SU>
                                     
                                    <SU>7</SU>
                                     two step, or
                                </ENT>
                                <ENT>
                                    1106.2 
                                    <SU>22</SU>
                                </ENT>
                                <ENT>
                                    9230 C-2013 
                                    <SU>30</SU>
                                </ENT>
                                <ENT O="xl">
                                    D5259-92.
                                    <SU>8</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Single step, or</ENT>
                                <ENT>
                                    1600.1 
                                    <SU>23</SU>
                                </ENT>
                                <ENT O="xl">
                                    9230 C-2013.
                                    <SU>30</SU>
                                </ENT>
                            </ROW>
                            <ROW RUL="s">
                                <ENT I="22"> </ENT>
                                <ENT>Plate count</ENT>
                                <ENT O="xl">
                                    p. 143.
                                    <SU>3</SU>
                                </ENT>
                            </ROW>
                            <ROW EXPSTB="05" RUL="s">
                                <ENT I="21">
                                    <E T="03">Protozoa</E>
                                </ENT>
                            </ROW>
                            <ROW EXPSTB="00">
                                <ENT I="01">
                                    6. 
                                    <E T="03">Cryptosporidium</E>
                                </ENT>
                                <ENT>Filtration/IMS/FA</ENT>
                                <ENT O="xl">
                                    1622 
                                    <SU>24</SU>
                                    , 1623 
                                    <SU>25</SU>
                                    , 1623.1.
                                    <SU>25</SU>
                                     
                                    <SU>31</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    7. 
                                    <E T="03">Giardia</E>
                                </ENT>
                                <ENT>Filtration/IMS/FA</ENT>
                                <ENT O="xl">
                                    1623 
                                    <SU>25</SU>
                                    , 1623.1.
                                    <SU>25</SU>
                                     
                                    <SU>31</SU>
                                </ENT>
                            </ROW>
                            <TNOTE>
                                <E T="02">Table 1H notes:</E>
                                <PRTPAGE P="50"/>
                            </TNOTE>
                            <TNOTE>
                                <SU>1</SU>
                                 The method must be specified when results are reported.
                            </TNOTE>
                            <TNOTE>
                                <SU>2</SU>
                                 A 0.45-µm membrane filter (MF) or other pore size certified by the manufacturer to fully retain organisms to be cultivated and to be free of extractables which could interfere with their growth.
                            </TNOTE>
                            <TNOTE>
                                <SU>3</SU>
                                 Microbiological Methods for Monitoring the Environment, Water and Wastes. EPA/600/8-78/017. 1978. US EPA.
                            </TNOTE>
                            <TNOTE>
                                <SU>4</SU>
                                 U.S. Geological Survey Techniques of Water-Resource Investigations, Book 5, Laboratory Analysis, Chapter A4, Methods for Collection and Analysis of Aquatic Biological and Microbiological Samples. 1989. USGS.
                            </TNOTE>
                            <TNOTE>
                                <SU>5</SU>
                                 Tests must be conducted to provide organism enumeration (density). Select the appropriate configuration of tubes/filtrations and dilutions/volumes to account for the quality, character, consistency, and anticipated organism density of the water sample.
                            </TNOTE>
                            <TNOTE>
                                <SU>6</SU>
                                 When the MF method has not been used previously to test waters with high turbidity, large numbers of noncoliform bacteria, or samples that may contain organisms stressed by chlorine, a parallel test should be conducted with a multiple-tube technique to demonstrate applicability and comparability of results.
                            </TNOTE>
                            <TNOTE>
                                <SU>7</SU>
                                 To assess the comparability of results obtained with individual methods, it is suggested that side-by-side tests be conducted across seasons of the year with the water samples routinely tested in accordance with the most current 
                                <E T="03">Standard Methods for the Examination of Water and Wastewater</E>
                                 or EPA alternate test procedure (ATP) guidelines.
                            </TNOTE>
                            <TNOTE>
                                <SU>8</SU>
                                 Annual Book of ASTM Standards—Water and Environmental Technology. Section 11.02. 2000, 1999, 1996. ASTM International.
                            </TNOTE>
                            <TNOTE>
                                <SU>9</SU>
                                 Official Methods of Analysis of AOAC International, 16th Edition, Volume I, Chapter 17. 1995. AOAC International.
                            </TNOTE>
                            <TNOTE>
                                <SU>10</SU>
                                 The multiple-tube fermentation test is used in 9221B.3-2014. Lactose broth may be used in lieu of lauryl tryptose broth (LTB), if at least 25 parallel tests are conducted between this broth and LTB using the water samples normally tested, and this comparison demonstrates that the false-positive rate and false-negative rate for total coliform using lactose broth is less than 10 percent. No requirement exists to run the completed phase on 10 percent of all total coliform-positive tubes on a seasonal basis.
                            </TNOTE>
                            <TNOTE>
                                <SU>11</SU>
                                 These tests are collectively known as defined enzyme substrate tests.
                            </TNOTE>
                            <TNOTE>
                                <SU>12</SU>
                                 After prior enrichment in a presumptive medium for total coliform using 9221B.3-2014, all presumptive tubes or bottles showing any amount of gas, growth or acidity within 48 h ± 3 h of incubation shall be submitted to 9221F-2014. Commercially available EC-MUG media or EC media supplemented in the laboratory with 50 µg/mL of MUG may be used.
                            </TNOTE>
                            <TNOTE>
                                <SU>13</SU>
                                 Samples shall be enumerated by the multiple-tube or multiple-well procedure. Using multiple-tube procedures, employ an appropriate tube and dilution configuration of the sample as needed and report the Most Probable Number (MPN). Samples tested with Colilert® may be enumerated with the multiple-well procedures, Quanti-Tray® or Quanti-Tray®/2000, and the MPN calculated from the table provided by the manufacturer.
                            </TNOTE>
                            <TNOTE>
                                <SU>14</SU>
                                 Colilert-18® is an optimized formulation of the Colilert® for the determination of total coliforms and 
                                <E T="03">E. coli</E>
                                 that provides results within 18 h of incubation at 35 °C, rather than the 24 h required for the Colilert® test and is recommended for marine water samples.
                            </TNOTE>
                            <TNOTE>
                                <SU>15</SU>
                                 Descriptions of the Colilert®, Colilert-18®, Quanti-Tray
                                <SU>®,</SU>
                                 and Quanti-Tray®/2000 may be obtained from IDEXX Laboratories Inc.
                            </TNOTE>
                            <TNOTE>
                                <SU>16</SU>
                                 A description of the mColiBlue24® test may be obtained from Hach Company.
                            </TNOTE>
                            <TNOTE>
                                <SU>17</SU>
                                 Subject coliform positive samples determined by 9222B-2015 or other membrane filter procedure to 9222I-2015 using NA-MUG media.
                            </TNOTE>
                            <TNOTE>
                                <SU>18</SU>
                                 Method 1103.2: 
                                <E T="03">Escherichia coli</E>
                                 (
                                <E T="03">E. coli</E>
                                ) in Water by Membrane Filtration Using membrane-Thermotolerant 
                                <E T="03">Escherichia coli</E>
                                 Agar (mTEC), EPA-821-R-23-009. September 2023. US EPA.
                            </TNOTE>
                            <TNOTE>
                                <SU>19</SU>
                                 Method 1603.1: 
                                <E T="03">Escherichia coli</E>
                                 (
                                <E T="03">E. coli</E>
                                ) in Water by Membrane Filtration Using Modified membrane-Thermotolerant 
                                <E T="03">Escherichia coli</E>
                                 Agar (Modified mTEC), EPA-821-R-23-008. September 2023 . US EPA.
                            </TNOTE>
                            <TNOTE>
                                <SU>20</SU>
                                 Method 1604: Total Coliforms and 
                                <E T="03">Escherichia coli</E>
                                 (
                                <E T="03">E. coli</E>
                                ) in Water by Membrane Filtration by Using a Simultaneous Detection Technique (MI Medium), EPA 821-R-02-024. September 2002. US EPA.
                            </TNOTE>
                            <TNOTE>
                                <SU>21</SU>
                                 A description of the Enterolert® test may be obtained from IDEXX Laboratories Inc.
                            </TNOTE>
                            <TNOTE>
                                <SU>22</SU>
                                 Method 1106.2: Enterococci in Water by Membrane Filtration Using membrane-
                                <E T="03">Enterococcus</E>
                                -Esculin Iron Agar (mE-EIA), EPA-821-R-23-007. September 2023. US EPA.
                            </TNOTE>
                            <TNOTE>
                                <SU>23</SU>
                                 Method 1600.1: Enterococci in Water by Membrane Filtration Using membrane-
                                <E T="03">Enterococcus</E>
                                 Indoxyl-β-D-Glucoside Agar (mEI), EPA-821-R-21-006. September 2023. US EPA.
                            </TNOTE>
                            <TNOTE>
                                <SU>24</SU>
                                 Method 1622 uses a filtration, concentration, immunomagnetic separation of oocysts from captured material, immunofluorescence assay to determine concentrations, and confirmation through vital dye staining and differential interference contrast microscopy for the detection of 
                                <E T="03">Cryptosporidium.</E>
                                 Method 1622: 
                                <E T="03">Cryptosporidium</E>
                                 in Water by Filtration/IMS/FA, EPA-821-R-05-001. December 2005. US EPA.
                            </TNOTE>
                            <TNOTE>
                                <SU>25</SU>
                                 Methods 1623 and 1623.1 use a filtration, concentration, immunomagnetic separation of oocysts and cysts from captured material, immunofluorescence assay to determine concentrations, and confirmation through vital dye staining and differential interference contrast microscopy for the simultaneous detection of 
                                <E T="03">Cryptosporidium</E>
                                 and 
                                <E T="03">Giardia</E>
                                 oocysts and cysts. Method 1623: 
                                <E T="03">Cryptosporidium</E>
                                 and 
                                <E T="03">Giardia</E>
                                 in Water by Filtration/IMS/FA. EPA-821-R-05-002. December 2005. US EPA. Method 1623.1: 
                                <E T="03">Cryptosporidium</E>
                                 and 
                                <E T="03">Giardia</E>
                                 in Water by Filtration/IMS/FA. EPA 816-R-12-001. January 2012. US EPA.
                                <PRTPAGE P="51"/>
                            </TNOTE>
                            <TNOTE>
                                <SU>26</SU>
                                 On a monthly basis, at least ten blue colonies from positive samples must be verified using Lauryl Tryptose Broth and EC broth, followed by count adjustment based on these results; and representative non-blue colonies should be verified using Lauryl Tryptose Broth. Where possible, verifications should be done from randomized sample sources.
                            </TNOTE>
                            <TNOTE>
                                <SU>27</SU>
                                 On a monthly basis, at least ten sheen colonies from positive samples must be verified using Lauryl Tryptose Broth and brilliant green lactose bile broth, followed by count adjustment based on these results; and representative non-sheen colonies should be verified using Lauryl Tryptose Broth. Where possible, verifications should be done from randomized sample sources.
                            </TNOTE>
                            <TNOTE>
                                <SU>28</SU>
                                 A description of KwikCount
                                <E T="0731">TM</E>
                                 EC may be obtained from Roth Bioscience, LLC.
                            </TNOTE>
                            <TNOTE>
                                <SU>29</SU>
                                 Approved for the analyses of 
                                <E T="03">E. coli</E>
                                 in freshwater only.
                            </TNOTE>
                            <TNOTE>
                                <SU>30</SU>
                                 Verification of colonies by incubation of BHI agar at 10 ± 0.5 °C for 48 ± 3 h is optional. As per the Errata to the 23rd Edition of 
                                <E T="03">Standard Methods for the Examination of Water and Wastewater</E>
                                 “Growth on a BHI agar plate incubated at 10 ± 0.5 °C for 48 ± 3 h is further verification that the colony belongs to the genus Enterococcus.”
                            </TNOTE>
                            <TNOTE>
                                <SU>31</SU>
                                 Method 1623.1 includes updated acceptance criteria for IPR, OPR, and MS/MSD and clarifications and revisions based on the use of Method 1623 for years and technical support questions.
                            </TNOTE>
                            <TNOTE>
                                <SU>32</SU>
                                 9221 F.2-2014 allows for simultaneous detection of 
                                <E T="03">E. coli</E>
                                 and thermotolerant fecal coliforms by adding inverted vials to EC-MUG; the inverted vials collect gas produced by thermotolerant fecal coliforms.
                            </TNOTE>
                        </GPOTABLE>
                        <PRTPAGE P="52"/>
                        <P>
                            (b) The material listed in this paragraph (b) is incorporated by reference into this section with the approval of the Director of the Federal Register under 5 U.S.C. 552(a) and 1 CFR part 51. All approved incorporation by reference (IBR) material is available for inspection at the EPA and at the National Archives and Records Administration (NARA). Contact the EPA at: EPA's Water Docket, EPA West, 1301 Constitution Avenue NW, Room 3334, Washington, DC 20004; telephone: 202-566-2426; email: 
                            <E T="03">docket-customerservice@epa.gov.</E>
                             For information on the availability of this material at NARA, visit 
                            <E T="03">www.archives.gov/federal-register/cfr/ibr-locations</E>
                             or email 
                            <E T="03">fr.inspection@nara.gov.</E>
                             The material may be obtained from the following sources in this paragraph (b).
                        </P>
                        <P>
                            (1) Environmental Monitoring and Support Laboratory, U.S. Environmental Protection Agency, Cincinnati OH (US EPA). Available at 
                            <E T="03">http://water.epa.gov/scitech/methods/cwa/index.cfm</E>
                             or from: National Technical Information Service, 5285 Port Royal Road, Springfield, Virginia 22161
                        </P>
                        <P>(i) Microbiological Methods for Monitoring the Environment, Water, and Wastes. 1978. EPA/600/8-78/017, Pub. No. PB-290329/A.S.</P>
                        <P>(A) Part III Analytical Methodology, Section B Total Coliform Methods, page 108. Table IA, Note 3; Table IH, Note 3.</P>
                        <P>(B) Part III Analytical Methodology, Section B Total Coliform Methods, 2.6.2 Two-Step Enrichment Procedure, page 111. Table IA, Note 3; Table IH, Note 3.</P>
                        <P>(C) Part III Analytical Methodology, Section B Total Coliform Methods, 4 Most Probable Number (MPN) Method, page 114. Table IA, Note 3; Table IH, Note 3.</P>
                        <P>(D) Part III Analytical Methodology, Section C Fecal Coliform Methods, 2 Direct Membrane Filter (MF) Method, page 124. Table IA, Note 3; Table IH, Note 3.</P>
                        <P>(E) Part III, Analytical Methodology, Section C Fecal Coliform Methods, 5 Most Probable Number (MPN) Method, page 132. Table IA, Note 3; Table IH, Note 3.</P>
                        <P>(F) Part III Analytical Methodology, Section D Fecal Streptococci, 2 Membrane Filter (MF) Method, page 136. Table IA, Note 3; Table IH, Note 3.</P>
                        <P>(G) Part III Analytical Methodology, Section D Fecal Streptococci, 4 Most Probable Number Method, page 139. Table IA, Note 3; Table IH, Note 3.</P>
                        <P>(H) Part III Analytical Methodology, Section D Fecal Streptococci, 5 Pour Plate Method, page 143. Table IA, Note 3; Table IH, Note 3.</P>
                        <P>(ii) [Reserved]</P>
                        <P>
                            (2) Environmental Monitoring and Support Laboratory, U.S. Environmental Protection Agency, Cincinnati OH (US EPA). Available at 
                            <E T="03">http://water.epa.gov/scitech/methods/cwa/index.cfm.</E>
                        </P>
                        <P>(i) Method 300.1 (including Errata Cover Sheet, April 27, 1999), Determination of Inorganic Ions in Drinking Water by Ion Chromatography, Revision 1.0, 1997. Table IB, Note 52.</P>
                        <P>(ii) Method 551, Determination of Chlorination Disinfection Byproducts and Chlorinated Solvents in Drinking Water by Liquid-Liquid Extraction and Gas Chromatography With Electron-Capture Detection. 1990. Table IF.</P>
                        <P>
                            (3) National Exposure Risk Laboratory-Cincinnati, U.S. Environmental Protection Agency, Cincinnati OH (US EPA). Available from 
                            <E T="03">http://water.epa.gov/scitech/methods/cwa/index.cfm</E>
                             or from the National Technical Information Service (NTIS), 5285 Port Royal Road, Springfield, VA 22161. Telephone: 800-553-6847.
                        </P>
                        <P>(i) Methods for the Determination of Inorganic Substances in Environmental Samples. August 1993. EPA/600/R-93/100, Pub. No. PB 94120821. Table IB, Note 52.</P>
                        <P>(A) Method 180.1, Determination of Turbidity by Nephelometry. Revision 2.0. Table IB, Note 52.</P>
                        <P>(B) Method 300.0, Determination of Inorganic Anions by Ion Chromatography. Revision 2.1. Table IB, Note 52.</P>
                        <P>(C) Method 335.4, Determination of Total Cyanide by Semi-Automated Colorimetry. Revision 1.0. Table IB, Notes 52 and 57.</P>
                        <P>
                            (D) Method 350.1, Determination of Ammonium Nitrogen by Semi-Automated Colorimetry. Revision 2.0. Table IB, Notes 30 and 52.
                            <PRTPAGE P="53"/>
                        </P>
                        <P>(E) Method 351.2, Determination of Total Kjeldahl Nitrogen by Semi-Automated Colorimetry. Revision 2.0. Table IB, Note 52.</P>
                        <P>(F) Method 353.2, Determination of Nitrate-Nitrite Automated Colorimetry. Revision 2.0. Table IB, Note 52.</P>
                        <P>(G) Method 365.1, Determination of Phosphorus by Automated Colorimetry. Revision 2.0. Table IB, Note 52.</P>
                        <P>(H) Method 375.2, Determination of Sulfate by Automated Colorimetry. Revision 2.0. Table IB, Note 52.</P>
                        <P>(I) Method 410.4, Determination of Chemical Oxygen Demand by Semi-Automated Colorimetry. Revision 2.0. Table IB, Note 52.</P>
                        <P>(ii) Methods for the Determination of Metals in Environmental Samples, Supplement I. May 1994. EPA/600/R-94/111, Pub. No. PB 95125472. Table IB, Note 52.</P>
                        <P>(A) Method 200.7, Determination of Metals and Trace Elements in Water and Wastes by Inductively Coupled Plasma-Atomic Emission Spectrometry. Revision 4.4. Table IB, Note 52.</P>
                        <P>(B) Method 200.8, Determination of Trace Elements in Water and Wastes by Inductively Coupled Plasma Mass Spectrometry. Revision 5.3. Table IB, Note 52.</P>
                        <P>(C) Method 200.9, Determination of Trace Elements by Stabilized Temperature Graphite Furnace Atomic Absorption Spectrometry. Revision 2.2. Table IB, Note 52.</P>
                        <P>(D) Method 218.6, Determination of Dissolved Hexavalent Chromium in Drinking Water, Groundwater, and Industrial Wastewater Effluents by Ion Chromatography. Revision 3.3. Table IB, Note 52.</P>
                        <P>(E) Method 245.1, Determination of Mercury in Water by Cold Vapor Atomic Absorption Spectrometry. Revision 3.0. Table IB, Note 52.</P>
                        <P>
                            (4) National Exposure Risk Laboratory-Cincinnati, U.S. Environmental Protection Agency, Cincinnati OH (US EPA). Available at 
                            <E T="03">http://water.epa.gov/scitech/methods/cwa/index.cfm.</E>
                        </P>
                        <P>(i) EPA Method 200.5, Determination of Trace Elements in Drinking Water by Axially Viewed Inductively Coupled Plasma-Atomic Emission Spectrometry. Revision 4.2, October 2003. EPA/600/R-06/115. Table IB, Note 68.</P>
                        <P>(ii) EPA Method 525.2, Determination of Organic Compounds in Drinking Water by Liquid-Solid Extraction and Capillary Column Gas Chromatography/Mass Spectrometry. Revision 2.0, 1995. Table ID, Note 10.</P>
                        <P>
                            (5) Office of Research and Development, Cincinnati OH. U.S. Environmental Protection Agency, Cincinnati OH (US EPA). Available at 
                            <E T="03">http://water.epa.gov/scitech/methods/cwa/index.cfm</E>
                             or from ORD Publications, CERI, U.S. Environmental Protection Agency, Cincinnati OH 45268.
                        </P>
                        <P>(i) Methods for Benzidine, Chlorinated Organic Compounds, Pentachlorophenol, and Pesticides in Water and Wastewater. 1978. Table IC, Note 3; Table ID, Note 3.</P>
                        <P>(ii) Methods for Chemical Analysis of Water and Wastes. March 1979. EPA-600/4-79-020. Table IB, Note 1.</P>
                        <P>(iii) Methods for Chemical Analysis of Water and Wastes. Revised March 1983. EPA-600/4-79-020. Table IB, Note 1.</P>
                        <P>(A) Method 120.1, Conductance, Specific Conductance, µmhos at 25 °C. Revision 1982. Table IB, Note 1.</P>
                        <P>
                            (B) Method 130.1, Hardness, Total (mg/L as CaCO
                            <E T="52">3</E>
                            ), Colorimetric, Automated EDTA. Issued 1971. Table IB, Note 1.
                        </P>
                        <P>(C) Method 150.2, pH, Continuous Monitoring (Electrometric). December 1982. Table IB, Note 1.</P>
                        <P>(D) Method 160.4, Residue, Volatile, Gravimetric, Ignition at 550 °C. Issued 1971. Table IB, Note 1.</P>
                        <P>(E) Method 206.5, Arsenic, Sample Digestion Prior to Total Arsenic Analysis by Silver Diethyldithiocarbamate or Hydride Procedures. Issued 1978. Table IB, Note 1.</P>
                        <P>(F) Method 231.2, Gold, Atomic Absorption, Furnace Technique. Issued 1978. Table IB, Note 1.</P>
                        <P>(G) Method 245.2, Mercury, Automated Cold Vapor Technique. Issued 1974. Table IB, Note 1.</P>
                        <P>(H) Method 252.2, Osmium, Atomic Absorption, Furnace Technique. Issued 1978. Table IB, Note 1.</P>
                        <P>(I) Method 253.2, Palladium, Atomic Absorption, Furnace Technique. Issued 1978. Table IB, Note 1.</P>
                        <P>
                            (J) Method 255.2, Platinum, Atomic Absorption, Furnace Technique. Issued 1978. Table IB, Note 1.
                            <PRTPAGE P="54"/>
                        </P>
                        <P>(K) Method 265.2, Rhodium, Atomic Absorption, Furnace Technique. Issued 1978. Table IB, Note 1.</P>
                        <P>(L) Method 279.2, Thallium, Atomic Absorption, Furnace Technique. Issued 1978. Table IB, Note 1.</P>
                        <P>(M) Method 283.2, Titanium, Atomic Absorption, Furnace Technique. Issued 1978. Table IB, Note 1.</P>
                        <P>(N) Method 289.2, Zinc, Atomic Absorption, Furnace Technique. Issued 1978. Table IB, Note 1.</P>
                        <P>(O) Method 310.2, Alkalinity, Colorimetric, Automated, Methyl Orange. Revision 1974. Table IB, Note 1.</P>
                        <P>(P) Method 351.1, Nitrogen, Kjeldahl, Total, Colorimetric, Automated Phenate. Revision 1978. Table IB, Note 1.</P>
                        <P>(Q) Method 352.1, Nitrogen, Nitrate, Colorimetric, Brucine. Issued 1971. Table IB, Note 1.</P>
                        <P>(R) Method 365.3, Phosphorus, All Forms, Colorimetric, Ascorbic Acid, Two Reagent. Issued 1978. Table IB, Note 1.</P>
                        <P>(S) Method 365.4, Phosphorus, Total, Colorimetric, Automated, Block Digestor AA II. Issued 1974. Table IB, Note 1.</P>
                        <P>(T) Method 410.3, Chemical Oxygen Demand, Titrimetric, High Level for Saline Waters. Revision 1978. Table IB, Note 1.</P>
                        <P>(U) Method 420.1, Phenolics, Total Recoverable, Spectrophotometric, Manual 4-AAP With Distillation. Revision 1978. Table IB, Note 1.</P>
                        <P>(iv) Prescribed Procedures for Measurement of Radioactivity in Drinking Water. 1980. EPA-600/4-80-032. Table IE.</P>
                        <P>(A) Method 900.0, Gross Alpha and Gross Beta Radioactivity. Table IE.</P>
                        <P>(B) Method 903.0, Alpha-Emitting iRadio Isotopes. Table IE.</P>
                        <P>(C) Method 903.1, Radium-226, Radon Emanation Technique. Table IE.</P>
                        <P>(D) Appendix B, Error and Statistical Calculations. Table IE.</P>
                        <P>
                            (6) Office of Science and Technology, U.S. Environmental Protection Agency, Washington DC (US EPA). Available at 
                            <E T="03">http://water.epa.gov/scitech/methods/cwa/index.cfm.</E>
                        </P>
                        <P>(i) Method 1625C, Semivolatile Organic Compounds by Isotope Dilution GCMS. 1989. Table IF.</P>
                        <P>(ii) [Reserved]</P>
                        <P>
                            (7) Office of Water, U.S. Environmental Protection Agency, Washington DC (US EPA). Available at 
                            <E T="03">http://water.epa.gov/scitech/methods/cwa/index.cfm</E>
                             or from National Technical Information Service, 5285 Port Royal Road, Springfield, Virginia 22161.
                        </P>
                        <P>(i) Method 1631, Mercury in Water by Oxidation, Purge and Trap, and Cold Vapor Atomic Fluorescence Spectrometry. Revision E, August 2002. EPA-821-R-02-019, Pub. No. PB2002-108220. Table IB, Note 43.</P>
                        <P>(ii) Kelada-01, Kelada Automated Test Methods for Total Cyanide, Acid Dissociable Cyanide, and Thiocyanate. Revision 1.2, August 2001. EPA 821-B-01-009, Pub. No. PB 2001-108275. Table IB, Note 55.</P>
                        <P>
                            (iii) In the compendium 
                            <E T="03">Analytical Methods for the Determination of Pollutants in Pharmaceutical Manufacturing Industry Wastewaters.</E>
                             July 1998. EPA 821-B-98-016, Pub. No. PB95201679. Table IF, Note 1.
                        </P>
                        <P>(A) EPA Method 1666, Volatile Organic Compounds Specific to the Pharmaceutical Industry by Isotope Dilution GC/MS. Table IF, Note 1.</P>
                        <P>(B) EPA Method 1667, Formaldehyde, Isobutyraldehyde, and Furfural by Derivatization Followed by High Performance Liquid Chromatography. Table IF.</P>
                        <P>(C) Method 1671, Volatile Organic Compounds Specific to the Pharmaceutical Manufacturing Industry by GC/FID. Table IF.</P>
                        <P>(iv) Methods For The Determination of Nonconventional Pesticides In Municipal and Industrial Wastewater, Volume I. Revision I, August 1993. EPA 821-R-93-010A, Pub. No. PB 94121654. Tables ID, IG.</P>
                        <P>(A) Method 608.1, Organochlorine Pesticides. Table ID, Note 10; Table IG, Note 3.</P>
                        <P>(B) Method 608.2, Certain Organochlorine Pesticides. Table ID, Note 10; Table IG, Note 3.</P>
                        <P>(C) Method 614, Organophosphorus Pesticides. Table ID, Note 10; Table IG, Note 3.</P>
                        <P>(D) Method 614.1, Organophosphorus Pesticides. Table ID, Note 10; Table IG, Note 3.</P>
                        <P>
                            (E) Method 615, Chlorinated Herbicides. Table ID, Note 10; Table IG, Note 3.
                            <PRTPAGE P="55"/>
                        </P>
                        <P>(F) Method 617, Organohalide Pesticides and PCBs. Table ID, Note 10; Table IG, Note 3.</P>
                        <P>(G) Method 619, Triazine Pesticides. Table ID, Note 10; Table IG, Note 3.</P>
                        <P>(H) Method 622, Organophosphorus Pesticides. Table ID, Note 10; Table IG, Note 3.</P>
                        <P>(I) Method 622.1, Thiophosphate Pesticides. Table ID, Note 10; Table IG, Note 3.</P>
                        <P>(J) Method 627, Dinitroaniline Pesticides. Table ID, Note 10; Table IG, Notes 1 and 3.</P>
                        <P>(K) Method 629, Cyanazine. Table IG, Note 3.</P>
                        <P>(L) Method 630, Dithiocarbamate Pesticides. Table IG, Note 3.</P>
                        <P>(M) Method 630.1, Dithiocarbamate Pesticides. Table IG, Note 3.</P>
                        <P>(N) Method 631, Benomyl and Carbendazim. Table IG, Note 3.</P>
                        <P>(O) Method 632, Carbamate and Urea Pesticides. Table ID, Note 10; Table IG, Note 3.</P>
                        <P>(P) Method 632.1, Carbamate and Amide Pesticides. Table IG, Note 3.</P>
                        <P>(Q) Method 633, Organonitrogen Pesticides. Table IG, Note 3.</P>
                        <P>(R) Method 633.1, Neutral Nitrogen-Containing Pesticides. Table IG, Note 3.</P>
                        <P>(S) Method 637, MBTS and TCMTB. Table IG, Note 3.</P>
                        <P>(T) Method 644, Picloram. Table IG, Note 3.</P>
                        <P>(U) Method 645, Certain Amine Pesticides and Lethane. Table IG, Note 3.</P>
                        <P>(V) Method 1656, Organohalide Pesticides. Table ID, Note 10; Table IG, Notes 1 and 3.</P>
                        <P>(W) Method 1657, Organophosphorus Pesticides. Table ID, Note 10; Table IG, Note 3.</P>
                        <P>(X) Method 1658, Phenoxy-Acid Herbicides. Table IG, Note 3.</P>
                        <P>(Y) Method 1659, Dazomet. Table IG, Note 3.</P>
                        <P>(Z) Method 1660, Pyrethrins and Pyrethroids. Table IG, Note 3.</P>
                        <P>(AA) Method 1661, Bromoxynil. Table IG, Note 3.</P>
                        <P>(BB) Ind-01. Methods EV-024 and EV-025, Analytical Procedures for Determining Total Tin and Triorganotin in Wastewater. Table IG, Note 3.</P>
                        <P>(v) Methods For The Determination of Nonconventional Pesticides In Municipal and Industrial Wastewater, Volume II. August 1993. EPA 821-R-93-010B, Pub. No. PB 94166311. Table IG.</P>
                        <P>(A) Method 200.9, Determination of Trace Elements by Stabilized Temperature Graphite Furnace Atomic Absorption Spectrometry. Table IG, Note 3.</P>
                        <P>(B) Method 505, Analysis of Organohalide Pesticides and Commercial Polychlorinated Biphenyl (PCB) Products in Water by Microextraction and Gas Chromatography. Table ID, Note 10; Table IG, Note 3.</P>
                        <P>(C) Method 507, The Determination of Nitrogen- and Phosphorus-Containing Pesticides in Water by Gas Chromatography with a Nitrogen-Phosphorus Detector. Table ID, Note 10; Table IG, Note 3.</P>
                        <P>(D) Method 508, Determination of Chlorinated Pesticides in Water by Gas Chromatography with an Electron Capture Detector. Table ID, Note 10; Table IG, Note 3.</P>
                        <P>(E) Method 515.1, Determination of Chlorinated Acids in Water by Gas Chromatography with an Electron Capture Detector. Table IG, Notes 2 and 3.</P>
                        <P>(F) Method 515.2, Determination of Chlorinated Acids in Water Using Liquid-Solid Extraction and Gas Chromatography with an Electron Capture Detector. Table IG, Notes 2 and 3.</P>
                        <P>(G) Method 525.1, Determination of Organic Compounds in Drinking Water by Liquids-Solid Extraction and Capillary Column Gas Chromatography/Mass Spectrometry. Table ID, Note 10; Table IG, Note 3.</P>
                        <P>(H) Method 531.1, Measurement of N-Methylcarbamoyloximes and N-Methylcarbamates in Water by Direct Aqueous Injection HPLC with Post-Column Derivatization. Table ID, Note 10; Table IG, Note 3.</P>
                        <P>(I) Method 547, Determination of Glyphosate in Drinking Water by Direct-Aqueous-Injection HPLC, Post-Column Derivatization, and Fluorescence Detection. Table IG, Note 3.</P>
                        <P>(J) Method 548, Determination of Endothall in Drinking Water by Aqueous Derivatization, Liquid-Solid Extraction, and Gas Chromatography with Electron-Capture Detector. Table IG, Note 3.</P>
                        <P>
                            (K) Method 548.1, Determination of Endothall in Drinking Water by Ion-Exchange Extraction, Acidic Methanol 
                            <PRTPAGE P="56"/>
                            Methylation and Gas Chromatography/Mass Spectrometry. Table IG, Note 3.
                        </P>
                        <P>(L) Method 553, Determination of Benzidines and Nitrogen-Containing Pesticides in Water by Liquid-Liquid Extraction or Liquid-Solid Extraction and Reverse Phase High Performance Liquid Chromatography/Particle Beam/Mass Spectrometry Table ID, Note 10; Table IG, Note 3.</P>
                        <P>(M) Method 555, Determination of Chlorinated Acids in Water by High Performance Liquid Chromatography With a Photodiode Array Ultraviolet Detector. Table IG, Note 3.</P>
                        <P>
                            (vi) In the compendium 
                            <E T="03">Methods for the Determination of Organic Compounds in Drinking Water.</E>
                             Revised July 1991, December 1998. EPA-600/4-88-039, Pub. No. PB92-207703. Table IF.
                        </P>
                        <P>(A) EPA Method 502.2, Volatile Organic Compounds in Water by Purge and Trap Capillary Column Gas Chromatography with Photoionization and Electrolytic Conductivity Detectors in Series. Table IF.</P>
                        <P>(B) [Reserved]</P>
                        <P>
                            (vii) In the compendium 
                            <E T="03">Methods for the Determination of Organic Compounds in Drinking Water-Supplement II.</E>
                             August 1992. EPA-600/R-92-129, Pub. No. PB92-207703. Table IF.
                        </P>
                        <P>(A) EPA Method 524.2, Measurement of Purgeable Organic Compounds in Water by Capillary Column Gas Chromatography/Mass Spectrometry. Table IF.</P>
                        <P>(B) [Reserved]</P>
                        <P>(viii) Methods for Measuring the Acute Toxicity of Effluents and Receiving Waters to Freshwater and Marine Organisms, Fifth Edition. October 2002. EPA 821-R-02-012, Pub. No. PB2002-108488. Table IA, Note 26.</P>
                        <P>(ix) Short-Term Methods for Measuring the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms, Fourth Edition. October 2002. EPA 821-R-02-013, Pub. No. PB2002-108489. Table IA, Note 27.</P>
                        <P>(x) Short-Term Methods for Measuring the Chronic Toxicity of Effluents and Receiving Waters to Marine and Estuarine Organisms, Third Edition. October 2002. EPA 821-R-02-014, Pub. No. PB2002-108490. Table IA, Note 28.</P>
                        <P>
                            (8) Office of Water, U.S. Environmental Protection Agency (U.S. EPA), mail code 4303T, 1301 Constitution Avenue NW, Washington, DC 20460; website: 
                            <E T="03">www.epa.gov/cwa-methods.</E>
                        </P>
                        <P>(i) Method 245.7, Mercury in Water by Cold Vapor Atomic Fluorescence Spectrometry. Revision 2.0, February 2005. EPA-821-R-05-001. Table IB, Note 17.</P>
                        <P>
                            (ii) Method 1103.2: 
                            <E T="03">Escherichia coli (E. coli)</E>
                             in Water by Membrane Filtration Using membrane-Thermotolerant 
                            <E T="03">Escherichia coli</E>
                             Agar (mTEC), EPA-821-R-23-009. September 2023. Table IH, Note 18.
                        </P>
                        <P>
                            (iii) Method 1106.2: Enterococci in Water by Membrane Filtration Using membrane-
                            <E T="03">Enterococcus</E>
                            -Esculin Iron Agar (mE-EIA), EPA-821-R-23-007. September 2023. Table IH, Note 22.
                        </P>
                        <P>
                            (iv) Method 1600.1: Enterococci in Water by Membrane Filtration Using membrane-
                            <E T="03">Enterococcus</E>
                             Indoxyl-β-D-Glucoside Agar (mEI), EPA-821-R-23-006, September 2023. Table 1A, Note 24; Table IH, Note 23.
                        </P>
                        <P>
                            (v) Method 1603.1: 
                            <E T="03">Escherichia coli (E. coli)</E>
                             in Water by Membrane Filtration Using Modified membrane-Thermotolerant 
                            <E T="03">Escherichia coli</E>
                             Agar (Modified mTEC), EPA-821-R-23-008, September 2023. Table IA, Note 21; Table IH, Note 19.
                        </P>
                        <P>
                            (vi) Method 1604: Total Coliforms and 
                            <E T="03">Escherichia coli</E>
                             (
                            <E T="03">E. coli</E>
                            ) in Water by Membrane Filtration Using a Simultaneous Detection Technique (MI Medium). September 2002. EPA-821-R-02-024. Table IH, Note 21.
                        </P>
                        <P>(vii) Whole Effluent Toxicity Methods Errata Sheet, EPA 821-R-02-012-ES. December 2016, Table IA, Notes 25, 26, and 27.</P>
                        <P>
                            (viii) Method 1623: 
                            <E T="03">Cryptosporidium</E>
                             and 
                            <E T="03">Giardia</E>
                             in Water by Filtration/IMS/FA. December 2005. EPA-821-R-05-002. Table IH, Note 26.
                        </P>
                        <P>
                            (ix) Method 1623.1: 
                            <E T="03">Cryptosporidium</E>
                             and 
                            <E T="03">Giardia</E>
                             in Water by Filtration/IMS/FA. EPA 816-R-12-001. January 2012. U.S. EPA, Table IH, Notes 25 and 31.
                        </P>
                        <P>(x) Method 1627, Kinetic Test Method for the Prediction of Mine Drainage Quality. December 2011. EPA-821-R-09-002. Table IB, Note 69.</P>
                        <P>
                            (xi) Method 1664, 
                            <E T="03">n</E>
                            -Hexane Extractable Material (HEM; Oil and Grease) and Silica Gel Treated 
                            <E T="03">n</E>
                            -Hexane Extractable Material (SGT-HEM; Nonpolar Material) by Extraction and Gravimetry. Revision A, February 1999. 
                            <PRTPAGE P="57"/>
                            EPA-821-R-98-002. Table IB, Notes 38 and 42.
                        </P>
                        <P>
                            (xii) Method 1664, 
                            <E T="03">n</E>
                            -Hexane Extractable Material (HEM; Oil and Grease) and Silica Gel Treated 
                            <E T="03">n</E>
                            -Hexane Extractable Material (SGT-HEM; Nonpolar Material) by Extraction and Gravimetry, Revision B, February 2010. EPA-821-R-10-001. Table IB, Notes 38 and 42.
                        </P>
                        <P>(xiii) Method 1669, Sampling Ambient Water for Trace Metals at EPA Water Quality Criteria Levels. July 1996. Table IB, Note 43.</P>
                        <P>(xiv) Method 1680: Fecal Coliforms in Sewage Sludge (Biosolids) by Multiple-Tube Fermentation using Lauryl Tryptose Broth (LTB) and EC Medium. September 2014. EPA-821-R-14-009.Table IA, Note 15.</P>
                        <P>(xv) Method 1681: Fecal Coliforms in Sewage Sludge (Biosolids) by Multiple-Tube Fermentation using A-1 Medium. July 2006. EPA 821-R-06-013. Table IA, Note 20.</P>
                        <P>
                            (xvi) Method 1682: 
                            <E T="03">Salmonella</E>
                             in Sewage Sludge (Biosolids) by Modified Semisolid Rappaport-Vassiliadis (MSRV) Medium. September 2014. EPA 821-R-14-012. Table IA, Note 23.
                        </P>
                        <P>(9) American National Standards Institute, 1430 Broadway, New York NY 10018.</P>
                        <P>(i) ANSI. American National Standard on Photographic Processing Effluents. April 2, 1975. Table IB, Note 9.</P>
                        <P>(ii) [Reserved]</P>
                        <P>
                            (10) American Public Health Association, 800 I Street, NW, Washington, DC 20001; phone: (202)777-2742, website: 
                            <E T="03">www.standardmethods.org.</E>
                        </P>
                        <P>
                            (i) 
                            <E T="03">Standard Methods for the Examination of Water and Wastewater.</E>
                             14th Edition, 1975. Table IB, Notes 27 and 86.
                        </P>
                        <P>(ii) Standard Methods for the Examination of Water and Wastewater. 15th Edition, 1980, Table IB, Note 30; Table ID.</P>
                        <P>(iii) Selected Analytical Methods Approved and Cited by the United States Environmental Protection Agency, Supplement to the 15th Edition of Standard Methods for the Examination of Water and Wastewater. 1981. Table IC, Note 6; Table ID, Note 6.</P>
                        <P>(iv) Standard Methods for the Examination of Water and Wastewater. 18th Edition, 1992. Tables IA, IB, IC, ID, IE, and IH.</P>
                        <P>(v) Standard Methods for the Examination of Water and Wastewater. 19th Edition, 1995. Tables IA, IB, IC, ID, IE, and IH.</P>
                        <P>(vi) Standard Methods for the Examination of Water and Wastewater. 20th Edition, 1998. Tables IA, IB, IC, ID, IE, and IH.</P>
                        <P>(vii) Standard Methods for the Examination of Water and Wastewater. 21st Edition, 2005. Table IB, Notes 17 and 27.</P>
                        <P>(viii) 2120, Color. Revised September 4, 2021. Table IB.</P>
                        <P>(ix) 2130, Turbidity. Revised 2020. Table IB.</P>
                        <P>(x) 2310, Acidity. Revised 2020. Table IB.</P>
                        <P>(xi) 2320, Alkalinity. Revised 2021. Table IB.</P>
                        <P>(xii) 2340, Hardness. Revised 2021. Table IB.</P>
                        <P>(xiii) 2510, Conductivity. Revised 2021. Table IB.</P>
                        <P>(xiv) 2540, Solids. Revised 2020. Table IB.</P>
                        <P>(xv) 2550, Temperature. 2010. Table IB.</P>
                        <P>(xvi) 3111, Metals by Flame Atomic Absorption Spectrometry. Revised 2019. Table IB.</P>
                        <P>(xvii) 3112, Metals by Cold-Vapor Atomic Absorption Spectrometry. Revised 2020. Table IB.</P>
                        <P>(xviii) 3113, Metals by Electrothermal Atomic Absorption Spectrometry. Revised 2020. Table IB.</P>
                        <P>(xix) 3114, Arsenic and Selenium by Hydride Generation/Atomic Absorption Spectrometry. Revised 2020, Table IB.</P>
                        <P>(xx) 3120, Metals by Plasma Emission Spectroscopy. Revised 2020. Table IB.</P>
                        <P>(xxi) 3125, Metals by Inductively Coupled Plasma-Mass Spectrometry. Revised 2020. Table IB.</P>
                        <P>(xxii) 3500-Al, Aluminum. Revised 2020. Table IB.</P>
                        <P>(xxiii) 3500-As, Arsenic. Revised 2020. Table IB.</P>
                        <P>(xxiv) 3500-Ca, Calcium. Revised 2020. Table IB.</P>
                        <P>(xxv) 3500-Cr, Chromium. Revised 2020. Table IB.</P>
                        <P>(xxvi) 3500-Cu, Copper. Revised 2020. Table IB.</P>
                        <P>(xxvii) 3500-Fe, Iron. 2011. Table IB.</P>
                        <P>
                            (xxviii) 3500-Pb, Lead. Revised 2020. Table IB.
                            <PRTPAGE P="58"/>
                        </P>
                        <P>(xxix) 3500-Mn, Manganese. Revised 2020. Table IB.</P>
                        <P>(xxx) 3500-K, Potassium. Revised 2020. Table IB.</P>
                        <P>(xxxi) 3500-Na, Sodium. Revised 2020. Table IB.</P>
                        <P>(xxxii) 3500-V, Vanadium. 2011. Table IB.</P>
                        <P>(xxxiii) 3500-Zn, Zinc. Revised 2020. Table IB.</P>
                        <P>(xxxiv) 4110, Determination of Anions by Ion Chromatography. Revised 2020. Table IB.</P>
                        <P>(xxxv) 4140, Inorganic Anions by Capillary Ion Electrophoresis. Revised 2020. Table IB.</P>
                        <P>(xxxvi) 4500-B, Boron. 2011. Table IB.</P>
                        <P>
                            (xxxvii) 4500 Cl
                            <E T="51">−</E>
                            , Chloride. Revised 2021. Table IB.
                        </P>
                        <P>(xxxviii) 4500-Cl, Chlorine (Residual). 2011. Table IB.</P>
                        <P>
                            (xxxix) 4500-CN
                            <E T="51">−</E>
                            , Cyanide. Revised 2021. Table IB.
                        </P>
                        <P>
                            (xl) 4500-F
                            <E T="51">−</E>
                            , Fluoride. Revised 2021. Table IB.
                        </P>
                        <P>
                            (xli) 4500-H
                            <SU>+</SU>
                            , pH. 2021. Table IB.
                        </P>
                        <P>
                            (xlii) 4500-NH
                            <E T="52">3</E>
                            , Nitrogen (Ammonia). Revised 2021. Table IB.
                        </P>
                        <P>
                            (xliii) 4500-NO
                            <E T="52">2</E>
                            <E T="51">−</E>
                            , Nitrogen (Nitrite). Revised 2021. Table IB.
                        </P>
                        <P>
                            (xliv) 4500-NO
                            <E T="52">3</E>
                            <E T="51">−</E>
                            , Nitrogen (Nitrate). Revised 2019. Table IB.
                        </P>
                        <P>
                            (xlv) 4500-N
                            <E T="52">(org)</E>
                            , Nitrogen (Organic). Revised 2021. Table IB.
                        </P>
                        <P>(xlvi) 4500-O, Oxygen (Dissolved). Revised 2021. Table IB.</P>
                        <P>(xlvii) 4500-P, Phosphorus. Revised 2021. Table IB.</P>
                        <P>
                            (xlviii) 4500-SiO
                            <E T="52">2</E>
                            , Silica. Revised 2021. Table IB.
                        </P>
                        <P>
                            (xlix) 4500-S
                            <E T="51">2−</E>
                            , Sulfide. Revised 2021. Table IB.
                        </P>
                        <P>
                            (l) 4500-SO
                            <E T="52">3</E>
                            <E T="51">2−</E>
                            , Sulfite. Revised 2021. Table IB.
                        </P>
                        <P>
                            (li) 4500-SO
                            <E T="52">4</E>
                            <E T="51">2−</E>
                            , Sulfate. Revised 2021. Table IB.
                        </P>
                        <P>(lii) 5210, Biochemical Oxygen Demand (BOD). Revised 2016. Table IB.</P>
                        <P>(liii) 5220, Chemical Oxygen Demand (COD). 2011. Table IB.</P>
                        <P>(liv) 5310, Total Organic Carbon (TOC). Revised 2014. Table IB.</P>
                        <P>(lv) 5520, Oil and Grease. Revised 2021. Table IB.</P>
                        <P>(lvi) 5530, Phenols. Revised 2021. Table IB.</P>
                        <P>(lvii) 5540, Surfactants. Revised 2021. Table IB.</P>
                        <P>(lviii) 6200, Volatile Organic Compounds. Revised 2020. Table IC.</P>
                        <P>(lix) 6410, Extractable Base/Neutrals and Acids. Revised 2020. Tables IC and ID.</P>
                        <P>(lx) 6420, Phenols. Revised 2021. Table IC.</P>
                        <P>(lxi) 6440, Polynuclear Aromatic Hydrocarbons. Revised 2021. Table IC.</P>
                        <P>(lxii) 6630, Organochlorine Pesticides. Revised 2021. Table ID.</P>
                        <P>(lxiii) 6640, Acidic Herbicide Compounds. Revised 2021. Table ID.</P>
                        <P>(lxiv) 7110, Gross Alpha and Gross Beta Radioactivity (Total, Suspended, and Dissolved). 2000. Table IE.</P>
                        <P>(lxv) 7500, Radium. 2001. Table IE.</P>
                        <P>(lxvi) 9213, Recreational Waters. 2007. Table IH.</P>
                        <P>(lxvii) 9221, Multiple-Tube Fermentation Technique for Members of the Coliform Group. Approved 2014. Table IA, Notes 12, 14; and 33; Table IH, Notes 10, 12, and 32.</P>
                        <P>(lxviii) 9222, Membrane Filter Technique for Members of the Coliform Group. 2015. Table IA, Note 31; Table IH, Note 17.</P>
                        <P>(lxix) 9223 Enzyme Substrate Coliform Test. 2016. Table IA; Table IH.</P>
                        <P>(lxx) 9230 Fecal Enterococcus/Streptococcus Groups. 2013. Table IA, Note 32; Table IH.</P>
                        <P>(11) The Analyst, The Royal Society of Chemistry, RSC Publishing, Royal Society of Chemistry, Thomas Graham House, Science Park, Milton Road, Cambridge CB4 0WF, United Kingdom. (Also available from most public libraries.)</P>
                        <P>(i) Spectrophotometric Determination of Ammonia: A Study of a Modified Berthelot Reaction Using Salicylate and Dichloroisocyanurate. Krom, M.D. 105:305-316, April 1980. Table IB, Note 60.</P>
                        <P>(ii) [Reserved]</P>
                        <P>(12) Analytical Chemistry, ACS Publications, 1155 Sixteenth St. NW., Washington DC 20036. (Also available from most public libraries.)</P>
                        <P>(i) Spectrophotometric and Kinetics Investigation of the Berthelot Reaction for the Determination of Ammonia. Patton, C.J. and S.R. Crouch. 49(3):464-469, March 1977. Table IB, Note 60.</P>
                        <P>
                            (ii) [Reserved]
                            <PRTPAGE P="59"/>
                        </P>
                        <P>(13) AOAC International, 481 North Frederick Avenue, Suite 500, Gaithersburg, MD 20877-2417.</P>
                        <P>(i) Official Methods of Analysis of AOAC International. 16th Edition, 4th Revision, 1998.</P>
                        <P>(A) 920.203, Manganese in Water, Persulfate Method. Table IB, Note 3.</P>
                        <P>(B) 925.54, Sulfate in Water, Gravimetric Method. Table IB, Note 3.</P>
                        <P>(C) 973.40, Specific Conductance of Water. Table IB, Note 3.</P>
                        <P>(D) 973.41, pH of Water. Table IB, Note 3.</P>
                        <P>(E) 973.43, Alkalinity of Water, Titrimetric Method. Table IB, Note 3.</P>
                        <P>(F) 973.44, Biochemical Oxygen Demand (BOD) of Water, Incubation Method. Table IB, Note 3.</P>
                        <P>(G) 973.45, Oxygen (Dissolved) in Water, Titrimetric Methods. Table IB, Note 3.</P>
                        <P>(H) 973.46, Chemical Oxygen Demand (COD) of Water, Titrimetric Methods. Table IB, Note 3.</P>
                        <P>(I) 973.47, Organic Carbon in Water, Infrared Analyzer Method. Table IB, Note 3.</P>
                        <P>(J) 973.48, Nitrogen (Total) in Water, Kjeldahl Method. Table IB, Note 3.</P>
                        <P>(K) 973.49, Nitrogen (Ammonia) in Water, Colorimetric Method. Table IB, Note 3.</P>
                        <P>(L) 973.50, Nitrogen (Nitrate) in Water, Brucine Colorimetric Method. Table IB, Note 3.</P>
                        <P>(M) 973.51, Chloride in Water, Mercuric Nitrate Method. Table IB, Note 3.</P>
                        <P>(N) 973.52, Hardness of Water. Table IB, Note 3.</P>
                        <P>(O) 973.53, Potassium in Water, Atomic Absorption Spectrophotometric Method. Table IB, Note 3.</P>
                        <P>(P) 973.54, Sodium in Water, Atomic Absorption Spectrophotometric Method. Table IB, Note 3.</P>
                        <P>(Q) 973.55, Phosphorus in Water, Photometric Method. Table IB, Note 3.</P>
                        <P>(R) 973.56, Phosphorus in Water, Automated Method. Table IB, Note 3.</P>
                        <P>(S) 974.27, Cadmium, Chromium, Copper, Iron, Lead, Magnesium, Manganese, Silver, Zinc in Water, Atomic Absorption Spectrophotometric Method. Table IB, Note 3.</P>
                        <P>(T) 977.22, Mercury in Water, Flameless Atomic Absorption Spectrophotometric Method. Table IB, Note 3.</P>
                        <P>
                            (U) 991.15. Total Coliforms and 
                            <E T="03">Escherichia coli</E>
                             in Water Defined Substrate Technology (Colilert) Method. Table IA, Note 10; Table IH, Note 10.
                        </P>
                        <P>(V) 993.14, Trace Elements in Waters and Wastewaters, Inductively Coupled Plasma-Mass Spectrometric Method. Table IB, Note 3.</P>
                        <P>(W) 993.23, Dissolved Hexavalent Chromium in Drinking Water, Ground Water, and Industrial Wastewater Effluents, Ion Chromatographic Method. Table IB, Note 3.</P>
                        <P>(X) 993.30, Inorganic Anions in Water, Ion Chromatographic Method. Table IB, Note 3.</P>
                        <P>(ii) [Reserved]</P>
                        <P>(14) Applied and Environmental Microbiology, American Society for Microbiology, 1752 N Street NW., Washington DC 20036. (Also available from most public libraries.)</P>
                        <P>
                            (i) New Medium for the Simultaneous Detection of Total Coliforms and 
                            <E T="03">Escherichia coli</E>
                             in Water. Brenner, K.P., C.C. Rankin, Y.R. Roybal, G.N. Stelma, Jr., P.V. Scarpino, and A.P. Dufour. 59:3534-3544, November 1993. Table IH, Note 21.
                        </P>
                        <P>(ii) [Reserved]</P>
                        <P>
                            (15) ASTM International, 100 Barr Harbor Drive, P.O. Box C700, West Conshohocken, PA 19428-2959; phone: (877)909-2786; website: 
                            <E T="03">www.astm.org.</E>
                        </P>
                        <P>(i) Annual Book of ASTM Standards, Water, and Environmental Technology, Section 11, Volumes 11.01 and 11.02. 1994. Tables IA, IB, IC, ID, IE, and IH.</P>
                        <P>(ii) Annual Book of ASTM Standards, Water, and Environmental Technology, Section 11, Volumes 11.01 and 11.02. 1996. Tables IA, IB, IC, ID, IE, and IH.</P>
                        <P>(iii) Annual Book of ASTM Standards, Water, and Environmental Technology, Section 11, Volumes 11.01 and 11.02. 1999. Tables IA, IB, IC, ID, IE, and IH.</P>
                        <P>(iv) Annual Book of ASTM Standards, Water, and Environmental Technology, Section 11, Volumes 11.01 and 11.02. 2000. Tables IA, IB, IC, ID, IE, and IH.</P>
                        <P>(v) ASTM D511-14, Standard Test Methods for Calcium and Magnesium in Water. Approved October 1, 2014. Table IB.</P>
                        <P>
                            (vi) ASTM D512-12, Standard Test Methods for Chloride Ion in Water. Approved June 15, 2012. Table IB.
                            <PRTPAGE P="60"/>
                        </P>
                        <P>(vii) ASTM D515-88, Test Methods for Phosphorus in Water, March 1989. Table IB.</P>
                        <P>(viii) ASTM D516-16, Standard Test Method for Sulfate Ion in Water. Approved June 1, 2016. Table IB.</P>
                        <P>(ix) ASTM D858-17, Standard Test Methods for Manganese in Water. Approved June 1, 2017. Table IB.</P>
                        <P>(x) ASTM D859-16, Standard Test Method for Silica in Water. Approved June 15, 2016. Table IB.</P>
                        <P>(xi) ASTM D888-18, Standard Test Methods for Dissolved Oxygen in Water. Approved May 1, 2018. Table IB.</P>
                        <P>(xii) ASTM D1067-16, Standard Test Methods for Acidity or Alkalinity of Water. Approved June 15, 2016. Table IB.</P>
                        <P>(xiii) ASTM D1068-15, Standard Test Methods for Iron in Water. Approved October 1, 2015. Table IB.</P>
                        <P>(xiv) ASTM D1125-95 (Reapproved 1999), Standard Test Methods for Electrical Conductivity and Resistivity of Water. December 1995. Table IB.</P>
                        <P>(xv) ASTM D1126-17, Standard Test Method for Hardness in Water. Approved December 1, 2017. Table IB.</P>
                        <P>(xvi) ASTM D1179-16, Standard Test Methods for Fluoride Ion in Water. Approved June 15, 2016. Table IB.</P>
                        <P>(xvii) ASTM D1246-16, Standard Test Method for Bromide Ion in Water. June 15, 2016. Table IB.</P>
                        <P>(xviii) ASTM D1252-06 (Reapproved 2012), Standard Test Methods for Chemical Oxygen Demand (Dichromate Oxygen Demand) of Water. Approved June 15, 2012. Table IB.</P>
                        <P>(xix) ASTM D1253-14, Standard Test Method for Residual Chlorine in Water. Approved January 15, 2014. Table IB.</P>
                        <P>(xx) ASTM D1293-18, Standard Test Methods for pH of Water. Approved January 15, 2018. Table IB.</P>
                        <P>(xxi) ASTM D1426-15, Standard Test Methods for Ammonia Nitrogen in Water. Approved March 15, 2015. Table IB.</P>
                        <P>(xxii) ASTM D1687-17, Standard Test Methods for Chromium in Water. Approved June 1, 2017. Table IB.</P>
                        <P>(xxiii) ASTM D1688-17, Standard Test Methods for Copper in Water. Approved June 1, 2017. Table IB.</P>
                        <P>(xxiv) ASTM D1691-17, Standard Test Methods for Zinc in Water. Approved June 1, 2017. Table IB.</P>
                        <P>(xxv) ASTM D1783-01 (Reapproved 2012), Standard Test Methods for Phenolic Compounds in Water. Approved June 15, 2012. Table IB.</P>
                        <P>(xxvi) ASTM D1886-14, Standard Test Methods for Nickel in Water. Approved October 1, 2014. Table IB.</P>
                        <P>(xxvii) ASTM D1889-00, Standard Test Method for Turbidity of Water. October 2000. Table IB.</P>
                        <P>(xxviii) ASTM D1890-96, Standard Test Method for Beta Particle Radioactivity of Water. April 1996. Table IE.</P>
                        <P>(xxix) ASTM D1943-96, Standard Test Method for Alpha Particle Radioactivity of Water. April 1996. Table IE.</P>
                        <P>(xxx) ASTM D1976-20, Standard Test Method for Elements in Water by Inductively-Coupled Argon Plasma Atomic Emission Spectroscopy. Approved May 1, 2020. Table IB.</P>
                        <P>(xxxi) ASTM D2036-09 (Reapproved 2015), Standard Test Methods for Cyanides in Water. Approved July 15, 2015. Table IB.</P>
                        <P>(xxxii) ASTM D2330-20, Standard Test Method for Methylene Blue Active Substances. Approved January 1, 2020. Table 1B.</P>
                        <P>(xxxiii) ASTM D2460-97, Standard Test Method for Alpha-Particle-Emitting Isotopes of Radium in Water. October 1997. Table IE.</P>
                        <P>(xxxiv) ASTM D2972-15, Standard Tests Method for Arsenic in Water. Approved February 1, 2015. Table IB.</P>
                        <P>(xxxv) ASTM D3223-17, Standard Test Method for Total Mercury in Water. Approved June 1, 2017. Table IB.</P>
                        <P>(xxxvi) ASTM D3371-95, Standard Test Method for Nitriles in Aqueous Solution by Gas-Liquid Chromatography, February 1996. Table IF.</P>
                        <P>(xxxvii) ASTM D3373-17, Standard Test Method for Vanadium in Water. Approved June 1, 2017. Table IB.</P>
                        <P>(xxxviii) ASTM D3454-97, Standard Test Method for Radium-226 in Water. February 1998. Table IE.</P>
                        <P>(xxxix) ASTM D3557-17, Standard Test Method for Cadmium in Water. Approved June 1, 2017. Table IB.</P>
                        <P>(xl) ASTM D3558-15, Standard Test Method for Cobalt in Water. Approved February 1, 2015. Table IB.</P>
                        <P>
                            (xli) ASTM D3559-15, Standard Test Methods for Lead in Water. Approved June 1, 2015. Table IB.
                            <PRTPAGE P="61"/>
                        </P>
                        <P>(xlii) ASTM D3590-17, Standard Test Methods for Total Kjeldahl Nitrogen in Water. Approved June 1, 2017. Table IB.</P>
                        <P>(xliii) ASTM D3645-15, Standard Test Methods for Beryllium in Water. Approved February 1, 2015. Table IB.</P>
                        <P>(xliv) ASTM D3695-95, Standard Test Method for Volatile Alcohols in Water by Direct Aqueous-Injection Gas Chromatography. April 1995. Table IF.</P>
                        <P>(xlv) ASTM D3859-15, Standard Test Methods for Selenium in Water. Approved March 15, 2015. Table IB.</P>
                        <P>(xlvi) ASTM D3867-16, Standard Test Method for Nitrite-Nitrate in Water. Approved June 1, 2016. Table IB.</P>
                        <P>(xlvii) ASTM D4190-15, Standard Test Method for Elements in Water by Direct- Current Plasma Atomic Emission Spectroscopy. Approved February 1, 2015. Table IB.</P>
                        <P>(xlviii) ASTM D4282-15, Standard Test Method for Determination of Free Cyanide in Water and Wastewater by Microdiffusion. Approved July 15, 2015. Table IB.</P>
                        <P>(xlix) ASTM D4327-17, Standard Test Method for Anions in Water by Suppressed Ion Chromatography. Approved December 1, 2017. Table IB.</P>
                        <P>(l) ASTM D4382-18, Standard Test Method for Barium in Water, Atomic Absorption Spectrophotometry, Graphite Furnace. Approved February 1, 2018. Table IB.</P>
                        <P>(li) ASTM D4657-92 (Reapproved 1998), Standard Test Method for Polynuclear Aromatic Hydrocarbons in Water. January 1993. Table IC.</P>
                        <P>(lii) ASTM D4658-15, Standard Test Method for Sulfide Ion in Water. Approved March 15, 2015. Table IB.</P>
                        <P>(liii) ASTM D4763-88 (Reapproved 2001), Standard Practice for Identification of Chemicals in Water by Fluorescence Spectroscopy. September 1988. Table IF.</P>
                        <P>(liv) ASTM D4839-03 (Reapproved 2017), Standard Test Method for Total Carbon and Organic Carbon in Water by Ultraviolet, or Persulfate Oxidation, or Both, and Infrared Detection. Approved December 15, 2017. Table IB.</P>
                        <P>(lv) ASTM D5257-17, Standard Test Method for Dissolved Hexavalent Chromium in Water by Ion Chromatography. Approved December 1, 2017. Table IB.</P>
                        <P>(lvi) ASTM D5259-92, Standard Test Method for Isolation and Enumeration of Enterococci from Water by the Membrane Filter Procedure. October 1992. Table IH, Note 9.</P>
                        <P>
                            (lvii) ASTM D5392-93, Standard Test Method for Isolation and Enumeration of 
                            <E T="03">Escherichia coli</E>
                             in Water by the Two-Step Membrane Filter Procedure. September 1993. Table IH, Note 9.
                        </P>
                        <P>(lviii) ASTM D5673-16, Standard Test Method for Elements in Water by Inductively Coupled Plasma—Mass Spectrometry. Approved February 1, 2016. Table IB.</P>
                        <P>(lix) ASTM D5907-18, Standard Test Methods for Filterable Matter (Total Dissolved Solids) and Nonfilterable Matter (Total Suspended Solids) in Water. Approved May 1, 2018. Table IB.</P>
                        <P>(lx) ASTM D6503-99, Standard Test Method for Enterococci in Water Using Enterolert. April 2000. Table IA Note 9, Table IH, Note 9.</P>
                        <P>(lxi) ASTM. D6508-15, Standard Test Method for Determination of Dissolved Inorganic Anions in Aqueous Matrices Using Capillary Ion Electrophoresis and Chromate Electrolyte. Approved October 1, 2015. Table IB, Note 54.</P>
                        <P>(lxii) ASTM. D6888-16, Standard Test Method for Available Cyanides with Ligand Displacement and Flow Injection Analysis (FIA) Utilizing Gas Diffusion Separation and Amperometric Detection. Approved February 1, 2016. Table IB, Note 59.</P>
                        <P>(lxiii) ASTM. D6919-17, Standard Test Method for Determination of Dissolved Alkali and Alkaline Earth Cations and Ammonium in Water and Wastewater by Ion Chromatography. Approved June 1, 2017. Table IB.</P>
                        <P>
                            (lxiv) ASTM. D7065-17, Standard Test Method for Determination of Nonylphenol, Bisphenol A, 
                            <E T="03">p-tert</E>
                            -Octylphenol, Nonylphenol Monoethoxylate and Nonylphenol Diethoxylate in Environmental Waters by Gas Chromatography Mass Spectrometry. Approved December 15, 2017. Table IC.
                        </P>
                        <P>
                            (lxv) ASTM D7237-18, Standard Test Method for Free Cyanide with Flow Injection Analysis (FIA) Utilizing Gas Diffusion Separation and Amperometric Detection. Approved December 1, 2018. Table IB.
                            <PRTPAGE P="62"/>
                        </P>
                        <P>(lxvi) ASTM D7284-20, Standard Test Method for Total Cyanide in Water by Micro Distillation followed by Flow Injection Analysis with Gas Diffusion Separation and Amperometric Detection. Approved August 1, 2020. Table IB.</P>
                        <P>(lxvii) ASTM D7365-09a (Reapproved 2015), Standard Practice for Sampling, Preservation and Mitigating Interferences in Water Samples for Analysis of Cyanide. Approved July 15, 2015. Table II, Notes 5 and 6.</P>
                        <P>
                            (lxviii) ASTM. D7511-12 (Reapproved 2017)
                            <SU>e1</SU>
                            , Standard Test Method for Total Cyanide by Segmented Flow Injection Analysis, In-Line Ultraviolet Digestion and Amperometric Detection. Approved July 1, 2017. Table IB.
                        </P>
                        <P>
                            (lxix) ASTM D7573-18a
                            <SU>e1</SU>
                            , Standard Test Method for Total Carbon and Organic Carbon in Water by High Temperature Catalytic Combustion and Infrared Detection. Approved December 15, 2018. Table IB.
                        </P>
                        <P>(lxx) ASTM D7781-14, Standard Test Method for Nitrite-Nitrate in Water by Nitrate Reductase, Approved April 1, 2014. Table IB.</P>
                        <P>(16) Bran &amp; Luebbe Analyzing Technologies, Inc., Elmsford NY 10523.</P>
                        <P>(i) Industrial Method Number 378-75WA, Hydrogen Ion (pH) Automated Electrode Method, Bran &amp; Luebbe (Technicon) Auto Analyzer II. October 1976. Table IB, Note 21.</P>
                        <P>(ii) [Reserved]</P>
                        <P>(17) CEM Corporation, P.O. Box 200, Matthews NC 28106-0200.</P>
                        <P>(i) Closed Vessel Microwave Digestion of Wastewater Samples for Determination of Metals. April 16, 1992. Table IB, Note 36.</P>
                        <P>(ii) [Reserved]</P>
                        <P>(18) Craig R. Chinchilla, 900 Jorie Blvd., Suite 35, Oak Brook IL 60523. Telephone: 630-645-0600.</P>
                        <P>(i) Nitrate by Discrete Analysis Easy (1-Reagent) Nitrate Method, (Colorimetric, Automated, 1 Reagent). Revision 1, November 12, 2011. Table IB, Note 62.</P>
                        <P>(ii) [Reserved]</P>
                        <P>
                            (19) FIAlab Instruments, Inc., 334 2151 N. Northlake Way, Seattle, WA 98103; phone: (425)376-0450; website: 
                            <E T="03">www.flowinjection.com/app-notes/epafialab100.</E>
                        </P>
                        <P>(i) FIAlab 100, Determination of Inorganic Ammonia by Continuous Flow Gas Diffusion and Fluorescence Detector Analysis, April 4, 2018. Table IB, Note 82.</P>
                        <P>(ii) [Reserved]</P>
                        <P>(20) Hach Company, P.O. Box 389, Loveland CO 80537.</P>
                        <P>(i) Method 8000, Chemical Oxygen Demand. Hach Handbook of Water Analysis. 1979. Table IB, Note 14.</P>
                        <P>(ii) Method 8008, 1,10-Phenanthroline Method using FerroVer Iron Reagent for Water. 1980. Table IB, Note 22.</P>
                        <P>(iii) Method 8009, Zincon Method for Zinc. Hach Handbook for Water Analysis. 1979. Table IB, Note 33.</P>
                        <P>(iv) Method 8034, Periodate Oxidation Method for Manganese. Hach Handbook for Water Analysis. 1979. Table IB, Note 23.</P>
                        <P>(v) Method 8506, Bicinchoninate Method for Copper. Hach Handbook of Water Analysis. 1979. Table IB, Note 19.</P>
                        <P>(vi) Method 8507, Nitrogen, Nitrite—Low Range, Diazotization Method for Water and Wastewater. 1979. Table IB, Note 25.</P>
                        <P>(vii) Method 10206, Hach Company TNTplus 835/836 Nitrate Method 10206, Spectrophotometric Measurement of Nitrate in Water and Wastewater. Revision 2.1, January 10, 2013. Table IB, Note 75.</P>
                        <P>(viii) Method 10242, Hach Company TNTplus 880 Total Kjeldahl Nitrogen Method 10242, Simplified Spectrophotometric Measurement of Total Kjeldahl Nitrogen in Water and Wastewater. Revision 1.1, January 10, 2013. Table IB, Note 76.</P>
                        <P>
                            (ix) Hach Method 10360, Luminescence Measurement of Dissolved Oxygen in Water and Wastewater and for Use in the Determination of BOD
                            <E T="52">5</E>
                             and cBOD
                            <E T="52">5</E>
                            . Revision 1.2, October 2011. Table IB, Note 63.
                        </P>
                        <P>
                            (x) m-ColiBlue24® Method, for total Coliforms and 
                            <E T="03">E. coli.</E>
                             Revision 2, 1999. Table IA, Note 18; Table IH, Note 17.
                        </P>
                        <P>(21) IDEXX Laboratories Inc., One Idexx Drive, Westbrook ME 04092.</P>
                        <P>(i) Colilert. 2013. Table IA, Notes 17 and 18; Table IH, Notes 14, 15 and 16.</P>
                        <P>(ii) Colilert-18. 2013. Table IA, Notes 17 and 18; Table IH, Notes 14, 15 and 16.</P>
                        <P>(iii) Enterolert. 2013. Table IA, Note 24; Table IH, Note 12.</P>
                        <P>
                            (iv) Quanti-Tray Insert and Most Probable Number (MPN) Table. 2013. 
                            <PRTPAGE P="63"/>
                            Table IA, Note 18; Table IH, Notes 14 and 16.
                        </P>
                        <P>(22) In-Situ Incorporated, 221 E. Lincoln Ave., Ft. Collins CO 80524. Telephone: 970-498-1500.</P>
                        <P>(i) In-Situ Inc. Method 1002-8-2009, Dissolved Oxygen Measurement by Optical Probe. 2009. Table IB, Note 64.</P>
                        <P>(ii) In-Situ Inc. Method 1003-8-2009, Biochemical Oxygen Demand (BOD) Measurement by Optical Probe. 2009. Table IB, Note 10.</P>
                        <P>(iii) In-Situ Inc. Method 1004-8-2009, Carbonaceous Biochemical Oxygen Demand (CBOD) Measurement by Optical Probe. 2009. Table IB, Note 35.</P>
                        <P>(23) Journal of Chromatography, Elsevier/North-Holland, Inc., Journal Information Centre, 52 Vanderbilt Avenue, New York NY 10164. (Also available from most public libraries.</P>
                        <P>(i) Direct Determination of Elemental Phosphorus by Gas-Liquid Chromatography. Addison, R.F. and R.G. Ackman. 47(3): 421-426, 1970. Table IB, Note 28.</P>
                        <P>(ii) [Reserved]</P>
                        <P>(24) Lachat Instruments, 6645 W. Mill Road, Milwaukee WI 53218, Telephone: 414-358-4200.</P>
                        <P>(i) QuikChem Method 10-204-00-1-X, Digestion and Distillation of Total Cyanide in Drinking and Wastewaters using MICRO DIST and Determination of Cyanide by Flow Injection Analysis. Revision 2.2, March 2005. Table IB, Note 56.</P>
                        <P>(ii) [Reserved]</P>
                        <P>(25) Leck Mitchell, Ph.D., P.E., 656 Independence Valley Dr., Grand Junction CO 81507. Telephone: 970-244-8661.</P>
                        <P>(i) Mitchell Method M5271, Determination of Turbidity by Nephelometry. Revision 1.0, July 31, 2008. Table IB, Note 66.</P>
                        <P>(ii) Mitchell Method M5331, Determination of Turbidity by Nephelometry. Revision 1.0, July 31, 2008. Table IB, Note 65.</P>
                        <P>(26) MACHEREY-NAGEL GmbH and Co., 2850 Emrick Blvd., Bethlehem, PA 18020; Phone: (888)321-6224.</P>
                        <P>(i) Method 036/038 NANOCOLOR® COD LR/HR, Spectrophotometric Measurement of Chemical Oxygen Demand in Water and Wastewater, Revision 1.5, May 2018. Table IB, Note 83.</P>
                        <P>(ii) [Reserved]</P>
                        <P>(27) Micrology Laboratories, LLC (now known as Roth Bioscience, LLC), 1303 Eisenhower Drive, Goshen, IN 46526; phone: (574)533-3351.</P>
                        <P>
                            (i) KwikCount
                            <SU>TM</SU>
                             EC Medium E. coli enzyme substrate test, Rapid Detection of E. coli in Beach Water By KwikCount
                            <SU>TM</SU>
                             EC Membrane Filtration. 2014. Table IH, Notes 28 and 29.
                        </P>
                        <P>(ii) [Reserved]</P>
                        <P>(28) National Council of the Paper Industry for Air and Stream Improvements, Inc. (NCASI), 260 Madison Avenue, New York NY 10016.</P>
                        <P>(i) NCASI Method TNTP-W10900, Total Nitrogen and Total Phophorus in Pulp and Paper Biologically Treated Effluent by Alkaline Persulfate Digestion. June 2011. Table IB, Note 77.</P>
                        <P>(ii) NCASI Technical Bulletin No. 253, An Investigation of Improved Procedures for Measurement of Mill Effluent and Receiving Water Color. December 1971. Table IB, Note 18.</P>
                        <P>(iii) NCASI Technical Bulletin No. 803, An Update of Procedures for the Measurement of Color in Pulp Mill Wastewaters. May 2000. Table IB, Note 18.</P>
                        <P>(29) The Nitrate Elimination Co., Inc. (NECi), 334 Hecla St., Lake Linden NI 49945.</P>
                        <P>(i) NECi Method N07-0003, Method for Nitrate Reductase Nitrate-Nitrogen Analysis. Revision 9.0. March 2014. Table IB, Note 73.</P>
                        <P>(ii) [Reserved]</P>
                        <P>(30) Oceanography International Corporation, 512 West Loop, P.O. Box 2980, College Station TX 77840.</P>
                        <P>(i) OIC Chemical Oxygen Demand Method. 1978. Table IB, Note 13.</P>
                        <P>(ii) [Reserved]</P>
                        <P>(31) OI Analytical, Box 9010, College Station TX 77820-9010.</P>
                        <P>(i) Method OIA-1677-09, Available Cyanide by Ligand Exchange and Flow Injection Analysis (FIA). Copyright 2010. Table IB, Note 59.</P>
                        <P>(ii) Method PAI-DK01, Nitrogen, Total Kjeldahl, Block Digestion, Steam Distillation, Titrimetric Detection. Revised December 22, 1994. Table IB, Note 39.</P>
                        <P>
                            (iii) Method PAI-DK02, Nitrogen, Total Kjeldahl, Block Digestion, Steam Distillation, Colorimetric Detection. Revised December 22, 1994. Table IB, Note 40.
                            <PRTPAGE P="64"/>
                        </P>
                        <P>(iv) Method PAI-DK03, Nitrogen, Total Kjeldahl, Block Digestion, Automated FIA Gas Diffusion. Revised December 22, 1994. Table IB, Note 41.</P>
                        <P>(32) ORION Research Corporation, 840 Memorial Drive, Cambridge, Massachusetts 02138.</P>
                        <P>(i) ORION Research Instruction Manual, Residual Chlorine Electrode Model 97-70. 1977. Table IB, Note 16.</P>
                        <P>(ii) [Reserved]</P>
                        <P>(33) Pace Analytical Services, LLC, 1800 Elm Street, SE, Minneapolis, MN 55414; phone: (612)656-2240.</P>
                        <P>
                            (i) PAM-16130-SSI, Determination of 2,3,7,8-Substituted Tetra- through Octa-Chlorinated Dibenzo-
                            <E T="03">p</E>
                            -Dioxins and Dibenzofurans (CDDs/CDFs) Using Shimadzu Gas Chromatography Mass Spectrometry (GC-MS/MS), Revision 1.1, May 20, 2022. Table IC, Note 17.
                        </P>
                        <P>(ii) [Reserved]</P>
                        <P>(34) SGS AXYS Analytical Services, Ltd., 2045 Mills Road, Sidney, British Columbia, Canada, V8L 5X2; phone: (888)373-0881.</P>
                        <P>
                            (i) SGS AXYS Method 16130, Determination of 2,3,7,8-Substituted Tetra- through Octa-Chlorinated Dibenzo-
                            <E T="03">p</E>
                            -Dioxins and Dibenzofurans (CDDs/CDFs) Using Waters and Agilent Gas Chromatography-Mass Spectrometry (GC/MS/MS)., Revision 1.0, revised August 2020. Table IC, Note 16.
                        </P>
                        <P>(ii) [Reserved]</P>
                        <P>(35) Technicon Industrial Systems, Tarrytown NY 10591.</P>
                        <P>(i) Industrial Method Number 379-75WE Ammonia, Automated Electrode Method, Technicon Auto Analyzer II. February 19, 1976. Table IB, Note 7.</P>
                        <P>(ii) [Reserved]</P>
                        <P>(36) Thermo Jarrell Ash Corporation, 27 Forge Parkway, Franklin MA 02038.</P>
                        <P>(i) Method AES0029. Direct Current Plasma (DCP) Optical Emission Spectrometric Method for Trace Elemental Analysis of Water and Wastes. 1986, Revised 1991. Table IB, Note 34.</P>
                        <P>(ii) [Reserved]</P>
                        <P>
                            (37) Thermo Scientific, 166 Cummings Center, Beverly MA 01915. Telephone: 1-800-225-1480. 
                            <E T="03">www.thermoscientific.com.</E>
                        </P>
                        <P>(i) Thermo Scientific Orion Method AQ4500, Determination of Turbidity by Nephelometry. Revision 5, March 12, 2009. Table IB, Note 67.</P>
                        <P>(ii) [Reserved]</P>
                        <P>(38) 3M Corporation, 3M Center Building 220-9E-10, St. Paul MN 55144-1000.</P>
                        <P>
                            (i) Organochlorine Pesticides and PCBs in Wastewater Using Empore 
                            <SU>TM</SU>
                             Disk” Test Method 3M 0222. Revised October 28, 1994. Table IC, Note 8; Table ID, Note 8.
                        </P>
                        <P>(ii) [Reserved]</P>
                        <P>(39) Timberline Instruments, LLC, 1880 South Flatiron Ct., Unit I, Boulder CO 80301.</P>
                        <P>(i) Timberline Amonia-001, Determination of Inorganic Ammonia by Continuous Flow Gas Diffusion and Conductivity Cell Analysis. June 24, 2011. Table IB, Note 74.</P>
                        <P>(ii) [Reserved]</P>
                        <P>
                            (40) U.S. Geological Survey (USGS), U.S. Department of the Interior, Reston, Virginia. Available from USGS Books and Open-File Reports (OFR) Section, Federal Center, Box 25425, Denver, CO 80225; phone: (703)648-5953; website: 
                            <E T="03">ww.usgs.gov.</E>
                        </P>
                        <P>(i) Colorimetric determination of nitrate plus nitrite in water by enzymatic reduction, automated discrete analyzer methods. U.S. Geological Survey Techniques and Methods, Book 5—Laboratory Analysis, Section B—Methods of the National Water Quality Laboratory, Chapter 8. 2011. Table IB, Note 72.</P>
                        <P>(ii) Techniques and Methods—Book 5, Laboratory Analysis—Section B, Methods of the National Water Quality Laboratory—Chapter 12, Determination of Heat Purgeable and Ambient Purgeable Volatile Organic Compounds in Water by Gas Chromatography/Mass Spectrometry 2016.</P>
                        <P>(iii) Methods for Determination of Inorganic Substances in Water and Fluvial Sediments, editors, Techniques of Water-Resources Investigations of the U.S. Geological Survey, Book 5, Chapter A1. 1979. Table IB, Note 8.</P>
                        <P>(iv) Methods for Determination of Inorganic Substances in Water and Fluvial Sediments, Techniques of Water-Resources Investigations of the U.S. Geological Survey, Book 5, Chapter A1. 1989. Table IB, Notes 2 and 79.</P>
                        <P>
                            (v) Methods for the Determination of Organic Substances in Water and Fluvial Sediments. Techniques of Water-Resources Investigations of the U.S. Geological Survey, Book 5, Chapter A3. 
                            <PRTPAGE P="65"/>
                            1987. Table IB, Note 24; Table ID, Note 4.
                        </P>
                        <P>(vi) OFR 76-177, Selected Methods of the U.S. Geological Survey of Analysis of Wastewaters. 1976. Table IE, Note 2.</P>
                        <P>(vii) OFR 91-519, Methods of Analysis by the U.S. Geological Survey National Water Quality Laboratory—Determination of Organonitrogen Herbicides in Water by Solid-Phase Extraction and Capillary-Column Gas Chromatography/Mass Spectrometry With Selected-Ion Monitoring. 1992. Table ID, Note 14.</P>
                        <P>(viii) OFR 92-146, Methods of Analysis by the U.S. Geological Survey National Water Quality Laboratory—Determination of Total Phosphorus by a Kjeldahl Digestion Method and an Automated Colorimetric Finish That Includes Dialysis. 1992. Table IB, Note 48.</P>
                        <P>(ix) OFR 93-125, Methods of Analysis by the U.S. Geological Survey National Water Quality Laboratory—Determination of Inorganic and Organic Constituents in Water and Fluvial Sediments. 1993. Table IB, Notes 51 and 80; Table IC, Note 9.</P>
                        <P>(x) OFR 93-449, Methods of Analysis by the U.S. Geological Survey National Water Quality Laboratory—Determination of Chromium in Water by Graphite Furnace Atomic Absorption Spectrophotometry. 1993. Table IB, Note 46.</P>
                        <P>(xi) OFR 94-37, Methods of Analysis by the U.S. Geological Survey National Water Quality Laboratory—Determination of Triazine and Other Nitrogen-containing Compounds by Gas Chromatography with Nitrogen Phosphorus Detectors. 1994. Table ID, Note 9.</P>
                        <P>(xii) OFR 95-181, Methods of Analysis by the U.S. Geological Survey National Water Quality Laboratory—Determination of Pesticides in Water by C-18 Solid-Phase Extraction and Capillary-Column Gas Chromatography/Mass Spectrometry With Selected-Ion Monitoring. 1995. Table ID, Note 11.</P>
                        <P>(xiii) OFR 97-198, Methods of Analysis by the U.S. Geological Survey National Water Quality Laboratory—Determination of Molybdenum in Water by Graphite Furnace Atomic Absorption Spectrophotometry. 1997. Table IB, Note 47.</P>
                        <P>(xiv) OFR 97-829, Methods of Analysis by the U.S. Geological Survey National Water Quality Laboratory—Determination of 86 Volatile Organic Compounds in Water by Gas Chromatography/Mass Spectrometry, Including Detections Less Than Reporting Limits. 1998. Table IC, Note 13.</P>
                        <P>(xv) OFR 98-165, Methods of Analysis by the U.S. Geological Survey National Water Quality Laboratory—Determination of Elements in Whole-Water Digests Using Inductively Coupled Plasma-Optical Emission Spectrometry and Inductively Coupled Plasma-Mass Spectrometry. 1998. Table IB, Notes 50 and 81.</P>
                        <P>(xvi) OFR 98-639, Methods of Analysis by the U.S. Geological Survey National Water Quality Laboratory—Determination of Arsenic and Selenium in Water and Sediment by Graphite Furnace—Atomic Absorption Spectrometry. 1999. Table IB, Note 49.</P>
                        <P>(xvii) OFR 00-170, Methods of Analysis by the U.S. Geological Survey National Water Quality Laboratory—Determination of Ammonium Plus Organic Nitrogen by a Kjeldahl Digestion Method and an Automated Photometric Finish that Includes Digest Cleanup by Gas Diffusion. 2000. Table IB, Note 45.</P>
                        <P>(xviii) Techniques and Methods Book 5-B1, Determination of Elements in Natural-Water, Biota, Sediment and Soil Samples Using Collision/Reaction Cell Inductively Coupled Plasma-Mass Spectrometry. Chapter 1, Section B, Methods of the National Water Quality Laboratory, Book 5, Laboratory Analysis. 2006. Table IB, Note 70.</P>
                        <P>(xix) U.S. Geological Survey Techniques of Water-Resources Investigations, Book 5, Laboratory Analysis, Chapter A4, Methods for Collection and Analysis of Aquatic Biological and Microbiological Samples. 1989. Table IA, Note 4; Table IH, Note 4.</P>
                        <P>
                            (xx) Water-Resources Investigation Report 01-4098, Methods of Analysis by the U.S. Geological Survey National Water Quality Laboratory—Determination of Moderate-Use Pesticides and Selected Degradates in Water by C-18 Solid-Phase Extraction and Gas Chromatography/Mass Spectrometry. 2001. Table ID, Note 13.
                            <PRTPAGE P="66"/>
                        </P>
                        <P>(xxi) Water-Resources Investigations Report 01-4132, Methods of Analysis by the U.S. Geological Survey National Water Quality Laboratory—Determination of Organic Plus Inorganic Mercury in Filtered and Unfiltered Natural Water With Cold Vapor-Atomic Fluorescence Spectrometry. 2001. Table IB, Note 71.</P>
                        <P>(xxii) Water-Resources Investigation Report 01-4134, Methods of Analysis by the U.S. Geological Survey National Water Quality Laboratory—Determination of Pesticides in Water by Graphitized Carbon-Based Solid-Phase Extraction and High-Performance Liquid Chromatography/Mass Spectrometry. 2001. Table ID, Note 12.</P>
                        <P>(xxiii) Water Temperature—Influential Factors, Field Measurement and Data Presentation, Techniques of Water-Resources Investigations of the U.S. Geological Survey, Book 1, Chapter D1. 1975. Table IB, Note 32.</P>
                        <P>(41) Waters Corporation, 34 Maple Street, Milford MA 01757, Telephone: 508-482-2131, Fax: 508-482-3625.</P>
                        <P>(i) Method D6508, Test Method for Determination of Dissolved Inorganic Anions in Aqueous Matrices Using Capillary Ion Electrophoresis and Chromate Electrolyte. Revision 2, December 2000. Table IB, Note 54.</P>
                        <P>(ii) [Reserved]</P>
                        <P>(c) Under certain circumstances, the Director may establish limitations on the discharge of a parameter for which there is no test procedure in this part or in 40 CFR parts 405 through 499. In these instances the test procedure shall be specified by the Director.</P>
                        <P>(d) Under certain circumstances, the Administrator may approve additional alternate test procedures for nationwide use, upon recommendation by the Alternate Test Procedure Program Coordinator, Washington, DC.</P>
                        <P>(e) Sample preservation procedures, container materials, and maximum allowable holding times for parameters are cited in Tables IA, IB, IC, ID, IE, IF, IG, and IH are prescribed in Table II. Information in the table takes precedence over information in specific methods or elsewhere. Any person may apply for a change from the prescribed preservation techniques, container materials, and maximum holding times applicable to samples taken from a specific discharge. Applications for such limited use changes may be made by letters to the Regional Alternative Test Procedure (ATP) Program Coordinator or the permitting authority in the Region in which the discharge will occur. Sufficient data should be provided to assure such changes in sample preservation, containers or holding times do not adversely affect the integrity of the sample. The Regional ATP Coordinator or permitting authority will review the application and then notify the applicant and the appropriate State agency of approval or rejection of the use of the alternate test procedure. A decision to approve or deny any request on deviations from the prescribed Table II requirements will be made within 90 days of receipt of the application by the Regional Administrator. An analyst may not modify any sample preservation and/or holding time requirements of an approved method unless the requirements of this section are met.</P>
                        <GPOTABLE COLS="4" OPTS="L2,nj" CDEF="s50,r50,r50,r50">
                            <TTITLE>Table II—Required Containers, Preservation Techniques, and Holding Times</TTITLE>
                            <BOXHD>
                                <CHED H="1">Parameter number/name</CHED>
                                <CHED H="1">
                                    Container 
                                    <E T="0731">1</E>
                                </CHED>
                                <CHED H="1">
                                    Preservation 
                                    <E T="0731">2 3</E>
                                </CHED>
                                <CHED H="1">
                                    Maximum holding time 
                                    <E T="0731">4</E>
                                </CHED>
                            </BOXHD>
                            <ROW EXPSTB="03" RUL="s">
                                <ENT I="21">
                                    <E T="02">Table IA—Bacterial Tests</E>
                                </ENT>
                            </ROW>
                            <ROW EXPSTB="00">
                                <ENT I="01">
                                    1-4. Coliform, total, fecal, and 
                                    <E T="03">E. coli</E>
                                </ENT>
                                <ENT>PA, G</ENT>
                                <ENT>
                                    Cool, &lt;10 °C, 0.008% Na
                                    <E T="0732">2</E>
                                    S
                                    <E T="0732">2</E>
                                    O
                                    <E T="0732">3</E>
                                     
                                    <E T="0731">5</E>
                                </ENT>
                                <ENT>
                                    8 hours.
                                    <E T="0731">22 23</E>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">5. Fecal streptococci</ENT>
                                <ENT>PA, G</ENT>
                                <ENT>
                                    Cool, &lt;10 °C, 0.008% Na
                                    <E T="0732">2</E>
                                    S
                                    <E T="0732">2</E>
                                    O
                                    <E T="0732">3</E>
                                     
                                    <E T="0731">5</E>
                                </ENT>
                                <ENT>
                                    8 hours.
                                    <E T="0731">22</E>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">6. Enterococci</ENT>
                                <ENT>PA, G</ENT>
                                <ENT>
                                    Cool, &lt;10 °C, 0.008% Na
                                    <E T="0732">2</E>
                                    S
                                    <E T="0732">2</E>
                                    O
                                    <E T="0732">3</E>
                                     
                                    <E T="0731">5</E>
                                </ENT>
                                <ENT>
                                    8 hours.
                                    <E T="0731">22</E>
                                </ENT>
                            </ROW>
                            <ROW RUL="s">
                                <ENT I="01">
                                    7. 
                                    <E T="03">Salmonella</E>
                                </ENT>
                                <ENT>PA, G</ENT>
                                <ENT>
                                    Cool, &lt;10 °C, 0.008% Na
                                    <E T="0732">2</E>
                                    S
                                    <E T="0732">2</E>
                                    O
                                    <E T="0732">3</E>
                                     
                                    <E T="0731">5</E>
                                </ENT>
                                <ENT>
                                    8 hours.
                                    <E T="0731">22</E>
                                </ENT>
                            </ROW>
                            <ROW EXPSTB="03" RUL="s">
                                <ENT I="21">
                                    <E T="02">Table IA—Aquatic Toxicity Tests</E>
                                </ENT>
                            </ROW>
                            <ROW EXPSTB="00" RUL="s">
                                <ENT I="01">8-11. Toxicity, acute and chronic</ENT>
                                <ENT>P, FP, G</ENT>
                                <ENT>
                                    Cool, ≤6 °C 
                                    <E T="0731">16</E>
                                </ENT>
                                <ENT>36 hours.</ENT>
                            </ROW>
                            <ROW EXPSTB="03" RUL="s">
                                <PRTPAGE P="67"/>
                                <ENT I="21">
                                    <E T="02">Table IB—Inorganic Tests</E>
                                </ENT>
                            </ROW>
                            <ROW EXPSTB="00">
                                <ENT I="01">1. Acidity</ENT>
                                <ENT>P, FP, G</ENT>
                                <ENT>
                                    Cool, ≤6 °C 
                                    <E T="0731">18</E>
                                </ENT>
                                <ENT>14 days.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2. Alkalinity</ENT>
                                <ENT>P, FP, G</ENT>
                                <ENT>
                                    Cool, ≤6 °C 
                                    <E T="0731">18</E>
                                </ENT>
                                <ENT>14 days.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4. Ammonia</ENT>
                                <ENT>P, FP, G</ENT>
                                <ENT>
                                    Cool, ≤6 °C 
                                    <E T="0731">18</E>
                                    , H
                                    <E T="0732">2</E>
                                    SO
                                    <E T="0732">4</E>
                                     to pH &lt;2
                                </ENT>
                                <ENT>28 days.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">9. Biochemical oxygen demand</ENT>
                                <ENT>P, FP, G</ENT>
                                <ENT>
                                    Cool, ≤6 °C 
                                    <E T="0731">18</E>
                                </ENT>
                                <ENT>48 hours.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">10. Boron</ENT>
                                <ENT>P, FP, or Quartz</ENT>
                                <ENT>
                                    HNO
                                    <E T="0732">3</E>
                                     to pH &lt;2
                                </ENT>
                                <ENT>6 months.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">11. Bromide</ENT>
                                <ENT>P, FP, G</ENT>
                                <ENT>None required</ENT>
                                <ENT>28 days.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">14. Biochemical oxygen demand, carbonaceous</ENT>
                                <ENT>P, FP G</ENT>
                                <ENT>
                                    Cool, ≤6 °C 
                                    <E T="0731">18</E>
                                </ENT>
                                <ENT>48 hours.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">15. Chemical oxygen demand</ENT>
                                <ENT>P, FP, G</ENT>
                                <ENT>
                                    Cool, ≤6 °C 
                                    <E T="0731">18</E>
                                    , H
                                    <E T="0732">2</E>
                                    SO
                                    <E T="0732">4</E>
                                     to pH &lt;2
                                </ENT>
                                <ENT>28 days.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">16. Chloride</ENT>
                                <ENT>P, FP, G</ENT>
                                <ENT>None required</ENT>
                                <ENT>28 days.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">17. Chlorine, total residual</ENT>
                                <ENT>P, G</ENT>
                                <ENT>None required</ENT>
                                <ENT>Analyze within 15 minutes.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">21. Color</ENT>
                                <ENT>P, FP, G</ENT>
                                <ENT>
                                    Cool, ≤6 °C 
                                    <E T="0731">18</E>
                                </ENT>
                                <ENT>48 hours.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">23-24. Cyanide, total or available (or CATC) and free</ENT>
                                <ENT>P, FP, G</ENT>
                                <ENT>
                                    Cool, ≤6 °C 
                                    <E T="0731">18</E>
                                    , NaOH to pH &gt;10 
                                    <E T="0731">5 6</E>
                                    , reducing agent if oxidizer present
                                </ENT>
                                <ENT>14 days.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">25. Fluoride</ENT>
                                <ENT>P</ENT>
                                <ENT>None required</ENT>
                                <ENT>28 days.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">27. Hardness</ENT>
                                <ENT>P, FP, G</ENT>
                                <ENT>
                                    HNO
                                    <E T="0732">3</E>
                                     or H
                                    <E T="0732">2</E>
                                    SO
                                    <E T="0732">4</E>
                                     to pH &lt;2
                                </ENT>
                                <ENT>6 months.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">28. Hydrogen ion (pH)</ENT>
                                <ENT>P, FP, G</ENT>
                                <ENT>None required</ENT>
                                <ENT>Analyze within 15 minutes.</ENT>
                            </ROW>
                            <ROW RUL="s">
                                <ENT I="01">31, 43. Kjeldahl and organic N</ENT>
                                <ENT>P, FP, G</ENT>
                                <ENT>
                                    Cool, ≤6 °C 
                                    <E T="0731">18</E>
                                    , H
                                    <E T="0732">2</E>
                                    SO
                                    <E T="0732">4</E>
                                     to pH &lt;2
                                </ENT>
                                <ENT>28 days.</ENT>
                            </ROW>
                            <ROW EXPSTB="03" RUL="s">
                                <ENT I="21">
                                    <E T="02">Table IB—Metals</E>
                                     
                                    <E T="0731">7</E>
                                </ENT>
                            </ROW>
                            <ROW EXPSTB="00">
                                <ENT I="01">18. Chromium VI</ENT>
                                <ENT>P, FP, G</ENT>
                                <ENT>
                                    Cool, ≤6 °C 
                                    <E T="0731">18</E>
                                    , pH = 9.3-9.7 
                                    <E T="0731">20</E>
                                </ENT>
                                <ENT>28 days.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">35. Mercury (CVAA)</ENT>
                                <ENT>P, FP, G</ENT>
                                <ENT>
                                    HNO
                                    <E T="0732">3</E>
                                     to pH &lt;2
                                </ENT>
                                <ENT>28 days.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">35. Mercury (CVAFS)</ENT>
                                <ENT>
                                    FP, G; and FP-lined cap 
                                    <E T="0731">17</E>
                                </ENT>
                                <ENT>
                                    5 mL/L 12N HCl or 5 mL/L BrCl 
                                    <E T="0731">17</E>
                                </ENT>
                                <ENT>
                                    90 days.
                                    <E T="0731">17</E>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">3, 5-8, 12, 13, 19, 20, 22, 26, 29, 30, 32-34, 36, 37, 45, 47, 51, 52, 58-60, 62, 63, 70-72, 74, 75. Metals, except boron, chromium VI, and mercury</ENT>
                                <ENT>P, FP, G</ENT>
                                <ENT>
                                    HNO
                                    <E T="0732">3</E>
                                     to pH &lt;2, or at least 24 hours prior to analysis 
                                    <E T="0731">19</E>
                                </ENT>
                                <ENT>6 months.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">38. Nitrate</ENT>
                                <ENT>P, FP, G</ENT>
                                <ENT>
                                    Cool, ≤6 °C 
                                    <E T="0731">18</E>
                                </ENT>
                                <ENT>48 hours.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">39. Nitrate-nitrite</ENT>
                                <ENT>P, FP, G</ENT>
                                <ENT>
                                    Cool, ≤6 °C 
                                    <E T="0731">18</E>
                                    , H
                                    <E T="0732">2</E>
                                    SO
                                    <E T="0732">4</E>
                                     to pH &lt;2
                                </ENT>
                                <ENT>28 days.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">40. Nitrite</ENT>
                                <ENT>P, FP, G</ENT>
                                <ENT>
                                    Cool, ≤6 °C 
                                    <E T="0731">18</E>
                                </ENT>
                                <ENT>48 hours.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">41. Oil and grease</ENT>
                                <ENT>G</ENT>
                                <ENT>
                                    Cool to ≤6 °C 
                                    <E T="0731">18</E>
                                    , HCl or H
                                    <E T="0732">2</E>
                                    SO
                                    <E T="0732">4</E>
                                     to pH &lt;2
                                </ENT>
                                <ENT>28 days.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">42. Organic Carbon</ENT>
                                <ENT>P, FP, G</ENT>
                                <ENT>
                                    Cool to ≤6 °C 
                                    <E T="0731">18</E>
                                    , HCl, H
                                    <E T="0732">2</E>
                                    SO
                                    <E T="0732">4</E>
                                    , or H
                                    <E T="0732">3</E>
                                    PO
                                    <E T="0732">4</E>
                                     to pH &lt;2
                                </ENT>
                                <ENT>28 days.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">44. Orthophosphate</ENT>
                                <ENT>P, FP, G</ENT>
                                <ENT>
                                    Cool, to ≤6 °C 
                                    <E T="0731">18 24</E>
                                </ENT>
                                <ENT>Filter within 15 minutes; Analyze within 48 hours.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">46. Oxygen, Dissolved Probe</ENT>
                                <ENT>G, Bottle and top</ENT>
                                <ENT>None required</ENT>
                                <ENT>Analyze within 15 minutes.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">47. Winkler</ENT>
                                <ENT>G, Bottle and top</ENT>
                                <ENT>Fix on site and store in dark</ENT>
                                <ENT>8 hours.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">48. Phenols</ENT>
                                <ENT>G</ENT>
                                <ENT>
                                    Cool, ≤6 °C 
                                    <E T="0731">18</E>
                                    , H
                                    <E T="0732">2</E>
                                    SO
                                    <E T="0732">4</E>
                                     to pH &lt;2
                                </ENT>
                                <ENT>28 days.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">49. Phosphorus (elemental)</ENT>
                                <ENT>G</ENT>
                                <ENT>
                                    Cool, ≤6 °C 
                                    <E T="0731">18</E>
                                </ENT>
                                <ENT>48 hours.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">50. Phosphorus, total</ENT>
                                <ENT>P, FP, G</ENT>
                                <ENT>
                                    Cool, ≤6 °C 
                                    <E T="0731">18</E>
                                    , H
                                    <E T="0732">2</E>
                                    SO
                                    <E T="0732">4</E>
                                     to pH &lt;2
                                </ENT>
                                <ENT>28 days.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">53. Residue, total</ENT>
                                <ENT>P, FP, G</ENT>
                                <ENT>
                                    Cool, ≤6 °C 
                                    <E T="0731">18</E>
                                </ENT>
                                <ENT>7 days.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">54. Residue, Filterable (TDS)</ENT>
                                <ENT>P, FP, G</ENT>
                                <ENT>
                                    Cool, ≤6 °C 
                                    <E T="0731">18</E>
                                </ENT>
                                <ENT>7 days.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">55. Residue, Nonfilterable (TSS)</ENT>
                                <ENT>P, FP, G</ENT>
                                <ENT>
                                    Cool, ≤6 °C 
                                    <E T="0731">18</E>
                                </ENT>
                                <ENT>7 days.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">56. Residue, Settleable</ENT>
                                <ENT>P, FP, G</ENT>
                                <ENT>
                                    Cool, ≤6 °C 
                                    <E T="0731">18</E>
                                </ENT>
                                <ENT>48 hours.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">57. Residue, Volatile</ENT>
                                <ENT>P, FP, G</ENT>
                                <ENT>
                                    Cool, ≤6 °C 
                                    <E T="0731">18</E>
                                </ENT>
                                <ENT>7 days.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">61. Silica</ENT>
                                <ENT>P or Quartz</ENT>
                                <ENT>
                                    Cool, ≤6 °C 
                                    <E T="0731">18</E>
                                </ENT>
                                <ENT>28 days.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">64. Specific conductance</ENT>
                                <ENT>P, FP, G</ENT>
                                <ENT>
                                    Cool, ≤6 °C 
                                    <E T="0731">18</E>
                                </ENT>
                                <ENT>28 days.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">65. Sulfate</ENT>
                                <ENT>P, FP, G</ENT>
                                <ENT>
                                    Cool, ≤6 °C 
                                    <E T="0731">18</E>
                                </ENT>
                                <ENT>28 days.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">66. Sulfide</ENT>
                                <ENT>P, FP, G</ENT>
                                <ENT>
                                    Cool, ≤6 °C 
                                    <E T="0731">18</E>
                                    , add zinc acetate plus sodium hydroxide to pH &gt;9
                                </ENT>
                                <ENT>7 days.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">67. Sulfite</ENT>
                                <ENT>P, FP, G</ENT>
                                <ENT>None required</ENT>
                                <ENT>Analyze within 15 minutes.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">68. Surfactants</ENT>
                                <ENT>P, FP, G</ENT>
                                <ENT>
                                    Cool, ≤6 °C 
                                    <E T="0731">18</E>
                                </ENT>
                                <ENT>48 hours.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">69. Temperature</ENT>
                                <ENT>P, FP, G</ENT>
                                <ENT>None required</ENT>
                                <ENT>Analyze within 15 minutes.</ENT>
                            </ROW>
                            <ROW RUL="s">
                                <ENT I="01">73. Turbidity</ENT>
                                <ENT>P, FP, G</ENT>
                                <ENT>
                                    Cool, ≤6 °C 
                                    <E T="0731">18</E>
                                </ENT>
                                <ENT>48 hours.</ENT>
                            </ROW>
                            <ROW EXPSTB="03" RUL="s">
                                <PRTPAGE P="68"/>
                                <ENT I="21">
                                    <E T="02">Table IC—Organic Tests</E>
                                     
                                    <E T="0731">8</E>
                                </ENT>
                            </ROW>
                            <ROW EXPSTB="00">
                                <ENT I="01">13, 18-20, 22, 24, 25, 27, 28, 34-37, 39-43, 45-47, 56, 76, 104, 105, 108-111, 113. Purgeable Halocarbons</ENT>
                                <ENT>G, FP-lined septum</ENT>
                                <ENT>
                                    Cool, ≤6 °C 
                                    <E T="0731">18</E>
                                    , 0.008% Na
                                    <E T="0732">2</E>
                                    S
                                    <E T="0732">2</E>
                                    O
                                    <E T="0732">3</E>
                                     
                                    <E T="0731">5</E>
                                    , HCl to pH 2 
                                    <E T="0731">9</E>
                                </ENT>
                                <ENT>
                                    14 days.
                                    <E T="0731">9</E>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">26. 2-Chloroethylvinyl ether</ENT>
                                <ENT>G, FP-lined septum</ENT>
                                <ENT>
                                    Cool, ≤6 °C 
                                    <E T="0731">18</E>
                                    , 0.008% Na
                                    <E T="0732">2</E>
                                    S
                                    <E T="0732">2</E>
                                    O
                                    <E T="0732">3</E>
                                     
                                    <E T="0731">5</E>
                                </ENT>
                                <ENT>14 days.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">6, 57, 106. Purgeable aromatic hydrocarbons</ENT>
                                <ENT>G, FP-lined septum</ENT>
                                <ENT>
                                    Cool, ≤6 °C 
                                    <E T="0731">18</E>
                                    , 0.008% Na
                                    <E T="0732">2</E>
                                    S
                                    <E T="0732">2</E>
                                    O
                                    <E T="0732">3</E>
                                     
                                    <E T="0731">5</E>
                                    , HCl to pH 2 
                                    <E T="0731">9</E>
                                </ENT>
                                <ENT>
                                    14 days.
                                    <E T="0731">9</E>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">3, 4. Acrolein and acrylonitrile</ENT>
                                <ENT>G, FP-lined septum</ENT>
                                <ENT>
                                    Cool, ≤6 °C 
                                    <E T="0731">18</E>
                                    , 0.008% Na
                                    <E T="0732">2</E>
                                    S
                                    <E T="0732">2</E>
                                    O
                                    <E T="0732">3</E>
                                    , pH to 4-5 
                                    <E T="0731">10</E>
                                </ENT>
                                <ENT>
                                    14 days.
                                    <E T="0731">10</E>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    23, 30, 44, 49, 53, 77, 80, 81, 98, 100, 112. Phenols 
                                    <E T="0731">11</E>
                                </ENT>
                                <ENT>G, FP-lined cap</ENT>
                                <ENT>
                                    Cool, ≤6 °C 
                                    <E T="0731">18</E>
                                    , 0.008% Na
                                    <E T="0732">2</E>
                                    S
                                    <E T="0732">2</E>
                                    O
                                    <E T="0732">3</E>
                                </ENT>
                                <ENT>7 days until extraction, 40 days after extraction.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    7, 38. Benzidines 
                                    <E T="0731">11 12</E>
                                </ENT>
                                <ENT>G, FP-lined cap</ENT>
                                <ENT>
                                    Cool, ≤6 °C 
                                    <E T="0731">18</E>
                                    , 0.008% Na
                                    <E T="0732">2</E>
                                    S
                                    <E T="0732">2</E>
                                    O
                                    <E T="0732">3</E>
                                     
                                    <E T="0731">5</E>
                                </ENT>
                                <ENT>
                                    7 days until extraction.
                                    <E T="0731">13</E>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    14, 17, 48, 50-52. Phthalate esters 
                                    <E T="0731">11</E>
                                </ENT>
                                <ENT>G, FP-lined cap</ENT>
                                <ENT>
                                    Cool, ≤6 °C 
                                    <E T="0731">18</E>
                                </ENT>
                                <ENT>7 days until extraction, 40 days after extraction.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    82-84. Nitrosamines 
                                    <E T="0731">11 14</E>
                                </ENT>
                                <ENT>G, FP-lined cap</ENT>
                                <ENT>
                                    Cool, ≤6 °C 
                                    <E T="0731">18</E>
                                    , store in dark, 0.008% Na
                                    <E T="0732">2</E>
                                    S
                                    <E T="0732">2</E>
                                    O
                                    <E T="0732">3</E>
                                     
                                    <E T="0731">5</E>
                                </ENT>
                                <ENT>7 days until extraction, 40 days after extraction.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    88-94. PCBs 
                                    <E T="0731">11</E>
                                </ENT>
                                <ENT>G, FP-lined cap</ENT>
                                <ENT>
                                    Cool, ≤6 °C 
                                    <E T="0731">18</E>
                                </ENT>
                                <ENT>1 year until extraction, 1 year after extraction.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    54, 55, 75, 79. Nitroaromatics and isophorone 
                                    <E T="0731">11</E>
                                </ENT>
                                <ENT>G, FP-lined cap</ENT>
                                <ENT>
                                    Cool, ≤6 °C 
                                    <E T="0731">18</E>
                                    , store in dark, 0.008% Na
                                    <E T="0732">2</E>
                                    S
                                    <E T="0732">2</E>
                                    O
                                    <E T="0732">3</E>
                                     
                                    <E T="0731">5</E>
                                </ENT>
                                <ENT>7 days until extraction, 40 days after extraction.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    1, 2, 5, 8-12, 32, 33, 58, 59, 74, 78, 99, 101. Polynuclear aromatic hydrocarbons 
                                    <E T="0731">11</E>
                                </ENT>
                                <ENT>G, FP-lined cap</ENT>
                                <ENT>
                                    Cool, ≤6 °C 
                                    <E T="0731">18</E>
                                    , store in dark, 0.008% Na
                                    <E T="0732">2</E>
                                    S
                                    <E T="0732">2</E>
                                    O
                                    <E T="0732">3</E>
                                     
                                    <E T="0731">5</E>
                                </ENT>
                                <ENT>7 days until extraction, 40 days after extraction.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    15, 16, 21, 31, 87. Haloethers 
                                    <E T="0731">11</E>
                                </ENT>
                                <ENT>G, FP-lined cap</ENT>
                                <ENT>
                                    Cool, ≤6 °C 
                                    <E T="0731">18</E>
                                    , 0.008% Na
                                    <E T="0732">2</E>
                                    S
                                    <E T="0732">2</E>
                                    O
                                    <E T="0732">3</E>
                                     
                                    <E T="0731">5</E>
                                </ENT>
                                <ENT>7 days until extraction, 40 days after extraction.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    29, 35-37, 63-65, 73, 107. Chlorinated hydrocarbons 
                                    <E T="0731">11</E>
                                </ENT>
                                <ENT>G, FP-lined cap</ENT>
                                <ENT>
                                    Cool, ≤6 °C 
                                    <E T="0731">18</E>
                                </ENT>
                                <ENT>7 days until extraction, 40 days after extraction.</ENT>
                            </ROW>
                            <ROW RUL="s">
                                <ENT I="01">
                                    60-62, 66-72, 85, 86, 95-97, 102, 103. CDDs/CDFs 
                                    <E T="0731">11</E>
                                </ENT>
                                <ENT>G</ENT>
                                <ENT>See footnote 11</ENT>
                                <ENT>See footnote 11.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">Aqueous Samples: Field and Lab Preservation</ENT>
                                <ENT>G</ENT>
                                <ENT>
                                    Cool, ≤6 °C 
                                    <E T="0731">18</E>
                                    , 0.008% Na
                                    <E T="0732">2</E>
                                    S
                                    <E T="0732">2</E>
                                    O
                                    <E T="0732">3</E>
                                     
                                    <E T="0731">5</E>
                                    , pH &lt;9
                                </ENT>
                                <ENT>1 year.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">Solids and Mixed-Phase Samples: Field Preservation</ENT>
                                <ENT>G</ENT>
                                <ENT>
                                    Cool, ≤6 °C 
                                    <E T="0731">18</E>
                                </ENT>
                                <ENT>7 days.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">Tissue Samples: Field Preservation</ENT>
                                <ENT>G</ENT>
                                <ENT>
                                    Cool, ≤6 °C 
                                    <E T="0731">18</E>
                                </ENT>
                                <ENT>24 hours.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">Solids, Mixed-Phase, and Tissue Samples: Lab Preservation</ENT>
                                <ENT>G</ENT>
                                <ENT>Freeze, ≤−10 °C</ENT>
                                <ENT>1 year.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">114-118. Alkylated phenols</ENT>
                                <ENT>G</ENT>
                                <ENT>
                                    Cool, &lt;6 °C, H
                                    <E T="0732">2</E>
                                    SO
                                    <E T="0732">4</E>
                                     to pH &lt;2
                                </ENT>
                                <ENT>28 days until extraction, 40 days after extraction.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">119. Adsorbable Organic Halides (AOX)</ENT>
                                <ENT>G</ENT>
                                <ENT>
                                    Cool, &lt;6 °C, 0.008% Na
                                    <E T="0732">2</E>
                                    S
                                    <E T="0732">2</E>
                                    O
                                    <E T="0732">3</E>
                                    , HNO
                                    <E T="0732">3</E>
                                     to pH &lt;2
                                </ENT>
                                <ENT>
                                    Hold 
                                    <E T="03">at least</E>
                                     3 days, but not more than 6 months.
                                </ENT>
                            </ROW>
                            <ROW RUL="s">
                                <ENT I="01">120. Chlorinated Phenolics</ENT>
                                <ENT>G, FP-lined cap</ENT>
                                <ENT>
                                    Cool, &lt;6 °C, 0.008% Na
                                    <E T="0732">2</E>
                                    S
                                    <E T="0732">2</E>
                                    O
                                    <E T="0732">3</E>
                                    , H
                                    <E T="0732">2</E>
                                    SO
                                    <E T="0732">4</E>
                                     to pH &lt;2
                                </ENT>
                                <ENT>30 days until acetylation, 30 days after acetylation.</ENT>
                            </ROW>
                            <ROW EXPSTB="03" RUL="s">
                                <ENT I="21">
                                    <E T="02">Table ID—Pesticides Tests</E>
                                </ENT>
                            </ROW>
                            <ROW EXPSTB="00" RUL="s">
                                <ENT I="01">
                                    1-70. Pesticides 
                                    <E T="0731">11</E>
                                </ENT>
                                <ENT>G, FP-lined cap</ENT>
                                <ENT>
                                    Cool, ≤6 °C 
                                    <E T="0731">18</E>
                                    , pH 5-9 
                                    <E T="0731">15</E>
                                </ENT>
                                <ENT>7 days until extraction, 40 days after extraction.</ENT>
                            </ROW>
                            <ROW EXPSTB="03" RUL="s">
                                <ENT I="21">
                                    <E T="02">Table IE—Radiological Tests</E>
                                </ENT>
                            </ROW>
                            <ROW EXPSTB="00" RUL="s">
                                <ENT I="01">1-5. Alpha, beta, and radium</ENT>
                                <ENT>P, FP, G</ENT>
                                <ENT>
                                    HNO
                                    <E T="0732">3</E>
                                     to pH &lt;2
                                </ENT>
                                <ENT>6 months.</ENT>
                            </ROW>
                            <ROW EXPSTB="03" RUL="s">
                                <ENT I="21">
                                    <E T="02">Table IH—Bacterial Tests</E>
                                </ENT>
                            </ROW>
                            <ROW EXPSTB="00">
                                <ENT I="01">1, 2. Coliform, total, fecal</ENT>
                                <ENT>PA, G</ENT>
                                <ENT>
                                    Cool, &lt;10 °C, 0.008% Na
                                    <E T="0732">2</E>
                                    S
                                    <E T="0732">2</E>
                                    O
                                    <E T="0732">3</E>
                                     
                                    <E T="0731">5</E>
                                </ENT>
                                <ENT>
                                    8 hours.
                                    <E T="0731">22</E>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    3.
                                    <E T="03">E. coli</E>
                                </ENT>
                                <ENT>PA, G</ENT>
                                <ENT>
                                    Cool, &lt;10 °C, 0.008% Na
                                    <E T="0732">2</E>
                                    S
                                    <E T="0732">2</E>
                                    O
                                    <E T="0732">3</E>
                                     
                                    <E T="0731">5</E>
                                </ENT>
                                <ENT>
                                    8 hours.
                                    <E T="0731">22</E>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4. Fecal streptococci</ENT>
                                <ENT>PA, G</ENT>
                                <ENT>
                                    Cool, &lt;10 °C, 0.008% Na
                                    <E T="0732">2</E>
                                    S
                                    <E T="0732">2</E>
                                    O
                                    <E T="0732">3</E>
                                     
                                    <E T="0731">5</E>
                                </ENT>
                                <ENT>
                                    8 hours.
                                    <E T="0731">22</E>
                                </ENT>
                            </ROW>
                            <ROW RUL="s">
                                <ENT I="01">5. Enterococci</ENT>
                                <ENT>PA, G</ENT>
                                <ENT>
                                    Cool, &lt;10 °C, 0.008% Na
                                    <E T="0732">2</E>
                                    S
                                    <E T="0732">2</E>
                                    O
                                    <E T="0732">3</E>
                                     
                                    <E T="0731">5</E>
                                </ENT>
                                <ENT>
                                    8 hours.
                                    <E T="0731">22</E>
                                </ENT>
                            </ROW>
                            <ROW EXPSTB="03" RUL="s">
                                <PRTPAGE P="69"/>
                                <ENT I="21">
                                    <E T="02">Table IH—Protozoan Tests</E>
                                </ENT>
                            </ROW>
                            <ROW EXPSTB="00">
                                <ENT I="01">
                                    6. 
                                    <E T="03">Cryptosporidium</E>
                                </ENT>
                                <ENT>LDPE; field filtration</ENT>
                                <ENT>1-10 °C</ENT>
                                <ENT>
                                    96 hours.
                                    <E T="0731">21</E>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    7. 
                                    <E T="03">Giardia</E>
                                </ENT>
                                <ENT>LDPE; field filtration</ENT>
                                <ENT>1-10 °C</ENT>
                                <ENT>
                                    96 hours.
                                    <E T="0731">21</E>
                                </ENT>
                            </ROW>
                            <TNOTE>
                                <E T="0731">1</E>
                                 ”P” is for polyethylene; “FP” is fluoropolymer (polytetrafluoroethylene [PTFE]; Teflon®), or other fluoropolymer, unless stated otherwise in this Table II; “G” is glass; “PA” is any plastic that is made of a sterilizable material (polypropylene or other autoclavable plastic); “LDPE” is low density polyethylene.
                            </TNOTE>
                            <TNOTE>
                                <E T="0731">2</E>
                                 Except where noted in this Table II and the method for the parameter, preserve each grab sample within 15 minutes of collection. For a composite sample collected with an automated sample (e.g., using a 24-hour composite sample; see 40 CFR 122.21(g)(7)(i) or 40 CFR part 403, appendix E), refrigerate the sample at ≤6 °C during collection unless specified otherwise in this Table II or in the method(s). For a composite sample to be split into separate aliquots for preservation and/or analysis, maintain the sample at ≤6 °C, unless specified otherwise in this Table II or in the method(s), until collection, splitting, and preservation is completed. Add the preservative to the sample container prior to sample collection when the preservative will not compromise the integrity of a grab sample, a composite sample, or aliquot split from a composite sample within 15 minutes of collection. If a composite measurement is required but a composite sample would compromise sample integrity, individual grab samples must be collected at prescribed time intervals (e.g., 4 samples over the course of a day, at 6-hour intervals). Grab samples must be analyzed separately and the concentrations averaged. Alternatively, grab samples may be collected in the field and composited in the laboratory if the compositing procedure produces results equivalent to results produced by arithmetic averaging of results of analysis of individual grab samples. For examples of laboratory compositing procedures, see EPA Method 1664 Rev. A (oil and grease) and the procedures at 40 CFR 141.24(f)(14)(iv) and (v) (volatile organics).
                            </TNOTE>
                            <TNOTE>
                                <E T="0731">3</E>
                                 When any sample is to be shipped by common carrier or sent via the U.S. Postal Service, it must comply with the Department of Transportation Hazardous Materials Regulations (49 CFR part 172). The person offering such material for transportation is responsible for ensuring such compliance. For the preservation requirement of Table II, the Office of Hazardous Materials, Materials Transportation Bureau, Department of Transportation has determined that the Hazardous Materials Regulations do not apply to the following materials: Hydrochloric acid (HCl) in water solutions at concentrations of 0.04% by weight or less (pH about 1.96 or greater; Nitric acid (HNO
                                <E T="0732">3</E>
                                ) in water solutions at concentrations of 0.15% by weight or less (pH about 1.62 or greater); Sulfuric acid (H
                                <E T="0732">2</E>
                                SO
                                <E T="0732">4</E>
                                ) in water solutions at concentrations of 0.35% by weight or less (pH about 1.15 or greater); and Sodium hydroxide (NaOH) in water solutions at concentrations of 0.080% by weight or less (pH about 12.30 or less).
                            </TNOTE>
                            <TNOTE>
                                <E T="0731">4</E>
                                 Samples should be analyzed as soon as possible after collection. The times listed are the maximum times that samples may be held before the start of analysis and still be considered valid. Samples may be held for longer periods only if the permittee or monitoring laboratory have data on file to show that, for the specific types of samples under study, the analytes are stable for the longer time, and has received a variance from the Regional ATP Coordinator under § 136.3(e). For a grab sample, the holding time begins at the time of collection. For a composite sample collected with an automated sampler (e.g., using a 24-hour composite sampler; see 40 CFR 122.21(g)(7)(i) or 40 CFR part 403, appendix E), the holding time begins at the time of the end of collection of the composite sample. For a set of grab samples composited in the field or laboratory, the holding time begins at the time of collection of the last grab sample in the set. Some samples may not be stable for the maximum time period given in the table. A permittee or monitoring laboratory is obligated to hold the sample for a shorter time if it knows that a shorter time is necessary to maintain sample stability. See § 136.3(e) for details. The date and time of collection of an individual grab sample is the date and time at which the sample is collected. For a set of grab samples to be composited, and that are all collected on the same calendar date, the date of collection is the date on which the samples are collected. For a set of grab samples to be composited, and that are collected across two calendar dates, the date of collection is the dates of the two days; e.g., November 14-15. For a composite sample collected automatically on a given date, the date of collection is the date on which the sample is collected. For a composite sample collected automatically, and that is collected across two calendar dates, the date of collection is the dates of the two days; e.g., November 14-15. For static-renewal toxicity tests, each grab or composite sample may also be used to prepare test solutions for renewal at 24 h, 48 h, and/or 72 h after first use, if stored at 0-6 °C, with minimum head space.
                            </TNOTE>
                            <TNOTE>
                                <E T="0731">5</E>
                                 ASTM D7365-09a (15) specifies treatment options for samples containing oxidants (e.g., chlorine) for cyanide analyses. Also, Section 9060A of 
                                <E T="03">Standard Methods for the Examination of Water and Wastewater</E>
                                 (23rd edition) addresses dechlorination procedures for microbiological analyses.
                            </TNOTE>
                            <TNOTE>
                                <E T="0731">6</E>
                                 Sampling, preservation and mitigating interferences in water samples for analysis of cyanide are described in ASTM D7365-09a (15). There may be interferences that are not mitigated by the analytical test methods or D7365-09a (15). Any technique for removal or suppression of interference may be employed, provided the laboratory demonstrates that it more accurately measures cyanide through quality control measures described in the analytical test method. Any removal or suppression technique not described in D7365-09a (15) or the analytical test method must be documented along with supporting data.
                            </TNOTE>
                            <TNOTE>
                                <E T="0731">7</E>
                                 For dissolved metals, filter grab samples within 15 minutes of collection and before adding preservatives. For a composite sample collected with an automated sampler (e.g., using a 24-hour composite sampler; see 40 CFR 122.21(g)(7)(i) or 40 CFR part 403, appendix E), filter the sample within 15 minutes after completion of collection and before adding preservatives. If it is known or suspected that dissolved sample integrity will be compromised during collection of a composite sample collected automatically over time (e.g., by interchange of a metal between dissolved and suspended forms), collect and filter grab samples to be composited (footnote 2) in place of a composite sample collected automatically.
                            </TNOTE>
                            <TNOTE>
                                <E T="0731">8</E>
                                 Guidance applies to samples to be analyzed by GC, LC, or GC/MS for specific compounds.
                            </TNOTE>
                            <TNOTE>
                                <E T="0731">9</E>
                                 If the sample is not adjusted to pH 2, then the sample must be analyzed within seven days of sampling.
                            </TNOTE>
                            <TNOTE>
                                <E T="0731">10</E>
                                 The pH adjustment is not required if acrolein will not be measured. Samples for acrolein receiving no pH adjustment must be analyzed within 3 days of sampling.
                            </TNOTE>
                            <TNOTE>
                                <E T="0731">11</E>
                                 When the extractable analytes of concern fall within a single chemical category, the specified preservative and maximum holding times should be observed for optimum safeguard of sample integrity (
                                <E T="03">i.e.,</E>
                                 use all necessary preservatives and hold for the shortest time listed). When the analytes of concern fall within two or more chemical categories, the sample may be preserved by cooling to ≤6 °C, reducing residual chlorine with 0.008% sodium thiosulfate, storing in the dark, and adjusting the pH to 6-9; samples preserved in this manner may be held for seven days before extraction and for forty days after extraction. Exceptions to this optional preservation and holding time procedure are noted in footnote 5 (regarding the requirement for thiosulfate reduction), and footnotes 12, 13 (regarding the analysis of benzidine).
                            </TNOTE>
                            <TNOTE>
                                <E T="0731">12</E>
                                 If 1,2-diphenylhydrazine is likely to be present, adjust the pH of the sample to 4.0 ± 0.2 to prevent rearrangement to benzidine.
                            </TNOTE>
                            <TNOTE>
                                <E T="0731">13</E>
                                 Extracts may be stored up to 30 days at &lt;0 °C.
                            </TNOTE>
                            <TNOTE>
                                <E T="0731">14</E>
                                 For the analysis of diphenylnitrosamine, add 0.008% Na
                                <E T="0732">2</E>
                                S
                                <E T="0732">2</E>
                                O
                                <E T="0732">3</E>
                                 and adjust pH to 7-10 with NaOH within 24 hours of sampling.
                            </TNOTE>
                            <TNOTE>
                                <E T="0731">15</E>
                                 The pH adjustment may be performed upon receipt at the laboratory and may be omitted if the samples are extracted within 72 hours of collection. For the analysis of aldrin, add 0.008% Na
                                <E T="0732">2</E>
                                S
                                <E T="0732">2</E>
                                O
                                <E T="0732">3</E>
                                .
                                <PRTPAGE P="70"/>
                            </TNOTE>
                            <TNOTE>
                                <E T="0731">16</E>
                                 Place sufficient ice with the samples in the shipping container to ensure that ice is still present when the samples arrive at the laboratory. However, even if ice is present when the samples arrive, immediately measure the temperature of the samples and confirm that the preservation temperature maximum has not been exceeded. In the isolated cases where it can be documented that this holding temperature cannot be met, the permittee can be given the option of on-site testing or can request a variance. The request for a variance should include supportive data which show that the toxicity of the effluent samples is not reduced because of the increased holding temperature. Aqueous samples must not be frozen. Hand-delivered samples used on the day of collection do not need to be cooled to 0 to 6 °C prior to test initiation.
                            </TNOTE>
                            <TNOTE>
                                <E T="0731">17</E>
                                 Samples collected for the determination of trace level mercury (&lt;100 ng/L) using EPA Method 1631 must be collected in tightly-capped fluoropolymer or glass bottles and preserved with BrCl or HCl solution within 48 hours of sample collection. The time to preservation may be extended to 28 days if a sample is oxidized in the sample bottle. A sample collected for dissolved trace level mercury should be filtered in the laboratory within 24 hours of the time of collection. However, if circumstances preclude overnight shipment, the sample should be filtered in a designated clean area in the field in accordance with procedures given in Method 1669. If sample integrity will not be maintained by shipment to and filtration in the laboratory, the sample must be filtered in a designated clean area in the field within the time period necessary to maintain sample integrity. A sample that has been collected for determination of total or dissolved trace level mercury must be analyzed within 90 days of sample collection.
                            </TNOTE>
                            <TNOTE>
                                <E T="0731">18</E>
                                 Aqueous samples must be preserved at ≤6 °C, and should not be frozen unless data demonstrating that sample freezing does not adversely impact sample integrity is maintained on file and accepted as valid by the regulatory authority. Also, for purposes of NPDES monitoring, the specification of “≤ °C” is used in place of the “4 °C” and “&lt;4 °C” sample temperature requirements listed in some methods. It is not necessary to measure the sample temperature to three significant figures (1/100th of 1 degree); rather, three significant figures are specified so that rounding down to 6 °C may not be used to meet the ≤6 °C requirement. The preservation temperature does not apply to samples that are analyzed immediately (less than 15 minutes).
                            </TNOTE>
                            <TNOTE>
                                <E T="0731">19</E>
                                 An aqueous sample may be collected and shipped without acid preservation. However, acid must be added at least 24 hours before analysis to dissolve any metals that adsorb to the container walls. If the sample must be analyzed within 24 hours of collection, add the acid immediately (see footnote 2). Soil and sediment samples do not need to be preserved with acid. The allowances in this footnote supersede the preservation and holding time requirements in the approved metals methods.
                            </TNOTE>
                            <TNOTE>
                                <E T="0731">20</E>
                                 To achieve the 28-day holding time, use the ammonium sulfate buffer solution specified in EPA Method 218.6. The allowance in this footnote supersedes preservation and holding time requirements in the approved hexavalent chromium methods, unless this supersession would compromise the measurement, in which case requirements in the method must be followed.
                            </TNOTE>
                            <TNOTE>
                                <E T="0731">21</E>
                                 Holding time is calculated from time of sample collection to elution for samples shipped to the laboratory in bulk and calculated from the time of sample filtration to elution for samples filtered in the field.
                            </TNOTE>
                            <TNOTE>
                                <E T="0731">22</E>
                                 Sample analysis should begin as soon as possible after receipt; sample incubation must be started no later than 8 hours from time of collection.
                            </TNOTE>
                            <TNOTE>
                                <E T="0731">23</E>
                                 For fecal coliform samples for sewage sludge (biosolids) only, the holding time is extended to 24 hours for the following sample types using either EPA Method 1680 (LTB-EC) or 1681 (A-1): Class A composted, Class B aerobically digested, and Class B anaerobically digested.
                            </TNOTE>
                            <TNOTE>
                                <E T="0731">24</E>
                                 The immediate filtration requirement in orthophosphate measurement is to assess the dissolved or bio-available form of orthophosphorus (
                                <E T="03">i.e.,</E>
                                 that which passes through a 0.45-micron filter), hence the requirement to filter the sample immediately upon collection (
                                <E T="03">i.e.,</E>
                                 within 15 minutes of collection).
                            </TNOTE>
                        </GPOTABLE>
                        <CITA>[38 FR 28758, Oct. 16, 1973]</CITA>
                        <EDNOTE>
                            <HD SOURCE="HED">Editorial Note:</HD>
                            <P>
                                For 
                                <E T="04">Federal Register</E>
                                 citations affecting § 136.3, see the List of CFR Sections Affected, which appears in the Finding Aids section of the printed volume and at 
                                <E T="03">www.govinfo.gov.</E>
                            </P>
                        </EDNOTE>
                    </SECTION>
                    <SECTION>
                        <SECTNO>§ 136.4</SECTNO>
                        <SUBJECT>Application for and approval of alternate test procedures for nationwide use.</SUBJECT>
                        <P>(a) A written application for review of an alternate test procedure (alternate method) for nationwide use may be made by letter via email or by hard copy in triplicate to the National Alternate Test Procedure (ATP) Program Coordinator (National Coordinator), Office of Science and Technology (4303T), Office of Water, U.S. Environmental Protection Agency, 1200 Pennsylvania Ave. NW., Washington, DC 20460. Any application for an ATP under this paragraph (a) shall:</P>
                        <P>(1) Provide the name and address of the responsible person or firm making the application.</P>
                        <P>(2) Identify the pollutant(s) or parameter(s) for which nationwide approval of an alternate test procedure is being requested.</P>
                        <P>(3) Provide a detailed description of the proposed alternate test procedure, together with references to published or other studies confirming the general applicability of the alternate test procedure for the analysis of the pollutant(s) or parameter(s) in wastewater discharges from representative and specified industrial or other categories.</P>
                        <P>(4) Provide comparability data for the performance of the proposed alternative test procedure compared to the performance of the reference method.</P>
                        <P>(b) The National Coordinator may request additional information and analyses from the applicant in order to evaluate whether the alternate test procedure satisfies the applicable requirements of this part.</P>
                        <P>
                            (c) 
                            <E T="03">Approval for nationwide use.</E>
                             (1) After a review of the application and any additional analyses requested from the applicant, the National Coordinator will notify the applicant, in writing, of whether the National Coordinator will recommend approval or disapproval of the alternate test procedure for nationwide use in CWA programs. If the application is not recommended for approval, the National Coordinator may specify what additional information might lead to a reconsideration of the application and notify the Regional Alternate Test 
                            <PRTPAGE P="71"/>
                            Procedure Coordinators of the disapproval recommendation. Based on the National Coordinator's recommended disapproval of a proposed alternate test procedure and an assessment of any current approvals for limited uses for the unapproved method, the Regional ATP Coordinator may decide to withdraw approval of the method for limited use in the Region.
                        </P>
                        <P>
                            (2) Where the National Coordinator has recommended approval of an applicant's request for nationwide use of an alternate test procedure, the National Coordinator will notify the applicant. The National Coordinator will also notify the Regional ATP Coordinators that they may consider approval of this alternate test procedure for limited use in their Regions based on the information and data provided in the application until the alternate test procedure is approved by publication in a final rule in the 
                            <E T="04">Federal Register</E>
                            .
                        </P>
                        <P>(3) EPA will propose to amend this part to include the alternate test procedure in § 136.3. EPA shall make available for review all the factual bases for its proposal, including the method, any performance data submitted by the applicant and any available EPA analysis of those data.</P>
                        <P>
                            (4) Following public comment, EPA shall publish in the 
                            <E T="04">Federal Register</E>
                             a final decision on whether to amend this part to include the alternate test procedure as an approved analytical method for nationwide use.
                        </P>
                        <P>(5) Whenever the National Coordinator has recommended approval of an applicant's ATP request for nationwide use, any person may request an approval of the method for limited use under § 136.5 from the EPA Region.</P>
                        <CITA>[77 FR 29809, May 18, 2012, as amended at 82 FR 40874, Aug. 28, 2017]</CITA>
                    </SECTION>
                    <SECTION>
                        <SECTNO>§ 136.5</SECTNO>
                        <SUBJECT>Approval of alternate test procedures for limited use.</SUBJECT>
                        <P>(a) Any person may request the Regional ATP Coordinator to approve the use of an alternate test procedure in the Region.</P>
                        <P>
                            (b) When the request for the use of an alternate test procedure concerns use in a State with an NPDES permit program approved pursuant to section 402 of the Act, the requestor shall first submit an application for limited use to the Director of the State agency having responsibility for issuance of NPDES permits within such State (
                            <E T="03">i.e.,</E>
                             permitting authority). The Director will forward the application to the Regional ATP Coordinator with a recommendation for or against approval.
                        </P>
                        <P>(c) Any application for approval of an alternate test procedure for limited use may be made by letter, email or by hard copy. The application shall include the following:</P>
                        <P>(1) Provide the name and address of the applicant and the applicable ID number of the existing or pending permit(s) and issuing agency for which use of the alternate test procedure is requested, and the discharge serial number.</P>
                        <P>(2) Identify the pollutant or parameter for which approval of an alternate test procedure is being requested.</P>
                        <P>(3) Provide justification for using testing procedures other than those specified in Tables IA through IH of § 136.3, or in the NPDES permit.</P>
                        <P>(4) Provide a detailed description of the proposed alternate test procedure, together with references to published studies of the applicability of the alternate test procedure to the effluents in question.</P>
                        <P>(5) Provide comparability data for the performance of the proposed alternate test procedure compared to the performance of the reference method.</P>
                        <P>
                            (d) 
                            <E T="03">Approval for limited use.</E>
                             (1) The Regional ATP Coordinator will review the application and notify the applicant and the appropriate State agency of approval or rejection of the use of the alternate test procedure. The approval may be restricted to use only with respect to a specific discharge or facility (and its laboratory) or, at the discretion of the Regional ATP Coordinator, to all dischargers or facilities (and their associated laboratories) specified in the approval for the Region. If the application is not approved, the Regional ATP Coordinator shall specify what additional information might lead to a reconsideration of the application.
                        </P>
                        <P>
                            (2) The Regional ATP Coordinator will forward a copy of every approval 
                            <PRTPAGE P="72"/>
                            and rejection notification to the National Alternate Test Procedure Coordinator.
                        </P>
                        <CITA>[77 FR 29809, May 18, 2012, as amended at 82 FR 40875, Aug. 28, 2017]</CITA>
                    </SECTION>
                    <SECTION>
                        <SECTNO>§ 136.6</SECTNO>
                        <SUBJECT>Method modifications and analytical requirements.</SUBJECT>
                        <P>
                            (a) 
                            <E T="03">Definitions of terms used in this section</E>
                            —(1) 
                            <E T="03">Analyst</E>
                             means the person or laboratory using a test procedure (analytical method) in this part.
                        </P>
                        <P>
                            (2) 
                            <E T="03">Chemistry of the method</E>
                             means the reagents and reactions used in a test procedure that allow determination of the analyte(s) of interest in an environmental sample.
                        </P>
                        <P>
                            (3) 
                            <E T="03">Determinative technique</E>
                             means the way in which an analyte is identified and quantified (e.g., colorimetry, mass spectrometry).
                        </P>
                        <P>
                            (4) 
                            <E T="03">Equivalent performance</E>
                             means that the modified method produces results that meet or exceed the QC acceptance criteria of the approved method.
                        </P>
                        <P>
                            (5) 
                            <E T="03">Method-defined analyte</E>
                             means an analyte defined solely by the method used to determine the analyte. Such an analyte may be a physical parameter, a parameter that is not a specific chemical, or a parameter that may be comprised of a number of substances. Examples of such analytes include temperature, oil and grease, total suspended solids, total phenolics, turbidity, chemical oxygen demand, and biochemical oxygen demand.
                        </P>
                        <P>
                            (6) 
                            <E T="03">QC</E>
                             means “quality control.”
                        </P>
                        <P>
                            (b) 
                            <E T="03">Method modifications.</E>
                             (1) If the underlying chemistry and determinative technique in a modified method are essentially the same as an approved Part 136 method, then the modified method is an equivalent and acceptable alternative to the approved method provided the requirements of this section are met. However, those who develop or use a modification to an approved (Part 136) method must document that the performance of the modified method, in the matrix to which the modified method will be applied, is equivalent to the performance of the approved method. If such a demonstration cannot be made and documented, then the modified method is not an acceptable alternative to the approved method. Supporting documentation must, if applicable, include the routine initial demonstration of capability and ongoing QC including determination of precision and accuracy, detection limits, and matrix spike recoveries. Initial demonstration of capability typically includes analysis of four replicates of a mid-level standard and a method detection limit study. Ongoing quality control typically includes method blanks, mid-level laboratory control samples, and matrix spikes (QC is as specified in the method). The method is considered equivalent if the quality control requirements in the reference method are achieved. Where the laboratory is using a vendor-supplied method, it is the QC criteria in the reference method, not the vendor's method, that must be met to show equivalency. Where a sample preparation step is required (
                            <E T="03">i.e.,</E>
                             digestion, distillation), QC tests are to be run using standards treated in the same way as the samples. The method user's Standard Operating Procedure (SOP) must clearly document the modifications made to the reference method. Examples of allowed method modifications are listed in this section. If the method user is uncertain whether a method modification is allowed, the Regional ATP Coordinator or Director should be contacted for approval 
                            <E T="03">prior</E>
                             to implementing the modification. The method user should also complete necessary performance checks to verify that acceptable performance is achieved with the method modification 
                            <E T="03">prior</E>
                             to analyses of compliance samples.
                        </P>
                        <P>
                            (2) 
                            <E T="03">Requirements.</E>
                             The modified method must meet or exceed performance of the approved method(s) for the analyte(s) of interest, as documented by meeting the initial and ongoing quality control requirements in the method.
                        </P>
                        <P>
                            (i) 
                            <E T="03">Requirements for establishing equivalent performance.</E>
                             If the approved method contains QC tests and QC acceptance criteria, the modified method must use these QC tests and the modified method must meet the QC acceptance criteria with the following conditions:
                        </P>
                        <P>
                            (A) The analyst may only rely on QC tests and QC acceptance criteria in a 
                            <PRTPAGE P="73"/>
                            method if it includes wastewater matrix QC tests and QC acceptance criteria (e.g., matrix spikes) and both initial (start-up) and ongoing QC tests and QC acceptance criteria.
                        </P>
                        <P>(B) If the approved method does not contain QC tests and QC acceptance criteria or if the QC tests and QC acceptance criteria in the method do not meet the requirements of this section, then the analyst must employ QC tests published in the “equivalent” of a Part 136 method that has such QC, or the essential QC requirements specified at 136.7, as applicable. If the approved method is from a compendium or VCSB and the QA/QC requirements are published in other parts of that organization's compendium rather than within the Part 136 method then that part of the organization's compendium must be used for the QC tests.</P>
                        <P>(C) In addition, the analyst must perform ongoing QC tests, including assessment of performance of the modified method on the sample matrix (e.g., analysis of a matrix spike/matrix spike duplicate pair for every twenty samples), and analysis of an ongoing precision and recovery sample (e.g., laboratory fortified blank or blank spike) and a blank with each batch of 20 or fewer samples.</P>
                        <P>(D) If the performance of the modified method in the wastewater matrix or reagent water does not meet or exceed the QC acceptance criteria, the method modification may not be used.</P>
                        <P>
                            (ii) 
                            <E T="03">Requirements for documentation.</E>
                             The modified method must be documented in a method write-up or an addendum that describes the modification(s) to the approved method prior to the use of the method for compliance purposes. The write-up or addendum must include a reference number (e.g., method number), revision number, and revision date so that it may be referenced accurately. In addition, the organization that uses the modified method must document the results of QC tests and keep these records, along with a copy of the method write-up or addendum, for review by an auditor.
                        </P>
                        <P>
                            (3) 
                            <E T="03">Restrictions.</E>
                             An analyst may not modify an approved Clean Water Act analytical method for a method-defined analyte. In addition, an analyst may not modify an approved method if the modification would result in measurement of a different form or species of an analyte. Changes in method procedures are not allowed if such changes would alter the defined chemistry (
                            <E T="03">i.e.,</E>
                             method principle) of the unmodified method. For example, phenol method 420.1 or 420.4 defines phenolics as ferric iron oxidized compounds that react with 4-aminoantipyrine (4-AAP) at pH 10 after being distilled from acid solution. Because total phenolics represents a group of compounds that all react at different efficiencies with 4-AAP, changing test conditions likely would change the behavior of these different phenolic compounds. An analyst may not modify any sample collection, preservation, or holding time requirements of an approved method. Such modifications to sample collection, preservation, and holding time requirements do not fall within the scope of the flexibility allowed at § 136.6. Method flexibility refers to modifications of the analytical procedures used for identification and measurement of the analyte only and does not apply to sample collection, preservation, or holding time procedures, which may only be modified as specified in § 136.3(e).
                        </P>
                        <P>
                            (4) 
                            <E T="03">Allowable changes.</E>
                             Except as noted under paragraph (b)(3) of this section, an analyst may modify an approved test procedure (analytical method) provided that the underlying reactions and principles used in the approved method remain essentially the same, and provided that the requirements of this section are met. If equal or better performance can be obtained with an alternative reagent, then it is allowed. A laboratory wishing to use these modifications must demonstrate acceptable method performance by performing and documenting all applicable initial demonstration of capability and ongoing QC tests and meeting all applicable QC acceptance criteria as described in § 136.7. Some examples of the allowed types of changes, provided the requirements of this section are met include:
                        </P>
                        <P>(i) Changes between manual method, flow analyzer, and discrete instrumentation.</P>
                        <P>
                            (ii) Changes in chromatographic columns or temperature programs.
                            <PRTPAGE P="74"/>
                        </P>
                        <P>(iii) Changes between automated and manual sample preparation, such as digestions, distillations, and extractions; in-line sample preparation is an acceptable form of automated sample preparation for CWA methods.</P>
                        <P>(iv) In general, ICP-MS is a sensitive and selective detector for metal analysis; however isobaric interference can cause problems for quantitative determination, as well as identification based on the isotope pattern. Interference reduction technologies, such as collision cells or reaction cells, are designed to reduce the effect of spectroscopic interferences that may bias results for the element of interest. The use of interference reduction technologies is allowed, provided the method performance specifications relevant to ICP-MS measurements are met.</P>
                        <P>(v) The use of EPA Method 200.2 or the sample preparation steps from EPA Method 1638, including the use of closed-vessel digestion, is allowed for EPA Method 200.8, provided the method performance specifications relevant to the ICP-MS are met.</P>
                        <P>(vi) Changes in pH adjustment reagents. Changes in compounds used to adjust pH are acceptable as long as they do not produce interference. For example, using a different acid to adjust pH in colorimetric methods.</P>
                        <P>(vii) Changes in buffer reagents are acceptable provided that the changes do not produce interferences.</P>
                        <P>(viii) Changes in the order of reagent addition are acceptable provided that the change does not alter the chemistry and does not produce an interference. For example, using the same reagents, but adding them in different order, or preparing them in combined or separate solutions (so they can be added separately), is allowed, provided reagent stability or method performance is equivalent or improved.</P>
                        <P>(ix) Changes in calibration range (provided that the modified range covers any relevant regulatory limit and the method performance specifications for calibration are met).</P>
                        <P>(x) Changes in calibration model. (A) Linear calibration models do not adequately fit calibration data with one or two inflection points. For example, vendor-supplied data acquisition and processing software on some instruments may provide quadratic fitting functions to handle such situations. If the calibration data for a particular analytical method routinely display quadratic character, using quadratic fitting functions may be acceptable. In such cases, the minimum number of calibrators for second order fits should be six, and in no case should concentrations be extrapolated for instrument responses that exceed that of the most concentrated calibrator. Examples of methods with nonlinear calibration functions include chloride by SM4500-Cl-E-1997, hardness by EPA Method 130.1, cyanide by ASTM D6888 or OIA1677, Kjeldahl nitrogen by PAI-DK03, and anions by EPA Method 300.0.</P>
                        <P>(B) As an alternative to using the average response factor, the quality of the calibration may be evaluated using the Relative Standard Error (RSE). The acceptance criterion for the RSE is the same as the acceptance criterion for Relative Standard Deviation (RSD), in the method. RSE is calculated as:</P>
                        <GPH SPAN="2" DEEP="69">
                            <GID>ER18MY12.000</GID>
                        </GPH>
                        <EXTRACT>
                            <FP>Where:</FP>
                            <FP SOURCE="FP-2">
                                x′
                                <E T="52">i</E>
                                 = Calculated concentration at level i
                            </FP>
                            <FP SOURCE="FP-2">
                                x
                                <E T="52">i</E>
                                 = Actual concentration of the calibration level i
                            </FP>
                            <FP SOURCE="FP-2">n = Number of calibration points</FP>
                            <FP SOURCE="FP-2">p = Number of terms in the fitting equation (average = 1, linear = 2, quadratic = 3)</FP>
                        </EXTRACT>
                        <PRTPAGE P="75"/>
                        <P>(C) Using the RSE as a metric has the added advantage of allowing the same numerical standard to be applied to the calibration model, regardless of the form of the model. Thus, if a method states that the RSD should be ≤20% for the traditional linear model through the origin, then the RSE acceptance limit can remain ≤20% as well. Similarly, if a method provides an RSD acceptance limit of ≤15%, then that same figure can be used as the acceptance limit for the RSE. The RSE may be used as an alternative to correlation coefficients and coefficients of determination for evaluating calibration curves for any of the methods at part 136. If the method includes a numerical criterion for the RSD, then the same numerical value is used for the RSE. Some older methods do not include any criterion for the calibration curve—for these methods, if RSE is used the value should be ≤20%. Note that the use of the RSE is included as an alternative to the use of the correlation coefficient as a measure of the suitability of a calibration curve. It is not necessary to evaluate both the RSE and the correlation coefficient.</P>
                        <P>(xi) Changes in equipment such as equipment from a vendor different from the one specified in the method.</P>
                        <P>(xii) The use of micro or midi distillation apparatus in place of macro distillation apparatus.</P>
                        <P>(xiii) The use of prepackaged reagents.</P>
                        <P>(xiv) The use of digital titrators and methods where the underlying chemistry used for the determination is similar to that used in the approved method.</P>
                        <P>(xv) Use of selected ion monitoring (SIM) mode for analytes that cannot be effectively analyzed in full-scan mode and reach the required sensitivity. False positives are more of a concern when using SIM analysis, so at a minimum, one quantitation and two qualifying ions must be monitored for each analyte (unless fewer than three ions with intensity greater than 15% of the base peak are available). The ratio of each of the two qualifying ions to the quantitation ion must be evaluated and should agree with the ratio observed in an authentic standard within ±20 percent. Analyst judgment must be applied to the evaluation of ion ratios because the ratios can be affected by co-eluting compounds present in the sample matrix. The signal-to-noise ratio of the least sensitive ion should be at least 3:1. Retention time in the sample should match within 0.05 minute of an authentic standard analyzed under identical conditions. Matrix interferences can cause minor shifts in retention time and may be evident as shifts in the retention times of the internal standards. The total scan time should be such that a minimum of eight scans are obtained per chromatographic peak.</P>
                        <P>(xvi) Changes are allowed in purge-and-trap sample volumes or operating conditions. Some examples are:</P>
                        <P>(A) Changes in purge time and purge-gas flow rate. A change in purge time and purge-gas flow rate is allowed provided that sufficient total purge volume is used to achieve the required minimum detectible concentration and calibration range for all compounds. In general, a purge rate in the range 20-200 mL/min and a total purge volume in the range 240-880 mL are recommended.</P>
                        <P>(B) Use of nitrogen or helium as a purge gas, provided that the required sensitivities for all compounds are met.</P>
                        <P>(C) Sample temperature during the purge state. Gentle heating of the sample during purging (e.g., 40 °C) increases purging efficiency of hydrophilic compounds and may improve sample-to-sample repeatability because all samples are purged under precisely the same conditions.</P>
                        <P>(D) Trap sorbent. Any trap design is acceptable, provided that the data acquired meet all QC criteria.</P>
                        <P>
                            (E) Changes to the desorb time. Shortening the desorb time (e.g., from4 minutes to 1 minute) may not affect compound recoveries, and can shorten overall cycle time and significantly reduce the amount of water introduced to the analytical system, thus improving the precision of analysis, especially for water-soluble analytes. A desorb time of four minutes is recommended, however a shorter desorb time may be used, provided that all QC specifications in the method are met.
                            <PRTPAGE P="76"/>
                        </P>
                        <P>(F) Use of water management techniques is allowed. Water is always collected on the trap along with the analytes and is a significant interference for analytical systems (GC and GC/MS). Modern water management techniques (e.g., dry purge or condensation points) can remove moisture from the sample stream and improve analytical performance.</P>
                        <P>(xvii) If the characteristics of a wastewater matrix prevent efficient recovery of organic pollutants and prevent the method from meeting QC requirements, the analyst may attempt to resolve the issue by adding salts to the sample, provided that such salts do not react with or introduce the target pollutant into the sample (as evidenced by the analysis of method blanks, laboratory control samples, and spiked samples that also contain such salts), and that all requirements of paragraph (b)(2) of this section are met. Samples having residual chlorine or other halogen must be dechlorinated prior to the addition of such salts.</P>
                        <P>(xviii) If the characteristics of a wastewater matrix result in poor sample dispersion or reagent deposition on equipment and prevent the analyst from meeting QC requirements, the analyst may attempt to resolve the issue by adding a inert surfactant that does not affect the chemistry of the method, such as Brij-35 or sodium dodecyl sulfate (SDS), provided that such surfactant does not react with or introduce the target pollutant into the sample (as evidenced by the analysis of method blanks, laboratory control samples, and spiked samples that also contain such surfactant) and that all requirements of paragraph (b)(1) and (b)(2) of this section are met. Samples having residual chlorine or other halogen must be dechlorinated prior to the addition of such surfactant.</P>
                        <P>(xix) The use of gas diffusion (using pH change to convert the analyte to gaseous form and/or heat to separate an analyte contained in steam from the sample matrix) across a hydrophobic semi-permeable membrane to separate the analyte of interest from the sample matrix may be used in place of manual or automated distillation in methods for analysis such as ammonia, total cyanide, total Kjeldahl nitrogen, and total phenols. These procedures do not replace the digestion procedures specified in the approved methods and must be used in conjunction with those procedures.</P>
                        <P>(xx) Changes in equipment operating parameters such as the monitoring wavelength of a colorimeter or the reaction time and temperature as needed to achieve the chemical reactions defined in the unmodified CWA method. For example, molybdenum blue phosphate methods have two absorbance maxima, one at about 660 nm and another at about 880 nm. The former is about 2.5 times less sensitive than the latter. Wavelength choice provides a cost-effective, dilution-free means to increase sensitivity of molybdenum blue phosphate methods.</P>
                        <P>(xxi) Interchange of oxidants, such as the use of titanium oxide in UV-assisted automated digestion of TOC and total phosphorus, as long as complete oxidation can be demonstrated.</P>
                        <P>(xxii) Use of an axially viewed torch with Method 200.7.</P>
                        <P>
                            (xxiii) When analyzing metals by inductively coupled plasma-atomic emission spectroscopy, inductively coupled plasma-mass spectrometry, and stabilized temperature graphite furnace atomic absorption, closed-vessel microwave digestion of wastewater samples is allowed as alternative heating source for Method 200.2—“Sample Preparation Procedure for Spectrochemical Determination of Total Recoverable Elements” for the following elements: Aluminum, antimony, arsenic, barium, beryllium, boron, cadmium, calcium, chromium, cobalt, copper, iron, lead, magnesium, manganese, molybdenum, nickel, potassium, selenium, silver, sodium, thallium, tin, titanium, vanadium, zinc, provided the performance specifications in the relevant determinative method are met. (Note that this list does not include Mercury.) Each laboratory determining total recoverable metals is required to operate a formal quality control (QC) program. The minimum requirements include initial demonstration of capability, method detection limit (MDL), analysis of reagent blanks, fortified blanks, matrix spike samples, and blind proficiency testing samples, as continuing quality control checks on performance. 
                            <PRTPAGE P="77"/>
                            The laboratory is required to maintain performance records on file that define the quality of the data generated.
                        </P>
                        <P>(c) The permittee must notify their permitting authority of the intent to use a modified method. Such notification should be of the form “Method xxx has been modified within the flexibility allowed in 40 CFR 136.6.” The permittee may indicate the specific paragraph of § 136.6 allowing the method modification. Specific details of the modification need not be provided, but must be documented in the Standard Operating Procedure (SOP) and maintained by the analytical laboratory that performs the analysis.</P>
                        <CITA>[77 FR 29810, May 18, 2012, as amended at 82 FR 40875, Aug. 28, 2017; 86 FR 27260, May 19, 2021]</CITA>
                    </SECTION>
                    <SECTION>
                        <SECTNO>§ 136.7</SECTNO>
                        <SUBJECT>Quality assurance and quality control.</SUBJECT>
                        <P>The permittee/laboratory shall use suitable QA/QC procedures when conducting compliance analyses with any part 136 chemical method or an alternative method specified by the permitting authority. These QA/QC procedures are generally included in the analytical method or may be part of the methods compendium for approved Part 136 methods from a consensus organization. For example, Standard Methods contains QA/QC procedures in the Part 1000 section of the Standard Methods Compendium. The permittee/laboratory shall follow these QA/QC procedures, as described in the method or methods compendium. If the method lacks QA/QC procedures, the permittee/laboratory has the following options to comply with the QA/QC requirements:</P>
                        <P>(a) Refer to and follow the QA/QC published in the “equivalent” EPA method for that parameter that has such QA/QC procedures;</P>
                        <P>(b) Refer to the appropriate QA/QC section(s) of an approved part 136 method from a consensus organization compendium;</P>
                        <P>(c)(1) Incorporate the following twelve quality control elements, where applicable, into the laboratory's documented standard operating procedure (SOP) for performing compliance analyses when using an approved part 136 method when the method lacks such QA/QC procedures. One or more of the twelve QC elements may not apply to a given method and may be omitted if a written rationale is provided indicating why the element(s) is/are inappropriate for a specific method.</P>
                        <P>(i) Demonstration of Capability (DOC);</P>
                        <P>(ii) Method Detection Limit (MDL);</P>
                        <P>(iii) Laboratory reagent blank (LRB), also referred to as method blank (MB);</P>
                        <P>(iv) Laboratory fortified blank (LFB), also referred to as a spiked blank, or laboratory control sample (LCS);</P>
                        <P>(v) Matrix spike (MS) and matrix spike duplicate (MSD), or laboratory fortified matrix (LFM) and LFM duplicate, may be used for suspected matrix interference problems to assess precision;</P>
                        <P>(vi) Internal standards (for GC/MS analyses), surrogate standards (for organic analysis) or tracers (for radiochemistry);</P>
                        <P>(vii) Calibration (initial and continuing), also referred to as initial calibration verification (ICV) and continuing calibration verification (CCV);</P>
                        <P>(viii) Control charts (or other trend analyses of quality control results);</P>
                        <P>(ix) Corrective action (root cause analysis);</P>
                        <P>(x) QC acceptance criteria;</P>
                        <P>(xi) Definitions of preparation and analytical batches that may drive QC frequencies; and</P>
                        <P>(xii) Minimum frequency for conducting all QC elements.</P>
                        <P>(2) These twelve quality control elements must be clearly documented in the written standard operating procedure for each analytical method not containing QA/QC procedures, where applicable.</P>
                        <CITA>[77 FR 29813, May 18, 2012]</CITA>
                    </SECTION>
                    <APPENDIX>
                        <EAR>Pt. 136, App. A, Meth. 601</EAR>
                        <HD SOURCE="HED">Appendix A to Part 136—Methods for Organic Chemical Analysis of Municipal and Industrial Wastewater</HD>
                        <HD SOURCE="HD1">Method 601—Purgeable Halocarbons</HD>
                        <HD SOURCE="HD2">1. Scope and Application</HD>
                        <P>1.1 This method covers the determination of 29 purgeable halocarbons.</P>
                        <P>
                            The following parameters may be determined by this method:
                            <PRTPAGE P="78"/>
                        </P>
                        <GPOTABLE COLS="3" OPTS="L2" CDEF="s10,6,12">
                            <BOXHD>
                                <CHED H="1">Parameter</CHED>
                                <CHED H="1">STORET No.</CHED>
                                <CHED H="1">CAS No.</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">Bromodichloromethane</ENT>
                                <ENT>32101</ENT>
                                <ENT>75-27-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Bromoform</ENT>
                                <ENT>32104</ENT>
                                <ENT>75-25-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Bromomethane</ENT>
                                <ENT>34413</ENT>
                                <ENT>74-83-9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Carbon tetrachloride</ENT>
                                <ENT>32102</ENT>
                                <ENT>56-23-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chlorobenzene</ENT>
                                <ENT>34301</ENT>
                                <ENT>108-90-7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chloroethane</ENT>
                                <ENT>34311</ENT>
                                <ENT>75-00-3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-Chloroethylvinyl ether</ENT>
                                <ENT>34576</ENT>
                                <ENT>100-75-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chloroform</ENT>
                                <ENT>32106</ENT>
                                <ENT>67-66-3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chloromethane</ENT>
                                <ENT>34418</ENT>
                                <ENT>74-87-3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dibromochloromethane</ENT>
                                <ENT>32105</ENT>
                                <ENT>124-48-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2-Dichlorobenzene</ENT>
                                <ENT>34536</ENT>
                                <ENT>95-50-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,3-Dichlorobenzene</ENT>
                                <ENT>34566</ENT>
                                <ENT>541-73-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,4-Dichlorobenzene</ENT>
                                <ENT>34571</ENT>
                                <ENT>106-46-7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dichlorodifluoromethane</ENT>
                                <ENT>34668</ENT>
                                <ENT>75-71-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1-Dichloroethane</ENT>
                                <ENT>34496</ENT>
                                <ENT>75-34-3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2-Dichloroethane</ENT>
                                <ENT>34531</ENT>
                                <ENT>107-06-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1-Dichloroethane</ENT>
                                <ENT>34501</ENT>
                                <ENT>75-35-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">trans-1,2-Dichloroethene</ENT>
                                <ENT>34546</ENT>
                                <ENT>156-60-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2-Dichloropropane</ENT>
                                <ENT>34541</ENT>
                                <ENT>78-87-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">cis-1,3-Dichloropropene</ENT>
                                <ENT>34704</ENT>
                                <ENT>10061-01-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">trans-1,3-Dichloropropene</ENT>
                                <ENT>34699</ENT>
                                <ENT>10061-02-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Methylene chloride</ENT>
                                <ENT>34423</ENT>
                                <ENT>75-09-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1,2,2-Tetrachloroethane</ENT>
                                <ENT>34516</ENT>
                                <ENT>79-34-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Tetrachloroethene</ENT>
                                <ENT>34475</ENT>
                                <ENT>127-18-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1,1-Trichloroethane</ENT>
                                <ENT>34506</ENT>
                                <ENT>71-55-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1,2-Trichloroethane</ENT>
                                <ENT>34511</ENT>
                                <ENT>79-00-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Tetrachloroethene</ENT>
                                <ENT>39180</ENT>
                                <ENT>79-01-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Trichlorofluoromethane</ENT>
                                <ENT>34488</ENT>
                                <ENT>75-69-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Vinyl chloride</ENT>
                                <ENT>39715</ENT>
                                <ENT>75-01-4</ENT>
                            </ROW>
                        </GPOTABLE>
                        <P>1.2 This is a purge and trap gas chromatographic (GC) method applicable to the determination of the compounds listed above in municipal and industrial discharges as provided under 40 CFR 136.1. When this method is used to analyze unfamiliar samples for any or all of the compounds above, compound identifications should be supported by at least one additional qualitative technique. This method describes analytical conditions for a second gas chromatographic column that can be used to confirm measurements made with the primary column. Method 624 provides gas chromatograph/mass spectrometer (GC/MS) conditions appropriate for the qualitative and quantitative confirmation of results for most of the parameters listed above.</P>
                        <P>
                            1.3 The method detection limit (MDL, defined in Section 12.1) 
                            <SU>1</SU>
                             for each parameter is listed in Table 1. The MDL for a specific wastewater may differ from those listed, depending upon the nature of interferences in the sample matrix.
                        </P>
                        <P>1.4 Any modification of this method, beyond those expressly permitted, shall be considered as a major modification subject to application and approval of alternate test procedures under 40 CFR 136.4 and 136.5.</P>
                        <P>1.5 This method is restricted to use by or under the supervision of analysts experienced in the operation of a purge and trap system and a gas chromatograph and in the interpretation of gas chromatograms. Each analyst must demonstrate the ability to generate acceptable results with this method using the procedure described in Section 8.2.</P>
                        <HD SOURCE="HD2">2. Summary of Method</HD>
                        <P>
                            2.1 An inert gas is bubbled through a 5-mL water sample contained in a specially-designed purging chamber at ambient temperature. The halocarbons are efficiently transferred from the aqueous phase to the vapor phase. The vapor is swept through a sorbent trap where the halocarbons are trapped. After purging is completed, the trap is heated and backflushed with the inert gas to desorb the halocarbons onto a gas chromatographic column. The gas chromatograph is temperature programmed to separate the halocarbons which are then detected with a halide-specific detector. 
                            <SU>2 3</SU>
                        </P>
                        <P>2.2 The method provides an optional gas chromatographic column that may be helpful in resolving the compounds of interest from interferences that may occur.</P>
                        <HD SOURCE="HD2">3. Interferences</HD>
                        <P>3.1 Impurities in the purge gas and organic compounds outgassing from the plumbing ahead of the trap account for the majority of contamination problems. The analytical system must be demonstrated to be free from contamination under the conditions of the analysis by running laboratory reagent blanks as described in Section 8.1.3. The use of non-Teflon plastic tubing, non-Teflon thread sealants, or flow controllers with rubber components in the purge and trap system should be avoided.</P>
                        <P>3.2 Samples can be contaminated by diffusion of volatile organics (particularly fluorocarbons and methylene chloride) through the septum seal ilto the sample during shipment and storage. A field reagent blank prepared from reagent water and carried through the sampling and handling protocol can serve as a check on such contamination.</P>
                        <P>3.3 Contamination by carry-over can occur whenever high level and low level samples are sequentially analyzed. To reduce carry-over, the purging device and sample syringe must be rinsed with reagent water between sample analyses. Whenever an unusually concentrated sample is encountered, it should be followed by an analysis of reagent water to check for cross contamination. For samples containing large amounts of water-soluble materials, suspended solids, high boiling compounds or high organohalide levels, it may be necessary to wash out the purging device with a detergent solution, rinse it with distilled water, and then dry it in a 105 °C oven between analyses. The trap and other parts of the system are also subject to contamination; therefore, frequent bakeout and purging of the entire system may be required.</P>
                        <HD SOURCE="HD2">4. Safety</HD>
                        <P>
                            4.1 The toxicity or carcinogenicity of each reagent used in this method has not 
                            <PRTPAGE P="79"/>
                            been precisely defined; however, each chemical compound should be treated as a potential health hazard. From this viewpoint, exposure to these chemicals must be reduced to the lowest possible level by whatever means available. The laboratory is responsible for maintaining a current awareness file of OSHA regulations regarding the safe handling of the chemicals specified in this method. A reference file of material data handling sheets should also be made available to all personnel involved in the chemical analysis. Additional references to laboratory safety are available and have been identified 
                            <SU>4 6</SU>
                             for the information of the analyst.
                        </P>
                        <P>4.2 The following parameters covered by this method have been tentatively classified as known or suspected, human or mammalian carcinogens: carbon tetrachloride, chloroform, 1,4-dichlorobenzene, and vinyl chloride. Primary standards of these toxic compounds should be prepared in a hood. A NIOSH/MESA approved toxic gas respirator should be worn when the analyst handles high concentrations of these toxic compounds.</P>
                        <HD SOURCE="HD2">5. Apparatus and Materials</HD>
                        <P>5.1 Sampling equipment, for discrete sampling.</P>
                        <P>5.1.1 Vial—25-mL capacity or larger, equipped with a screw cap with a hole in the center (Pierce #13075 or equivalent). Detergent wash, rinse with tap and distilled water, and dry at 105 °C before use.</P>
                        <P>5.1.2 Septum—Teflon-faced silicone (Pierce #12722 or equivalent). Detergent wash, rinse with tap and distilled water, and dry at 105 °C for 1 h before use.</P>
                        <P>5.2 Purge and trap system—The purge and trap system consists of three separate pieces of equipment: a purging device, trap, and desorber. Several complete systems are now commercially available.</P>
                        <P>5.2.1 The purging device must be designed to accept 5-mL samples with a water column at least 3 cm deep. The gaseous head space between the water column and the trap must have a total volume of less than 15 mL. The purge gas must pass through the water column as finely divided bubbles with a diameter of less than 3 mm at the origin. The purge gas must be introduced no more than 5 mm from the base of the water column. The purging device illustrated in Figure 1 meets these design criteria.</P>
                        <P>5.2.2 The trap must be at least 25 cm long and have an inside diameter of at least 0.105 in. The trap must be packed to contain the following minimum lengths of adsorbents: 1.0 cm of methyl silicone coated packing (Section 6.3.3), 7.7 cm of 2,6-diphenylene oxide polymer (Section 6.3.2), 7.7 cm of silica gel (Section 6.3.4), 7.7 cm of coconut charcoal (Section 6.3.1). If it is not necessary to analyze for dichlorodifluoromethane, the charcoal can be eliminated, and the polymer section lengthened to 15 cm. The minimum specifications for the trap are illustrated in Figure 2.</P>
                        <P>5.2.3 The desorber must be capable of rapidly heating the trap to 180 °C. The polymer section of the trap should not be heated higher than 180 °C and the remaining sections should not exceed 200 °C. The desorber illustrated in Figure 2 meets these design criteria.</P>
                        <P>5.2.4 The purge and trap system may be assembled as a separate unit or be coupled to a gas chromatograph as illustrated in Figures 3 and 4.</P>
                        <P>5.3 Gas chromatograph—An analytical system complete with a temperature programmable gas chromatograph suitable for on-column injection and all required accessories including syringes, analytical columns, gases, detector, and strip-chart recorder. A data system is recommended for measuring peak areas.</P>
                        <P>5.3.1 Column 1—8 ft long × 0.1 in. ID stainless steel or glass, packed with 1% SP-1000 on Carbopack B (60/80 mesh) or equivalent. This column was used to develop the method performance statements in Section 12. Guidelines for the use of alternate column packings are provided in Section 10.1.</P>
                        <P>5.3.2 Column 2—6 ft long × 0.1 in. ID stainless steel or glass, packed with chemically bonded n-octane on Porasil-C (100/120 mesh) or equivalent.</P>
                        <P>5.3.3 Detector—Electrolytic conductivity or microcoulometric detector. These types of detectors have proven effective in the analysis of wastewaters for the parameters listed in the scope (Section 1.1). The electrolytic conductivity detector was used to develop the method performance statements in Section 12. Guidelines for the use of alternate detectors are provided in Section 10.1.</P>
                        <P>5.4 Syringes—5-mL glass hypodermic with Luerlok tip (two each), if applicable to the purging device.</P>
                        <P>5.5 Micro syringes—25-µL, 0.006 in. ID needle.</P>
                        <P>5.6 Syringe valve—2-way, with Luer ends (three each).</P>
                        <P>5.7 Syringe—5-mL, gas-tight with shut-off valve.</P>
                        <P>5.8 Bottle—15-mL, screw-cap, with Teflon cap liner.</P>
                        <P>5.9 Balance—Analytical, capable of accurately weighing 0.0001 g.</P>
                        <HD SOURCE="HD2">6. Reagents</HD>
                        <P>6.1 Reagent water—Reagent water is defined as a water in which an interferent is not observed at the MDL of the parameters of interest.</P>
                        <P>
                            6.1.1 Reagent water can be generated by passing tap water through a carbon filter bed containing about 1 lb of activated carbon (Filtrasorb-300, Calgon Corp., or equivalent).
                            <PRTPAGE P="80"/>
                        </P>
                        <P>6.1.2 A water purification system (Millipore Super-Q or equivalent) may be used to generate reagent water.</P>
                        <P>6.1.3 Reagent water may also be prepared by boiling water for 15 min. Subsequently, while maintaining the temperature at 90 °C, bubble a contaminant-free inert gas through the water for 1 h. While still hot, transfer the water to a narrow mouth screw-cap bottle and seal with a Teflon-lined septum and cap.</P>
                        <P>6.2 Sodium thiosulfate—(ACS) Granular.</P>
                        <P>6.3 Trap Materials:</P>
                        <P>6.3.1 Coconut charcoal—6/10 mesh sieved to 26 mesh, Barnabey Cheney, CA-580-26 lot # M-2649 or equivalent.</P>
                        <P>6.3.2 2,6-Diphenylene oxide polymer—Tenax, (60/80 mesh), chromatographic grade or equivalent.</P>
                        <P>6.3.3 Methyl silicone packing—3% OV-1 on Chromosorb-W (60/80 mesh) or equivalent.</P>
                        <P>6.3.4 Silica gel—35/60 mesh, Davison, grade-15 or equivalent.</P>
                        <P>6.4 Methanol—Pesticide quality or equivalent.</P>
                        <P>6.5 Stock standard solutions—Stock standard solutions may be prepared from pure standard materials or purchased as certified solutions. Prepare stock standard solutions in methanol using assayed liquids or gases as appropriate. Because of the toxicity of some of the organohalides, primary dilutions of these materials should be prepared in a hood. A NIOSH/MESA approved toxic gas respirator should be used when the analyst handles high concentrations of such materials.</P>
                        <P>6.5.1 Place about 9.8 mL of methanol into a 10-mL ground glass stoppered volumetric flask. Allow the flask to stand, unstoppered, for about 10 min or until all alcohol wetted surfaces have dried. Weigh the flask to the learest 0.1 mg.</P>
                        <P>6.5.2 Add the assayed reference material:</P>
                        <P>6.5.2.1 Liquid—Using a 100 µL syringe, immediately add two or more drops of assayed reference material to the flask, then reweigh. Be sure that the drops fall directly into the alcohol without contacting the neck of the flask.</P>
                        <P>6.5.2.2 Gases—To prepare standards for any of the six halocarbons that boil below 30 °C (bromomethane, chloroethane, chloromethane, dichlorodifluoromethane, trichlorofluoromethane, vinyl chloride), fill a 5-mL valved gas-tight syringe with the reference standard to the 5.0-mL mark. Lower the needle to 5 mm above the methanol meniscus. Slowly introduce the reference standard above the surface of the liquid (the heavy gas will rapidly dissolve into the methanol).</P>
                        <P>6.5.3 Reweigh, dilute to volume, stopper, then mix by inverting the flask several times. Calculate the concentration in µg/µL from the net gain in weight. When compound purity is assayed to be 96% or greater, the weight can be used without correction to calculate the concentration of the stock standard. Commercially prepared stock standards can be used at any concentration if they are certified by the malufacturer or by an independent source.</P>
                        <P>6.5.4 Transfer the stock standard solution into a Teflon-sealed screw-cap bottle. Store, with minimal headspace, at −10 to −20 °C and protect from light.</P>
                        <P>6.5.5 Prepare fresh standards weekly for the six gases and 2-chloroethylvinyl ether. All other standards must be replaced after one month, or sooner if comparison with check standards indicates a problem.</P>
                        <P>6.6 Secondary dilution standards—Using stock standard solutions, prepare secondary dilution standards in methanol that contain the compounds of interest, either singly or mixed together. The secondary dilution standards should be prepared at concentrations such that the aqueous calibration standards prepared in Section 7.3.1 or 7.4.1 will bracket the working range of the analytical system. Secondary dilution standards should be stored with minimal headspace and should be checked frequently for signs of degradation or evaporation, especially just prior to preparing calibration standards from them.</P>
                        <P>6.7 Quality control check sample concentrate—See Section 8.2.1.</P>
                        <HD SOURCE="HD2">7. Calibration</HD>
                        <P>7.1 Assemble a purge and trap system that meets the specifications in Section 5.2. Condition the trap overnight at 180 °C by backflushing with an inert gas flow of at least 20 mL/min. Condition the trap for 10 min once daily prior to use.</P>
                        <P>7.2 Connect the purge and trap system to a gas chromatograph. The gas chromatograph must be operated using temperature and flow rate conditions equivalent to those given in Table 1. Calibrate the purge and trap-gas chromatographic system using either the external standard technique (Section 7.3) or the internal standard technique (Section 7.4).</P>
                        <P>7.3 External standard calibration procedure:</P>
                        <P>
                            7.3.1 Prepare calibration standards at a miminum of three concentration levels for each parameter by carefully adding 20.0 µL of one or more secondary dilution standards to 100, 500, or 1000 µL of reagent water. A 25-µL syringe with a 0.006 in. ID needle should be used for this operation. One of the external standards should be at a concentration near, but above, the MDL (Table 1) and the other concentrations should correspond to the expected range of concentrations found in real samples or should define the working range of the detector. These aqueous standards can be stored up to 24 h, if held in sealed vials with zero headspace as described in Section 9.2. If not so stored, they must be discarded after 1 h.
                            <PRTPAGE P="81"/>
                        </P>
                        <P>7.3.2 Analyze each calibration standard according to Section 10, and tabulate peak height or area responses versus the concentration in the standard. The results can be used to prepare a calibration curve for each compound. Alternatively, if the ratio of response to concentration (calibration factor) is a constant over the working range (&lt;10% relative standard deviation, RSD), linearity through the origin can be assumed and the average ratio or calibration factor can be used in place of a calibration curve.</P>
                        <P>7.4 Internal standard calibration procedure—To use this approach, the analyst must select one or more internal standards that are similar in analytical behavior to the compounds of interest. The analyst must further demonstrate that the measurement of the internal standard is not affected by method or matrix interferences. Because of these limitations, no internal standard can be suggested that is applicable to all samples. The compounds recommended for use as surrogate spikes in Section 8.7 have been used successfully as internal standards, because of their generally unique retention times.</P>
                        <P>7.4.1 Prepare calibration standards at a minimum of three concentration levels for each parameter of interest as described in Section 7.3.1.</P>
                        <P>7.4.2 Prepare a spiking solution containing each of the internal standards using the procedures described in Sections 6.5 and 6.6. It is recommended that the secondary dilution standard be prepared at a concentration of 15 µg/mL of each internal standard compound. The addition of 10 µL of this standard to 5.0 mL of sample or calibration standard would be equivalent to 30 µg/L.</P>
                        <P>7.4.3 Analyze each calibration standard according to Section 10, adding 10 µL of internal standard spiking solution directly to the syringe (Section 10.4). Tabulate peak height or area responses against concentration for each compound and internal standard, and calculate response factors (RF) for each compound using Equation 1.</P>
                        <MATH SPAN="1" DEEP="31">
                            <MID>EC15NO91.094</MID>
                        </MATH>
                        <FP SOURCE="FRP0">Equation 1</FP>
                        <FP>where:</FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">s</E>
                             = Response for the parameter to be measured.
                        </FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">is</E>
                             = Response for the internal standard.
                        </FP>
                        <FP SOURCE="FP-2">
                            C
                            <E T="52">is</E>
                             = Concentration of the internal standard.
                        </FP>
                        <FP SOURCE="FP-2">
                            C
                            <E T="52">s</E>
                             = Concentration of the parameter to be measured.
                        </FP>
                        <FP>
                            If the RF value over the working range is a constant (&lt;10% RSD), the RF can be assumed to be invariant and the average RF can be used for calculations. Alternatively, the results can be used to plot a calibration curve of response ratios, A
                            <E T="52">s</E>
                            /A
                            <E T="52">is</E>
                            , vs. RF.
                        </FP>
                        <P>7.5 The working calibration curve, calibration factor, or RF must be verified on each working day by the measurement of a QC check sample.</P>
                        <P>7.5.1 Prepare the QC check sample as described in Section 8.2.2.</P>
                        <P>7.5.2 Analyze the QC check sample according to Section 10.</P>
                        <P>7.5.3 For each parameter, compare the response (Q) with the corresponding calibration acceptance criteria found in Table 2. If the responses for all parameters of interest fall within the designated ranges, analysis of actual samples can begin. If any individual Q falls outside the range, proceed according to Section 7.5.4.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>The large number of parameters in Table 2 present a substantial probability that one or more will not meet the calibration acceptance criteria when all parameters are analyzed.</P>
                        </NOTE>
                        <P>7.5.4 Repeat the test only for those parameters that failed to meet the calibration acceptance criteria. If the response for a parameter does not fall within the range in this second test, a new calibration curve, calibration factor, or RF must be prepared for that parameter according to Section 7.3 or 7.4.</P>
                        <HD SOURCE="HD2">8. Quality Control</HD>
                        <P>8.1 Each laboratory that uses this method is required to operate a formal quality control program. The minimum requirements of this program consist of an initial demonstration of laboratory capability and an ongoing analysis of spiked samples to evaluate and document data quality. The laboratory must maintain records to document the quality of data that is generated. Ongoing data quality checks are compared with established performance criteria to determine if the results of analyses meet the performance characteristics of the method. When results of sample spikes indicate atypical method performance, a quality control check standard must be analyzed to confirm that the measurements were performed in an in-control mode of operation.</P>
                        <P>8.1.1 The analyst must make an initial, one-time, demonstration of the ability to generate acceptable accuracy and precision with this method. This ability is established as described in Section 8.2.</P>
                        <P>8.1.2 In recognition of advances that are occurring in chromatography, the analyst is permitted certain options (detailed in Section 10.1) to improve the separations or lower the cost of measurements. Each time such a modification is made to the method, the analyst is required to repeat the procedure in Section 8.2.</P>
                        <P>
                            8.1.3 Each day, the analyst must analyze a reagent water blank to demonstrate that 
                            <PRTPAGE P="82"/>
                            interferences from the analytical system are under control.
                        </P>
                        <P>8.1.4 The laboratory must, on an ongoing basis, spike and analyze a minimum of 10% of all samples to monitor and evaluate laboratory data quality. This procedure is described in Section 8.3.</P>
                        <P>8.1.5 The laboratory must, on an ongoing basis, demonstrate through the analyses of quality control check standards that the operation of the measurement system is in control. This procedure is described in Section 8.4. The frequency of the check standard analyses is equivalent to 10% of all samples analyzed but may be reduced if spike recoveries from samples (Section 8.3) meet all specified quality control criteria.</P>
                        <P>8.1.6 The laboratory must maintain performance records to document the quality of data that is generated. This procedure is described in Section 8.5.</P>
                        <P>8.2 To establish the ability to generate acceptable accuracy and precision, the analyst must perform the following operations.</P>
                        <P>8.2.1 A quality control (QC) check sample concentrate is required containing each parameter of interest at a concentration of 10 µg/mL in methanol. The QC check sample concentrate must be obtained from the U.S. Environmental Protection Agency, Environmental Monitoring and Support Laboratory in Cincinnati, Ohio, if available. If not available from that source, the QC check sample concentrate must be obtained from another external source. If not available from either source above, the QC check sample concentrate must be prepared by the laboratory using stock standards prepared independently from those used for calibration.</P>
                        <P>8.2.2 Prepare a QC check sample to contain 20 µg/L of each parameter by adding 200 µL of QC check sample concentrate to 100 mL of reagent water.</P>
                        <P>8.2.3 Analyze four 5-mL aliquots of the well-mixed QC check sample according to Section 10.</P>
                        <P>
                            8.2.4 Calculate the average recovery (X
                            <AC T="8"/>
                            ) in µg/L, and the standard deviation of the recovery (s) in µg/L, for each parameter of interest using the four results.
                        </P>
                        <P>
                            8.2.5 For each parameter compare s and X
                            <AC T="8"/>
                             with the corresponding acceptance criteria for precision and accuracy, respectively, found in Table 2. If s and X
                            <AC T="8"/>
                             for all parameters of interest meet the acceptance criteria, the system performance is acceptable and analysis of actual samples can begin. If any individual s exceeds the precision limit or any individual X
                            <AC T="8"/>
                             falls outside the range for accuracy, then the system performance is unacceptable for that parameter.
                        </P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>The large number of parameters in Table 2 present a substantial probability that one or more will fail at least one of the acceptance criteria when all parameters are analyzed.</P>
                        </NOTE>
                        <P>8.2.6 When one or more of the parameters tested fail at least one of the acceptance criteria, the analyst must proceed according to Section 8.2.6.1 or 8.2.6.2.</P>
                        <P>8.2.6.1 Locate and correct the source of the problem and repeat the test for all parameters of interest beginning with Section 8.2.3.</P>
                        <P>8.2.6.2 Beginning with Section 8.2.3, repeat the test only for those parameters that failed to meet criteria. Repeated failure, however, will confirm a general problem with the measurement system. If this occurs, locate and correct the source of the problem and repeat the test for all compounds of interest beginning with Section 8.2.3.</P>
                        <P>8.3 The laboratory must, on an ongoing basis, spike at least 10% of the samples from each sample site being monitored to assess accuracy. For laboratories analyzing one to ten samples per month, at least one spiked sample per month is required.</P>
                        <P>8.3.1 The concentration of the spike in the sample should be determined as follows:</P>
                        <P>8.3.1.1 If, as in compliance monitoring, the concentration of a specific parameter in the sample is being checked against a regulatory concentration limit, the spike should be at that limit or 1 to 5 times higher than the background concentration determined in Section 8.3.2, whichever concentration would be larger.</P>
                        <P>8.3.1.2 If the concentration of a specific parameter in the sample is not being checked against a limit specific to that parameter, the spike should be at 20 µg/L or 1 to 5 times higher than the background concentration determined in Section 8.3.2, whichever concentration would be larger.</P>
                        <P>8.3.2 Analyze one 5-mL sample aliquot to determine the background concentration (B) of each parameter. If necessary, prepare a new QC check sample concentrate (Section 8.2.1) appropriate for the background concentrations in the sample. Spike a second 5-mL sample aliquot with 10 µL of the QC check sample concentrate and analyze it to determine the concentration after spiking (A) of each parameter. Calculate each percent recovery (P) as 100(A−B)%/T, where T is the known true value of the spike.</P>
                        <P>
                            8.3.3 Compare the percent recovery (P) for each parameter with the corresponding QC acceptance criteria found in Table 2. These acceptance criteria were calculated to include an allowance for error in measurement of both the background and spike concentrations, assuming a spike to background ratio of 5:1. This error will be accounted for to the extent that the analyst's spike to background ratio approaches 5:1. 
                            <SU>7</SU>
                             If spiking was performed at a concentration lower than 20 µg/L, the analyst must use either the QC acceptance criteria in Table 2, or optional QC acceptance criteria calculated for the specific spike concentration. To calculate optional acceptance criteria for the recovery of 
                            <PRTPAGE P="83"/>
                            a parameter: (1) Calculate accuracy (X′) using the equation in Table 3, substituting the spike concentration (T) for C; (2) calculate overall precision (S′) using the equation in Table 3, substituting X′ for X
                            <AC T="8"/>
                            ; (3) calculate the range for recovery at the spike concentration as (100 X′/T)±2.44(100 S′/T)%. 
                            <SU>7</SU>
                        </P>
                        <P>8.3.4 If any individual P falls outside the designated range for recovery, that parameter has failed the acceptance criteria. A check standard containing each parameter that failed the criteria must be analyzed as described in Section 8.4.</P>
                        <P>8.4 If any parameter fails the acceptance criteria for recovery in Section 8.3, a QC check standard containing each parameter that failed must be prepared and analyzed.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>The frequency for the required analysis of a QC check standard will depend upon the number of parameters being simultaneously tested, the complexity of the sample matrix, and the performance of the laboratory. If the entire list of parameters in Table 2 must be measured in the sample in Section 8.3, the probability that the analysis of a QC check standard will be required is high. In this case the QC check standard should be routinely analyzed with the spiked sample.</P>
                        </NOTE>
                        <P>8.4.1 Prepare the QC check standard by adding 10 µL of QC check sample concentrate (Section 8.2.1 or 8.3.2) to 5 mL of reagent water. The QC check standard needs only to contain the parameters that failed criteria in the test in Section 8.3.</P>
                        <P>
                            8.4.2 Analyze the QC check standard to determine the concentration measured (A) of each parameter. Calculate each percent recovery (P
                            <E T="52">s</E>
                            ) as 100 (A/T)%, where T is the true value of the standard concentration.
                        </P>
                        <P>
                            8.4.3 Compare the percent recovery (P
                            <E T="52">s</E>
                            ) for each parameter with the corresponding QC acceptance criteria found in Table 2. Only parameters that failed the test in Section 8.3 need to be compared with these criteria. If the recovery of any such parameter falls outside the designated range, the laboratory performance for that parameter is judged to be out of control, and the problem must be immediately identified and corrected. The analytical result for that parameter in the unspiked sample is suspect and may not be reported for regulatory compliance purposes.
                        </P>
                        <P>
                            8.5 As part of the QC program for the laboratory, method accuracy for wastewater samples must be assessed and records must be maintained. After the analysis of five spiked wastewater samples as in Section 8.3, calculate the average percent recovery (P
                            <AC T="8"/>
                            ) and the standard deviation of the percent recovery (s
                            <E T="52">p</E>
                            ). Express the accuracy assessment as a percent recovery interval from P
                            <AC T="8"/>
                            −2s
                            <E T="52">p</E>
                             to P
                            <AC T="8"/>
                             + 2s
                            <E T="52">p</E>
                            . If p
                            <AC T="8"/>
                             = 90% and s
                            <E T="52">p</E>
                             = 10%, for example, the accuracy interval is expressed as 70-110%. Update the accuracy assessment for each parameter on a regular basis (e.g. after each five to ten new accuracy measurements).
                        </P>
                        <P>8.6 It is recommended that the laboratory adopt additional quality assurance practices for use with this method. The specific practices that are most productive depend upon the needs of the laboratory and the nature of the samples. Field duplicates may be analyzed to assess the precision of the environmental measurements. When doubt exists over the identification of a peak on the chromatogram, confirmatory techniques such as gas chromatography with a dissimilar column, specific element detector, or mass spectrometer must be used. Whenever possible, the laboratory should analyze standard reference materials and participate in relevant performance evaluation studies.</P>
                        <P>8.7 The analyst should monitor both the performance of the analytical system and the effectiveness of the method in dealing with each sample matrix by spiking each sample, standard, and reagent water blank with surrogate halocarbons. A combination of bromochloromethane, 2-bromo-1-chloropropane, and 1,4-dichlorobutane is recommended to encompass the range of the temperature program used in this method. From stock standard solutions prepared as in Section 6.5, add a volume to give 750 µg of each surrogate to 45 mL of reagent water contained in a 50-mL volumetric flask, mix and dilute to volume for a concentration of 15 ng/µL. Add 10 µL of this surrogate spiking solution directly into the 5-mL syringe with every sample and reference standard analyzed. Prepare a fresh surrogate spiking solution on a weekly basis. If the internal standard calibration procedure is being used, the surrogate compounds may be added directly to the internal standard spiking solution (Section 7.4.2).</P>
                        <HD SOURCE="HD2">9. Sample Collection, Preservation, and Handling</HD>
                        <P>
                            9.1 All samples must be iced or refrigerated from the time of collection until analysis. If the sample contains free or combined chlorine, add sodium thiosulfate preservative (10 mg/40 mL is sufficient for up to 5 ppm Cl
                            <E T="52">2</E>
                            ) to the empty sample bottle just prior to shipping to the sampling site. EPA Methods 330.4 and 330.5 may be used for measurement of residual chlorine. 
                            <SU>8</SU>
                             Field test kits are available for this purpose.
                        </P>
                        <P>9.2 Grab samples must be collected in glass containers having a total volume of at least 25 mL. Fill the sample bottle just to overflowing in such a manner that no air bubbles pass through the sample as the bottle is being filled. Seal the bottle so that no air bubbles are entrapped in it. If preservative has been added, shake vigorously for 1 min. Maintain the hermetic seal on the sample bottle until time of analysis.</P>
                        <P>
                            9.3 All samples must be analyzed within 14 days of collection. 
                            <SU>3</SU>
                            <PRTPAGE P="84"/>
                        </P>
                        <HD SOURCE="HD2">10. Procedure</HD>
                        <P>10.1 Table 1 summarizes the recommended operating conditions for the gas chromatograph. Included in this table are estimated retention times and MDL that can be achieved under these conditions. An example of the separations achieved by Column 1 is shown in Figure 5. Other packed columns, chromatographic conditions, or detectors may be used if the requirements of Section 8.2 are met.</P>
                        <P>10.2 Calibrate the system daily as described in Section 7.</P>
                        <P>10.3 Adjust the purge gas (nitrogen or helium) flow rate to 40 mL/min. Attach the trap inlet to the purging device, and set the purge and trap system to purge (Figure 3). Open the syringe valve located on the purging device sample introduction needle.</P>
                        <P>10.4 Allow the sample to come to ambient temperature prior to introducing it to the syringe. Remove the plunger from a 5-mL syringe and attach a closed syringe valve. Open the sample bottle (or standard) and carefully pour the sample into the syringe barrel to just short of overflowing. Replace the syringe plunger and compress the sample. Open the syringe valve and vent any residual air while adjusting the sample volume to 5.0 mL. Since this process of taking an aliquot destroys the validity of the sample for future analysis, the analyst should fill a second syringe at this time to protect against possible loss of data. Add 10.0 µL of the surrogate spiking solution (Section 8.7) and 10.0 µL of the internal standard spiking solution (Section 7.4.2), if applicable, through the valve bore, then close the valve.</P>
                        <P>10.5 Attach the syringe-syringe valve assembly to the syringe valve on the purging device. Open the syringe valves and inject the sample into the purging chamber.</P>
                        <P>10.6 Close both valves and purge the sample for 11.0 ±0.1 min at ambient temperature.</P>
                        <P>10.7 After the 11-min purge time, attach the trap to the chromatograph, adjust the purge and trap system to the desorb mode (Figure 4), and begin to temperature program the gas chromatograph. Introduce the trapped materials to the GC column by rapidly heating the trap to 180 °C while backflushing the trap with an inert gas between 20 and 60 mL/min for 4 min. If rapid heating of the trap cannot be achieved, the GC column must be used as a secondary trap by cooling it to 30 °C (subambient temperature, if poor peak geometry or random retention time problems persist) instead of the initial program temperature of 45 °C</P>
                        <P>10.8 While the trap is being desorbed into the gas chromatograph, empty the purging chamber using the sample introduction syringe. Wash the chamber with two 5-mL flushes of reagent water.</P>
                        <P>10.9 After desorbing the sample for 4 min, recondition the trap by returning the purge and trap system to the purge mode. Wait 15 s then close the syringe valve on the purging device to begin gas flow through the trap. The trap temperature should be maintained at 180 °C After approximately 7 min, turn off the trap heater and open the syringe valve to stop the gas flow through the trap. When the trap is cool, the next sample can be analyzed.</P>
                        <P>10.10 Identify the parameters in the sample by comparing the retention times of the peaks in the sample chromatogram with those of the peaks in standard chromatograms. The width of the retention time window used to make identifications should be based upon measurements of actual retention time variations of standards over the course of a day. Three times the standard deviation of a retention time for a compound can be used to calculate a suggested window size; however, the experience of the analyst should weigh heavily in the interpretation of chromatograms.</P>
                        <P>10.11 If the response for a peak exceeds the working range of the system, prepare a dilution of the sample with reagent water from the aliquot in the second syringe and reanalyze.</P>
                        <HD SOURCE="HD2">11. Calculations</HD>
                        <P>11.1 Determine the concentration of individual compounds in the sample.</P>
                        <P>11.1.1 If the external standard calibration procedure is used, calculate the concentration of the parameter being measured from the peak response using the calibration curve or calibration factor determined in Section 7.3.2.</P>
                        <P>11.1.2 If the internal standard calibration procedure is used, calculate the concentration in the sample using the response factor (RF) determined in Section 7.4.3 and Equation 2.</P>
                        <FP SOURCE="FRP0">Equation 2</FP>
                        <MATH SPAN="1" DEEP="31">
                            <MID>EC15NO91.095</MID>
                        </MATH>
                        <FP>where:</FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">s</E>
                             = Response for the parameter to be measured.
                        </FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">is</E>
                             = Response for the internal standard.
                        </FP>
                        <FP SOURCE="FP-2">
                            C
                            <E T="52">is</E>
                             = Concentration of the internal standard.
                        </FP>
                        <P>11.2 Report results in µg/L without correction for recovery data. All QC data obtained should be reported with the sample results.</P>
                        <HD SOURCE="HD2">12. Method Performance</HD>
                        <P>
                            12.1 The method detection limit (MDL) is defined as the minimum concentration of a substance that can be measured and reported with 99% confidence that the value is above zero. 
                            <SU>1</SU>
                             The MDL concentration listed in Table 1 were obtained using reagent water. 
                            <SU>11</SU>
                            . 
                            <PRTPAGE P="85"/>
                            Similar results were achieved using representative wastewaters. The MDL actually achieved in a given analysis will vary depending on instrument sensitivity and matrix effects.
                        </P>
                        <P>12.2 This method is recommended for use in the concentration range from the MDL to 1000 × MDL. Direct aqueous injection techniques should be used to measure concentration levels above 1000 × MDL.</P>
                        <P>
                            12.3 This method was tested by 20 laboratories using reagent water, drinking water, surface water, and three industrial wastewaters spiked at six concentrations over the range 8.0 to 500 µg/L. 
                            <SU>9</SU>
                             Single operator precision, overall precision, and method accuracy were found to be directly related to the concentration of the parameter and essentially independent of the sample matrix. Linear equations to describe these relationships are presented in Table 3.
                        </P>
                        <HD SOURCE="HD2">References</HD>
                        <P>1. 40 CFR part 136, appendix B.</P>
                        <P>
                            2. Bellar, T.A., and Lichtenberg, J.J. “Determining Volatile Organics at Microgram-per-Litre-Levels by Gas Chromatography,” 
                            <E T="03">Journal of the American Water Works Association, 66,</E>
                             739 (1974).
                        </P>
                        <P>3. Bellar, T.A., and Lichtenberg, J.J. “Semi-Automated Headspace Analysis of Drinking Waters and Industrial Waters for Purgeable Volatile Organic Compounds,” Proceedings from Symposium on Measurement of Organic Pollutants in Water and Wastewater, American Society for Testing and Materials, STP 686, C.E. Van Hall, editor, 1978.</P>
                        <P>4. “Carcinogens—Working With Carcinogens,” Department of Health, Education, and Welfare, Public Health Service, Center for Disease Control, National Institute for Occupational Safety and Health, Publication No. 77-206, August 1977.</P>
                        <P>5. “OSHA Safety and Health Standards, General Industry” (29 CFR part 1910), Occupational Safety and Health Administration, OSHA 2206 (Revised, January 1976).</P>
                        <P>6. “Safety in Academic Chemistry Laboratories,” American Chemical Society Publication, Committee on Chemical Safety, 3rd Edition, 1979.</P>
                        <P>
                            7. Provost, L.P., and Elder, R.S. “Interpretation of Percent Recovery Data,” 
                            <E T="03">American Laboratory, 15,</E>
                             58-63 (1983). (The value 2.44 used in the equation in Section 8.3.3 is two times the value 1.22 derived in this report.)
                        </P>
                        <P>8. “Methods 330.4 (Titrimetric, DPD-FAS) and 330.5 (Spectrophotometric, DPD) for Chlorine, Total Residual,” Methods for Chemical Analysis of Water and Wastes, EPA 600/4-79-020, U.S. Environmental Protection Agency, Environmental Monitoring and Support Laboratory, Cincinnati, Ohio 45268, March 1979.</P>
                        <P>9. “EPA Method Study 24, Method 601—Purgeable Halocarbons by the Purge and Trap Method,” EPA 600/4-84-064, National Technical Information Service, PB84-212448, Springfield, Virginia 22161, July 1984.</P>
                        <P>10. “Method Validation Data for EPA Method 601,” Memorandum from B. Potter, U.S. Environmental Protection Agency, Environmental Monitoring and Support Laboratory, Cincinnati, Ohio 45268, November 10, 1983.</P>
                        <P>11. Bellar, T. A., Unpublished data, U.S. Environmental Protection Agency, Environmental Monitoring and Support Laboratory, Cincinnati, Ohio 45268, 1981.</P>
                        <GPOTABLE COLS="4" OPTS="L2" CDEF="s50,7.7,7.7,7.7">
                            <TTITLE>Table 1—Chromatographic Conditions and Method Detection Limits</TTITLE>
                            <BOXHD>
                                <CHED H="1">Parameter</CHED>
                                <CHED H="1">Retention time (min)</CHED>
                                <CHED H="2">Column 1</CHED>
                                <CHED H="2">Column 2</CHED>
                                <CHED H="1">Method detection limit (µg/L)</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">Chloromethane</ENT>
                                <ENT>1.50</ENT>
                                <ENT>5.28</ENT>
                                <ENT>0.08</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Bromomethane</ENT>
                                <ENT>2.17</ENT>
                                <ENT>7.05</ENT>
                                <ENT>1.18</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dichlorodifluoromethane</ENT>
                                <ENT>2.62</ENT>
                                <ENT>nd</ENT>
                                <ENT>1.81</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Vinyl chloride</ENT>
                                <ENT>2.67</ENT>
                                <ENT>5.28</ENT>
                                <ENT>0.18</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chloroethane</ENT>
                                <ENT>3.33</ENT>
                                <ENT>8.68</ENT>
                                <ENT>0.52</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Methylene chloride</ENT>
                                <ENT>5.25</ENT>
                                <ENT>10.1</ENT>
                                <ENT>0.25</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Trichlorofluoromethane</ENT>
                                <ENT>7.18</ENT>
                                <ENT>nd</ENT>
                                <ENT>nd</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1-Dichloroethene</ENT>
                                <ENT>7.93</ENT>
                                <ENT>7.72</ENT>
                                <ENT>0.13</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1-Dichloroethane</ENT>
                                <ENT>9.30</ENT>
                                <ENT>12.6</ENT>
                                <ENT>0.07</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">trans-1,2-Dichloroethene</ENT>
                                <ENT>10.1</ENT>
                                <ENT>9.38</ENT>
                                <ENT>0.10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chloroform</ENT>
                                <ENT>10.7</ENT>
                                <ENT>12.1</ENT>
                                <ENT>0.05</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2-Dichloroethane</ENT>
                                <ENT>11.4</ENT>
                                <ENT>15.4</ENT>
                                <ENT>0.03</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1,1-Trichloroethane</ENT>
                                <ENT>12.6</ENT>
                                <ENT>13.1</ENT>
                                <ENT>0.03</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Carbon tetrachloride</ENT>
                                <ENT>13.0</ENT>
                                <ENT>14.4</ENT>
                                <ENT>0.12</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Bromodichloromethane</ENT>
                                <ENT>13.7</ENT>
                                <ENT>14.6</ENT>
                                <ENT>0.10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2-Dichloropropane</ENT>
                                <ENT>14.9</ENT>
                                <ENT>16.6</ENT>
                                <ENT>0.04</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">cis-1,3-Dichloropropene</ENT>
                                <ENT>15.2</ENT>
                                <ENT>16.6</ENT>
                                <ENT>0.34</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Trichloroethene</ENT>
                                <ENT>15.8</ENT>
                                <ENT>13.1</ENT>
                                <ENT>0.12</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dibromochloromethane</ENT>
                                <ENT>16.5</ENT>
                                <ENT>16.6</ENT>
                                <ENT>0.09</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1,2-Trichloroethane</ENT>
                                <ENT>16.5</ENT>
                                <ENT>18.1</ENT>
                                <ENT>0.02</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">trans-1,3-Dichloropropene</ENT>
                                <ENT>16.5</ENT>
                                <ENT>18.0</ENT>
                                <ENT>0.20</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-Chloroethylvinyl ether</ENT>
                                <ENT>18.0</ENT>
                                <ENT>nd</ENT>
                                <ENT>0.13</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Bromoform</ENT>
                                <ENT>19.2</ENT>
                                <ENT>19.2</ENT>
                                <ENT>0.20</ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="86"/>
                                <ENT I="01">1,1,2,2-Tetrachloroethane</ENT>
                                <ENT>21.6</ENT>
                                <ENT>nd</ENT>
                                <ENT>0.03</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Tetrachloroethene</ENT>
                                <ENT>21.7</ENT>
                                <ENT>15.0</ENT>
                                <ENT>0.03</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chlorobenzene</ENT>
                                <ENT>24.2</ENT>
                                <ENT>18.8</ENT>
                                <ENT>0.25</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,3-Dichlorobenzene</ENT>
                                <ENT>34.0</ENT>
                                <ENT>22.4</ENT>
                                <ENT>0.32</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2-Dichlorobenzene</ENT>
                                <ENT>34.9</ENT>
                                <ENT>23.5</ENT>
                                <ENT>0.15</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,4-Dichlorobenzene</ENT>
                                <ENT>35.4</ENT>
                                <ENT>22.3</ENT>
                                <ENT>0.24</ENT>
                            </ROW>
                            <TNOTE>Column 1 conditions: Carbopack B (60/80 mesh) coated with 1% SP-1000 packed in an 8 ft × 0.1 in. ID stainless steel or glass column with helium carrier gas at 40 mL/min flow rate. Column temperature held at 45 °C for 3 min then programmed at 8 °C/min to 220 °C and held for 15 min.</TNOTE>
                            <TNOTE>Column 2 conditions: Porisil-C (100/120 mesh) coated with n-octane packed in a 6 ft × 0.1 in. ID stainless steel or glass column with helium carrier gas at 40 mL/min flow rate. Column temperature held at 50 °C for 3 min then programmed at 6 °C/min to 170 °C and held for 4 min.</TNOTE>
                            <TNOTE>nd = not determined.</TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="5" OPTS="L2" CDEF="s50,12,9,12,9">
                            <TTITLE>
                                Table 2—Calibration and QC Acceptance Criteria—Method 601 
                                <E T="01">
                                    <SU>a</SU>
                                </E>
                            </TTITLE>
                            <BOXHD>
                                <CHED H="1">Parameter</CHED>
                                <CHED H="1">Range for Q (µg/L)</CHED>
                                <CHED H="1">Limit for s (µg/L)</CHED>
                                <CHED H="1">
                                    Range for X
                                    <AC T="8"/>
                                     (µg/L)
                                </CHED>
                                <CHED H="1">
                                    Range P, P
                                    <E T="52">s</E>
                                     (%)
                                </CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">Bromodichloromethane</ENT>
                                <ENT>15.2-24.8</ENT>
                                <ENT>4.3</ENT>
                                <ENT>10.7-32.0</ENT>
                                <ENT>42-172</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Bromoform</ENT>
                                <ENT>14.7-25.3</ENT>
                                <ENT>4.7</ENT>
                                <ENT>5.0-29.3</ENT>
                                <ENT>13-159</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Bromomethane</ENT>
                                <ENT>11.7-28.3</ENT>
                                <ENT>7.6</ENT>
                                <ENT>3.4-24.5</ENT>
                                <ENT>D-144</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Carbon tetrachloride</ENT>
                                <ENT>13.7-26.3</ENT>
                                <ENT>5.6</ENT>
                                <ENT>11.8-25.3</ENT>
                                <ENT>43-143</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chlorobenzene</ENT>
                                <ENT>14.4-25.6</ENT>
                                <ENT>5.0</ENT>
                                <ENT>10.2-27.4</ENT>
                                <ENT>38-150</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chloroethane</ENT>
                                <ENT>15.4-24.6</ENT>
                                <ENT>4.4</ENT>
                                <ENT>11.3-25.2</ENT>
                                <ENT>46-137</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-Chloroethylvinyl ether</ENT>
                                <ENT>12.0-28.0</ENT>
                                <ENT>8.3</ENT>
                                <ENT>4.5-35.5</ENT>
                                <ENT>14-186</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chloroform</ENT>
                                <ENT>15.0-25.0</ENT>
                                <ENT>4.5</ENT>
                                <ENT>12.4-24.0</ENT>
                                <ENT>49-133</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chloromethane</ENT>
                                <ENT>11.9-28.1</ENT>
                                <ENT>7.4</ENT>
                                <ENT>D-34.9</ENT>
                                <ENT>D-193</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dibromochloromethane</ENT>
                                <ENT>13.1-26.9</ENT>
                                <ENT>6.3</ENT>
                                <ENT>7.9-35.1</ENT>
                                <ENT>24-191</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2-Dichlorobenzene</ENT>
                                <ENT>14.0-26.0</ENT>
                                <ENT>5.5</ENT>
                                <ENT>1.7-38.9</ENT>
                                <ENT>D-208</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,3-Dichlorobenzene</ENT>
                                <ENT>9.9-30.1</ENT>
                                <ENT>9.1</ENT>
                                <ENT>6.2-32.6</ENT>
                                <ENT>7-187</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,4-Dichlorobenzene</ENT>
                                <ENT>13.9-26.1</ENT>
                                <ENT>5.5</ENT>
                                <ENT>11.5-25.5</ENT>
                                <ENT>42-143</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1-Dichloroethane</ENT>
                                <ENT>16.8-23.2</ENT>
                                <ENT>3.2</ENT>
                                <ENT>11.2-24.6</ENT>
                                <ENT>47-132</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2-Dichloroethane</ENT>
                                <ENT>14.3-25.7</ENT>
                                <ENT>5.2</ENT>
                                <ENT>13.0-26.5</ENT>
                                <ENT>51-147</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1-Dichloroethene</ENT>
                                <ENT>12.6-27.4</ENT>
                                <ENT>6.6</ENT>
                                <ENT>10.2-27.3</ENT>
                                <ENT>28-167</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">trans-1,2-Dichloroethene</ENT>
                                <ENT>12.8-27.2</ENT>
                                <ENT>6.4</ENT>
                                <ENT>11.4-27.1</ENT>
                                <ENT>38-155</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2-Dichloropropane</ENT>
                                <ENT>14.8-25.2</ENT>
                                <ENT>5.2</ENT>
                                <ENT>10.1-29.9</ENT>
                                <ENT>44-156</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">cis-1,3-Dichloropropene</ENT>
                                <ENT>12.8-27.2</ENT>
                                <ENT>7.3</ENT>
                                <ENT>6.2-33.8</ENT>
                                <ENT>22-178</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">trans-1,3-Dichloropropene</ENT>
                                <ENT>12.8-27.2</ENT>
                                <ENT>7.3</ENT>
                                <ENT>6.2-33.8</ENT>
                                <ENT>22-178</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Methylene chloride</ENT>
                                <ENT>15.5-24.5</ENT>
                                <ENT>4.0</ENT>
                                <ENT>7.0-27.6</ENT>
                                <ENT>25-162</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1,2,2-Tetrachloroethane</ENT>
                                <ENT>9.8-30.2</ENT>
                                <ENT>9.2</ENT>
                                <ENT>6.6-31.8</ENT>
                                <ENT>8-184</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Tetrachloroethene</ENT>
                                <ENT>14.0-26.0</ENT>
                                <ENT>5.4</ENT>
                                <ENT>8.1-29.6</ENT>
                                <ENT>26-162</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1,1-Trichloroethane</ENT>
                                <ENT>14.2-25.8</ENT>
                                <ENT>4.9</ENT>
                                <ENT>10.8-24.8</ENT>
                                <ENT>41-138</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1,2-Trichloroethane</ENT>
                                <ENT>15.7-24.3</ENT>
                                <ENT>3.9</ENT>
                                <ENT>9.6-25.4</ENT>
                                <ENT>39-136</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Trichloroethene</ENT>
                                <ENT>15.4-24.6</ENT>
                                <ENT>4.2</ENT>
                                <ENT>9.2-26.6</ENT>
                                <ENT>35-146</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Trichlorofluoromethane</ENT>
                                <ENT>13.3-26.7</ENT>
                                <ENT>6.0</ENT>
                                <ENT>7.4-28.1</ENT>
                                <ENT>21-156</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Vinyl chloride</ENT>
                                <ENT>13.7-26.3</ENT>
                                <ENT>5.7</ENT>
                                <ENT>8.2-29.9</ENT>
                                <ENT>28-163</ENT>
                            </ROW>
                            <TNOTE>
                                <SU>a</SU>
                                 Criteria were calculated assuming a QC check sample concentration of 20 µg/L.
                            </TNOTE>
                            <TNOTE>Q = Concentration measured in QC check sample, in µg/L (Section 7.5.3).</TNOTE>
                            <TNOTE>s = Standard deviation of four recovery measurements, in µg/L (Section 8.2.4).</TNOTE>
                            <TNOTE>
                                X
                                <AC T="8"/>
                                 = Average recovery for four recovery measurements, in µg/L (Section 8.2.4).
                            </TNOTE>
                            <TNOTE>
                                P, P
                                <E T="52">s</E>
                                 = Percent recovery measured (Section 8.3.2, Section 8.4.2).
                            </TNOTE>
                            <TNOTE>D = Detected; result must be greater than zero.</TNOTE>
                            <TNOTE>
                                <E T="04">Note:</E>
                                 These criteria are based directly upon the method performance data in Table 3. Where necessary, the limits for recovery have been broadened to assure applicability of the limits to concentrations below those used to develop Table 3.
                            </TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="4" OPTS="L2" CDEF="s50,xls50,xls50,xls50">
                            <TTITLE>Table 3—Method Accuracy and Precision as Functions of Concentration—Method 601</TTITLE>
                            <BOXHD>
                                <CHED H="1">Parameter</CHED>
                                <CHED H="1">Accuracy, as recovery, X′ (µg/L)</CHED>
                                <CHED H="1">
                                    Single analyst precision, s
                                    <E T="52">r</E>
                                    ′ (µg/L)
                                </CHED>
                                <CHED H="1">Overall precision, S′ (µg/L)</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">Bromodichloromethane</ENT>
                                <ENT>1.12C−1.02</ENT>
                                <ENT>
                                    0.11X
                                    <AC T="8"/>
                                     + 0.04
                                </ENT>
                                <ENT>
                                    0.20X
                                    <AC T="8"/>
                                     + 1.00
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Bromoform</ENT>
                                <ENT>0.96C−2.05</ENT>
                                <ENT>
                                    0.12X
                                    <AC T="8"/>
                                     + 0.58
                                </ENT>
                                <ENT>
                                    0.21X
                                    <AC T="8"/>
                                     + 2.41
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Bromomethane</ENT>
                                <ENT>0.76C−1.27</ENT>
                                <ENT>
                                    0.28X
                                    <AC T="8"/>
                                     + 0.27
                                </ENT>
                                <ENT>
                                    0.36X
                                    <AC T="8"/>
                                     + 0.94
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Carbon tetrachloride</ENT>
                                <ENT>0.98C−1.04</ENT>
                                <ENT>
                                    0.15X
                                    <AC T="8"/>
                                     + 0.38
                                </ENT>
                                <ENT>
                                    0.20X
                                    <AC T="8"/>
                                     + 0.39
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chlorobenzene</ENT>
                                <ENT>1.00C−1.23</ENT>
                                <ENT>
                                    0.15X
                                    <AC T="8"/>
                                    −0.02
                                </ENT>
                                <ENT>
                                    0.18X
                                    <AC T="8"/>
                                     + 1.21
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Choroethane</ENT>
                                <ENT>0.99C−1.53</ENT>
                                <ENT>
                                    0.14X
                                    <AC T="8"/>
                                    −0.13
                                </ENT>
                                <ENT>
                                    0.17X
                                    <AC T="8"/>
                                     + 0.63
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    2-Chloroethylvinyl ether 
                                    <SU>a</SU>
                                     
                                </ENT>
                                <ENT>1.00C</ENT>
                                <ENT>
                                    0.20X
                                    <AC T="8"/>
                                </ENT>
                                <ENT>
                                    0.35X
                                    <AC T="8"/>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chloroform</ENT>
                                <ENT>0.93C−0.39</ENT>
                                <ENT>
                                    0.13X
                                    <AC T="8"/>
                                     + 0.15
                                </ENT>
                                <ENT>
                                    0.19X
                                    <AC T="8"/>
                                    −0.02
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chloromethane</ENT>
                                <ENT>0.77C + 0.18</ENT>
                                <ENT>
                                    0.28X
                                    <AC T="8"/>
                                    −0.31
                                </ENT>
                                <ENT>
                                    0.52X
                                    <AC T="8"/>
                                     + 1.31
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dibromochloromethane</ENT>
                                <ENT>0.94C + 2.72</ENT>
                                <ENT>
                                    0.11X
                                    <AC T="8"/>
                                     + 1.10
                                </ENT>
                                <ENT>
                                    0.24X
                                    <AC T="8"/>
                                     + 1.68
                                </ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="87"/>
                                <ENT I="01">1,2-Dichlorobenzene</ENT>
                                <ENT>0.93C + 1.70</ENT>
                                <ENT>
                                    0.20X
                                    <AC T="8"/>
                                     + 0.97
                                </ENT>
                                <ENT>
                                    0.13X
                                    <AC T="8"/>
                                     + 6.13
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,3-Dichlorobenzene</ENT>
                                <ENT>0.95C + 0.43</ENT>
                                <ENT>
                                    0.14X
                                    <AC T="8"/>
                                     + 2.33
                                </ENT>
                                <ENT>
                                    0.26X
                                    <AC T="8"/>
                                     + 2.34
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,4-Dichlorobenzene</ENT>
                                <ENT>0.93C−0.09</ENT>
                                <ENT>
                                    0.15X
                                    <AC T="8"/>
                                     + 0.29
                                </ENT>
                                <ENT>
                                    0.20X
                                    <AC T="8"/>
                                     + 0.41
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1-Dichloroethane</ENT>
                                <ENT>0.95C−1.08</ENT>
                                <ENT>
                                    0.09X
                                    <AC T="8"/>
                                     + 0.17
                                </ENT>
                                <ENT>
                                    0.14X
                                    <AC T="8"/>
                                     + 0.94
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2-Dichloroethane</ENT>
                                <ENT>1.04C−1.06</ENT>
                                <ENT>
                                    0.11X
                                    <AC T="8"/>
                                     + 0.70
                                </ENT>
                                <ENT>
                                    0.15X
                                    <AC T="8"/>
                                     + 0.94
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1-Dichloroethene</ENT>
                                <ENT>0.98C−0.87</ENT>
                                <ENT>
                                    0.21X
                                    <AC T="8"/>
                                    −0.23
                                </ENT>
                                <ENT>
                                    0.29X
                                    <AC T="8"/>
                                    −0.40
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">trans-1,2-Dichloroethene</ENT>
                                <ENT>0.97C−0.16</ENT>
                                <ENT>
                                    0.11X
                                    <AC T="8"/>
                                     + 1.46
                                </ENT>
                                <ENT>
                                    0.17X
                                    <AC T="8"/>
                                     + 1.46
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    1,2-Dichloropropane 
                                    <SU>a</SU>
                                     
                                </ENT>
                                <ENT>1.00C</ENT>
                                <ENT>
                                    0.13X
                                    <AC T="8"/>
                                </ENT>
                                <ENT>
                                    0.23X
                                    <AC T="8"/>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    cis-1,3-Dichloropropene 
                                    <SU>a</SU>
                                     
                                </ENT>
                                <ENT>1.00C</ENT>
                                <ENT>
                                    0.18X
                                    <AC T="8"/>
                                </ENT>
                                <ENT>
                                    0.32X
                                    <AC T="8"/>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    trans-1,3-Dichloropropene 
                                    <SU>a</SU>
                                     
                                </ENT>
                                <ENT>1.00C</ENT>
                                <ENT>
                                    0.18X
                                    <AC T="8"/>
                                </ENT>
                                <ENT>
                                    0.32X
                                    <AC T="8"/>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Methylene chloride</ENT>
                                <ENT>0.91C−0.93</ENT>
                                <ENT>
                                    0.11X
                                    <AC T="8"/>
                                     + 0.33
                                </ENT>
                                <ENT>
                                    0.21X
                                    <AC T="8"/>
                                     + 1.43
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1,2,2-Tetrachloroethene</ENT>
                                <ENT>0.95C + 0.19</ENT>
                                <ENT>
                                    0.14X
                                    <AC T="8"/>
                                     + 2.41
                                </ENT>
                                <ENT>
                                    0.23X
                                    <AC T="8"/>
                                     + 2.79
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Tetrachloroethene</ENT>
                                <ENT>0.94C + 0.06</ENT>
                                <ENT>
                                    0.14X
                                    <AC T="8"/>
                                     + 0.38
                                </ENT>
                                <ENT>
                                    0.18X
                                    <AC T="8"/>
                                     + 2.21
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1,1-Trichloroethane</ENT>
                                <ENT>0.90C−0.16</ENT>
                                <ENT>
                                    0.15X
                                    <AC T="8"/>
                                     + 0.04
                                </ENT>
                                <ENT>
                                    0.20X
                                    <AC T="8"/>
                                     + 0.37
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1,2-Trichloroethane</ENT>
                                <ENT>0.86C + 0.30</ENT>
                                <ENT>
                                    0.13X
                                    <AC T="8"/>
                                    −0.14
                                </ENT>
                                <ENT>
                                    0.19X
                                    <AC T="8"/>
                                     + 0.67
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Trichloroethene</ENT>
                                <ENT>0.87C + 0.48</ENT>
                                <ENT>
                                    0.13X
                                    <AC T="8"/>
                                    −0.03
                                </ENT>
                                <ENT>
                                    0.23X
                                    <AC T="8"/>
                                     + 0.30
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Trichlorofluoromethane</ENT>
                                <ENT>0.89C−0.07</ENT>
                                <ENT>
                                    0.15X
                                    <AC T="8"/>
                                     + 0.67
                                </ENT>
                                <ENT>
                                    0.26X
                                    <AC T="8"/>
                                     + 0.91
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Vinyl chloride</ENT>
                                <ENT>0.97C−0.36</ENT>
                                <ENT>
                                    0.13X
                                    <AC T="8"/>
                                     + 0.65
                                </ENT>
                                <ENT>
                                    0.27X
                                    <AC T="8"/>
                                     + 0.40
                                </ENT>
                            </ROW>
                            <TNOTE>
                                X
                                <AC T="8"/>
                                ′ = Expected recovery for one or more measurements of a sample containing a concentration of C, in µg/L.
                            </TNOTE>
                            <TNOTE>
                                s
                                <E T="52">n</E>
                                ′ = Expected single analyst standard deviation of measurements at an average concentration found of X
                                <AC T="8"/>
                                , in µg/L.
                            </TNOTE>
                            <TNOTE>
                                S
                                <SU>1</SU>
                                 = Expected interlaboratory standard deviation of measurements at an average concentration found of X
                                <AC T="8"/>
                                , in µg/L.
                            </TNOTE>
                            <TNOTE>C = True value for the concentration, in µg/L.</TNOTE>
                            <TNOTE>
                                X
                                <AC T="8"/>
                                 = Average recovery found for measurements of samples containing a concentration of C, in µg/L.
                            </TNOTE>
                            <TNOTE>
                                <SU>a</SU>
                                 Estimates based upon the performance in a single laboratory. 
                                <SU>10</SU>
                            </TNOTE>
                        </GPOTABLE>
                        <GPH SPAN="2" DEEP="424">
                            <PRTPAGE P="88"/>
                            <GID>EC02JY92.000</GID>
                        </GPH>
                        <GPH SPAN="2" DEEP="291">
                            <PRTPAGE P="89"/>
                            <GID>EC02JY92.001</GID>
                        </GPH>
                        <GPH SPAN="2" DEEP="462">
                            <PRTPAGE P="90"/>
                            <GID>EC02JY92.002</GID>
                        </GPH>
                        <GPH SPAN="2" DEEP="470">
                            <PRTPAGE P="91"/>
                            <GID>EC02JY92.003</GID>
                        </GPH>
                        <PRTPAGE P="92"/>
                        <HD SOURCE="HD1">Method 602—Purgeable Aromatics</HD>
                        <EAR>Pt. 136, App. A, Meth. 602</EAR>
                        <HD SOURCE="HD2">1. Scope and Application</HD>
                        <P>1.1 This method covers the determination of various purgeable aromatics. The following parameters may be determined by this method:</P>
                        <GPOTABLE COLS="3" OPTS="L2" CDEF="s10,7,10">
                            <BOXHD>
                                <CHED H="1">Parameter</CHED>
                                <CHED H="1">STORET No.</CHED>
                                <CHED H="1">CAS No.</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">Benzene</ENT>
                                <ENT>34030</ENT>
                                <ENT>71-43-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chlorobenzene</ENT>
                                <ENT>34301</ENT>
                                <ENT>108-90-7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2-Dichlorobenzene</ENT>
                                <ENT>34536</ENT>
                                <ENT>95-50-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,3-Dichlorobenzene</ENT>
                                <ENT>34566</ENT>
                                <ENT>541-73-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,4-Dichlorobenzene</ENT>
                                <ENT>34571</ENT>
                                <ENT>106-46-7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ethylbenzene</ENT>
                                <ENT>34371</ENT>
                                <ENT>100-41-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Toluene</ENT>
                                <ENT>34010</ENT>
                                <ENT>108-88-3</ENT>
                            </ROW>
                        </GPOTABLE>
                        <P>1.2 This is a purge and trap gas chromatographic (GC) method applicable to the determination of the compounds listed above in municipal and industrial discharges as provided under 40 CFR 136.1. When this method is used to analyze unfamiliar samples for any or all of the compounds above, compound identifications should be supported by at least one additional qualitative technique. This method describes analytical conditions for a second gas chromatographic column that can be used to confirm measurements made with the primary column. Method 624 provides gas chromatograph/mass spectrometer (GC/MS) conditions appropriate for the qualitative and quantitative confirmation of results for all of the parameters listed above.</P>
                        <P>
                            1.3 The method detection limit (MDL, defined in Section 12.1) 
                            <SU>1</SU>
                             for each parameter is listed in Table 1. The MDL for a specific wastewater may differ from those listed, depending upon the nature of interferences in the sample matrix.
                        </P>
                        <P>1.4 Any modification of this method, beyond those expressly permitted, shall be considered as a major modification subject to application and approval of alternate test procedures under 40 CFR 136.4 and 136.5.</P>
                        <P>1.5 This method is restricted to use by or under the supervision of analysts experienced in the operation of a purge and trap system and a gas chromatograph and in the interpretation of gas chromatograms. Each analyst must demonstrate the ability to generate acceptable results with this method using the procedure described in Section 8.2.</P>
                        <HD SOURCE="HD2">2. Summary of Method</HD>
                        <P>
                            2.1 An inert gas is bubbled through a 5-mL water sample contained in a specially-designed purging chamber at ambient temperature. The aromatics are efficiently transferred from the aqueous phase to the vapor phase. The vapor is swept through a sorbent trap where the aromatics are trapped. After purging is completed, the trap is heated and backflushed with the inert gas to desorb the aromatics onto a gas chromatographic column. The gas chromatograph is temperature programmed to separate the aromatics which are then detected with a photoionization detector. 
                            <SU>2 3</SU>
                        </P>
                        <P>2.2 The method provides an optional gas chromatographic column that may be helpful in resolving the compounds of interest from interferences that may occur.</P>
                        <HD SOURCE="HD2">3. Interferences</HD>
                        <P>3.1 Impurities in the purge gas and organic compounds outgassing from the plumbing ahead of the trap account for the majority of contamination problems. The analytical system must be demonstrated to be free from contamination under the conditions of the analysis by running laboratory reagent blanks as described in Section 8.1.3. The use of non-Teflon plastic tubing, non-Teflon thread sealants, or flow controllers with rubber components in the purge and trap system should be avoided.</P>
                        <P>3.2 Samples can be contaminated by diffusion of volatile organics through the septum seal into the sample during shipment and storage. A field reagent blank prepared from reagent water and carried through the sampling and handling protocol can serve as a check on such contamination.</P>
                        <P>3.3 Contamination by carry-over can occur whenever high level and low level samples are sequentially analyzed. To reduce carry-over, the purging device and sample syringe must be rinsed with reagent water between sample analyses. Whenever an unusually concentrated sample is encountered, it should be followed by an analysis of reagent water to check for cross contamination. For samples containing large amounts of water-soluble materials, suspended solids, high boiling compounds or high aromatic levels, it may be necessary to wash the purging device with a detergent solution, rinse it with distilled water, and then dry it in an oven at 105 °C between analyses. The trap and other parts of the system are also subject to contamination; therefore, frequent bakeout and purging of the entire system may be required.</P>
                        <HD SOURCE="HD2">4. Safety</HD>
                        <P>
                            4.1 The toxicity or carcinogenicity of each reagent used in this method has not been precisely defined; however, each chemical compound should be treated as a potential health hazard. From this viewpoint, exposure to these chemicals must be reduced to the lowest possible level by whatever means available. The laboratory is responsible for maintaining a current awareness file of OSHA regulations regarding the safe handling of the chemicals specified in this method. A reference file of material data handling sheets should also be made available to all personnel involved in the chemical analysis. Additional references to laboratory safety 
                            <PRTPAGE P="93"/>
                            are available and have been identified 
                            <SU>4 6</SU>
                             for the information of the analyst.
                        </P>
                        <P>4.2 The following parameters covered by this method have been tentatively classified as known or suspected, human or mammalian carcinogens: benzene and 1,4-dichlorobenzene. Primary standards of these toxic compounds should be prepared in a hood. A NIOSH/MESA approved toxic gas respirator should be worn when the analyst handles high concentrations of these toxic compounds.</P>
                        <HD SOURCE="HD2">5. Apparatus and Materials</HD>
                        <P>5.1 Sampling equipment, for discrete sampling.</P>
                        <P>5.1.1 Vial]25-mL capacity or larger, equipped with a screw cap with a hole in the center (Pierce #13075 or equivalent). Detergent wash, rinse with tap and distilled water, and dry at 105 °C before use.</P>
                        <P>5.1.2 Septum—Teflon-faced silicone (Pierce #12722 or equivalent). Detergent wash, rinse with tap and distilled water, and dry at 105 °C for 1 h before use.</P>
                        <P>5.2 Purge and trap system—The purge and trap system consists of three separate pieces of equipment: A purging device, trap, and desorber. Several complete systems are now commercially available.</P>
                        <P>5.2.1 The purging device must be designed to accept 5-mL samples with a water column at least 3 cm deep. The gaseous head space between the water column and the trap must have a total volume of less than 15 mL. The purge gas must pass through the water column as finely divided bubbles with a diameter of less than 3 mm at the origin. The purge gas must be introduced no more than 5 mm from the base of the water column. The purging device illustrated in Figure 1 meets these design criteria.</P>
                        <P>5.2.2 The trap must be at least 25 cm long and have an inside diameter of at least 0.105 in.</P>
                        <P>5.2.2.1 The trap is packed with 1 cm of methyl silicone coated packing (Section 6.4.2) and 23 cm of 2,6-diphenylene oxide polymer (Section 6.4.1) as shown in Figure 2. This trap was used to develop the method performance statements in Section 12.</P>
                        <P>5.2.2.2 Alternatively, either of the two traps described in Method 601 may be used, although water vapor will preclude the measurement of low concentrations of benzene.</P>
                        <P>5.2.3 The desorber must be capable of rapidly heating the trap to 180 °C. The polymer section of the trap should not be heated higher than 180 °C and the remaining sections should not exceed 200 °C. The desorber illustrated in Figure 2 meets these design criteria.</P>
                        <P>5.2.4 The purge and trap system may be assembled as a separate unit or be coupled to a gas chromatograph as illustrated in Figures 3, 4, and 5.</P>
                        <P>5.3 Gas chromatograph—An analytical system complete with a temperature programmable gas chromatograph suitable for on-column injection and all required accessories including syringes, analytical columns, gases, detector, and strip-chart recorder. A data system is recommended for measuring peak areas.</P>
                        <P>5.3.1 Column 1—6 ft long × 0.082 in. ID stainless steel or glass, packed with 5% SP-1200 and 1.75% Bentone-34 on Supelcoport (100/120 mesh) or equivalent. This column was used to develop the method performance statements in Section 12. Guidelines for the use of alternate column packings are provided in Section 10.1.</P>
                        <P>5.3.2 Column 2—8 ft long × 0.1 in ID stainless steel or glass, packed with 5% 1,2,3-Tris(2-cyanoethoxy)propane on Chromosorb W-AW (60/80 mesh) or equivalent.</P>
                        <P>5.3.3 Detector—Photoionization detector (h-Nu Systems, Inc. Model PI-51-02 or equivalent). This type of detector has been proven effective in the analysis of wastewaters for the parameters listed in the scope (Section 1.1), and was used to develop the method performance statements in Section 12. Guidelines for the use of alternate detectors are provided in Section 10.1.</P>
                        <P>5.4 Syringes—5-mL glass hypodermic with Luerlok tip (two each), if applicable to the purging device.</P>
                        <P>5.5 Micro syringes—25-µL, 0.006 in. ID needle.</P>
                        <P>5.6 Syringe valve—2-way, with Luer ends (three each).</P>
                        <P>5.7 Bottle—15-mL, screw-cap, with Teflon cap liner.</P>
                        <P>5.8 Balance—Analytical, capable of accurately weighing 0.0001 g.</P>
                        <HD SOURCE="HD2">6. Reagents</HD>
                        <P>6.1 Reagent water—Reagent water is defined as a water in which an interferent is not observed at the MDL of the parameters of interest.</P>
                        <P>6.1.1 Reagent water can be generated by passing tap water through a carbon filter bed containing about 1 lb of activated carbon (Filtrasorb-300, Calgon Corp., or equivalent).</P>
                        <P>6.1.2 A water purification system (Millipore Super-Q or equivalent) may be used to generate reagent water.</P>
                        <P>6.1.3 Reagent water may also be prepared by boiling water for 15 min. Subsequently, while maintaining the temperature at 90 °C, bubble a contaminant-free inert gas through the water for 1 h. While still hot, transfer the water to a narrow mouth screw-cap bottle and seal with a Teflon-lined septum and cap.</P>
                        <P>6.2 Sodium thiosulfate—(ACS) Granular.</P>
                        <P>6.3 Hydrochloric acid (1 + 1)—Add 50 mL of concentrated HCl (ACS) to 50 mL of reagent water.</P>
                        <P>
                            6.4 Trap Materials:
                            <PRTPAGE P="94"/>
                        </P>
                        <P>6.4.1 2,6-Diphenylene oxide polymer—Tenax, (60/80 mesh), chromatographic grade or equivalent.</P>
                        <P>6.4.2 Methyl silicone packing—3% OV-1 on Chromosorb-W (60/80 mesh) or equivalent.</P>
                        <P>6.5 Methanol—Pesticide quality or equivalent.</P>
                        <P>6.6 Stock standard solutions—Stock standard solutions may be prepared from pure standard materials or purchased as certified solutions. Prepare stock standard solutions in methanol using assayed liquids. Because of the toxicity of benzene and 1,4-dichlorobenzene, primary dilutions of these materials should be prepared in a hood. A NIOSH/MESA approved toxic gas respirator should be used when the analyst handles high concentrations of such materials.</P>
                        <P>6.6.1 Place about 9.8 mL of methanol into a 10-mL ground glass stoppered volumetric flask. Allow the flask to stand, unstoppered, for about 10 min or until all alcohol wetted surfaces have dried. Weigh the flask to the nearest 0.1 mg.</P>
                        <P>6.6.2 Using a 100-µL syringe, immediately add two or more drops of assayed reference material to the flask, then reweigh. Be sure that the drops fall directly into the alcohol without contacting the neck of the flask.</P>
                        <P>6.6.3 Reweigh, dilute to volume, stopper, then mix by inverting the flask several times. Calculate the concentration in µg/µL from the net gain in weight. When compound purity is assayed to be 96% or greater, the weight can be used without correction to calculate the concentration of the stock standard. Commercially prepared stock standards can be used at any concentration if they are certified by the manufacturer or by an independent source.</P>
                        <P>6.6.4 Transfer the stock standard solution into a Teflon-sealed screw-cap bottle. Store at 4 °C and protect from light.</P>
                        <P>6.6.5 All standards must be replaced after one month, or sooner if comparison with check standards indicates a problem.</P>
                        <P>6.7 Secondary dilution standards—Using stock standard solutions, prepare secondary dilution standards in methanol that contain the compounds of interest, either singly or mixed together. The secondary dilution standards should be prepared at concentrations such that the aqueous calibration standards prepared in Section 7.3.1 or 7.4.1 will bracket the working range of the analytical system. Secondary solution standards must be stored with zero headspace and should be checked frequently for signs of degradation or evaporation, especially just prior to preparing calibration standards from them.</P>
                        <P>6.8 Quality control check sample concentrate—See Section 8.2.1.</P>
                        <HD SOURCE="HD2">7. Calibration</HD>
                        <P>7.1 Assemble a purge and trap system that meets the specifications in Section 5.2. Condition the trap overnight at 180 °C by backflushing with an inert gas flow of at least 20 mL/min. Condition the trap for 10 min once daily prior to use.</P>
                        <P>7.2 Connect the purge and trap system to a gas chromatograph. The gas chromatograph must be operated using temperature and flow rate conditions equivalent to those given in Table 1. Calibrate the purge and trap-gas chromatographic system using either the external standard technique (Section 7.3) or the internal standard technique (Section 7.4).</P>
                        <P>7.3 External standard calibration procedure:</P>
                        <P>7.3.1 Prepare calibration standards at a minimum of three concentration levels for each parameter by carefully adding 20.0 µL of one or more secondary dilution standards to 100, 500, or 1000 mL of reagent water. A 25-µL syringe with a 0.006 in. ID needle should be used for this operation. One of the external standards should be at a concentration near, but above, the MDL (Table 1) and the other concentrations should correspond to the expected range of concentrations found in real samples or should define the working range of the detector. These aqueous standards must be prepared fresh daily.</P>
                        <P>7.3.2 Analyze each calibration standard according to Section 10, and tabulate peak height or area responses versus the concentration in the standard. The results can be used to prepare a calibration curve for each compound. Alternatively, if the ratio of response to concentration (calibration factor) is a constant over the working range (&lt;10% relative standard deviation, RSD), linearity through the origin can be assumed and the average ratio or calibration factor can be used in place of a calibration curve.</P>
                        <P>7.4 Internal standard calibration procedure—To use this approach, the analyst must select one or more internal standards that are similar in analytical behavior to the compounds of interest. The analyst must further demonstrate that the measurement of the internal standard is not affected by method or matrix interferences. Because of these limitations, no internal standard can be suggested that is applicable to all samples. The compound, α,α,α,-trifluorotoluene, recommended as a surrogate spiking compound in Section 8.7 has been used successfully as an internal standard.</P>
                        <P>7.4.1 Prepare calibration standards at a minimum of three concentration levels for each parameter of interest as described in Section 7.3.1.</P>
                        <P>
                            7.4.2 Prepare a spiking solution containing each of the internal standards using the procedures described in Sections 6.6 and 6.7. It is recommended that the secondary dilution standard be prepared at a concentration of 15 µg/mL of each internal standard compound. The addition of 10 µl of this 
                            <PRTPAGE P="95"/>
                            standard to 5.0 mL of sample or calibration standard would be equivalent to 30 µg/L.
                        </P>
                        <P>7.4.3 Analyze each calibration standard according to Section 10, adding 10 µL of internal standard spiking solution directly to the syringe (Section 10.4). Tabulate peak height or area responses against concentration for each compound and internal standard, and calculate response factors (RF) for each compound using Equation 1.</P>
                        <FP SOURCE="FP-2">
                            RF = (A
                            <E T="52">s</E>
                            )(C
                            <E T="52">is</E>
                             (A
                            <E T="52">is</E>
                            )(C
                            <E T="52">s</E>
                            )
                        </FP>
                        <FP>Equation 1</FP>
                        <FP>where:</FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">s</E>
                             = Response for the parameter to be measured.
                        </FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">is</E>
                             = Response for the internal standard.
                        </FP>
                        <FP SOURCE="FP-2">
                            C
                            <E T="52">is</E>
                             = Concentration of the internal standard
                        </FP>
                        <FP SOURCE="FP-2">
                            C
                            <E T="52">s</E>
                             = Concentration of the parameter to be measured.
                        </FP>
                        <FP>
                            If the RF value over the working range is a constant (&lt;10% RSD), the RF can be assumed to be invariant and the average RF can be used for calculations. Alternatively, the results can be used to plot a calibration curve of response ratios, A
                            <E T="52">s</E>
                            /A
                            <E T="52">is</E>
                            , vs. RF.
                        </FP>
                        <P>7.5 The working calibration curve, calibration factor, or RF must be verified on each working day by the measurement of a QC check sample.</P>
                        <P>7.5.1 Prepare the QC check sample as described in Section 8.2.2.</P>
                        <P>7.5.2 Analyze the QC check sample according to Section 10.</P>
                        <P>7.5.3 For each parameter, compare the response (Q) with the corresponding calibration acceptance criteria found in Table 2. If the responses for all parameters of interest fall within the designated ranges, analysis of actual samples can begin. If any individual Q falls outside the range, a new calibration curve, calibration factor, or RF must be prepared for that parameter according to Section 7.3 or 7.4.</P>
                        <HD SOURCE="HD2">8. Quality Control</HD>
                        <P>8.1 Each laboratory that uses this method is required to operate a formal quality control program. The minimum requirements of this program consist of an initial demonstration of laboratory capability and an ongoing analysis of spiked samples to evaluate and document data quality. The laboratory must maintain records to document the quality of data that is generated. Ongoing data quality checks are compared with established performance criteria to determine if the results of analyses meet the performance characteristics of the method. When results of sample spikes indicate atypical method performance, a quality control check standard must be analyzed to confirm that the measurements were performed in an in-control mode of operation.</P>
                        <P>8.1.1 The analyst must make an initial, one-time, demonstration of the ability to generate acceptable accuracy and precision with this method. This ability is established as described in Section 8.2.</P>
                        <P>8.1.2 In recognition of advances that are occurring in chromatography, the analyst is permitted certain options (detailed in Section 10.1) to improve the separations or lower the cost of measurements. Each time such a modification is made to the method, the analyst is required to repeat the procedure in Section 8.2.</P>
                        <P>8.1.3 Each day, the analyst must analyze a reagent water blank to demonstrate that interferences from the analytical system are under control.</P>
                        <P>8.1.4 The laboratory must, on an ongoing basis, spike and analyze a minimum of 10% of all samples to monitor and evaluate laboratory data quality. This procedure is described in Section 8.3.</P>
                        <P>8.1.5 The laboratory must, on an ongoing basis, demonstrate through the analyses of quality control check standards that the operation of the measurement system is in control. This procedure is described in Section 8.4. The frequency of the check standard analyses is equivalent to 10% of all samples analyzed but may be reduced if spike recoveries from samples (Section 8.3) meet all specified quality control criteria.</P>
                        <P>8.1.6 The laboratory must maintain performance records to document the quality of data that is generated. This procedure is described in Section 8.5.</P>
                        <P>8.2 To establish the ability to generate acceptable accuracy and precision, the analyst must perform the following operations.</P>
                        <P>8.2.1 A quality control (QC) check sample concentrate is required containing each parameter of interest at a concentration of 10 µg/mL in methanol. The QC check sample concentrate must be obtained from the U.S. Environmental Protection Agency, Environmental Monitoring and Support Laboratory in Cincinnati, Ohio, if available. If not available from that source, the QC check sample concentrate must be obtained from another external source. If not available from either source above, the QC check sample concentrate must be prepared by the laboratory using stock standards prepared independently from those used for calibration.</P>
                        <P>8.2.2 Prepare a QC check sample to contain 20 µg/L of each parameter by adding 200 µL of QC check sample concentrate to 100 mL of reagant water.</P>
                        <P>8.2.3 Analyze four 5-mL aliquots of the well-mixed QC check sample according to Section 10.</P>
                        <P>
                            8.2.4 Calculate the average recovery (X
                            <AC T="8"/>
                            ) in µg/L, and the standard deviation of the recovery (s) in µg/L, for each parameter of interest using the four results.
                        </P>
                        <P>
                            8.2.5 For each parameter compare s and X
                            <AC T="8"/>
                             with the corresponding acceptance criteria for precision and accuracy, respectively, 
                            <PRTPAGE P="96"/>
                            found in Table 2. If s and X
                            <AC T="8"/>
                             for all parameters of interest meet the acceptance criteria, the system performance is acceptable and analysis of actual samples can begin. If any individual s exceeds the precision limit or any individual X
                            <AC T="8"/>
                             falls outside the range for accuracy, the system performance is unacceptable for that parameter.
                        </P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>The large number of parameters in Table 2 present a substantial probability that one or more will fail at least one of the acceptance criteria when all parameters are analyzed.</P>
                        </NOTE>
                        <P>8.2.6 When one or more of the parameters tested fail at least one of the acceptance criteria, the analyst must proceed according to Section 8.2.6.1 or 8.2.6.2.</P>
                        <P>8.2.6.1 Locate and correct the source of the problem and repeat the test for all parameters of interest beginning with Section 8.2.3.</P>
                        <P>8.2.6.2 Beginning with Section 8.2.3, repeat the test only for those parameters that failed to meet criteria. Repeated failure, however, will confirm a general problem with the measurement system. If this occurs, locate and correct the source of the problem and repeat the test for all compounds of interest beginning with Section 8.2.3.</P>
                        <P>8.3 The laboratory must, on an ongoing basis, spike at least 10% of the samples from each sample site being monitored to assess accuracy. For laboratories analyzing one to ten samples per month, at least one spiked sample per month is required.</P>
                        <P>8.3.1 The concentration of the spike in the sample should be determined as follows:</P>
                        <P>8.3.1.1 If, as in compliance monitoring, the concentration of a specific parameter in the sample is being checked against a regulatory concentration limit, the spike should be at that limit or 1 to 5 times higher than the background concentration determined in Section 8.3.2, whichever concentration would be larger.</P>
                        <P>8.3.1.2 If the concentration of a specific parameter in the sample is not being checked against a limit specific to that parameter, the spike should be at 20 µg/L or 1 to 5 times higher than the background concentration determined in Section 8.3.2, whichever concentration would be larger.</P>
                        <P>8.3.2 Analyze one 5-mL sample aliquot to determine the background concentration (B) of each parameter. If necessary, prepare a new QC check sample concentrate (Section 8.2.1) appropriate for the background concentrations in the sample. Spike a second 5-mL sample aliquot with 10 µL of the QC check sample concentrate and analyze it to determine the concentration after spiking (A) of each parameter. Calculate each percent recovery (P) as 100(A−B)%/T, where T is the known true value of the spike.</P>
                        <P>
                            8.3.3 Compare the percent recovery (P) for each parameter with the corresponding QC acceptance criteria found in Table 2. These acceptance criteria were calculated to include an allowance for error in measurement of both the background and spike concentrations, assuming a spike to background ratio of 5:1. This error will be accounted for to the extent that the analyst's spike to background ratio approaches 5:1. 
                            <SU>7</SU>
                             If spiking was performed at a concentration lower than 20 µg/L, the analyst must use either the QC acceptance criteria in Table 2, or optional QC acceptance criteria calculated for the specific spike concentration. To calculate optional acceptance criteria for the recovery of a parameter: (1) Calculate accuracy (X′) using the equation in Table 3, substituting the spike concentration (T) for C; (2) calculate overall precision (S′) using the equation in Table 3, substituting X′ for X
                            <AC T="8"/>
                            ; (3) calculate the range for recovery at the spike concentration as (100 X′/T) ±2.44(100 S′/T)%. 
                            <SU>7</SU>
                        </P>
                        <P>8.3.4 If any individual P falls outside the designated range for recovery, that parameter has failed the acceptance criteria. A check standard containing each parameter that failed the criteria must be analyzed as described in Section 8.4.</P>
                        <P>8.4 If any parameter fails the acceptance criteria for recovery in Section 8.3, a QC check standard containing each parameter that failed must be prepared and analyzed.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>The frequency for the required analysis of a QC check standard will depend upon the number of parameters being simultaneously tested, the complexity of the sample matrix, and the performance of the laboratory.</P>
                        </NOTE>
                        <P>8.4.1 Prepare the QC check standard by adding 10 µL of QC check sample concentrate (Section 8.2.1 or 8.3.2) to 5 mL of reagent water. The QC check standard needs only to contain the parameters that failed criteria in the test in Section 8.3.</P>
                        <P>
                            8.4.2 Analyze the QC check standard to determine the concentration measured (A) of each parameter. Calculate each percent recovery (P
                            <E T="52">s</E>
                            ) as 100 (A/T)%, where T is the true value of the standard concentration.
                        </P>
                        <P>
                            8.4.3 Compare the percent recovery (P
                            <E T="52">s</E>
                            ) for each parameter with the corresponding QC acceptance criteria found in Table 2. Only parameters that failed the test in Section 8.3 need to be compared with these criteria. If the recovery of any such parameter falls outside the designated range, the laboratory performance for that parameter is judged to be out of control, and the problem must be immediately identified and corrected. The analytical result for that parameter in the unspiked sample is suspect and may not be reported for regulatory compliance purposes.
                        </P>
                        <P>
                            8.5 As part of the QC program for the laboratory, method accuracy for wastewater samples must be assessed and records must be maintained. After the analysis of five spiked wastewater samples as in Section 8.3, calculate the average percent recovery (P
                            <AC T="8"/>
                            ) 
                            <PRTPAGE P="97"/>
                            and the standard deviation of the percent recovery (s
                            <E T="52">p</E>
                            ). Express the accuracy assessment as a percent recovery interval from P
                            <AC T="8"/>
                            −2s
                            <E T="52">p</E>
                             to P
                            <AC T="8"/>
                             + 2s
                            <E T="52">p</E>
                            . If P
                            <AC T="8"/>
                             = 90% and s
                            <E T="52">p</E>
                             = 10%, for example, the accuracy interval is expressed as 70-110%. Update the accuracy assessment for each parameter on a regular basis (e.g. after each five to ten new accuracy measurements).
                        </P>
                        <P>8.6 It is recommended that the laboratory adopt additional quality assurance practices for use with this method. The specific practices that are most productive depend upon the needs of the laboratory and the nature of the samples. Field duplicates may be analyzed to assess the precision of the environmental measurements. When doubt exists over the identification of a peak on the chromatogram, confirmatory techniques such as gas chromatography with a dissimilar column, specific element detector, or mass spectrometer must be used. Whenever possible, the laboratory should analyze standard reference materials and participate in relevant performance evaluation studies.</P>
                        <P>8.7 The analyst should monitor both the performance of the analytical system and the effectiveness of the method in dealing with each sample matrix by spiking each sample, standard, and reagent water blank with surrogate compounds (e.g. α, α, α,-trifluorotoluene) that encompass the range of the temperature program used in this method. From stock standard solutions prepared as in Section 6.6, add a volume to give 750 µg of each surrogate to 45 mL of reagent water contained in a 50-mL volumetric flask, mix and dilute to volume for a concentration of 15 mg/µL. Add 10 µL of this surrogate spiking solution directly into the 5-mL syringe with every sample and reference standard analyzed. Prepare a fresh surrogate spiking solution on a weekly basis. If the internal standard calibration procedure is being used, the surrogate compounds may be added directly to the internal standard spiking solution (Section 7.4.2).</P>
                        <HD SOURCE="HD2">9. Sample Collection, Preservation, and Handling</HD>
                        <P>
                            9.1 The samples must be iced or refrigerated from the time of collection until analysis. If the sample contains free or combined chlorine, add sodium thiosulfate preservative (10 mg/40 mL is sufficient for up to 5 ppm Cl
                            <E T="52">2</E>
                            ) to the empty sample bottle just prior to shipping to the sampling site. EPA Method 330.4 or 330.5 may be used for measurement of residual chlorine. 
                            <SU>8</SU>
                             Field test kits are available for this purpose.
                        </P>
                        <P>9.2 Collect about 500 mL of sample in a clean container. Adjust the pH of the sample to about 2 by adding 1 + 1 HCl while stirring. Fill the sample bottle in such a manner that no air bubbles pass through the sample as the bottle is being filled. Seal the bottle so that no air bubbles are entrapped in it. Maintain the hermetic seal on the sample bottle until time of analysis.</P>
                        <P>
                            9.3 All samples must be analyzed within 14 days of collection. 
                            <SU>3</SU>
                        </P>
                        <HD SOURCE="HD2">10. Procedure</HD>
                        <P>10.1 Table 1 summarizes the recommended operating conditions for the gas chromatograph. Included in this table are estimated retention times and MDL that can be achieved under these conditions. An example of the separations achieved by Column 1 is shown in Figure 6. Other packed columns, chromatographic conditions, or detectors may be used if the requirements of Section 8.2 are met.</P>
                        <P>10.2 Calibrate the system daily as described in Section 7.</P>
                        <P>10.3 Adjust the purge gas (nitrogen or helium) flow rate to 40 mL/min. Attach the trap inlet to the purging device, and set the purge and trap system to purge (Figure 3). Open the syringe valve located on the purging device sample introduction needle.</P>
                        <P>10.4 Allow the sample to come to ambient temperature prior to introducing it to the syringe. Remove the plunger from a 5-mL syringe and attach a closed syringe valve. Open the sample bottle (or standard) and carefully pour the sample into the syringe barrel to just short of overflowing. Replace the syringe plunger and compress the sample. Open the syringe valve and vent any residual air while adjusting the sample volume to 5.0 mL. Since this process of taking an aliquot destroys the validity of the sample for future analysis, the analyst should fill a second syringe at this time to protect against possible loss of data. Add 10.0 µL of the surrogate spiking solution (Section 8.7) and 10.0 µL of the internal standard spiking solution (Section 7.4.2), if applicable, through the valve bore, then close the valve.</P>
                        <P>10.5 Attach the syringe-syringe valve assembly to the syringe valve on the purging device. Open the syringe valves and inject the sample into the purging chamber.</P>
                        <P>10.6 Close both valves and purge the sample for 12.0 ±0.1 min at ambient temperature.</P>
                        <P>
                            10.7 After the 12-min purge time, disconnect the purging device from the trap. Dry the trap by maintaining a flow of 40 mL/min of dry purge gas through it for 6 min (Figure 4). If the purging device has no provision for bypassing the purger for this step, a dry purger should be inserted into the device to minimize moisture in the gas. Attach the trap to the chromatograph, adjust the purge and trap system to the desorb mode (Figure 5), and begin to temperature program the gas chromatograph. Introduce the trapped materials to the GC column by rapidly heating the trap to 180 °C while backflushing the trap with an inert gas between 20 and 60 mL/min for 4 min. If rapid heating of the trap cannot be achieved, the GC column must be used as 
                            <PRTPAGE P="98"/>
                            a secondary trap by cooling it to 30 °C (subambient temperature, if poor peak geometry and random retention time problems persist) instead of the initial program temperature of 50 °C.
                        </P>
                        <P>10.8 While the trap is being desorbed into the gas chromatograph column, empty the purging chamber using the sample introduction syringe. Wash the chamber with two 5-mL flushes of reagent water.</P>
                        <P>10.9 After desorbing the sample for 4 min, recondition the trap by returning the purge and trap system to the purge mode. Wait 15 s, then close the syringe valve on the purging device to begin gas flow through the trap. The trap temperature should be maintained at 180 °C. After approximately 7 min, turn off the trap heater and open the syringe valve to stop the gas flow through the trap. When the trap is cool, the next sample can be analyzed.</P>
                        <P>10.10 Identify the parameters in the sample by comparing the retention times of the peaks in the sample chromatogram with those of the peaks in standard chromatograms. The width of the retention time window used to make identifications should be based upon measurements of actual retention time variations of standards over the course of a day. Three times the standard deviation of a retention time for a compound can be used to calculate a suggested window size; however, the experience of the analyst should weigh heavily in the interpretation of chromatograms.</P>
                        <P>10.11 If the response for a peak exceeds the working range of the system, prepare a dilution of the sample with reagent water from the aliquot in the second syringe and reanalyze.</P>
                        <HD SOURCE="HD2">11. Calculations</HD>
                        <P>11.1 Determine the concentration of individual compounds in the sample.</P>
                        <P>11.1.1 If the external standard calibration procedure is used, calculate the concentration of the parameter being measured from the peak response using the calibration curve or calibration factor determined in Section 7.3.2.</P>
                        <P>11.1.2 If the internal standard calibration procedure is used, calculate the concentration in the sample using the response factor (RF) determined in Section 7.4.3 and Equation 2.</P>
                        <MATH SPAN="1" DEEP="31">
                            <MID>EC15NO91.096</MID>
                        </MATH>
                        <P>Equation 2</P>
                        <FP>where:</FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">s</E>
                             = Response for the parameter to be measured.
                        </FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">is</E>
                             = Response for the internal standard.
                        </FP>
                        <FP SOURCE="FP-2">
                            C
                            <E T="52">is</E>
                             = Concentration of the internal standard.
                        </FP>
                        <P>11.2 Report results in µg/L without correction for recovery data. All QC data obtained should be reported with the sample results.</P>
                        <HD SOURCE="HD2">12. Method Performance</HD>
                        <P>
                            12.1 The method detection limit (MDL) is defined as the minimum concentration of a substance that can be measured and reported with 99% confidence that the value is above zero. 
                            <SU>1</SU>
                             The MDL concentrations listed in Table 1 were obtained using reagent water. 
                            <SU>9</SU>
                             Similar results were achieved using representative wastewaters. The MDL actually achieved in a given analysis will vary depending on instrument sensitivity and matrix effects.
                        </P>
                        <P>
                            12.2 This method has been demonstrated to be applicable for the concentration range from the MDL to 100 × MDL. 
                            <SU>9</SU>
                             Direct aqueous injection techniques should be used to measure concentration levels above 1000 × MDL.
                        </P>
                        <P>
                            12.3 This method was tested by 20 laboratories using reagent water, drinking water, surface water, and three industrial wastewaters spiked at six concentrations over the range 2.1 to 550 µg/L. 
                            <SU>9</SU>
                             Single operator precision, overall precision, and method accuracy were found to be directly related to the concentration of the parameter and essentially independent of the sample matrix. Linear equations to describe these relationships are presented in Table 3.
                        </P>
                        <HD SOURCE="HD2">References</HD>
                        <P>1. 40 CFR part 136, appendix B.</P>
                        <P>
                            2. Lichtenberg, J.J. “Determining Volatile Organics at Microgram-per-Litre-Levels by Gas Chromatography,” Journal American Water Works Association, 
                            <E T="03">66,</E>
                             739 (1974).
                        </P>
                        <P>3. Bellar, T.A., and Lichtenberg, J.J. “Semi-Automated Headspace Analysis of Drinking Waters and Industrial Waters for Purgeable Volatile Organic Compounds,” Proceedings of Symposium on Measurement of Organic Pollutants in Water and Wastewater. American Society for Testing and Materials, STP 686, C.E. Van Hall, editor, 1978.</P>
                        <P>4. “Carcinogens—Working with Carcinogens,” Department of Health, Education, and Welfare, Public Health Service, Center for Disease Control, National Institute for Occupational Safety and Health. Publication No. 77-206, August 1977.</P>
                        <P>5. “OSHA Safety and Health Standards, General Industry,” (29 CFR part 1910), Occupational Safety and Health Administration, OSHA 2206 (Revised, January 1976).</P>
                        <P>6. “Safety in Academic Chemistry Laboratories,” American Chemical Society Publication, Committee on Safety, 3rd Edition, 1979.</P>
                        <P>
                            7. Provost, L.P., and Elder, R.S. “Interpretation of Percent Recovery Data,” 
                            <E T="03">American Laboratory, 15,</E>
                             58-63 (1983). (The value 2.44 used in the equation in Section 8.3.3. is two times the value 1.22 derived in this report.)
                            <PRTPAGE P="99"/>
                        </P>
                        <P>8.“Methods 330.4 (Titrimetric, DPD-FAS) and 330.5 (Spectrophotometric, DPD) for Chlorine, Total Residual,” Methods for Chemical Analysis of Water and Wastes, EPA-600/4-79-020, U.S. Environmental Protection Agency, Office of Research and Development, Environmental Monitoring and Support Laboratory, Cincinnati, Ohio 45268. March 1979.</P>
                        <P>9. “EPA Method Study 25, Method 602, Purgeable Aromatics,” EPA 600/4-84-042, National Technical Information Service, PB84-196682, Springfield, Virginia 22161, May 1984.</P>
                        <GPOTABLE COLS="4" OPTS="L2" CDEF="s50,5.2,5.2,5.2">
                            <TTITLE>Table 1—Chromatographic Conditions and Method Detection Limits</TTITLE>
                            <BOXHD>
                                <CHED H="1">Parameter</CHED>
                                <CHED H="1">Retention time (min)</CHED>
                                <CHED H="2">Column 1</CHED>
                                <CHED H="2">Column 2</CHED>
                                <CHED H="1">Method detection limit (µg/L)</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">Benzene</ENT>
                                <ENT>3.33</ENT>
                                <ENT>2.75</ENT>
                                <ENT>0.2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Toluene</ENT>
                                <ENT>5.75</ENT>
                                <ENT>4.25</ENT>
                                <ENT>0.2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ethylbenzene</ENT>
                                <ENT>8.25</ENT>
                                <ENT>6.25</ENT>
                                <ENT>0.2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chlorobenzene</ENT>
                                <ENT>9.17</ENT>
                                <ENT>8.02</ENT>
                                <ENT>0.2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,4-Dichlorobenzene</ENT>
                                <ENT>16.8</ENT>
                                <ENT>16.2</ENT>
                                <ENT>0.3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,3-Dichlorobenzene</ENT>
                                <ENT>18.2</ENT>
                                <ENT>15.0</ENT>
                                <ENT>0.4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2-Dichlorobenzene</ENT>
                                <ENT>25.9</ENT>
                                <ENT>19.4</ENT>
                                <ENT>0.4</ENT>
                            </ROW>
                            <TNOTE>Column 1 conditions: Supelcoport (100/120 mesh) coated with 5% SP-1200/1.75% Bentone-34 packed in a 6 ft × 0.085 in. ID stainless steel column with helium carrier gas at 36 mL/min flow rate. Column temperature held at 50 °C for 2 min then programmed at 6 °C/min to 90 °C for a final hold.</TNOTE>
                            <TNOTE>Column 2 conditions: Chromosorb W-AW (60/80 mesh) coated with 5% 1,2,3-Tris(2-cyanoethyoxy)propane packed in a 6 ft × 0.085 in. ID stainless steel column with helium carrier gas at 30 mL/min flow rate. Column temperature held at 40 °C for 2 min then programmed at 2 °C/min to 100 °C for a final hold.</TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="5" OPTS="L2" CDEF="s50,10,7,10,8">
                            <TTITLE>
                                Table 2—Calibration and QC Acceptance Criteria—Method 602 
                                <E T="01">
                                    <SU>a</SU>
                                </E>
                            </TTITLE>
                            <BOXHD>
                                <CHED H="1">Parameter</CHED>
                                <CHED H="1">Range for Q (µg/L)</CHED>
                                <CHED H="1">Limit for s (µg/L)</CHED>
                                <CHED H="1">
                                    Range for X
                                    <AC T="8"/>
                                     (µg/L)
                                </CHED>
                                <CHED H="1">
                                    Range for P, P
                                    <E T="52">s</E>
                                    (%)
                                </CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">Benzene</ENT>
                                <ENT>15.4-24.6</ENT>
                                <ENT>4.1</ENT>
                                <ENT>10.0-27.9</ENT>
                                <ENT>39-150</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chlorobenzene</ENT>
                                <ENT>16.1-23.9</ENT>
                                <ENT>3.5</ENT>
                                <ENT>12.7-25.4</ENT>
                                <ENT>55-135</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2-Dichlorobenzene</ENT>
                                <ENT>13.6-26.4</ENT>
                                <ENT>5.8</ENT>
                                <ENT>10.6-27.6</ENT>
                                <ENT>37-154</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,3-Dichlorobenzene</ENT>
                                <ENT>14.5-25.5</ENT>
                                <ENT>5.0</ENT>
                                <ENT>12.8-25.5</ENT>
                                <ENT>50-141</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,4-Dichlorobenzene</ENT>
                                <ENT>13.9-26.1</ENT>
                                <ENT>5.5</ENT>
                                <ENT>11.6-25.5</ENT>
                                <ENT>42-143</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ethylbenzene</ENT>
                                <ENT>12.6-27.4</ENT>
                                <ENT>6.7</ENT>
                                <ENT>10.0-28.2</ENT>
                                <ENT>32-160</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Toluene</ENT>
                                <ENT>15.5-24.5</ENT>
                                <ENT>4.0</ENT>
                                <ENT>11.2-27.7</ENT>
                                <ENT>46-148</ENT>
                            </ROW>
                            <TNOTE>Q = Concentration measured in QC check sample, in µg/L (Section 7.5.3).</TNOTE>
                            <TNOTE>s = Standard deviation of four recovery measurements, in µg/L (Section 8.2.4).</TNOTE>
                            <TNOTE>
                                X
                                <AC T="8"/>
                                 = Average recovery for four recovery measurements, in µg/L (Section 8.2.4).
                            </TNOTE>
                            <TNOTE>
                                P
                                <E T="52">s</E>
                                , P = Percent recovery measured (Section 8.3.2, Section 8.4.2).
                            </TNOTE>
                            <TNOTE>
                                <SU>a</SU>
                                 Criteria were calculated assuming a QC check sample concentration of 20 µg/L.
                            </TNOTE>
                            <TNOTE>Note: These criteria are based directly upon the method performance data in Table 3. Where necessary, the limits for recovery have been broadened to assure applicability of the limits to concentrations below those used to develop Table 3.</TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="4" OPTS="L2" CDEF="s50,12,12,12">
                            <TTITLE>Table 3—Method Accuracy and Precision as Functions of Concentration—Method 602</TTITLE>
                            <BOXHD>
                                <CHED H="1">Parameter</CHED>
                                <CHED H="1">Accuracy, as recovery, X′ (µg/L)</CHED>
                                <CHED H="1">Single analyst precision, s′ (µg/L)</CHED>
                                <CHED H="1">Overall precision, S′ (µg/L)</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">Benzene</ENT>
                                <ENT>0.92C + 0.57</ENT>
                                <ENT>
                                    0.09X
                                    <AC T="8"/>
                                     + 0.59
                                </ENT>
                                <ENT>
                                    0.21X
                                    <AC T="8"/>
                                     + 0.56
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chlorobenzene</ENT>
                                <ENT>0.95C + 0.02</ENT>
                                <ENT>
                                    0.09X
                                    <AC T="8"/>
                                     + 0.23
                                </ENT>
                                <ENT>
                                    0.17X
                                    <AC T="8"/>
                                     + 0.10
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2-Dichlorobenzene</ENT>
                                <ENT>0.93C + 0.52</ENT>
                                <ENT>
                                    0.17X
                                    <AC T="8"/>
                                    −0.04
                                </ENT>
                                <ENT>
                                    0.22X
                                    <AC T="8"/>
                                     + 0.53
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,3-Dichlorobenzene</ENT>
                                <ENT>0.96C−0.05</ENT>
                                <ENT>
                                    0.15X
                                    <AC T="8"/>
                                    −0.10
                                </ENT>
                                <ENT>
                                    0.19X
                                    <AC T="8"/>
                                     + 0.09
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,4-Dichlorobenzene</ENT>
                                <ENT>0.93C−0.09</ENT>
                                <ENT>
                                    0.15X
                                    <AC T="8"/>
                                     + 0.28
                                </ENT>
                                <ENT>
                                    0.20X
                                    <AC T="8"/>
                                     + 0.41
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ethylbenzene</ENT>
                                <ENT>0.94C + 0.31</ENT>
                                <ENT>
                                    0.17X
                                    <AC T="8"/>
                                     + 0.46
                                </ENT>
                                <ENT>
                                    0.26X
                                    <AC T="8"/>
                                     + 0.23
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Toluene</ENT>
                                <ENT>0.94C + 0.65</ENT>
                                <ENT>
                                    0.09X
                                    <AC T="8"/>
                                     + 0.48
                                </ENT>
                                <ENT>
                                    0.18X
                                    <AC T="8"/>
                                     + 0.71
                                </ENT>
                            </ROW>
                            <TNOTE>X′ = Expected recovery for one or more measurements of a sample containing a concentration of C, in µg/L.</TNOTE>
                            <TNOTE>
                                S′ = Expected single analyst standard deviation of measurements at an average concentration found of X
                                <AC T="8"/>
                                , in X µg/L.
                            </TNOTE>
                            <TNOTE>
                                S′ = Expected interlaboratory standard deviation of measurements at an average concentration found of X
                                <AC T="8"/>
                                , in µg/L.
                            </TNOTE>
                            <TNOTE>C = True value for the Concentration, in µg/L.</TNOTE>
                            <TNOTE>
                                X
                                <AC T="8"/>
                                 = Average recovery found for measurements of samples containing a concentration of C, in µg/L.
                            </TNOTE>
                        </GPOTABLE>
                        <GPH SPAN="2" DEEP="421">
                            <PRTPAGE P="100"/>
                            <GID>EC02JY92.004</GID>
                        </GPH>
                        <GPH SPAN="2" DEEP="267">
                            <PRTPAGE P="101"/>
                            <GID>EC02JY92.005</GID>
                        </GPH>
                        <GPH SPAN="2" DEEP="470">
                            <PRTPAGE P="102"/>
                            <GID>EC02JY92.006</GID>
                        </GPH>
                        <GPH SPAN="2" DEEP="470">
                            <PRTPAGE P="103"/>
                            <GID>EC02JY92.007</GID>
                        </GPH>
                        <PRTPAGE P="104"/>
                        <HD SOURCE="HD1">Method 603—Acrolein and Acrylonitrile</HD>
                        <EAR>Pt. 136, App. A, Meth. 603</EAR>
                        <HD SOURCE="HD2">1. Scope and Application</HD>
                        <P>1.1 This method covers the determination of acrolein and acrylonitrile. The following parameters may be determined by this method:</P>
                        <GPOTABLE COLS="3" OPTS="L2" CDEF="s10,7,10">
                            <BOXHD>
                                <CHED H="1">Parameter</CHED>
                                <CHED H="1">STORET No.</CHED>
                                <CHED H="1">CAS No.</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">Acrolein</ENT>
                                <ENT>34210</ENT>
                                <ENT>107-02-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Acrylonitrile</ENT>
                                <ENT>34215</ENT>
                                <ENT>107-13-1</ENT>
                            </ROW>
                            <TNOTE> </TNOTE>
                        </GPOTABLE>
                        <P>1.2 This is a purge and trap gas chromatographic (GC) method applicable to the determination of the compounds listed above in municipal and industrial discharges as provided under 40 CFR 136.1. When this method is used to analyze unfamiliar samples for either or both of the compounds above, compound identifications should be supported by at least one additional qualitative technique. This method describes analytical conditions for a second gas chromatographic column that can be used to confirm measurements made with the primary column. Method 624 provides gas chromatograph/mass spectrometer (GC/MS) conditions appropriate for the qualitative and quantitative confirmation of results for the parameters listed above, if used with the purge and trap conditions described in this method.</P>
                        <P>
                            1.3 The method detection limit (MDL, defined in Section 12.1) 
                            <SU>1</SU>
                             for each parameter is listed in Table 1. The MDL for a specific wastewater may differ from those listed, depending upon the nature of interferences in the sample matrix.
                        </P>
                        <P>1.4 Any modification of this method, beyond those expressly permitted, shall be considered as a major modification subject to application and approval of alternate test procedures under 40 CFR 136.4 and 136.5.</P>
                        <P>1.5 This method is restricted to use by or under the supervision of analysts experienced in the operation of a purge and trap system and a gas chromatograph and in the interpretation of gas chromatograms. Each analyst must demonstrate the ability to generate acceptable results with this method using the procedure described in Section 8.2.</P>
                        <HD SOURCE="HD2">2. Summary of Method</HD>
                        <P>
                            2.1 An inert gas is bubbled through a 5-mL water sample contained in a heated purging chamber. Acrolein and acrylonitrile are transferred from the aqueous phase to the vapor phase. The vapor is swept through a sorbent trap where the analytes are trapped. After the purge is completed, the trap is heated and backflushed with the inert gas to desorb the compound onto a gas chromatographic column. The gas chromatograph is temperature programmed to separate the analytes which are then detected with a flame ionization detector. 
                            <SU>2 3</SU>
                        </P>
                        <P>2.2 The method provides an optional gas chromatographic column that may be helpful in resolving the compounds of interest from the interferences that may occur.</P>
                        <HD SOURCE="HD2">3. Interferences</HD>
                        <P>3.1 Impurities in the purge gas and organic compound outgassing from the plumbing of the trap account for the majority of contamination problems. The analytical system must be demonstrated to be free from contamination under the conditions of the analysis by running laboratory reagent blanks as described in Section 8.1.3. The use of non-Teflon plastic tubing, non-Teflon thread sealants, or flow controllers with rubber components in the purge and trap system should be avoided.</P>
                        <P>3.2 Samples can be contaminated by diffusion of volatile organics through the septum seal into the sample during shipment and storage. A field reagent blank prepared from reagent water and carried through the sampling and handling protocol can serve as a check on such contamination.</P>
                        <P>3.3 Contamination by carry-over can occur whenever high level and low level samples are sequentially analyzed. To reduce carry-over, the purging device and sample syringe must be rinsed between samples with reagent water. Whenever an unusually concentrated sample is encountered, it should be followed by an analysis of reagent water to check for cross contamination. For samples containing large amounts of water-soluble materials, suspended solids, high boiling compounds or high analyte levels, it may be necessary to wash the purging device with a detergent solution, rinse it with distilled water, and then dry it in an oven at 105 °C between analyses. The trap and other parts of the system are also subject to contamination, therefore, frequent bakeout and purging of the entire system may be required.</P>
                        <HD SOURCE="HD2">4. Safety</HD>
                        <P>
                            4.1 The toxicity or carcinogenicity of each reagent used in this method has not been precisely defined; however, each chemical compound should be treated as a potential health hazard. From this view point, exposure to these chemicals must be reduced to the lowest possible level by whatever means available. The laboratory is responsible for maintaining a current awareness file of OSHA regulations regarding the safe handling of the chemicals specified in this method. A reference file of material data handling sheets should also be made available to all personnel involved in the chemical analysis. Additional references to laboratory safety are available and have been identified 
                            <SU>4 6</SU>
                             for the information of the analyst.
                            <PRTPAGE P="105"/>
                        </P>
                        <HD SOURCE="HD2">5. Apparatus and Materials</HD>
                        <P>5.1 Sampling equipment, for discrete sampling.</P>
                        <P>5.1.1 Vial—25-mL capacity or larger, equipped with a screw cap with a hole in the center (Pierce #13075 or equivalent). Detergent wash, rinse with tap and distilled water, and dry at 105 °C before use.</P>
                        <P>5.1.2 Septum—Teflon-faced silicone (Pierce #12722 or equivalent). Detergent wash, rinse with tap and distilled water and dry at 105 °C for 1 h before use.</P>
                        <P>5.2 Purge and trap system—The purge and trap system consists of three separate pieces of equipment: a purging device, trap, and desorber. Several complete systems are now commercially available.</P>
                        <P>5.2.1 The purging device must be designed to accept 5-mL, samples with a water column at least 3 cm deep. The gaseous head space between the water column and the trap must have a total volume of less than 15 mL. The purge gas must pass through the water column as finely divided bubbles with a diameter of less than 3 mm at the origin. The purge gas must be introduced no more than 5 mm from the base of the water column. The purging device must be capable of being heated to 85 °C within 3.0 min after transfer of the sample to the purging device and being held at 85 ±2 °C during the purge cycle. The entire water column in the purging device must be heated. Design of this modification to the standard purging device is optional, however, use of a water bath is suggested.</P>
                        <P>5.2.1.1 Heating mantle—To be used to heat water bath.</P>
                        <P>5.2.1.2 Temperature controller—Equipped with thermocouple/sensor to accurately control water bath temperature to ±2 °C. The purging device illustrated in Figure 1 meets these design criteria.</P>
                        <P>5.2.2 The trap must be at least 25 cm long and have an inside diameter of at least 0.105 in. The trap must be packed to contain 1.0 cm of methyl silicone coated packing (Section 6.5.2) and 23 cm of 2,6-diphenylene oxide polymer (Section 6.5.1). The minimum specifications for the trap are illustrated in Figure 2.</P>
                        <P>5.2.3 The desorber must be capable of rapidly heating the trap to 180 °C, The desorber illustrated in Figure 2 meets these design criteria.</P>
                        <P>5.2.4 The purge and trap system may be assembled as a separate unit as illustrated in Figure 3 or be coupled to a gas chromatograph.</P>
                        <P>5.3 pH paper—Narrow pH range, about 3.5 to 5.5 (Fisher Scientific Short Range Alkacid No. 2, #14-837-2 or equivalent).</P>
                        <P>5.4 Gas chromatograph—An analytical system complete with a temperature programmable gas chromatograph suitable for on-column injection and all required accessories including syringes, analytical columns, gases, detector, and strip-chart recorder. A data system is recommended for measuring peak areas.</P>
                        <P>5.4.1 Column 1—10 ft long × 2 mm ID glass or stainless steel, packed with Porapak-QS (80/100 mesh) or equivalent. This column was used to develop the method performance statements in Section 12. Guidelines for the use of alternate column packings are provided in Section 10.1.</P>
                        <P>5.4.2 Column 2—6 ft long × 0.1 in. ID glass or stainless steel, packed with Chromosorb 101 (60/80 mesh) or equivalent.</P>
                        <P>5.4.3 Detector—Flame ionization detector. This type of detector has proven effective in the analysis of wastewaters for the parameters listed in the scope (Section 1.1), and was used to develop the method performance statements in Section 12. Guidelines for the use of alternate detectors are provided in Section 10.1.</P>
                        <P>5.5 Syringes—5-mL, glass hypodermic with Luerlok tip (two each).</P>
                        <P>5.6 Micro syringes—25-µL, 0.006 in. ID needle.</P>
                        <P>5.7 Syringe valve—2-way, with Luer ends (three each).</P>
                        <P>5.8 Bottle—15-mL, screw-cap, with Teflon cap liner.</P>
                        <P>5.9 Balance—Analytical, capable of accurately weighing 0.0001 g.</P>
                        <HD SOURCE="HD2">6. Reagents</HD>
                        <P>6.1 Reagent water—Reagent water is defined as a water in which an interferent is not observed at the MDL of the parameters of interest.</P>
                        <P>6.1.1 Reagent water can be generated by passing tap water through a carbon filter bed containing about 1 lb of activated carbon (Filtrasorb-300, Calgon Corp., or equivalent).</P>
                        <P>6.1.2 A water purification system (Millipore Super-Q or equivalent) may be used to generate reagent water.</P>
                        <P>6.1.3 Regent water may also be prepared by boiling water for 15 min. Subsequently, while maintaining the temperature at 90 °C, bubble a contaminant-free inert gas through the water for 1 h. While still hot, transfer the water to a narrow mouth screw-cap bottle and seal with a Teflon-lined septum and cap.</P>
                        <P>6.2 Sodium thiosulfate—(ACS) Granular.</P>
                        <P>6.3 Sodium hydroxide solution (10 N)—Dissolve 40 g of NaOH (ACS) in reagent water and dilute to 100 mL.</P>
                        <P>6.4 Hydrochloric acid (1 + 1)—Slowly, add 50 mL of concentrated HCl (ACS) to 50 mL of reagent water.</P>
                        <P>6.5 Trap Materials:</P>
                        <P>6.5.1 2,6-Diphenylene oxide polymer—Tenax (60/80 mesh), chromatographic grade or equivalent.</P>
                        <P>
                            6.5.2 Methyl silicone packing—3% OV-1 on Chromosorb-W (60/80 mesh) or equivalent.
                            <PRTPAGE P="106"/>
                        </P>
                        <P>6.6 Stock standard solutions—Stock standard solutions may be prepared from pure standard materials or purchased as certified solutions. Prepare stock standard solutions in reagent water using assayed liquids. Since acrolein and acrylonitrile are lachrymators, primary dilutions of these compounds should be prepared in a hood. A NIOSH/MESA approved toxic gas respirator should be used when the analyst handles high concentrations of such materials.</P>
                        <P>6.6.1 Place about 9.8 mL of reagent water into a 10-mL ground glass stoppered volumetric flask. For acrolein standards the reagent water must be adjusted to pH 4 to 5. Weight the flask to the nearest 0.1 mg.</P>
                        <P>6.6.2 Using a 100-µL syringe, immediately add two or more drops of assayed reference material to the flask, then reweigh. Be sure that the drops fall directly into the water without contacting the neck of the flask.</P>
                        <P>6.6.3 Reweigh, dilute to volume, stopper, then mix by inverting the flask several times. Calculate the concentration in µg/µL from the net gain in weight. When compound purity is assayed to be 96% or greater, the weight can be used without correction to calculate the concentration of the stock staldard. Optionally, stock standard solutions may be prepared using the pure standard material by volumetrically measuring the appropriate amounts and determining the weight of the material using the density of the material. Commercially prepared stock standards may be used at any concentration if they are certified by the manufactaurer or by an independent source.</P>
                        <P>6.6.4 Transfer the stock standard solution into a Teflon-sealed screw-cap bottle. Store at 4 °C and protect from light.</P>
                        <P>6.6.5 Prepare fresh standards daily.</P>
                        <P>6.7 Secondary dilution standards—Using stock standard solutions, prepare secondary dilution standards in reagent water that contain the compounds of interest, either singly or mixed together. The secondary dilution standards should be prepared at concentrations such that the aqueous calibration standards prepared in Section 7.3.1 or 7.4.1 will bracket the working range of the analytical system. Secondary dilution standards should be prepared daily and stored at 4 °C.</P>
                        <P>6.8 Quality control check sample concentrate—See Section 8.2.1.</P>
                        <HD SOURCE="HD2">7. Calibration</HD>
                        <P>7.1 Assemble a purge and trap system that meets the specifications in Section 5.2. Condition the trap overnight at 180 °C by backflushing with an inert gas flow of at least 20 mL/min. Condition the trap for 10 min once daily prior to use.</P>
                        <P>7.2 Connect the purge and trap system to a gas chromatograph. The gas chromatograph must be operated using temperature and flow rate conditions equivalent to those given in Table 1. Calibrate the purge and trap-gas chromatographic system using either the external standard technique (Section 7.3) or the internal standard technique (Section 7.4).</P>
                        <P>7.3 External standard calibration procedure:</P>
                        <P>7.3.1 Prepare calibration standards at a minimum of three concentration levels for each parameter by carefully adding 20.0 µL of one or more secondary dilution standards to 100, 500, or 1000 mL of reagent water. A 25-µL syringe with a 0.006 in. ID needle should be used for this operation. One of the external standards should be at a concentration near, but above, the MDL and the other concentrations should correspond to the expected range of concentrations found in real samples or should define the working range of the detector. These standards must be prepared fresh daily.</P>
                        <P>7.3.2 Analyze each calibration standard according to Section 10, and tabulate peak height or area responses versus the concentration of the standard. The results can be used to prepare a calibration curve for each compound. Alternatively, if the ratio of response to concentration (calibration factor) is a constant over the working range (&lt;10% relative standard deviation, RSD), linearity through the origin can be assumed and the average ratio or calibration factor can be used in place of a calibration curve.</P>
                        <P>7.4 Internal standard calibration procedure—To use this approach, the analyst must select one or more internal standards that are similar in analytical behavior to the compounds of interest. The analyst must further demonstrate that the measurement of the internal standard is not affected by method or matrix interferences. Because of these limitations, no internal standard can be suggested that is applicable to all samples.</P>
                        <P>7.4.1 Prepare calibration standards at a minimum of three concentration levels for each parameter of interest as described in Section 7.3.1.</P>
                        <P>7.4.2 Prepare a spiking solution containing each of the internal standards using the procedures described in Sections 6.6 and 6.7. It is recommended that the secondary dilution standard be prepared at a concentration of 15 µg/mL of each internal standard compound. The addition of 10 µL of this standard to 5.0 mL of sample or calibration standard would be equivalent to 30 µg/L.</P>
                        <P>7.4.3 Analyze each calibration standard according to Section 10, adding 10 µL of internal standard spiking solution directly to the syringe (Section 10.4). Tabulate peak height or area responses against concentration for each compound and internal standard, and calculate response factors (RF) for each compound using Equation 1.</P>
                        <HD SOURCE="HD3">
                            RF = (A
                            <E T="52">s</E>
                            )(C
                            <E T="52">is</E>
                             (A
                            <E T="52">is</E>
                            )(C
                            <E T="52">s</E>
                            )
                        </HD>
                        <FP SOURCE="FRP">Equation 1</FP>
                        <PRTPAGE P="107"/>
                        <FP>where:</FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">s</E>
                             = Response for the parameter to be measured.
                        </FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">is</E>
                             = Response for the internal standard.
                        </FP>
                        <FP SOURCE="FP-2">
                            C
                            <E T="52">is</E>
                             = Concentration of the internal standard.
                        </FP>
                        <FP SOURCE="FP-2">
                            C
                            <E T="52">s</E>
                             = Concentration of the parameter to be measured.
                        </FP>
                        <FP>
                            If the RF value over the working range is a constant (&lt;10% RSD), the RF can be assumed to be invariant and the average RF can be used for calculations. Alternatively, the results can be used to plot a calibration curve of response ratios, A
                            <E T="52">s</E>
                            /A
                            <E T="52">is</E>
                            , vs. RF.
                        </FP>
                        <P>7.5 The working calibration curve, calibration factor, or RF must be verified on each working day by the measurement of a QC check sample.</P>
                        <P>7.5.1 Prepare the QC check sample as described in Section 8.2.2.</P>
                        <P>7.5.2 Analyze the QC check sample according to Section 10.</P>
                        <P>7.5.3 For each parameter, compare the response (Q) with the corresponding calibration acceptance criteria found in Table 2. If the responses for all parameters of interest fall within the designated ranges, analysis of actual samples can begin. If any individual Q falls outside the range, a new calibration curve, calibration factor, or RF must be prepared for that parameter according to Section 7.3 or 7.4.</P>
                        <HD SOURCE="HD2">8. Quality Control</HD>
                        <P>8.1 Each laboratory that uses this method is required to operate a formal quality control program. The minimum requirements of this program consist of an initial demonstration of laboratory capability and an ongoing analysis of spiked samples to evaluate and document data quality. The laboratory must maintain records to document the quality of data that is generated. Ongoing data quality checks are compared with established performance criteria to determine if the results of analyses meet the performance characteristics of the method. When results of sample spikes indicate atypical method performance, a quality control check standard must be analyzed to confirm that the measurements were performed in an in-control mode of operation.</P>
                        <P>8.1.1 The analyst must make an initial, one-time, demonstration of the ability to generate acceptable accuracy and precision with this method. This ability is established as described in Section 8.2.</P>
                        <P>8.1.2 In recognition of advances that are occurring in chromatography, the analyst is permitted certain options (detailed in Section 10.1) to improve the separations or lower the cost of measurements. Each time such a modification is made to the method, the analyst is required to repeat the procedure in Section 8.2.</P>
                        <P>8.1.3 Each day, the analyst must analyze a reagent water blank to demonstrate that interferences from the analytical system are under control.</P>
                        <P>8.1.4 The laboratory must, on an ongoing basis, spike and analyze a minimum of 10% of all samples to monitor and evaluate laboratory data quality. This procedure is described in Section 8.3.</P>
                        <P>8.1.5 The laboratory must, on an ongoing basis, demonstrate through the analyses of quality control check standards that the operation of the measurement system is in control. This procedure is described in Section 8.4. The frequency of the check standard analyses is equivalent to 10% of all samples analyzed but may be reduced if spike recoveries from samples (Section 8.3) meet all specified quality control criteria.</P>
                        <P>8.1.6 The laboratory must maintain performance records to document the quality of data that is generated. This procedure is described in Section 8.5.</P>
                        <P>8.2 To establish the ability to generate acceptable accuracy and precision, the analyst must perform the following operations.</P>
                        <P>8.2.1 A quality control (QC) check sample concentrate is required containing each parameter of interest at a concentration of 25 µg/mL in reagent water. The QC check sample concentrate must be obtained from the U.S. Environmental Protection Agency, Environmental Monitoring and Support Laboratory in Cincinnati, Ohio, if available. If not available from that source, the QC check sample concentrate must be obtained from another external source. If not available from either source above, the QC check sample concentrate must be prepared by the laboratory using stock standards prepared independently from those used for calibration.</P>
                        <P>8.2.2 Prepare a QC check sample to contain 50 µg/L of each parameter by adding 200 µL of QC check sample concentrate to 100 mL of reagent water.</P>
                        <P>8.2.3 Analyze four 5-mL aliquots of the well-mixed QC check sample according to Section 10.</P>
                        <P>
                            8.2.4 Calculate the average recovery (X
                            <AC T="8"/>
                            ) in µg/L, and the standard deviation of the recovery (s) in µg/L, for each parameter using the four results.
                        </P>
                        <P>
                            8.2.5 For each parameter compare s and X
                            <AC T="8"/>
                             with the corresponding acceptance criteria for precision and accuracy, respectively, found in Table 3. If s and X
                            <AC T="8"/>
                             for all parameters of interest meet the acceptance criteria, the system performance is acceptable and analysis of actual samples can begin. If either s exceeds the precision limit or X
                            <AC T="8"/>
                             falls outside the range for accuracy, the system performance is unacceptable for that parameter. Locate and correct the source of the problem and repeat the test for each compound of interest.
                        </P>
                        <P>
                            8.3 The laboratory must, on an ongoing basis, spike at least 10% of the samples from each sample site being monitored to assess accuracy. For laboratories analyzing one to 
                            <PRTPAGE P="108"/>
                            ten samples per month, at least one spiked sample per month is required.
                        </P>
                        <P>8.3.1 The concentration of the spike in the sample should be determined as follows:</P>
                        <P>8.3.1.1 If, as in compliance monitoring, the concentration of a specific parameter in the sample is being checked against a regulatory concentration limit, the spike should be at that limit or 1 to 5 times higher than the background concentration determined in Section 8.3.2, whichever concentration would be larger.</P>
                        <P>8.3.1.2 If the concentration of a specific parameter in the sample is not being checked against a limit specific to that parameter, the spike should be at 50 µg/L or 1 to 5 times higher than the background concentration determined in Section 8.3.2, whichever concentration would be larger.</P>
                        <P>8.3.2 Analyze one 5-mL sample aliquot to determine the background concentration (B) of each parameter. If necessary, prepare a new QC check sample concentrate (Section 8.2.1) appropriate for the background concentrations in the sample. Spike a second 5-mL sample aliquot with 10 µL of the QC check sample concentrate and analyze it to determine the concentration after spiking (A) of each parameter. Calculate each percent recovery (P) as 100(A−B)%/T, where T is the known true value of the spike.</P>
                        <P>
                            8.3.3 Compare the percent recovery (P) for each parameter with the corresponding QC acceptance criteria found in Table 3. These acceptance criteria were calculated to include an allowance for error in measurement of both the background and spike concentrations, assuming a spike to background ratio of 5:1. This error will be accounted for to the extent that the analyst's spike to background ratio approaches 5:1. 
                            <SU>7</SU>
                        </P>
                        <P>8.3.4 If any individual P falls outside the designated range for recovery, that parameter has failed the acceptance criteria. A check standard containing each parameter that failed the criteria must be analyzed as described in Section 8.4.</P>
                        <P>8.4 If any parameter fails the acceptance criteria for recovery in Section 8.3, a QC check standard containing each parameter that failed must be prepared and analyzed.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>The frequency for the required analysis of a QC check standard will depend upon the number of parameters being simultaneously tested, the complexity of the sample matrix, and the performance of the laboratory.</P>
                        </NOTE>
                        <P>8.4.1 Prepare the QC check standard by adding 10 µL of QC check sample concentrate (Section 8.2.1 or 8.3.2) to 5 mL of reagent water. The QC check standard needs only to contain the parameters that failed criteria in the test in Section 8.3.</P>
                        <P>
                            8.4.2 Analyze the QC check standard to determine the concentration measured (A) of each parameter. Calculate each percent recovery (P
                            <E T="52">s</E>
                            ) as 100 (A/T)%, where T is the true value of the standard concentration.
                        </P>
                        <P>
                            8.4.3 Compare the percent recovery (P
                            <E T="52">s</E>
                            ) for each parameter with the corresponding QC acceptance criteria found in Table 3. Only parameters that failed the test in Section 8.3 need to be compared with these criteria. If the recovery of any such parameter falls outside the designated range, the laboratory performance for that parameter is judged to be out of control, and the problem must be immediately identified and corrected. The analytical result for that parameter in the unspiked sample is suspect and may not be reported for regulatory compliance purposes.
                        </P>
                        <P>
                            8.5 As part of the QC program for the laboratory, method accuracy for wastewater samples must be assessed and records must be maintained. After the analysis of five spiked wastewater samples as in Section 8.3, calculate the average percent recovery (P
                            <AC T="8"/>
                            ) and the standard deviation of the percent recovery (s
                            <E T="52">p</E>
                            ). Express the accuracy assessment as a percent recovery interval from P
                            <AC T="8"/>
                            −2s
                            <E T="52">p</E>
                             to P
                            <AC T="8"/>
                             + 2s
                            <E T="52">p</E>
                            . If P
                            <AC T="8"/>
                             = 90% and s
                            <E T="52">p</E>
                             = 10%, for example, the accuracy interval is expressed as 70-110%. Update the accuracy assessment for each parameter on a regular basis (e.g. after each five to ten new accuracy measurements).
                        </P>
                        <P>8.6 It is recommended that the laboratory adopt additional quality assurance practices for use with this method. The specific practices that are most productive depend upon the needs of the laboratory and the nature of the samples. Field duplicates may be analyzed to assess the precision of the environmental measurements. When doubt exists over the identification of a peak on the chromatogram, confirmatory techniques such as gas chromatography with a dissimilar column or mass spectrometer must be used. Whenever possible, the laboratory should analyze standard reference materials and participate in relevant performance evaluation studies.</P>
                        <HD SOURCE="HD2">9. Sample Collection, Preservation, and Handling</HD>
                        <P>
                            9.1 All samples must be iced or refrigerated from the time of collection until analysis. If the sample contains free or combined chlorine, add sodium thiosulfate preservative (10 mg/40 mL is sufficient for up to 5 ppm Cl
                            <E T="52">2</E>
                            ) to the empty sample bottle just prior to shipping to the sampling site. EPA Methods 330.4 and 330.5 may be used for measurement of residual chlorine. 
                            <SU>8</SU>
                             Field test kits are available for this purpose.
                        </P>
                        <P>
                            9.2 If acrolein is to be analyzed, collect about 500 mL of sample in a clean glass container. Adjust the pH of the sample to 4 to 5 using acid or base, measuring with narrow range pH paper. Samples for acrolein analysis receiving no pH adjustment must be analyzed within 3 days of sampling.
                            <PRTPAGE P="109"/>
                        </P>
                        <P>9.3 Grab samples must be collected in glass containers having a total volume of at least 25 mL. Fill the sample bottle just to overflowing in such a manner that no air bubbles pass through the sample as the bottle is being filled. Seal the bottle so that no air bubbles are entrapped in it. If preservative has been added, shake vigorously for 1 min. Maintain the hermetic seal on the sample bottle until time of analysis.</P>
                        <P>
                            9.4 All samples must be analyzed within 14 days of collection. 
                            <SU>3</SU>
                        </P>
                        <HD SOURCE="HD2">10. Procedure</HD>
                        <P>10.1 Table 1 summarizes the recommended operating conditions for the gas chromatograph. Included in this table are estimated retention times and MDL that can be achieved under these conditions. An example of the separations achieved by Column 1 is shown in Figure 5. Other packed columns, chromatographic conditions, or detectors may be used if the requirements of Section 8.2 are met.</P>
                        <P>10.2 Calibrate the system daily as described in Section 7.</P>
                        <P>10.3 Adjust the purge gas (nitrogen or helium) flow rate to 20 mL-min. Attach the trap inlet to the purging device, and set the purge and trap system to purge (Figure 3). Open the syringe valve located on the purging device sample introduction needle.</P>
                        <P>10.4 Remove the plunger from a 5-mL syringe and attach a closed syringe valve. Open the sample bottle (or standard) and carefully pour the sample into the syringe barrel to just short of overflowing. Replace the syringe plunger and compress the sample. Open the syringe valve and vent any residual air while adjusting the sample volume to 5.0 mL. Since this process of taking an aliquot destroys the validity of the sample for future analysis, the analyst should fill a second syringe at this time to protect against possible loss of data. Add 10.0 µL of the internal standard spiking solution (Section 7.4.2), if applicable, through the valve bore then close the valve.</P>
                        <P>10.5 Attach the syringe-syringe valve assembly to the syringe valve on the purging device. Open the syringe valves and inject the sample into the purging chamber.</P>
                        <P>10.6 Close both valves and purge the sample for 15.0 ±0.1 min while heating at 85 ±2 °C.</P>
                        <P>10.7 After the 15-min purge time, attach the trap to the chromatograph, adjust the purge and trap system to the desorb mode (Figure 4), and begin to temperature program the gas chromatograph. Introduce the trapped materials to the GC column by rapidly heating the trap to 180 °C while backflushing the trap with an inert gas between 20 and 60 mL/min for 1.5 min.</P>
                        <P>10.8 While the trap is being desorbed into the gas chromatograph, empty the purging chamber using the sample introduction syringe. Wash the chamber with two 5-mL flushes of reagent water.</P>
                        <P>10.9 After desorbing the sample for 1.5 min, recondition the trap by returning the purge and trap system to the purge mode. Wait 15 s then close the syringe valve on the purging device to begin gas flow through the trap. The trap temperature should be maintained at 210 °C. After approximately 7 min, turn off the trap heater and open the syringe valve to stop the gas flow through the trap. When the trap is cool, the next sample can be analyzed.</P>
                        <P>10.10 Identify the parameters in the sample by comparing the retention times of the peaks in the sample chromatogram with those of the peaks in standard chromatograms. The width of the retention time window used to make identifications should be based upon measurements of actual retention time variations of standards over the course of a day. Three times the standard deviation of a retention time for a compound can be used to calculate a suggested window size; however, the experience of the analyst should weigh heavily in the interpretation of chromatograms.</P>
                        <HD SOURCE="HD2">11. Calculations</HD>
                        <P>11.1 Determine the concentration of individual compounds in the sample.</P>
                        <P>11.1.1 If the external standard calibration procedure is used, calculate the concentration of the parameter being measured from the peak response using the calibration curve or calibration factor determined in Section 7.3.2.</P>
                        <P>11.1.2 If the internal standard calibration procedure is used, calculate the concentration in the sample using the response factor (RF) determined in Section 7.4.3 and Equation 2.</P>
                        <MATH SPAN="1" DEEP="31">
                            <MID>EC15NO91.097</MID>
                        </MATH>
                        <FP SOURCE="FRP0">Equation 2</FP>
                        <FP>where:</FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">s</E>
                             = Response for the parameter to be measured.
                        </FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">is</E>
                             = Response for the internal standard.
                        </FP>
                        <FP SOURCE="FP-2">
                            C
                            <E T="52">is</E>
                             = Concentration of the internal standard.
                        </FP>
                        <P>11.2 Report results in µg/L without correction for recovery data. All QC data obtained should be reported with the sample results.</P>
                        <HD SOURCE="HD2">12. Method Performance</HD>
                        <P>
                            12.1 The method detection limit (MDL) is defined as the minimum concentration of a substance that can be measured and reported with 99% confidence that the value is above zero. 
                            <SU>1</SU>
                             The MDL concentrations listed in Table 1 were obtained using reagent water. 
                            <SU>9</SU>
                             
                            <PRTPAGE P="110"/>
                            The MDL actually achieved in a given analysis will vary depending on instrument sensitivity and matrix effects.
                        </P>
                        <P>12.2 This method is recommended for the concentration range from the MDL to 1,000 × MDL. Direct aqueous injection techniques should be used to measure concentration levels above 1,000 × MDL.</P>
                        <P>
                            12.3 In a single laboratory (Battelle-Columbus), the average recoveries and standard deviations presented in Table 2 were obtained. 
                            <SU>9</SU>
                             Seven replicate samples were analyzed at each spike level.
                        </P>
                        <HD SOURCE="HD2">References</HD>
                        <P>1. 40 CFR part 136, appendix B.</P>
                        <P>
                            2. Bellar, T.A., and Lichtenberg, J.J. “Determining Volatile Organics at Microgram-per-Litre-Levels by Gas Chromatography,” 
                            <E T="03">Journal American Water Works Association, 66,</E>
                             739 (1974).
                        </P>
                        <P>3. “Evaluate Test Procedures for Acrolein and Acrylonitrile,” Special letter report for EPA Project 4719-A, U.S. Environmental Protection Agency, Environmental Monitoring and Support Laboratory, Cincinnati, Ohio 45268, 27 June 1979.</P>
                        <P>4. “Carcinogens—Working With Carcinogens,” Department of Health, Education, and Welfare, Public Health Service, Center for Disease Control, National Institute for Occupational Safety and Health, Publication No. 77-206, August 1977.</P>
                        <P>5. “OSHA Safety and Health Standards, General Industry,” (29 CFR part 1910), Occupational Safety and Health Administration, OSHA 2206 (Revised, January 1976).</P>
                        <P>6. “Safety in Academic Chemistry Laboratories,” American Chemical Society Publication, Committee on Chemical Safety, 3rd Edition, 1979.</P>
                        <P>
                            7. Provost, L.P., and Elder, R.S. “Interpretation of Percent Recovery Data,” 
                            <E T="03">American Laboratory, 15,</E>
                             58-63 (1983).
                        </P>
                        <P>8. “Methods 330.4 (Titrimetric, DPD-FAS) and 330.5 (Spectrophotometric, DPD) for Chlorine, Total Residual,” Methods for Chemical Analysis of Water and Wastes, EPA-600/4-79-020, U.S. Environmental Protection Agency, Environmental Monitoring and Support Laboratory, Cincinnati, Ohio 45268, March 1979.</P>
                        <P>9. “Evaluation of Method 603 (Modified),” EPA-600/4-84-ABC, National Technical Information Service, PB84-, Springfield, Virginia 22161, Nov. 1984.</P>
                        <GPOTABLE COLS="4" OPTS="L2" CDEF="s50,4.4,4.4,4.4">
                            <TTITLE>Table 1—Chromatographic Conditions and Method Detection Limits</TTITLE>
                            <BOXHD>
                                <CHED H="1">Parameter</CHED>
                                <CHED H="1">Retention time (min)</CHED>
                                <CHED H="2">Column 1</CHED>
                                <CHED H="2">Column 2</CHED>
                                <CHED H="1">Method detection limit (µg/L)</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">Acrolein</ENT>
                                <ENT>10.6</ENT>
                                <ENT>8.2</ENT>
                                <ENT>0.7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Acrylonitrile</ENT>
                                <ENT>12.7</ENT>
                                <ENT>9.8</ENT>
                                <ENT>0.5</ENT>
                            </ROW>
                            <TNOTE>
                                Column 1 conditions: Porapak-QS (80/100 mesh) packed in a 10 ft × 2 mm ID glass or stainless steel column with helium carrier gas at 30 mL/min flow rate. Column temperature held isothermal at 110 °C for 1.5 min (during desorption), then heated as rapidly as possible to 150 °C and held for 20 min; column bakeout at 190 °C for 10 min. 
                                <SU>9</SU>
                            </TNOTE>
                            <TNOTE>Column 2 conditions: Chromosorb 101 (60/80 mesh) packed in a 6 ft. × 0.1 in. ID glass or stainless steel column with helium carrier gas at 40 mL/min flow rate. Column temperature held isothermal at 80 °C for 4 min, then programmed at 50 °C/min to 120 °C and held for 12 min.</TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="6" OPTS="L2" CDEF="s50,7,7,8,8,8">
                            <TTITLE>Table 2—Single Laboratory Accuracy and Precision—Method 603</TTITLE>
                            <BOXHD>
                                <CHED H="1">Parameter</CHED>
                                <CHED H="1">Sample matrix</CHED>
                                <CHED H="1">Spike conc. (µg/L)</CHED>
                                <CHED H="1">Average recovery (µg/L)</CHED>
                                <CHED H="1">Standard deviation (µg/L)</CHED>
                                <CHED H="1">Average percent recovery</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">Acrolein</ENT>
                                <ENT>RW</ENT>
                                <ENT>5.0</ENT>
                                <ENT>5.2</ENT>
                                <ENT>0.2</ENT>
                                <ENT>104</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>RW</ENT>
                                <ENT>50.0</ENT>
                                <ENT>51.4</ENT>
                                <ENT>0.7</ENT>
                                <ENT>103</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>POTW</ENT>
                                <ENT>5.0</ENT>
                                <ENT>4.0</ENT>
                                <ENT>0.2</ENT>
                                <ENT>80</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>POTW</ENT>
                                <ENT>50.0</ENT>
                                <ENT>44.4</ENT>
                                <ENT>0.8</ENT>
                                <ENT>89</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>IW</ENT>
                                <ENT>5.0</ENT>
                                <ENT>0.1</ENT>
                                <ENT>0.1</ENT>
                                <ENT>2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>IW</ENT>
                                <ENT>100.0</ENT>
                                <ENT>9.3</ENT>
                                <ENT>1.1</ENT>
                                <ENT>9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Acrylonitrile</ENT>
                                <ENT>RW</ENT>
                                <ENT>5.0</ENT>
                                <ENT>4.2</ENT>
                                <ENT>0.2</ENT>
                                <ENT>84</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>RW</ENT>
                                <ENT>50.0</ENT>
                                <ENT>51.4</ENT>
                                <ENT>1.5</ENT>
                                <ENT>103</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>POTW</ENT>
                                <ENT>20.0</ENT>
                                <ENT>20.1</ENT>
                                <ENT>0.8</ENT>
                                <ENT>100</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>POTW</ENT>
                                <ENT>100.0</ENT>
                                <ENT>101.3</ENT>
                                <ENT>1.5</ENT>
                                <ENT>101</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>IW</ENT>
                                <ENT>10.0</ENT>
                                <ENT>9.1</ENT>
                                <ENT>0.8</ENT>
                                <ENT>91</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>IW</ENT>
                                <ENT>100.0</ENT>
                                <ENT>104.0</ENT>
                                <ENT>3.2</ENT>
                                <ENT>104</ENT>
                            </ROW>
                            <TNOTE>RW = Reagent water.</TNOTE>
                            <TNOTE>POTW = Prechlorination secondary effluent from a municipal sewage treatment plant.</TNOTE>
                            <TNOTE>IW = Industrial wastewater containing an unidentified acrolein reactant.</TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="5" OPTS="L2" CDEF="s40,10,8,10,10">
                            <TTITLE>
                                Table 3—Calibration and QC Acceptance Criteria—Method 603 
                                <E T="01">
                                    <SU>a</SU>
                                </E>
                            </TTITLE>
                            <BOXHD>
                                <CHED H="1">Parameter</CHED>
                                <CHED H="1">Range for Q (µg/L)</CHED>
                                <CHED H="1">Limit for S (µg/L)</CHED>
                                <CHED H="1">Range for X (µg/L)</CHED>
                                <CHED H="1">
                                    Range for P, P
                                    <E T="52">s</E>
                                     (%)
                                </CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">Acrolein</ENT>
                                <ENT>45.9-54.1</ENT>
                                <ENT>4.6</ENT>
                                <ENT>42.9-60.1</ENT>
                                <ENT>88-118</ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="111"/>
                                <ENT I="01">Acrylonitrile</ENT>
                                <ENT>41.2-58.8</ENT>
                                <ENT>9.9</ENT>
                                <ENT>33.1-69.9</ENT>
                                <ENT>71-135</ENT>
                            </ROW>
                            <TNOTE>
                                <SU>a</SU>
                                 = Criteria were calculated assuming a QC check sample concentration of 50 µg/L. 
                                <SU>9</SU>
                            </TNOTE>
                            <TNOTE>Q = Concentration measured in QC check sample, in µg/L (Section 7.5.3).</TNOTE>
                            <TNOTE>s = Standard deviation of four recovery measurements, in µg/L (Section 8.2.4).</TNOTE>
                            <TNOTE>X = Average recovery for four recovery measurements, in µg/L (Section 8.2.4).</TNOTE>
                            <TNOTE>
                                P, P
                                <E T="52">s</E>
                                 = Percent recovery measured (Section 8.3.2, Section 8.4.2).
                            </TNOTE>
                        </GPOTABLE>
                        <GPH SPAN="2" DEEP="421">
                            <GID>EC02JY92.008</GID>
                        </GPH>
                        <GPH SPAN="2" DEEP="266">
                            <PRTPAGE P="112"/>
                            <GID>EC02JY92.009</GID>
                        </GPH>
                        <GPH SPAN="2" DEEP="470">
                            <PRTPAGE P="113"/>
                            <GID>EC02JY92.010</GID>
                        </GPH>
                        <GPH SPAN="2" DEEP="289">
                            <PRTPAGE P="114"/>
                            <GID>EC02JY92.011</GID>
                        </GPH>
                        <HD SOURCE="HD1">Method 604—Phenols</HD>
                        <EAR>Pt. 136, App. A, Meth. 604</EAR>
                        <HD SOURCE="HD2">1. Scope and Application</HD>
                        <P>1.1 This method covers the determination of phenol and certain substituted phenols. The following parameters may be determined by this method:</P>
                        <GPOTABLE COLS="3" OPTS="L2" CDEF="s10,7,10">
                            <BOXHD>
                                <CHED H="1">Parameter</CHED>
                                <CHED H="1">STORET No.</CHED>
                                <CHED H="1">CAS No.</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">4-Chloro-3-methylphenol</ENT>
                                <ENT>34452</ENT>
                                <ENT>59-50-7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2--Chlorophenol</ENT>
                                <ENT>34586</ENT>
                                <ENT>95-57-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4-Dichlorophenol</ENT>
                                <ENT>34601</ENT>
                                <ENT>120-83-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4-Dimethylphenol</ENT>
                                <ENT>34606</ENT>
                                <ENT>105-67-9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4-Dinitrophenol</ENT>
                                <ENT>34616</ENT>
                                <ENT>51-28-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-Methyl-4,6-dinitrophenol</ENT>
                                <ENT>34657</ENT>
                                <ENT>534-52-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-Nitrophenol</ENT>
                                <ENT>34591</ENT>
                                <ENT>88-75-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4-Nitrophenol</ENT>
                                <ENT>34646</ENT>
                                <ENT>100-02-7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Pentachlorophenol</ENT>
                                <ENT>39032</ENT>
                                <ENT>87-86-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Phenol</ENT>
                                <ENT>34694</ENT>
                                <ENT>108-95-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4,6-Trichlorophenol</ENT>
                                <ENT>34621</ENT>
                                <ENT>88-06-2</ENT>
                            </ROW>
                        </GPOTABLE>
                        <P>1.2 This is a flame ionization detector gas chromatographic (FIDGC) method applicable to the determination of the compounds listed above in municipal and industrial discharges as provided under 40 CFR 136.1. When this method is used to analyze unfamiliar samples for any or all of the compounds above, compound identifications should be supported by at least one additional qualitative technique. This method describes analytical conditions for derivatization, cleanup, and electron capture detector gas chromatography (ECDGC) that can be used to confirm measurements made by FIDGC. Method 625 provides gas chromatograph/mass spectrometer (GC/MS) conditions appropriate for the qualitative and quantitative confirmation of results for all of the parameters listed above, using the extract produced by this method.</P>
                        <P>
                            1.3 The method detection limit (MDL, defined in Section 14.1) 
                            <SU>1</SU>
                             for each parameter is listed in Table 1. The MDL for a specific wastewater may differ from those listed, depending upon the nature of interferences in the sample matrix. The MDL listed in Table 1 for each parameter was achieved with a flame ionization detector (FID). The MDLs that were achieved when the derivatization cleanup and electron capture detector (ECD) were employed are presented in Table 2.
                            <PRTPAGE P="115"/>
                        </P>
                        <P>1.4 Any modification of this method, beyond those expressly permitted, shall be considered as a major modification subject to application and approval of alternate test procedures under 40 CFR 136.4 and 136.5.</P>
                        <P>1.5 This method is restricted to use by or under the supervision of analysts experienced in the use of a gas chromatograph and in the interpretation of gas chromatograms. Each analyst must demonstrate the ability to generate acceptable results with this method using the procedure described in Section 8.2.</P>
                        <HD SOURCE="HD2">2. Summary of Method</HD>
                        <P>
                            2.1 A measured volume of sample, approximately 1-L, is acidified and extracted with methylene chloride using a separatory funnel. The methylene chloride extract is dried and exchanged to 2-propanol during concentration to a volume of 10 mL or less. The extract is separated by gas chromatography and the phenols are then measured with an FID. 
                            <SU>2</SU>
                        </P>
                        <P>2.2 A preliminary sample wash under basic conditions can be employed for samples having high general organic and organic base interferences.</P>
                        <P>
                            2.3 The method also provides for a derivatization and column chromatography cleanup procedure to aid in the elimination of interferences. 
                            <SU>2 3</SU>
                             The derivatives are analyzed by ECDGC.
                        </P>
                        <HD SOURCE="HD2">3. Interferences</HD>
                        <P>3.1 Method interferences may be caused by contaminants in solvents, reagents, glassware, and other sample processing hardware that lead to discrete artifacts and/or elevated baselines in gas chromatograms. All of these materials must be routinely demonstrated to be free from interferences under the conditions of the analysis by running laboratory reagent blanks as described in Section 8.1.3.</P>
                        <P>
                            3.1.1 Glassware must be scrupulously cleaned. 
                            <SU>4</SU>
                             Clean all glassware as soon as possible after use by rinsing with the last solvent used in it. Solvent rinsing should be followed by detergent washing with hot water, and rinses with tap water and distilled water. The glassware should then be drained dry, and heated in a muffle furnace at 400 °C for 15 to 30 min. Some thermally stable materials, such as PCBs, may not be eliminated by this treatment. Solvent rinses with acetone and pesticide quality hexane may be substituted for the muffle furnace heating. Thorough rinsing with such solvents usually eliminates PCB interference. Volumetric ware should not be heated in a muffle furnace. After drying and cooling, glassware should be sealed and stored in a clean environment to prevent any accumulation of dust or other contaminants. Store inverted or capped with aluminum foil.
                        </P>
                        <P>3.1.2 The use of high purity reagents and solvents helps to minimize interference problems. Purification of solvents by distillation in all-glass systems may be required.</P>
                        <P>3.2 Matrix interferences may be caused by contaminants that are coextracted from the sample. The extent of matrix interferences will vary considerably from source to source, depending upon the nature and diversity of the industrial complex or municipality being sampled. The derivatization cleanup procedure in Section 12 can be used to overcome many of these interferences, but unique samples may require additional cleanup approaches to achieve the MDL listed in Tables 1 and 2.</P>
                        <P>3.3 The basic sample wash (Section 10.2) may cause significantly reduced recovery of phenol and 2,4-dimethylphenol. The analyst must recognize that results obtained under these conditions are minimum concentrations.</P>
                        <HD SOURCE="HD2">4. Safety</HD>
                        <P>
                            4.1 The toxicity or carcinogenicity of each reagent used in this mothod has not been precisely defined; however, each chemical compound should be treated as a potential health hazard. From this viewpoint, exposure to these chemicals must be reduced to the lowest possible level by whatever means available. The laboratory is responsible for maintaining a current awareness file of OSHA regulations regarding the safe handling of the chemicals specified in this method. A reference file of material data handling sheets should also be made available to all personnel involved in the chemical analysis. Additional references to laboratory safety are available and have been identified 
                            <SU>5 7</SU>
                             for the information of analyst.
                        </P>
                        <P>4.2 Special care should be taken in handling pentafluorobenzyl bromide, which is a lachrymator, and 18-crown-6-ether, which is highly toxic.</P>
                        <HD SOURCE="HD2">5. Apparatus and Materials</HD>
                        <P>5.1 Sampling equipment, for discrete or composite sampling.</P>
                        <P>5.1.1 Grab sample bottle—1-L or 1-qt, amber glass, fitted with a screw cap lined with Teflon. Foil may be substituted for Teflon if the sample is not corrosive. If amber bottles are not available, protect samples from light. The bottle and cap liner must be washed, rinsed with acetone or methylene chloride, and dried before use to minimize contamination.</P>
                        <P>
                            5.1.2 Automatic sampler (optional)—The sampler must incorporate glass sample containers for the collection of a minimum of 250 mL of sample. Sample containers must be kept refrigerated at 4 °C and protected from light during compositing. If the sampler uses a peristaltic pump, a minimum length of compressible silicone rubber tubing may be 
                            <PRTPAGE P="116"/>
                            used. Before use, however, the compressible tubing should be thoroughly rinsed with methanol, followed by repeated rinsings with distilled water to minimize the potential for contamination of the sample. An integrating flow meter is required to collect flow proportional composites.
                        </P>
                        <P>5.2 Glassware (All specifications are suggested. Catalog numbers are included for illustration only.):</P>
                        <P>5.2.1 Separatory funnel—2-L, with Teflon stopcock.</P>
                        <P>5.2.2 Drying column—Chromatographic column, 400 mm long × 19 mm ID, with coarse frit filter disc.</P>
                        <P>5.2.3 Chromatographic column—100 mm long × 10 mm ID, with Teflon stopcock.</P>
                        <P>5.2.4 Concentrator tube, Kuderna-Danish—10-mL, graduated (Kontes K-570050-1025 or equivalent). Calibration must be checked at the volumes employed in the test. Ground glass stopper is used to prevent evaporation of extracts.</P>
                        <P>5.2.5 Evaporative flask, Kuderna-Danish—500-mL (Kontes K-570001-0500 or equivalent). Attach to concentrator tube with springs.</P>
                        <P>5.2.6 Snyder column, Kuderna-Danish—Three-ball macro (Kontes K-503000-0121 or equivalent).</P>
                        <P>5.2.7 Snyder column, Kuderna-Danish—Two-ball micro (Kontes K-569001-0219 or equivalent).</P>
                        <P>5.2.8 Vials—10 to 15-mL, amber glass, with Teflon-lined screw cap.</P>
                        <P>5.2.9 Reaction flask—15 to 25-mL round bottom flask, with standard tapered joint, fitted with a water-cooled condenser and U-shaped drying tube containing granular calcium chloride.</P>
                        <P>5.3 Boiling chips—Approximately 10/40 mesh. Heat to 400 °C for 30 min or Soxhlet extract with methylene chloride.</P>
                        <P>5.4 Water bath—Heated, with concentric ring cover, capable of temperature control (±2 °C). The bath should be used in a hood.</P>
                        <P>5.5 Balance—Analytical, capable of accurately weighting 0.0001 g.</P>
                        <P>5.6 Gas chromatograph—An analytical system complete with a temperature programmable gas chromatograph suitable for on-column injection and all required accessories including syringes, analytical columns, gases, detector, and strip-chart recorder. A data system is recommended for measuring peak areas.</P>
                        <P>5.6.1 Column for underivatized phenols—1.8 m long × 2 mm ID glass, packed with 1% SP-1240DA on Supelcoport (80/100 mesh) or equivalent. This column was used to develop the method performance statements in Section 14. Guidelines for the use of alternate column packings are provided in Section 11.1.</P>
                        <P>5.6.2 Column for derivatized phenols—1.8 m long × 2 mm ID glass, packed with 5% OV-17 on Chromosorb W-AW-DMCS (80/100 mesh) or equivalent. This column has proven effective in the analysis of wastewaters for derivatization products of the parameters listed in the scope (Section 1.1), and was used to develop the method performance statements in Section 14. Guidelines for the use of alternate column packings are provided in Section 11.1.</P>
                        <P>5.6.3 Detectors—Flame ionization and electron capture detectors. The FID is used when determining the parent phenols. The ECD is used when determining the derivatized phenols. Guidelines for the use of alternatve detectors are provided in Section 11.1.</P>
                        <HD SOURCE="HD2">6. Reagents</HD>
                        <P>6.1 Reagent water—Reagent water is defined as a water in which an interferent is not observed at the MDL of the parameters of interest.</P>
                        <P>6.2 Sodium hydroxide solution (10 N)—Dissolve 40 g of NaOH (ACS) in reagent water and dilute to 100 mL.</P>
                        <P>6.3 Sodium hydroxide solution (1 N)—Dissolve 4 g of NaOH (ACS) in reagent water and dilute to 100 mL.</P>
                        <P>6.4 Sodium sulfate—(ACS) Granular, anhydrous. Purify by heating at 400 °C for 4 h in a shallow tray.</P>
                        <P>6.5 Sodium thiosulfate—(ACS) Granular.</P>
                        <P>
                            6.6 Sulfuric acid (1 + 1)—Slowly, add 50 mL of H
                            <E T="52">2</E>
                            SO
                            <E T="52">4</E>
                             (ACS, sp. gr. 1.84) to 50 mL of reagent water.
                        </P>
                        <P>
                            6.7 Sulfuric acid (1 N)—Slowly, add 58 mL of H
                            <E T="52">2</E>
                            SO
                            <E T="52">4</E>
                             (ACS, sp. gr. 1.84) to reagent water and dilute to 1 L.
                        </P>
                        <P>6.8 Potassium carbonate—(ACS) Powdered.</P>
                        <P>6.9 Pentafluorobenzyl bromide (α-Bromopentafluorotoluene)—97% minimum purity.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>This chemical is a lachrymator. (See Section 4.2.)</P>
                        </NOTE>
                        <P>6.10 18-crown-6-ether (1,4,7,10,13,16-Hexaoxacyclooctadecane)—98% minimum purity.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>This chemical is highly toxic.</P>
                        </NOTE>
                        <P>6.11 Derivatization reagent—Add 1 mL of pentafluorobenzyl bromide and 1 g of 18-crown-6-ether to a 50-mL volumetric flask and dilute to volume with 2-propanol. Prepare fresh weekly. This operation should be carried out in a hood. Store at 4 °C and protect from light.</P>
                        <P>6.12 Acetone, hexane, methanol, methylene chloride, 2-propanol, toluene—Pesticide quality or equivalent.</P>
                        <P>6.13 Silica gel—100/200 mesh, Davison, grade-923 or equivalent. Activate at 130 °C overnight and store in a desiccator.</P>
                        <P>6.14 Stock standard solutions (1.00 µg/µL)—Stock standard solutions may be prepared from pure standard materials or purchased as certified solutions.</P>
                        <P>
                            6.14.1 Prepare stock standard solutions by accurately weighing about 0.0100 g of pure material. Dissolve the material in 2-propanol 
                            <PRTPAGE P="117"/>
                            and dilute to volume in a 10-mL volumetric flask. Larger volumes can be used at the convenience of the analyst. When compound purity is assayed to be 96% or greater, the weight can be used without correction to calculate the concentration of the stock standard. Commercially prepared stock standards can be used at any concentration if they are certified by the manufacturer or by an independent source.
                        </P>
                        <P>6.14.2 Transfer the stock standard solutions into Teflon-sealed screw-cap bottles. Store at 4 °C and protect from light. Stock standard solutions should be checked frequently for signs of degradation or evaporation, especially just prior to preparing calibration standards from them.</P>
                        <P>6.14.3 Stock standard solutions must be replaced after six months, or sooner if comparison with check standards indicates a problem.</P>
                        <P>6.15 Quality control check sample concentrate—See Section 8.2.1.</P>
                        <HD SOURCE="HD2">7. Calibration</HD>
                        <P>7.1 To calibrate the FIDGC for the analysis of underivatized phenols, establish gas chromatographic operating conditions equivalent to those given in Table 1. The gas chromatographic system can be calibrated using the external standard technique (Section 7.2) or the internal standard technique (Section 7.3).</P>
                        <P>7.2 External standard calibration procedure for FIDGC:</P>
                        <P>7.2.1 Prepare calibration standards at a minimum of three concentration levels for each parameter of interest by adding volumes of one or more stock standards to a volumetric flask and diluting to volume with 2-propanol. One of the external standards should be at a concentration near, but above, the MDL (Table 1) and the other concentrations should correspond to the expected range of concentrations found in real samples or should define the working range of the detector.</P>
                        <P>7.2.2 Using injections of 2 to 5 µl, analyze each calibration standard according to Section 11 and tabulate peak height or area responses against the mass injected. The results can be used to prepare a calibration curve for each compound. Alternatively, if the ratio of response to amount injected (calibration factor) is a constant over the working range (&lt;10% relative standard deviation, RSD), linearity through the origin can be assumed and the average ratio or calibration factor can be used in place of a calibration curve.</P>
                        <P>7.3 Internal standard calibration procedure for FIDGC—To use this approach, the analyst must select one or more internal standards that are similar in analytical behavior to the compounds of interest. The analyst must further demonstrate that the measurement of the internal standard is not affected by method or matrix interferences. Because of these limitations, no internal standard can be suggested that is applicable to all samples.</P>
                        <P>7.3.1 Prepare calibration standards at a minimum of three concentration levels for each parameter of interest by adding volumes of one or more stock standards to a volumetric flask. To each calibration standard, add a known constant amount of one or more internal standards, and dilute to volume with 2-propanol. One of the standards should be at a concentration near, but above, the MDL and the other concentrations should correspond to the expected range of concentrations found in real samples or should define the working range of the detector.</P>
                        <P>7.3.2 Using injections of 2 to 5 µL, analyze each calibration standard according to Section 11 and tabulate peak height or area responses against concentration for each compound and internal standard. Calculate response factors (RF) for each compound using Equation 1.</P>
                        <HD SOURCE="HD3">
                            RF = (A
                            <E T="52">s</E>
                            )(C
                            <E T="52">is</E>
                             (A
                            <E T="52">is</E>
                            )(C
                            <E T="52">s</E>
                            )
                        </HD>
                        <FP SOURCE="FRP">Equation 1</FP>
                        <FP>where:</FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">s</E>
                             = Response for the parameter to be measured.
                        </FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">is</E>
                             = Response for the internal standard.
                        </FP>
                        <FP SOURCE="FP-2">
                            C
                            <E T="52">is</E>
                             = Concentration of the internal standard (µg/L).
                        </FP>
                        <FP SOURCE="FP-2">
                            C
                            <E T="52">s</E>
                             = Concentration of the parameter to be measured (µg/L).
                        </FP>
                        <P>
                            If the RF value over the working range is a constant (&lt;10% RSD), the RF can be assumed to be invariant and the average RF can be used for calculations. Alternatively, the results can be used to plot a calibration curve of response ratios, A
                            <E T="52">s</E>
                            /A
                            <E T="52">is</E>
                            , vs. RF.
                        </P>
                        <P>7.4 The working calibration curve, calibration factor, or RF must be verified on each working day by the measurement of one or more calibration standards. If the response for any parameter varies from the predicted response by more than ±15%, a new calibration curve must be prepared for that compound.</P>
                        <P>7.5 To calibrate the ECDGC for the analysis of phenol derivatives, establish gas chromatographic operating conditions equivalent to those given in Table 2.</P>
                        <P>
                            7.5.1 Prepare calibration standards at a minimum of three concentration levels for each parameter of interest by adding volumes of one or more stock standards to a volumetric flask and diluting to volume with 2-propanol. One of the external standards should be at a concentration near, but above, the MDL (Table 2) and the other concentrations should correspond to the expected range of concentrations found in real samples or should define the working range of the detector.
                            <PRTPAGE P="118"/>
                        </P>
                        <P>7.5.2 Each time samples are to be derivatized, simultaneously treat a 1-mL aliquot of each calibration standard as described in Section 12.</P>
                        <P>7.5.3 After derivatization, analyze 2 to 5 µL of each column eluate collected according to the method beginning in Section 12.8 and tabulate peak height or area responses against the calculated equivalent mass of underivatized phenol injected. The results can be used to prepare a calibration curve for each compound.</P>
                        <P>7.6 Before using any cleanup procedure, the analyst must process a series of calibration standards through the procedure to validate elution patterns and the absence of interferences from the reagents.</P>
                        <HD SOURCE="HD2">8. Quality Control</HD>
                        <P>8.1 Each laboratory that uses this method is required to operate a formal quality control program. The minimum requirements of this program consist of an initial demonstration of laboratory capability and an ongoing analysis of spiked samples to evaluate and document data quality. The laboratory must maintain records to document the quality of data that is generated. Ongoing data quality checks are compared with established performance criteria to determine if the results of analyses meet the performance characteristics of the method. When results of sample spikes indicate atypical method performance, a quality control check standard must be analyzed to confirm that the measurements were performed in an in-control mode of operation.</P>
                        <P>8.1.1 The analyst must make an initial, one-time, demonstration of the ability to generate acceptable accuracy and precision with this method. This ability is established as described in Section 8.2.</P>
                        <P>8.1.2 In recognition of advances that are occurring in chromatography, the analyst is permitted certain options (detailed in Sections 10.6 and 11.1) to improve the separations or lower the cost of measurements. Each time such a modification is made to the method, the analyst is required to repeat the procedure in Section 8.2.</P>
                        <P>8.1.3 Before processing any samples the analyst must analyze a reagent water blank to demonstrate that interferences from the analytical system and glassware are under control. Each time a set of samples is extracted or reagents are changed a reagent water blank must be processed as a safeguard against laboratory contamination.</P>
                        <P>8.1.4 The laboratory must, on an ongoing basis, spike and analyze a minimum of 10% of all samples to monitor and evaluate laboratory data quality. This procedure is described in Section 8.3.</P>
                        <P>8.1.5 The laboratory must, on an ongoing basis, demonstrate through the analyses of quality control check standards that the operation of the measurement system is in control. This procedure is described in Section 8.4. The frequency of the check standard analyses is equivalent to 10% of all samples analyzed but may be reduced if spike recoveries from samples (Section 8.3) meet all specified quality control criteria.</P>
                        <P>8.1.6 The laboratory must maintain performance records to document the quality of data that is generated. This procedure is described in Section 8.5.</P>
                        <P>8.2 To establish the ability to generate acceptable accuracy and precision, the analyst must perform the following operations.</P>
                        <P>8.2.1 A quality control (QC) check sample concentrate is required containing each parameter of interest at a concentration of 100 µg/mL in 2-propanol. The QC check sample concentrate must be obtained from the U.S. Environmental Protection Agency, Environmental Monitoring and Support Laboratory in Cincinnati, Ohio, if available. If not available from that source, the QC check sample concentrate must be obtained from another external source. If not available from either source above, the QC check sample concentrate must be prepared by the laboratory using stock standards prepared independently from those used for calibration.</P>
                        <P>8.2.2 Using a pipet, prepare QC check samples at a concentration of 100 µg/L by adding 1.00 mL of QC check sample concentrate to each of four 1-L aliquots of reagent water.</P>
                        <P>8.2.3 Analyze the well-mixed QC check samples according to the method beginning in Section 10.</P>
                        <P>
                            8.2.4 Calculate the average recovery (X
                            <AC T="8"/>
                            ) in µg/L, and the standard deviation of the recovery (s) in µg/L, for each parameter using the four results.
                        </P>
                        <P>
                            8.2.5 For each parameter compare s and X
                            <AC T="8"/>
                             with the corresponding acceptance criteria for precision and accuracy, respectively, found in Table 3. If s and X
                            <AC T="8"/>
                             for all parameters of interest meet the acceptance criteria, the system performance is acceptable and analysis of actual samples can begin. If any individual s exceeds the precision limit or any individual X
                            <AC T="8"/>
                             falls outside the range for accuracy, the system performance is unacceptable for that parameter.
                        </P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>The large number of parameters in Talbe 3 present a substantial probability that one or more will fail at least one of the acceptance criteria when all parameters are analyzed.</P>
                        </NOTE>
                        <P>8.2.6 When one or more of the parameters tested fail at least one of the acceptance criteria, the analyst must proceed according to Section 8.2.6.1 or 8.2.6.2.</P>
                        <P>8.2.6.1 Locate and correct the source of the problem and repeat the test for all parameters of interest beginning with Section 8.2.2.</P>
                        <P>
                            8.2.6.2 Beginning with Section 8.2.2, repeat the test only for those parameters that failed to meet criteria. Repeated failure, however, will confirm a general problem 
                            <PRTPAGE P="119"/>
                            with the measurement system. If this occurs, locate and correct the source of the problem and repeat the test for all compounds of interest beginning with Section 8.2.2.
                        </P>
                        <P>8.3 The laboratory must, on an ongoing basis, spike at least 10% of the samples from each sample site being monitored to assess accuracy. For laboratories analyzing one to ten samples per month, at least one spiked sample per month is required.</P>
                        <P>8.3.1 The concentration of the spike in the sample should be determined as follows:</P>
                        <P>8.3.1.1 If, as in compliance monitoring, the concentration of a specific parameter in the sample is being checked against a regulatory concentration limit, the spike should be at that limit or 1 to 5 times higher than the background concentration determined in Section 8.3.2, whichever concentration would be larger.</P>
                        <P>8.3.1.2 If the concentration of a specific parameter in the sample is not being checked against a limit specific to that parameter, the spike should be at 100 µg/L or 1 to 5 times higher than the background concentration determined in Section 8.3.2, whichever concentration would be larger.</P>
                        <P>8.3.1.3 If it is impractical to determine background levels before spiking (e.g., maximum holding times will be exceeded), the spike concentration should be (1) the regulatory concentration limit, if any, or, if none, (2) the larger of either 5 times higher than the expected background concentration or 100 µg/L.</P>
                        <P>8.3.2 Analyze one sample aliquot to determine the background concentration (B) of each parameter. If necessary, prepare a new QC check sample concentrate (Section 8.2.1) appropriate for the background concentrations in the sample. Spike a second sample aliquot with 1.0 mL of the QC check sample concentrate and analyze it to determine the concentration after spiking (A) of each parameter. Calculate each percent recovery (P) as 100(A−B)%/T, where T is the known true value of the spike.</P>
                        <P>
                            8.3.3 Compare the percent recovery (P) for each parameter with the corresponding QC acceptance criteria found in Table 3. These acceptance criteria were calculated to include an allowance for error in measurement of both the background and spike concentrations, assuming a spike to background ratio of 5:1. This error will be accounted for to the extent that the analyst's spike to background ratio approaches 5:1. 
                            <SU>8</SU>
                             If spiking was performed at a concentration lower than 100 µg/L, the analyst must use either the QC acceptance criteria in Table 3, or optional QC acceptance criteria calculated for the specific spike concentration. To calculate optional acceptance criteria for the recovery of a parameter: (1) Calculate accuracy (X′) using the equation in Table 4, substituting the spike concentration (T) for C; (2) calculate overall precision (S′) using the equation in Table 4, substituting X′ for X
                            <AC T="8"/>
                            ; (3) calculate the range for recovery at the spike concentration as (100 X′/T)±2.44(100 S′/T)%. 
                            <SU>8</SU>
                        </P>
                        <P>8.3.4 If any individual P falls outside the designated range for recovery, that parameter has failed the acceptance criteria. A check standard containing each parameter that failed the criteria must be analyzed as described in Section 8.4.</P>
                        <P>8.4 If any parameter fails the acceptance criteria for recovery in Section 8.3, a QC check standard containing each parameter that failed must be prepared and analyzed.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>The frequency for the required analysis of a QC check standard will depend upon the number of parameters being simultaneously tested, the complexity of the sample matrix, and the performance of the laboratory.</P>
                        </NOTE>
                        <P>8.4.1 Prepare the QC check standard by adding 1.0 mL of QC check sample concentrate (Section 8.2.1 or 8.3.2) to 1 L of reagent water. The QC check standard needs only to contain the parameters that failed criteria in the test in Section 8.3.</P>
                        <P>
                            8.4.2 Analyze the QC check standard to determine the concentration measured (A) of each parameter. Calculate each percent recovery (P
                            <E T="52">s</E>
                            ) as 100 (A/T)%, where T is the true value of the standard concentration.
                        </P>
                        <P>
                            8.4.3 Compare the percent recovery (P
                            <E T="52">s</E>
                            ) for each parameter with the corresponding QC acceptance criteria found in Table 3. Only parameters that failed the test in Section 8.3 need to be compared with these criteria. If the recovery of any such parameter falls outside the designated range, the laboratory performance for that parameter is judged to be out of control, and the problem must be immediately identified and corrected. The analytical result for that parameter in the unspiked sample is suspect and may not be reported for regulatory compliance purposes.
                        </P>
                        <P>
                            8.5 As part of the QC program for the laboratory, method accuracy for wastewater samples must be assessed and records must be maintained. After the analysis of five spiked wastewater samples as in Section 8.3, calculate the average percent recovery (P
                            <AC T="8"/>
                            ) and the standard deviation of the percent recovery (s
                            <E T="52">p</E>
                            ). Express the accuracy assessment as a percent recovery interval from P
                            <AC T="8"/>
                            −2s
                            <E T="52">p</E>
                             to P
                            <AC T="8"/>
                             + 2s
                            <E T="52">p</E>
                            . If P
                            <AC T="8"/>
                             = 90% and s
                            <E T="52">p</E>
                             = 10%, for example, the accuracy interval is expressed as 70-110%. Update the accuracy assessment for each parameter on a regular basis (e.g. after each five to ten new accuracy measurements).
                        </P>
                        <P>
                            8.6. It is recommended that the laboratory adopt additional quality assurance practices for use with this method. The specific practices that are most productive depend upon the needs of the laboratory and the nature of the samples. Field duplicates may be analyzed to assess the precision of the environmental measurements. When 
                            <PRTPAGE P="120"/>
                            doubt exists over the identification of a peak on the chromatogram, confirmatory techniques such as gas chromatography with a dissimilar column, specific element detector, or mass spectrometer must be used. Whenever possible, the laboratory should analyze standard reference materials and participate in relevant performance evaluation studies.
                        </P>
                        <HD SOURCE="HD2">9. Sample Collection, Preservation, and Handling</HD>
                        <P>
                            9.1 Grab samples must be collected in glass containers. Conventional sampling practices 
                            <SU>9</SU>
                             should be followed, except that the bottle must not be prerinsed with sample before collection. Composite samples should be collected in refrigerated glass containers in accordance with the requirements of the program. Automatic sampling equipment must be as free as possible of Tygon tubing and other potential sources of contamination.
                        </P>
                        <P>
                            9.2 All samples must be iced or refrigerated at 4 °C from the time of collection until extraction. Fill the sample bottles and, if residual chlorine is present, add 80 mg of sodium thiosulfate per liter of sample and mix well. EPA Methods 330.4 and 330.5 may be used for measurement of residual chlorine. 
                            <SU>10</SU>
                             Field test kits are available for this purpose.
                        </P>
                        <P>
                            9.3 All samples must be extracted within 7 days of collection and completely analyzed within 40 days of extraction. 
                            <SU>2</SU>
                        </P>
                        <HD SOURCE="HD2">10. Sample Extraction</HD>
                        <P>10.1 Mark the water meniscus on the side of sample bottle for later determination of sample volume. Pour the entire sample into a 2-L separatory funnel.</P>
                        <P>10.2 For samples high in organic content, the analyst may solvent wash the sample at basic pH as prescribed in Sections 10.2.1 and 10.2.2 to remove potential method interferences. Prolonged or exhaustive contact with solvent during the wash may result in low recovery of some of the phenols, notably phenol and 2,4-dimethylphenol. For relatively clean samples, the wash should be omitted and the extraction, beginning with Section 10.3, should be followed.</P>
                        <P>10.2.1 Adjust the pH of the sample to 12.0 or greater with sodium hydroxide solution.</P>
                        <P>10.2.2 Add 60 mL of methylene chloride to the sample by shaking the funnel for 1 min with periodic venting to release excess pressure. Discard the solvent layer. The wash can be repeated up to two additional times if significant color is being removed.</P>
                        <P>10.3 Adjust the sample to a pH of 1 to 2 with sulfuric acid.</P>
                        <P>10.4 Add 60 mL of methylene chloride to the sample bottle, seal, and shake 30 s to rinse the inner surface. Transfer the solvent to the separatory funnel and extract the sample by shaking the funnel for 2 min. with periodic venting to release excess pressure. Allow the organic layer to separate from the water phase for a minimum of 10 min. If the emulsion interface between layers is more than one-third the volume of the solvent layer, the analyst must employ mechanical techniques to complete the phase separation. The optimum technique depends upon the sample, but may include stirring, filtration of the emulsion through glass wool, centrifugation, or other physical methods. Collect the methylene chloride extract in a 250-mL Erlenmeyer flask.</P>
                        <P>10.5 Add a second 60-mL volume of methylene chloride to the sample bottle and repeat the extraction procedure a second time, combining the extracts in the Erlenmeyer flask. Perform a third extraction in the same manner.</P>
                        <P>10.6 Assemble a Kuderna-Danish (K-D) concentrator by attaching a 10-mL concentrator tube to a 500-mL evaporative flask. Other concentration devices or techniques may be used in place of the K-D concentrator if the requirements of Section 8.2 are met.</P>
                        <P>10.7 Pour the combined extract through a solvent-rinsed drying column containing about 10 cm of anhydrous sodium sulfate, and collect the extract in the K-D concentrator. Rinse the Erlenmeyer flask and column with 20 to 30 mL of methylene chloride to complete the quantitative transfer.</P>
                        <P>10.8 Add one or two clean boiling chips to the evaporative flask and attach a three-ball Snyder column. Prewet the Snyder column by adding about 1 mL of methylene chloride to the top. Place the K-D apparatus on a hot water bath (60 to 65 °C) so that the concentrator tube is partially immersed in the hot water, and the entire lower rounded surface of the flask is bathed with hot vapor. Adjust the vertical position of the apparatus and the water temperature as required to complete the concentration in 15 to 20 min. At the proper rate of distillation the balls of the column will actively chatter but the chambers will not flood with condensed solvent. When the apparent volume of liquid reaches 1 mL, remove the K-D apparatus and allow it to drain and cool for at least 10 min.</P>
                        <P>
                            10.9 Increase the temperature of the hot water bath to 95 to 100 °C. Remove the Synder column and rinse the flask and its lower joint into the concentrator tube with 1 to 2 mL of 2-propanol. A 5-mL syringe is recommended for this operation. Attach a two-ball micro-Snyder column to the concentrator tube and prewet the column by adding about 0.5 mL of 2-propanol to the top. Place the micro-K-D apparatus on the water bath so that the concentrator tube is partially immersed in the hot water. Adjust the vertical position of the apparatus and the water temperature as required to complete concentration in 5 to 10 min. At the proper rate of distillation the balls of the column will actively chatter but the chambers will 
                            <PRTPAGE P="121"/>
                            not flood. When the apparent volume of liquid reaches 2.5 mL, remove the K-D apparatus and allow it to drain and cool for at least 10 min. Add an additional 2 mL of 2-propanol through the top of the micro-Snyder column and resume concentrating as before. When the apparent volume of liquid reaches 0.5 mL, remove the K-D apparatus and allow it to drain and cool for at least 10 min.
                        </P>
                        <P>10.10 Remove the micro-Snyder column and rinse its lower joint into the concentrator tube with a minimum amount of 2-propanol. Adjust the extract volume to 1.0 mL. Stopper the concentrator tube and store refrigerated at 4 °C if further processing will not be performed immediately. If the extract will be stored longer than two days, it should be transferred to a Teflon-sealed screw-cap vial. If the sample extract requires no further cleanup, proceed with FIDGC analysis (Section 11). If the sample requires further cleanup, proceed to Section 12.</P>
                        <P>10.11 Determine the original sample volume by refilling the sample bottle to the mark and transferring the liquid to a 1000-mL graduated cylinder. Record the sample volume to the nearest 5 mL.</P>
                        <HD SOURCE="HD2">11. Flame Ionization Detector Gas Chromatography</HD>
                        <P>11.1 Table 1 summarizes the recommended operating conditions for the gas chromatograph. Included in this table are retention times and MDL that can be achieved under these conditions. An example of the separations achieved by this column is shown in Figure 1. Other packed or capillary (open-tubular) columns, chromatographic conditions, or detectors may be used if the requirements of Section 8.2 are met.</P>
                        <P>11.2 Calibrate the system daily as described in Section 7.</P>
                        <P>11.3 If the internal standard calibration procedure is used, the internal standard must be added to the sample extract and mixed thoroughly immediately before injection into the gas chromatograph.</P>
                        <P>
                            11.4 Inject 2 to 5 µL of the sample extract or standard into the gas chromatograph using the solvent-flush technique. 
                            <SU>11</SU>
                             Smaller (1.0 µL) volumes may be injected if automatic devices are employed. Record the volume injected to the nearest 0.05 µL, and the resulting peak size in area or peak height units.
                        </P>
                        <P>11.5 Identify the parameters in the sample by comparing the retention times of the peaks in the sample chromatogram with those of the peaks in standard chromatograms. The width of the retention time window used to make identifications should be based upon measurements of actual retention time variations of standards over the course of a day. Three times the standard deviation of a retention time for a compound may be used to calculate a suggested window size; however, the experience of the analyst should weigh heavily in the interpretation of chromatograms.</P>
                        <P>11.6 If the response for a peak exceeds the working range of the system, dilute the extract and reanalyze.</P>
                        <P>11.7 If the measurement of the peak response is prevented by the presence of interferences, an alternative gas chromatographic procedure is required. Section 12 describes a derivatization and column chromatographic procedure which has been tested and found to be a practical means of analyzing phenols in complex extracts.</P>
                        <HD SOURCE="HD2">12. Derivatization and Electron Capture Detector Gas Chromatography</HD>
                        <P>12.1 Pipet a 1.0-mL aliquot of the 2-propanol solution of standard or sample extract into a glass reaction vial. Add 1.0 mL of derivatizing reagent (Section 6.11). This amount of reagent is sufficient to derivatize a solution whose total phenolic content does not exceed 0.3 mg/mL.</P>
                        <P>12.2 Add about 3 mg of potassium carbonate to the solution and shake gently.</P>
                        <P>12.3 Cap the mixture and heat it for 4 h at 80 °C in a hot water bath.</P>
                        <P>12.4 Remove the solution from the hot water bath and allow it to cool.</P>
                        <P>12.5 Add 10 mL of hexane to the reaction flask and shake vigorously for 1 min. Add 3.0 mL of distilled, deionized water to the reaction flask and shake for 2 min. Decant a portion of the organic layer into a concentrator tube and cap with a glass stopper.</P>
                        <P>12.6 Place 4.0 g of silica gel into a chromatographic column. Tap the column to settle the silica gel and add about 2 g of anhydrous sodium sulfate to the top.</P>
                        <P>12.7 Preelute the column with 6 mL of hexane. Discard the eluate and just prior to exposure of the sodium sulfate layer to the air, pipet onto the column 2.0 mL of the hexane solution (Section 12.5) that contains the derivatized sample or standard. Elute the column with 10.0 mL of hexane and discard the eluate. Elute the column, in order, with: 10.0 mL of 15% toluene in hexane (Fraction 1); 10.0 mL of 40% toluene in hexane (Fraction 2); 10.0 mL of 75% toluene in hexane (Fraction 3); and 10.0 mL of 15% 2-propanol in toluene (Fraction 4). All elution mixtures are prepared on a volume: volume basis. Elution patterns for the phenolic derivatives are shown in Table 2. Fractions may be combined as desired, depending upon the specific phenols of interest or level of interferences.</P>
                        <P>
                            12.8 Analyze the fractions by ECDGC. Table 2 summarizes the recommended operating conditions for the gas chromatograph. Included in this table are retention times and MDL that can be achieved under these conditions. An example of the separations achieved by this column is shown in Figure 2.
                            <PRTPAGE P="122"/>
                        </P>
                        <P>12.9 Calibrate the system daily with a minimum of three aliquots of calibration standards, containing each of the phenols of interest that are derivatized according to Section 7.5.</P>
                        <P>12.10 Inject 2 to 5 µL of the column fractions into the gas chromatograph using the solvent-flush technique. Smaller (1.0 µL) volumes can be injected if automatic devices are employed. Record the volume injected to the nearest 0.05 µL, and the resulting peak size in area or peak height units. If the peak response exceeds the linear range of the system, dilute the extract and reanalyze.</P>
                        <HD SOURCE="HD2">13. Calculations</HD>
                        <P>13.1 Determine the concentration of individual compounds in the sample analyzed by FIDGC (without derivatization) as indicated below.</P>
                        <P>13.1.1 If the external standard calibration procedure is used, calculate the amount of material injected from the peak response using the calibration curve or calibration factor determined in Section 7.2.2. The concentration in the sample can be calculated from Equation 2.</P>
                        <MATH SPAN="1" DEEP="31">
                            <MID>EC15NO91.098</MID>
                        </MATH>
                        <FP SOURCE="FRP0">Equation 2</FP>
                        <FP>where:</FP>
                        <FP SOURCE="FP-2">A = Amount of material injected (ng).</FP>
                        <FP SOURCE="FP-2">
                            V
                            <E T="52">i</E>
                             = Volume of extract injected (µL).
                        </FP>
                        <FP SOURCE="FP-2">
                            V
                            <E T="52">t</E>
                             = Volume of total extract (µL).
                        </FP>
                        <FP SOURCE="FP-2">
                            V
                            <E T="52">s</E>
                             = Volume of water extracted (mL).
                        </FP>
                        <P>13.1.2 If the internal standard calibration procedure is used, calculate the concentration in the sample using the response factor (RF) determined in Section 7.3.2 and Equation 3.</P>
                        <MATH SPAN="1" DEEP="31">
                            <MID>EC15NO91.099</MID>
                        </MATH>
                        <FP SOURCE="FRP0">Equation 3</FP>
                        <FP>where:</FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">s</E>
                             = Response for the parameter to be measured.
                        </FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">is</E>
                             = Response for the internal standard.
                        </FP>
                        <FP SOURCE="FP-2">
                            I
                            <E T="52">s</E>
                             = Amount of internal standard added to each extract (µg).
                        </FP>
                        <FP SOURCE="FP-2">
                            V
                            <E T="52">o</E>
                             = Volume of water extracted (L).
                        </FP>
                        <P>13.2 Determine the concentration of individual compounds in the sample analyzed by derivatization and ECDGC according to Equation 4.</P>
                        <MATH SPAN="1" DEEP="31">
                            <MID>EC15NO91.100</MID>
                        </MATH>
                        <FP SOURCE="FRP0">Equation 4</FP>
                        <FP>where:</FP>
                        <FP SOURCE="FP-2">A = Mass of underivatized phenol represented by area of peak in sample chromatogram, determined from calibration curve in Section 7.5.3 (ng).</FP>
                        <FP SOURCE="FP-2">
                            V
                            <E T="52">i</E>
                             = Volume of eluate injected (µL).
                        </FP>
                        <FP SOURCE="FP-2">
                            V
                            <E T="52">t</E>
                             = Total volume of column eluate or combined fractions from which V
                            <E T="52">i</E>
                             was taken (µL).
                        </FP>
                        <FP SOURCE="FP-2">
                            V
                            <E T="52">s</E>
                             = Volume of water extracted in Section 10.10 (mL).
                        </FP>
                        <FP SOURCE="FP-2">B = Total volume of hexane added in Section 12.5 (mL).</FP>
                        <FP SOURCE="FP-2">C = Volume of hexane sample solution added to cleanup column in Section 12.7 (mL).</FP>
                        <FP SOURCE="FP-2">D = Total volume of 2-propanol extract prior to derivatization (mL).</FP>
                        <FP SOURCE="FP-2">E = Volume of 2-propanol extract carried through derivatization in Section 12.1 (mL).</FP>
                        <P>13.3 Report results in µg/L without correction for recovery data. All QC data obtained should be reported with the sample results.</P>
                        <HD SOURCE="HD2">14. Method Performance</HD>
                        <P>
                            14.1 The method detection limit (MDL) is defined as the minimum concentration of a substance that can be measured and reported with 99% confidence that the value is above zero. 
                            <SU>1</SU>
                             The MDL concentrations listed in Tables 1 and 2 were obtained using reagent water. 
                            <SU>12</SU>
                             Similar results were achieved using representative wastewaters. The MDL actually achieved in a given analysis will vary depending on instrument sensitivity and matrix effects.
                        </P>
                        <P>
                            14.2 This method was tested by 20 laboratories using reagent water, drinking water, surface water, and three industrial wastewaters spiked as six concentrations over the range 12 to 450 µg/L. 
                            <SU>13</SU>
                             Single operator precision, overall precision, and method accuracy were found to be directly related to the concentration of the parameter and essentially independent of the sample matrix. Linear equations to describe these relationships for a flame ionization detector are presented in Table 4.
                        </P>
                        <HD SOURCE="HD2">References</HD>
                        <P>1. 40 CFR part 136, appendix B.</P>
                        <P>2. “Determination of Phenols in Industrial and Municipal Wastewaters,” EPA 600/4-84-ABC, National Technical Information Service, PBXYZ, Springfield, Virginia 22161, November 1984.</P>
                        <P>
                            3. Kawahara, F. K. “Microdetermination of Derivatives of Phenols and Mercaptans by Means of Electron Capture Gas Chromatography,” 
                            <E T="03">Analytical Chemistry, 40,</E>
                             1009 (1968).
                        </P>
                        <P>
                            4. ASTM Annual Book of Standards, Part 31, D3694-78. “Standard Practices for Preparation of Sample Containers and for Preservation of Organic Constituents,” American 
                            <PRTPAGE P="123"/>
                            Society for Testing and Materials, Philadelphia.
                        </P>
                        <P>5. “Carcinogens—Working With Carcinogens,” Department of Health, Education, and Welfare, Public Health Service, Center for Disease Control, National Institute for Occupational Safety and Health, Publication No. 77-206, August 1977.</P>
                        <P>6. “OSHA Safety and Health Standards, General Industry,” (29 CFR part 1910), Occupational Safety and Health Administration, OSHA 2206 (Revised, January 1976).</P>
                        <P>7. “Safety in Academic Chemistry Laboratories,” American Chemical Society Publication, Committee on Chemical Safety, 3rd Edition, 1979.</P>
                        <P>
                            8. Provost, L. P., and Elder, R. S. “Interpretation of Percent Recovery Data,” 
                            <E T="03">American Laboratory, 15,</E>
                             58-63 (1983). (The value 2.44 used in the equation in Section 8.3.3 is two times the value 1.22 derived in this report.)
                        </P>
                        <P>9. ASTM Annual Book of Standards, Part 31, D3370-76. “Standard Practices for Sampling Water,” American Society for Testing and Materials, Philadelphia.</P>
                        <P>10. “Methods 330.4 (Titrimetric, DPD-FAS) and 330.5 (Spectrophotometric, DPD) for Chlorine, Total Residual,” Methmds for Chemical Analysis of Water and Wastes, EPA-600/4-79-020, U.S. Environmental Protection Agency, Environmental Monitoring and Support Laboratory, Cincinnati, Ohio 45268, March 1979.</P>
                        <P>
                            11. Burke, J. A. “Gas Chromatography for Pesticide Residue Analysis; Some Practical Aspects,” 
                            <E T="03">Journal of the Association of Official Analytical Chemists, 48,</E>
                             1037 (1965).
                        </P>
                        <P>12. “Development of Detection Limits, EPA Method 604, Phenols,” Special letter report for EPA Contract 68-03-2625, U.S. Environmental Protection Agency, Environmental Monitoring and Support Laboratory, Cincinnati, Ohio 45268.</P>
                        <P>13. “EPA Method Study 14 Method 604-Phenols,” EPA 600/4-84-044, National Technical Information Service, PB84-196211, Springfield, Virginia 22161, May 1984.</P>
                        <GPOTABLE COLS="3" OPTS="L2" CDEF="s50,9,8.2">
                            <TTITLE>Table 1—Chromatographic Conditions and Method Detection Limits</TTITLE>
                            <BOXHD>
                                <CHED H="1">Parameter</CHED>
                                <CHED H="1">Retention time (min)</CHED>
                                <CHED H="1">Method detection limit (µg/L)</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">2-Chlorophenol</ENT>
                                <ENT>1.70</ENT>
                                <ENT>0.31</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-Nitrophenol</ENT>
                                <ENT>2.00</ENT>
                                <ENT>0.45</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Phenol</ENT>
                                <ENT>3.01</ENT>
                                <ENT>0.14</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4-Dimethylphenol</ENT>
                                <ENT>4.03</ENT>
                                <ENT>0.32</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4-Dichlorophenol</ENT>
                                <ENT>4.30</ENT>
                                <ENT>0.39</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4,6-Trichlorophenol</ENT>
                                <ENT>6.05</ENT>
                                <ENT>0.64</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4-Chloro-3-methylphenol</ENT>
                                <ENT>7.50</ENT>
                                <ENT>0.36</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4-Dinitrophenol</ENT>
                                <ENT>10.00</ENT>
                                <ENT>13.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-Methyl-4,6-dinitrophenol</ENT>
                                <ENT>10.24</ENT>
                                <ENT>16.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Pentachlorophenol</ENT>
                                <ENT>12.42</ENT>
                                <ENT>7.4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4-Nitrophenol</ENT>
                                <ENT>24.25</ENT>
                                <ENT>2.8</ENT>
                            </ROW>
                            <TNOTE>Column conditions: Supelcoport (80/100 mesh) coated with 1% SP-1240DA packed in a 1.8 m long × 2 mm ID glass column with nitrogen carrier gas at 30 mL/min flow rate. Column temperature was 80 °C at injection, programmed immediately at 8 °C/min to 150 °C final temperature. MDL were determined with an FID.</TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="7" OPTS="L2" CDEF="s50,4,4,4,4,8,6.2">
                            <TTITLE>Table 2—Silica Gel Fractionation and Electron Capture Gas Chromatography of PFBB Derivatives</TTITLE>
                            <BOXHD>
                                <CHED H="1">Parent compound</CHED>
                                <CHED H="1">
                                    Percent recovery by fraction 
                                    <SU>a</SU>
                                </CHED>
                                <CHED H="2">1</CHED>
                                <CHED H="2">2</CHED>
                                <CHED H="2">3</CHED>
                                <CHED H="2">4</CHED>
                                <CHED H="1">Retention time (min)</CHED>
                                <CHED H="1">Method detection limit (µg/L)</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">2-Chlorophenol</ENT>
                                <ENT/>
                                <ENT>90</ENT>
                                <ENT>1</ENT>
                                <ENT/>
                                <ENT>3.3</ENT>
                                <ENT>0.58</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-Nitrophenol</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>9</ENT>
                                <ENT>90</ENT>
                                <ENT>9.1</ENT>
                                <ENT>0.77</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Phenol</ENT>
                                <ENT/>
                                <ENT>90</ENT>
                                <ENT>10</ENT>
                                <ENT/>
                                <ENT>1.8</ENT>
                                <ENT>2.2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4-Dimethylphenol</ENT>
                                <ENT/>
                                <ENT>95</ENT>
                                <ENT>7</ENT>
                                <ENT/>
                                <ENT>2.9</ENT>
                                <ENT>0.63</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4-Dichlorophenol</ENT>
                                <ENT/>
                                <ENT>95</ENT>
                                <ENT>1</ENT>
                                <ENT/>
                                <ENT>5.8</ENT>
                                <ENT>0.68</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4,6-Trichlorophenol</ENT>
                                <ENT>50</ENT>
                                <ENT>50</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>7.0</ENT>
                                <ENT>0.58</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4-Chloro-3-methylphenol</ENT>
                                <ENT/>
                                <ENT>84</ENT>
                                <ENT>14</ENT>
                                <ENT/>
                                <ENT>4.8</ENT>
                                <ENT>1.8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Pentachlorophenol</ENT>
                                <ENT>75</ENT>
                                <ENT>20</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>28.8</ENT>
                                <ENT>0.59</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4-Nitrophenol</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>1</ENT>
                                <ENT>90</ENT>
                                <ENT>14.0</ENT>
                                <ENT>0.70</ENT>
                            </ROW>
                            <TNOTE>Column conditions: Chromosorb W-AW-DMCS (80/100 mesh) coated with 5% OV-17 packed in a 1.8 m long × 2.0 mm ID glass column with 5% methane/95% argon carrier gas at 30 mL/min flow rate. Column temperature held isothermal at 200 °C. MDL were determined with an ECD.</TNOTE>
                            <TNOTE>
                                <SU>a</SU>
                                 Eluant composition:
                            </TNOTE>
                            <TNOTE>  Fraction 1—15% toluene in hexane.</TNOTE>
                            <TNOTE>  Fraction 2—40% toluene in hexane.</TNOTE>
                            <TNOTE>  Fraction 3—75% toluene in hexane.</TNOTE>
                            <TNOTE>  Fraction 4—15% 2-propanol in toluene.</TNOTE>
                        </GPOTABLE>
                        <PRTPAGE P="124"/>
                        <GPOTABLE COLS="5" OPTS="L2" CDEF="s50,5,8,10,10">
                            <TTITLE>Table 3—QC Acceptance Criteria—Method 604</TTITLE>
                            <BOXHD>
                                <CHED H="1">Parameter</CHED>
                                <CHED H="1">Test conc. (µg/L)</CHED>
                                <CHED H="1">Limit for s (µg/L)</CHED>
                                <CHED H="1">
                                    Range for X
                                    <AC T="8"/>
                                     (µg/L)
                                </CHED>
                                <CHED H="1">
                                    Range for P, P
                                    <E T="52">s</E>
                                     (percent)
                                </CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">4-Chloro-3-methylphenol</ENT>
                                <ENT>100</ENT>
                                <ENT>16.6</ENT>
                                <ENT>56.7-113.4</ENT>
                                <ENT>49-122</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-Chlorophenol</ENT>
                                <ENT>100</ENT>
                                <ENT>27.0</ENT>
                                <ENT>54.1-110.2</ENT>
                                <ENT>38-126</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4-Dichlorophenol</ENT>
                                <ENT>100</ENT>
                                <ENT>25.1</ENT>
                                <ENT>59.7-103.3</ENT>
                                <ENT>44-119</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4-Dimethylphenol</ENT>
                                <ENT>100</ENT>
                                <ENT>33.3</ENT>
                                <ENT>50.4-100.0</ENT>
                                <ENT>24-118</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4,6-Dinitro-2-methylphenol</ENT>
                                <ENT>100</ENT>
                                <ENT>25.0</ENT>
                                <ENT>42.4-123.6</ENT>
                                <ENT>30-136</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4-Dinitrophenol</ENT>
                                <ENT>100</ENT>
                                <ENT>36.0</ENT>
                                <ENT>31.7-125.1</ENT>
                                <ENT>12-145</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-Nitrophenol</ENT>
                                <ENT>100</ENT>
                                <ENT>22.5</ENT>
                                <ENT>56.6-103.8</ENT>
                                <ENT>43-117</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4-Nitrophenol</ENT>
                                <ENT>100</ENT>
                                <ENT>19.0</ENT>
                                <ENT>22.7-100.0</ENT>
                                <ENT>13-110</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Pentachlorophenol</ENT>
                                <ENT>100</ENT>
                                <ENT>32.4</ENT>
                                <ENT>56.7-113.5</ENT>
                                <ENT>36-134</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Phenol</ENT>
                                <ENT>100</ENT>
                                <ENT>14.1</ENT>
                                <ENT>32.4-100.0</ENT>
                                <ENT>23-108</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4,6-Trichlorophenol</ENT>
                                <ENT>100</ENT>
                                <ENT>16.6</ENT>
                                <ENT>60.8-110.4</ENT>
                                <ENT>53-119</ENT>
                            </ROW>
                            <TNOTE>s—Standard deviation of four recovery measurements, in µg/L (Section 8.2.4).</TNOTE>
                            <TNOTE>
                                X
                                <AC T="8"/>
                                —Average recovery for four recovery measurements, in µg/L (Section 8.2.4).
                            </TNOTE>
                            <TNOTE>
                                P, P
                                <E T="52">s</E>
                                —Percent recovery measured (Section 8.3.2, Section 8.4.2).
                            </TNOTE>
                            <TNOTE>
                                <E T="04">Note:</E>
                                 These criteria are based directly upon the method performance data in Table 4. Where necessary, the limits for recovery have been broadened to assure applicability of the limits to concentrations below those used to develop Table 4.
                            </TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="4" OPTS="L2" CDEF="s50,15,15,15">
                            <TTITLE>Table 4—Method Accuracy and Precision as Functions of Concentration—Method 604</TTITLE>
                            <BOXHD>
                                <CHED H="1">Parameter</CHED>
                                <CHED H="1">Accuracy, as recovery, X′ (µg/L)</CHED>
                                <CHED H="1">
                                    Single Analyst precision, s
                                    <E T="52">r</E>
                                    ′ (µg/L)
                                </CHED>
                                <CHED H="1">Overall precision, S′ (µg/L)</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">4-Chloro-3-methylphenol</ENT>
                                <ENT>0.87C-1.97</ENT>
                                <ENT>
                                    0.11X
                                    <AC T="8"/>
                                    -0.21
                                </ENT>
                                <ENT>
                                    0.16X
                                    <AC T="8"/>
                                     + 1.41
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-Chlorophenol</ENT>
                                <ENT>0.83C-0.84</ENT>
                                <ENT>
                                    0.18X
                                    <AC T="8"/>
                                     + 0.20
                                </ENT>
                                <ENT>
                                    0.21X
                                    <AC T="8"/>
                                     + 0.75
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4-Dichlorophenol</ENT>
                                <ENT>0.81C + 0.48</ENT>
                                <ENT>
                                    0.17X
                                    <AC T="8"/>
                                    -0.02
                                </ENT>
                                <ENT>
                                    0.18X
                                    <AC T="8"/>
                                     + 0.62
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4-Dimethylphenol</ENT>
                                <ENT>0.62C-1.64</ENT>
                                <ENT>
                                    0.30X
                                    <AC T="8"/>
                                    -0.89
                                </ENT>
                                <ENT>
                                    0.25X
                                    <AC T="8"/>
                                     + 0.48
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4,6-Dinitro-2-methylphenol</ENT>
                                <ENT>0.84C-1.01</ENT>
                                <ENT>
                                    0.15X
                                    <AC T="8"/>
                                     + 1.25
                                </ENT>
                                <ENT>
                                    0.19X
                                    <AC T="8"/>
                                     + 5.85
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4-Dinitrophenol</ENT>
                                <ENT>0.80C-1.58</ENT>
                                <ENT>
                                    0.27X
                                    <AC T="8"/>
                                    -1.15
                                </ENT>
                                <ENT>
                                    0.29X
                                    <AC T="8"/>
                                     + 4.51
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-Nitrophenol</ENT>
                                <ENT>0.81C-0.76</ENT>
                                <ENT>
                                    0.15X
                                    <AC T="8"/>
                                     + 0.44
                                </ENT>
                                <ENT>
                                    0.14X
                                    <AC T="8"/>
                                     + 3.84
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4-Nitrophenol</ENT>
                                <ENT>0.46C + 0.18</ENT>
                                <ENT>
                                    0.17X
                                    <AC T="8"/>
                                     + 2.43
                                </ENT>
                                <ENT>
                                    0.19X
                                    <AC T="8"/>
                                     + 4.79
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Pentachlorophenol</ENT>
                                <ENT>0.83C + 2.07</ENT>
                                <ENT>
                                    0.22X
                                    <AC T="8"/>
                                    -0.58
                                </ENT>
                                <ENT>
                                    0.23X
                                    <AC T="8"/>
                                     + 0.57
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Phenol</ENT>
                                <ENT>0.43C + 0.11</ENT>
                                <ENT>
                                    0.20X
                                    <AC T="8"/>
                                    -0.88
                                </ENT>
                                <ENT>
                                    0.17X
                                    <AC T="8"/>
                                     + 0.77
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4,6-Trichlorophenol</ENT>
                                <ENT>0.86C-0.40</ENT>
                                <ENT>
                                    0.10X
                                    <AC T="8"/>
                                     + 0.53
                                </ENT>
                                <ENT>
                                    0.13X
                                    <AC T="8"/>
                                     + 2.40
                                </ENT>
                            </ROW>
                            <TNOTE>X′ = Expected recovery for one or more measurements of a sample containing a concentration of C, in µg/L.</TNOTE>
                            <TNOTE>
                                s
                                <E T="52">r</E>
                                ′ = Expected single analyst standard deviation of measurements at an average concentration found of X
                                <AC T="8"/>
                                , in µg/L.
                            </TNOTE>
                            <TNOTE>
                                S′ = Expected interlaboratory standard deviation of measurements at an average concentration found of X
                                <AC T="8"/>
                                , in µg/L.
                            </TNOTE>
                            <TNOTE>C = True value for the concentration, in µg/L.</TNOTE>
                            <TNOTE>
                                X
                                <AC T="8"/>
                                 = Average recovery found for measurements of samples containing a concentration of C, in µg/L.
                            </TNOTE>
                        </GPOTABLE>
                        <GPH SPAN="2" DEEP="440">
                            <PRTPAGE P="125"/>
                            <GID>EC02JY92.012</GID>
                        </GPH>
                        <GPH SPAN="2" DEEP="379">
                            <PRTPAGE P="126"/>
                            <GID>EC02JY92.013</GID>
                        </GPH>
                        <HD SOURCE="HD1">Method 605—Benzidines</HD>
                        <EAR>Pt. 136, App. A, Meth. 605</EAR>
                        <HD SOURCE="HD2">1. Scope and Application</HD>
                        <P>1.1 This method covers the determination of certain benzidines. The following parameters can be determined by this method:</P>
                        <GPOTABLE COLS="3" OPTS="L2" CDEF="s10,10,10">
                            <BOXHD>
                                <CHED H="1">Parameter</CHED>
                                <CHED H="1">Storet No</CHED>
                                <CHED H="1">CAS No.</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">Benzidine</ENT>
                                <ENT>39120</ENT>
                                <ENT>92-87-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">3,3′-Dichlorobenzidine</ENT>
                                <ENT>34631</ENT>
                                <ENT>91-94-1</ENT>
                            </ROW>
                        </GPOTABLE>
                        <P>1.2 This is a high performance liquid chromatography (HPLC) method applicable to the determination of the compounds listed above in municipal and industrial discharges as provided under 40 CFR 136.1. When this method is used to analyze unfamiliar samples for the compounds above, identifications should be supported by at least one additional qualitative technique. This method describes electrochemical conditions at a second potential which can be used to confirm measurements made with this method. Method 625 provides gas chromatograph/mass spectrometer (GC/MS) conditions appropriate for the qualitative and quantitative confirmation of results for the parameters listed above, using the extract produced by this method.</P>
                        <P>
                            1.3 The method detection limit (MDL, defined in Section 14.1) 
                            <SU>1</SU>
                             for each parameter is 
                            <PRTPAGE P="127"/>
                            listed in Table 1. The MDL for a specific wastewater may differ from those listed, depending upon the nature of the interferences in the sample matrix.
                        </P>
                        <P>1.4 Any modification of this method, beyond those expressly permitted, shall be considered as a major modification subject to application and approval of alternate test procedures under 40 CFR 136.4 and 136.5.</P>
                        <P>1.5 This method is restricted to use by or under the supervision of analysts experienced in the use of HPLC instrumentation and in the interpretation of liquid chromatograms. Each analyst must demonstrate the ability to generate acceptable results with this method using the procedure described in Section 8.2.</P>
                        <HD SOURCE="HD2">2. Summary of Method</HD>
                        <P>
                            2.1 A measured volume of sample, approximately 1-L, is extracted with chloroform using liquid-liquid extractions in a separatory funnel. The chloroform extract is extracted with acid. The acid extract is then neutralized and extracted with chloroform. The final chloroform extract is exchanged to methanol while being concentrated using a rotary evaporator. The extract is mixed with buffer and separated by HPLC. The benzidine compounds are measured with an electrochemical detector. 
                            <SU>2</SU>
                        </P>
                        <P>2.2 The acid back-extraction acts as a general purpose cleanup to aid in the elimination of interferences.</P>
                        <HD SOURCE="HD2">3. Interferences</HD>
                        <P>3.1 Method interferences may be caused by contaminants in solvents, reagents, glassware, and other sample processing hardware that lead to discrete artifacts and/or elevated baselines in chromatograms. All of these materials must be routinely demonstrated to be free from interferences under the conditions of the analysis by running laboratory reagent blanks as described in Section 8.1.3.</P>
                        <P>
                            3.1.1 Glassware must be scrupulously cleaned. 
                            <SU>3</SU>
                             Clean all glassware as soon as possible after use by rinsing with the last solvent used in it. Solvent rinsing should be followed by detergent washing with hot water, and rinses with tap water and distilled water. The glassware should then be drained dry, and heated in a muffle furnace at 400 °C for 15 to 30 min. Some thermally stable materials may not be eliminated by this treatment. Solvent rinses with acetone and pesticide quality hexane may be substituted for the muffle furnace heating. Volumetric ware should not be heated in a muffle furnace. After drying and cooling, glassware should be sealed and stored in a clean environment to prevent any accumulation of dust or other contaminants. Store inverted or capped with aluminum foil.
                        </P>
                        <P>3.1.2 The use of high purity reagents and solvents helps to minimize interference problems. Purification of solvents by distillation in all-glass systems may be required.</P>
                        <P>3.2 Matrix interferences may be caused by contaminants that are co-extracted from the sample. The extent of matrix interferences will vary considerably from source to source, depending upon the nature and diversity of the industrial complex or municipality being sampled. The cleanup procedures that are inherent in the extraction step are used to overcome many of these interferences, but unique samples may require additional cleanup approaches to achieve the MDL listed in Table 1.</P>
                        <P>3.3 Some dye plant effluents contain large amounts of components with retention times closed to benzidine. In these cases, it has been found useful to reduce the electrode potential in order to eliminate interferences and still detect benzidine. (See Section 12.7.)</P>
                        <HD SOURCE="HD2">4. Safety</HD>
                        <P>
                            4.1 The toxicity or carcinogenicity of each reagent used in this method has not been precisely defined; however, each chemical compound should be treated as a potential health harzard. From this viewpoint, exposure to these chemicals must be reduced to the lowest possible level by whatever means available. The laboratory is responsible for maintaining a current awareness file of OSHA regulations regarding the safe handling of the chemicals specified in this method. A reference file of material data handling sheets should also be made available to all personnel involved in the chemical analysis. Additional references to laboratory safety are available and have been identified 
                            <SU>4 6</SU>
                             for the information of the analyst.
                        </P>
                        <P>4.2 The following parameters covered by this method have been tentatively classified as known or suspected, human or mammalian carcinogens: benzidine and 3,3′-dichlorobenzidine. Primary standards of these toxic compounds should be prepared in a hood. A NIOSH/MESA approved toxic gas respirator should be worn when the analyst handles high concentrations of these toxic compounds.</P>
                        <P>4.3 Exposure to chloroform should be minimized by performing all extractions and extract concentrations in a hood or other well-ventiliated area.</P>
                        <HD SOURCE="HD2">5. Apparatus and Materials</HD>
                        <P>5.1 Sampling equipment, for discrete or composite sampling.</P>
                        <P>
                            5.1.1 Grab sample bottle—1-L or 1-qt, amber glass, fitted with a screw cap lined with Teflon. Foil may be substituted for Teflon if the sample is not corrosive. If amber bottles are not available, protect samples from light. The bottle and cap liner must be washed, rinsed with acetone or methylene 
                            <PRTPAGE P="128"/>
                            chloride, and dried before use to minimize contamination.
                        </P>
                        <P>5.1.2 Automatic sampler (optional)—The sampler must incorporate glass sample containers for the collection of a minimum of 250 mL of sample. Sample containers must be kept refrigerated at 4 °C and protected from light during compositing. If the sampler uses a peristaltic pump, a minimum length of compressible silicone rubber tubing may be used. Before use, however, the compressible tubing should be thoroughly rinsed with methanol, followed by repeated rinsings with distilled water to minimize the potential for contamination of the sample. An integrating flow meter is required to collect flow proportional composites.</P>
                        <P>5.2 Glassware (All specifications are suggested):</P>
                        <P>5.2.1 Separatory funnels—2000, 1000, and 250-mL, with Teflon stopcock.</P>
                        <P>5.2.2 Vials—10 to 15-mL, amber glass, with Teflon-lined screw cap.</P>
                        <P>5.2.3 Rotary evaporator.</P>
                        <P>5.2.4 Flasks—Round bottom, 100-mL, with 24/40 joints.</P>
                        <P>5.2.5 Centrifuge tubes—Conical, graduated, with Teflon-lined screw caps.</P>
                        <P>5.2.6 Pipettes—Pasteur, with bulbs.</P>
                        <P>5.3 Balance—Analytical, capable of accurately weighing 0.0001 g.</P>
                        <P>5.4 High performance liquid chromatograph (HPLC)—An analytical system complete with column supplies, high pressure syringes, detector, and compatible recorder. A data system is recommended for measuring peak areas and retention times.</P>
                        <P>5.4.1 Solvent delivery system—With pulse damper, Altex 110A or equivalent.</P>
                        <P>5.4.2 Injection valve (optional)—Waters U6K or equivalent.</P>
                        <P>5.4.3 Electrochemical detector—Bioanalytical Systems LC-2A with glassy carbon electrode, or equivalent. This detector has proven effective in the analysis of wastewaters for the parameters listed in the scope (Section 1.1), and was used to develop the method performance statements in Section 14. Guidelines for the use of alternate detectors are provided in Section 12.1.</P>
                        <P>5.4.4 Electrode polishing kit—Princeton Applied Research Model 9320 or equivalent.</P>
                        <P>5.4.5 Column—Lichrosorb RP-2, 5 micron particle diameter, in a 25 cm × 4.6 mm ID stainless steel column. This column was used to develop the method performance statements in Section 14. Guidelines for the use of alternate column packings are provided in Section 12.1.</P>
                        <HD SOURCE="HD2">6. Reagents</HD>
                        <P>6.1 Reagent water—Reagent water is defined as a water in which an interferent is not observed at the MDL of the parameters of interest.</P>
                        <P>6.2 Sodium hydroxide solution (5 N)—Dissolve 20 g of NaOH (ACS) in reagent water and dilute to 100 mL.</P>
                        <P>6.3 Sodium hydroxide solution (1 M)—Dissolve 40 g of NaOH (ACS) in reagent water and dilute to 1 L.</P>
                        <P>6.4 Sodium thiosulfate—(ACS) Granular.</P>
                        <P>6.5 Sodium tribasic phosphate (0.4 M)—Dissolve 160 g of trisodium phosphate decahydrate (ACS) in reagent water and dilute to 1 L.</P>
                        <P>
                            6.6 Sulfuric acid (1 + 1)—Slowly, add 50 mL of H
                            <E T="52">2</E>
                            SO
                            <E T="52">4</E>
                             (ACS, sp. gr. 1.84) to 50 mL of reagent water.
                        </P>
                        <P>
                            6.7 Sulfuric acid (1 M)—Slowly, add 58 mL of H
                            <E T="52">2</E>
                            SO
                            <E T="52">4</E>
                             (ACS, sp. gr. 1.84) to reagent water and dilute to 1 L.
                        </P>
                        <P>6.8 Acetate buffer (0.1 M, pH 4.7)—Dissolve 5.8 mL of glacial acetic acid (ACS) and 13.6 g of sodium acetate trihydrate (ACS) in reagent water which has been purified by filtration through a RO-4 Millipore System or equivalent and dilute to 1 L.</P>
                        <P>6.9 Acetonitrile, chloroform (preserved with 1% ethanol), methanol—Pesticide quality or equivalent.</P>
                        <P>6.10 Mobile phase—Place equal volumes of filtered acetonitrile (Millipore type FH filter or equivalent) and filtered acetate buffer (Millipore type GS filter or equivalent) in a narrow-mouth, glass container and mix thoroughly. Prepare fresh weekly. Degas daily by sonicating under vacuum, by heating and stirring, or by purging with helium.</P>
                        <P>6.11 Stock standard solutions (1.00 µg/µL)—Stock standard solutions may be prepared from pure standard materials or purchased as certified solutions.</P>
                        <P>6.11.1 Prepare stock standard solutions by accurately weighing about 0.0100 g of pure material. Dissolve the material in methanol and dilute to volume in a 10-mL volumetric flask. Larger volumes can be used at the convenience of the analyst. When compound purity is assayed to be 96% or greater, the weight can be used without correction to calculate the concentration of the stock standard. Commercially prepared stock standards can be used at any concentration if they are certified by the manufacturer or by an independent source.</P>
                        <P>6.11.2 Transfer the stock standard solutions into Teflon-sealed screw-cap bottles. Store at 4 °C and protect from light. Stock standard solutions should be checked frequently for signs of degradation or evaporation, especially just prior to preparing calibration standards from them.</P>
                        <P>6.11.3 Stock standard solutions must be replaced after six months, or sooner if comparison with check standards indicates a problem.</P>
                        <P>
                            6.12 Quality control check sample concentrate—See Section 8.2.1.
                            <PRTPAGE P="129"/>
                        </P>
                        <HD SOURCE="HD2">7. Calibration</HD>
                        <P>7.1 Establish chromatographic operating conditions equivalent to those given in Table 1. The HPLC system can be calibrated using the external standard technique (Section 7.2) or the internal standard technique (Section 7.3).</P>
                        <P>7.2 External standard calibration procedure:</P>
                        <P>7.2.1 Prepare calibration standards at a minimum of three concentration levels for each parameter of interest by adding volumes of one or more stock standards to a volumetric flask and diluting to volume with mobile phase. One of the external standards should be at a concentration near, but above, the MDL (Table 1) and the other concentrations should correspond to the expected range of concentrations found in real samples or should define the working range of the detector.</P>
                        <P>7.2.2 Using syringe injections of 5 to 25 µL or a constant volume injection loop, analyze each calibration standard according to Section 12 and tabulate peak height or area responses against the mass injected. The results can be used to prepare a calibration curve for each compound. Alternatively, if the ratio of response to amount injected (calibration factor) is a constant over the working range (&lt;10% relative standard deviation, RSD), linearity through the origin can be assumed and the average ratio or calibration factor can be used in place of a calibration curve.</P>
                        <P>7.3 Internal standard calibration procedure—To use this approach, the analyst must select one or more internal standards that are similar in analytical behavior to the compounds of interest. The analyst must further demonstrate that the measurement of the internal standard is not affected by method or matrix interferences. Because of these limitations, no internal standard can be suggested that is applicable to all samples.</P>
                        <P>7.3.1 Prepare calibration standards at a minimum of three concentration levels for each parameter of interest by adding volumes of one or more stock standards to a volumetric flask. To each calibration standard, add a known constant amount of one or more internal standards, and dilute to volume with mobile phase. One of the standards should be at a concentration near, but above, the MDL and the other concentrations should correspond to the expected range of concentrations found in real samples or should define the working range of the detector.</P>
                        <P>7.3.2 Using syringe injections of 5 to 25 µL or a constant volume injection loop, analyze each calibration standard according to Section 12 and tabulate peak height or area responses against concentration for each compound and internal standard. Calculate response factors (RF) for each compound using Equation 1.</P>
                        <HD SOURCE="HD3">
                            RF = (A
                            <E T="52">s</E>
                            )(C
                            <E T="52">is</E>
                             (A
                            <E T="52">is</E>
                            )(C
                            <E T="52">s</E>
                            )
                        </HD>
                        <FP SOURCE="FRP">Equation 1</FP>
                        <FP>where:</FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">s</E>
                             = Response for the parameter to be measured.
                        </FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">is</E>
                             = Response for the internal standard.
                        </FP>
                        <FP SOURCE="FP-2">
                            C
                            <E T="52">is</E>
                             = Concentration of the internal standard (µg/L).
                        </FP>
                        <FP SOURCE="FP-2">
                            C
                            <E T="52">s</E>
                             = Concentration of the parameter to be measured (µg/L).
                        </FP>
                        <P>
                            If the RF value over the working range is a constant (&lt;10% RSD), the RF can be assumed to be invariant and the average RF can be used for calculations. Alternatively, the results can be used to plot a calibration curve of response ratios, A
                            <E T="52">s</E>
                            /A
                            <E T="52">is</E>
                            , vs. RF.
                        </P>
                        <P>7.4 The working calibration curve, calibration factor, or RF must be verified on each working day by the measurement of one or more calibration standards. If the response for any parameter varies from the predicted response by more than ±15%, a new calibration curve must be prepared for that compound. If serious loss of response occurs, polish the electrode and recalibrate.</P>
                        <P>7.5 Before using any cleanup procedure, the analyst must process a series of calibration standards through the procedure to validate elution patterns and the absence of interferences from the reagents.</P>
                        <HD SOURCE="HD2">8. Quality Control</HD>
                        <P>8.1 Each laboratory that uses this method is required to operate a formal quality control program. The minimum requirements of this program consist of an initial demonstration of laboratory capability and an ongoing analysis of spiked samples to evaluate and document data quality. The laboratory must maintain records to document the quality of data that is generated. Ongoing data quality checks are compared with established performance criteria to determine if the results of analyses meet the performance characteristics of the method. When results of sample spikes indicate atypical method performance, a quality control check standard must be analyzed to confirm that the measurements were performed in an in-control mode of operation.</P>
                        <P>8.1.1 The analyst must make an initial, one-time, demonstration of the ability to generate acceptable accuracy and precision with this method. This ability is established as described in Section 8.2.</P>
                        <P>
                            8.1.2 In recognition of advances that are occurring in chromatography, the analyst is permitted certain options (detailed in Sections 10.9, 11.1, and 12.1) to improve the separations or lower the cost of measurements. Each time such a modification is made to the method, the analyst is required to repeat the procedure in Section 8.2.
                            <PRTPAGE P="130"/>
                        </P>
                        <P>8.1.3 Before processing any samples, the analyst must analyze a reagent water blank to demonstrate that interferences from the analytical system and glassware are under control. Each time a set of samples is extracted or reagents are changed, a reagent water blank must be processed as a safeguard against laboratory contamination.</P>
                        <P>8.1.4 The laboratory must, on an ongoing basis, spike and analyze a minimum of 10% of all samples to monitor and evaluate laboratory data quality. This procedure is described in Section 8.3.</P>
                        <P>8.1.5 The laboratory must, on an ongoing basis, demonstrate through the analyses of quality control check standards that the operation of the measurement system is in control. This procedure is described in Section 8.4. The frequency of the check standard analyses is equivalent to 10% of all samples analyzed but may be reduced if spike recoveries from samples (Section 8.3) meet all specified quality control criteria.</P>
                        <P>8.1.6 The laboratory must maintain performance records to document the quality of data that is generated. This procedure is described in Section 8.5.</P>
                        <P>8.2 To establish the ability to generate acceptable accuracy and precision, the analyst must perform the following operations.</P>
                        <P>8.2.1 A quality control (QC) check sample concentrate is required containing benzidine and/or 3,3′-dichlorobenzidine at a concentration of 50 µg/mL each in methanol. The QC check sample concentrate must be obtained from the U.S. Environmental Protection Agency, Environmental Monitoring and Support Laboratory in Cincinnati, Ohio, if available. If not available from that source, the QC check sample concentrate must be obtained from another external source. If not available from either source above, the QC check sample concentrate must be prepared by the laboratory using stock standards prepared independently from those used for calibration.</P>
                        <P>8.2.2 Using a pipet, prepare QC check samples at a concentration of 50 µg/L by adding 1.00 mL of QC check sample concentrate to each of four 1-L-L aliquots of reagent water.</P>
                        <P>8.2.3 Analyze the well-mixed QC check samples according to the method beginning in Section 10.</P>
                        <P>
                            8.2.4 Calculate the average recovery (X
                            <AC T="8"/>
                            ) in µg/L, and the standard deviation of the recovery (s) in µg/L, for each parameter using the four results.
                        </P>
                        <P>
                            8.2.5 For each parameter compare s and X
                            <AC T="8"/>
                             with the corresponding acceptance criteria for precision and accuracy, respectively, found in Table 2. If s and X
                            <AC T="8"/>
                             for all parameters of interest meet the acceptance criteria, the system performance is acceptable and analysis of actual samples can begin. If any individual s exceeds the precision limit or any individual X
                            <AC T="8"/>
                             falls outside the range for accuracy, the system performance is unacceptable for that parameter. Locate and correct the source of the problem and repeat the test for all parameters of interest beginning with Section 8.2.2.
                        </P>
                        <P>8.3 The laboratory must, on an ongoing basis, spike at least 10% of the samples from each sample site being monitored to assess accuracy. For laboratories analyzing one to ten samples per month, at least one spiked sample per month is required.</P>
                        <P>8.3.1 The concentration of the spike in the sample should be determined as follows:</P>
                        <P>8.3.1.1 If, as in compliance monitoring, the concentration of a specific parameter in the sample is being checked against a regulatory concentration limit, the spike should be at that limit or 1 to 5 times higher than the background concentration determined in Section 8.3.2, whichever concentration would be larger.</P>
                        <P>8.3.1.2 If the concentration of a specific parameter in the sample is not being checked against a limit specific to that parameter, the spike should be at 50 µg/L or 1 to 5 times higher than the background concentration determined in Section 8.3.2, whichever concentration would be larger.</P>
                        <P>8.3.1.3 If it is impractical to determine background levels before spiking (e.g., maximum holding times will be exceeded), the spike concentration should be (1) the regulatory concentration limit, if any; or, if none (2) the larger of either 5 times higher than the expected background concentration or 50 µg/L.</P>
                        <P>8.3.2 Analyze one sample aliquot to determine the background concentration (B) of each parameter. If necessary, prepare a new QC check sample concentrate (Section 8.2.1) appropriate for the background concentrations in the sample. Spike a second sample aliquot with 1.0 mL of the QC check sample concentrate and analyze it to determine the concentration after spiking (A) of each parameter. Calculate each percent recovery (P) as 100(A−B)%/T, where T is the known true value of the spike.</P>
                        <P>
                            8.3.3 Compare the percent recovery (P) for each parameter with the corresponding QC acceptance criteria found in Table 2. These acceptance criteria were calculated to include an allowance for error in measurement of both the background and spike concentrations, assuming a spike to background ratio of 5:1. This error will be accounted for to the extent that the analyst's spike to background ratio approaches 5:1. 
                            <SU>7</SU>
                             If spiking was performed at a concentration lower than 50 µg/L, the analyst must use either the QC acceptance criteria in Table 2, or optional QC acceptance criteria calculated for the specific spike concentration. To calculate optional acceptance criteria for the recovery of a parameter: (1) Calculate accuracy (X′) using the equation in Table 3, substituting 
                            <PRTPAGE P="131"/>
                            the spike concentration (T) for C; (2) calculate overall precision (S′) using the equation in Table 3, substituting X′ for X
                            <AC T="8"/>
                            ; (3) calculate the range for recovery at the spike concentration as (100 X′/T)±2.44(100 S′/T)%. 
                            <SU>7</SU>
                        </P>
                        <P>8.3.4 If any individual P falls outside the designated range for recovery, that parameter has failed the acceptance criteria. A check standard containing each parameter that failed the criteria must be analyzed as described in Section 8.4.</P>
                        <P>8.4 If any parameter fails the acceptance criteria for recovery in Section 8.3, a QC check standard containing each parameter that failed must be prepared and analyzed.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>The frequency for the required analysis of a QC check standard will depend upon the number of parameters being simultaneously tested, the complexity of the sample matrix, and the performance of the laboratory.</P>
                        </NOTE>
                        <P>8.4.1 Prepare the QC check standard by adding 1.0 mL of QC check sample concentrate (Sections 8.2.1 or 8.3.2) to 1 L of reagent water. The QC check standard needs only to contain the parameters that failed criteria in the test in Section 8.3.</P>
                        <P>
                            8.4.2 Analyze the QC check standard to determine the concentration measured (A) of each parameter. Calculate each percent recovery (P
                            <E T="52">s</E>
                            ) as 100 (A/T)%, where T is the true value of the standard concentration.
                        </P>
                        <P>
                            8.4.3 Compare the percent recovery (P
                            <E T="52">s</E>
                            ) for each parameter with the corresponding QC acceptance criteria found in Table 2. Only parameters that failed the test in Section 8.3 need to be compared with these criteria. If the recovery of any such parameter falls outside the designated range, the laboratory performance for that parameter is judged to be out of control, and the problem must be immediately identified and corrected. The analytical result for that parameter in the unspiked sample is suspect and may not be reported for regulatory compliance purposes.
                        </P>
                        <P>
                            8.5 As part of the QC program for the laboratory, method accuracy for wastewater samples must be assessed and records must be maintained. After the analysis of five spiked wastewater samples as in Section 8.3, calculate the average percent recovery (P
                            <AC T="8"/>
                            ) and the standard deviation of the percent recovery (s
                            <E T="52">p</E>
                            ). Express the accuracy assessment as a percent recovery interval from P
                            <AC T="8"/>
                            −2s
                            <E T="52">p</E>
                             to P
                            <AC T="8"/>
                             + 2s
                            <E T="52">p</E>
                            . If P
                            <AC T="8"/>
                             = 90% and s
                            <E T="52">p</E>
                             = 10%, for example, the accuracy interval is expressed as 70-110%. Update the accuracy assessment for each parameter on a regular basis (e.g. after each five to ten new accuracy measurements).
                        </P>
                        <P>8.6 It is recommended that the laboratory adopt additional quality assurance practices for use with this method. The specific practices that are most productive depend upon the needs of the laboratory and the nature of the samples. Field duplicates may be analyzed to assess the precision of the environmental measurements. When doubt exists over the identification of a peak on the chromatogram, confirmatory techniques such as HPLC with a dissimilar column, gas chromatography, or mass spectrometer must be used. Whenever possible, the laboratory should analyze standard reference materials and participate in relevant performance evaluation studies.</P>
                        <HD SOURCE="HD2">9. Sample Collection, Preservation, and Handling</HD>
                        <P>
                            9.1 Grab samples must be collected in glass containers. Conventional sampling practices 
                            <SU>8</SU>
                             should be followed, except that the bottle must not be prerinsed with sample before collection. Composite samples should be collected in refrigerated glass containers in accordance with the requirements of the program. Automatic sampling equipment must be as free as possible of Tygon tubing and other potential sources of contamination.
                        </P>
                        <P>
                            9.2 All samples must be iced or refrigerated at 4 °C and stored in the dark from the time of collection until extraction. Both benzidine and 3,3′-dichlorobenzidine are easily oxidized. Fill the sample bottles and, if residual chlorine is present, add 80 mg of sodium thiosulfate per liter of sample and mix well. EPA Methods 330.4 and 330.5 may be used for measurement of residual chlorine. 
                            <SU>9</SU>
                             Field test kits are available for this purpose. After mixing, adjust the pH of the sample to a range of 2 to 7 with sulfuric acid.
                        </P>
                        <P>9.3 If 1,2-diphenylhydrazine is likely to be present, adjust the pH of the sample to 4.0 ±0.2 to prevent rearrangement to benzidine.</P>
                        <P>
                            9.4 All samples must be extracted within 7 days of collection. Extracts may be held up to 7 days before analysis, if stored under an inert (oxidant free) atmosphere. 
                            <SU>2</SU>
                             The extract should be protected from light.
                        </P>
                        <HD SOURCE="HD2">10. Sample Extraction</HD>
                        <P>10.1 Mark the water meniscus on the side of the sample bottle for later determination of sample volume. Pour the entire sample into a 2-L separatory funnel. Check the pH of the sample with wide-range pH paper and adjust to within the range of 6.5 to 7.5 with sodium hydroxide solution or sulfuric acid.</P>
                        <P>
                            10.2 Add 100 mL of chloroform to the sample bottle, seal, and shake 30 s to rinse the inner surface. (Caution: Handle chloroform in a well ventilated area.) Transfer the solvent to the separatory funnel and extract the sample by shaking the funnel for 2 min with periodic venting to release excess pressure. Allow the organic layer to separate from the water phase for a minimum of 10 min. If the emulsion interface between layers is more than one-third the volume of the solvent layer, the analyst must employ mechanical techniques to complete the phase 
                            <PRTPAGE P="132"/>
                            separation. The optimum technique depends upon the sample, but may include stirring, filtration of the emulsion through glass wool, centrifugation, or other physical methods. Collect the chloroform extract in a 250-mL separatory funnel.
                        </P>
                        <P>10.3 Add a 50-mL volume of chloroform to the sample bottle and repeat the extraction procedure a second time, combining the extracts in the separatory funnel. Perform a third extraction in the same manner.</P>
                        <P>10.4 Separate and discard any aqueous layer remaining in the 250-mL separatory funnel after combining the organic extracts. Add 25 mL of 1 M sulfuric acid and extract the sample by shaking the funnel for 2 min. Transfer the aqueous layer to a 250-mL beaker. Extract with two additional 25-mL portions of 1 M sulfuric acid and combine the acid extracts in the beaker.</P>
                        <P>10.5 Place a stirbar in the 250-mL beaker and stir the acid extract while carefully adding 5 mL of 0.4 M sodium tribasic phosphate. While monitoring with a pH meter, neutralize the extract to a pH between 6 and 7 by dropwise addition of 5 N sodium hydroxide solution while stirring the solution vigorously. Approximately 25 to 30 mL of 5 N sodium hydroxide solution will be required and it should be added over at least a 2-min period. Do not allow the sample pH to exceed 8.</P>
                        <P>10.6 Transfer the neutralized extract into a 250-mL separatory funnel. Add 30 mL of chloroform and shake the funnel for 2 min. Allow the phases to separate, and transfer the organic layer to a second 250-mL separatory funnel.</P>
                        <P>10.7 Extract the aqueous layer with two additional 20-mL aliquots of chloroform as before. Combine the extracts in the 250-mL separatory funnel.</P>
                        <P>10.8 Add 20 mL of reagent water to the combined organic layers and shake for 30 s.</P>
                        <P>10.9 Transfer the organic extract into a 100-mL round bottom flask. Add 20 mL of methanol and concentrate to 5 mL with a rotary evaporator at reduced pressure and 35 °C. An aspirator is recommended for use as the source of vacuum. Chill the receiver with ice. This operation requires approximately 10 min. Other concentration techniques may be used if the requirements of Section 8.2 are met.</P>
                        <P>10.10 Using a 9-in. Pasteur pipette, transfer the extract to a 15-mL, conical, screw-cap centrifuge tube. Rinse the flask, including the entire side wall, with 2-mL portions of methanol and combine with the original extract.</P>
                        <P>10.11 Carefully concentrate the extract to 0.5 mL using a gentle stream of nitrogen while heating in a 30 °C water bath. Dilute to 2 mL with methanol, reconcentrate to 1 mL, and dilute to 5 mL with acetate buffer. Mix the extract thoroughly. Cap the centrifuge tube and store refrigerated and protected from light if further processing will not be performed immediately. If the extract will be stored longer than two days, it should be transferred to a Teflon-sealed screw-cap vial. If the sample extract requires no further cleanup, proceed with HPLC analysis (Section 12). If the sample requires further cleanup, proceed to Section 11.</P>
                        <P>10.12 Determine the original sample volume by refilling the sample bottle to the mark and transferring the liquid to a 1,000-mL graduated cylinder. Record the sample volume to the nearest 5 mL.</P>
                        <HD SOURCE="HD2">11. Cleanup and Separation</HD>
                        <P>11.1 Cleanup procedures may not be necessary for a relatively clean sample matrix. If particular circumstances demand the use of a cleanup procedure, the analyst first must demonstrate that the requirements of Section 8.2 can be met using the method as revised to incorporate the cleanup procedure.</P>
                        <HD SOURCE="HD2">12. High Performance Liquid Chromatography</HD>
                        <P>12.1 Table 1 summarizes the recommended operating conditions for the HPLC. Included in this table are retention times, capacity factors, and MDL that can be achieved under these conditions. An example of the separations achieved by this HPLC column is shown in Figure 1. Other HPLC columns, chromatographic conditions, or detectors may be used if the requirements of Section 8.2 are met. When the HPLC is idle, it is advisable to maintain a 0.1 mL/min flow through the column to prolong column life.</P>
                        <P>12.2 Calibrate the system daily as described in Section 7.</P>
                        <P>12.3 If the internal standard calibration procedure is being used, the internal standard must be added to the sample extract and mixed thoroughly immediately before injection into the instrument.</P>
                        <P>12.4 Inject 5 to 25 µL of the sample extract or standard into the HPLC. If constant volume injection loops are not used, record the volume injected to the nearest 0.05 µL, and the resulting peak size in area or peak height units.</P>
                        <P>12.5 Identify the parameters in the sample by comparing the retention times of the peaks in the sample chromatogram with those of the peaks in standard chromatograms. The width of the retention time window used to make identifications should be based upon measurements of actual retention time variations of standards over the course of a day. Three times the standard deviation of a retention time for a compound can be used to calculate a suggested window size; however, the experience of the analyst should weigh heavily in the interpretation of chromatograms.</P>
                        <P>
                            12.6 If the response for a peak exceeds the working range of the system, dilute the extract with mobile phase and reanalyze.
                            <PRTPAGE P="133"/>
                        </P>
                        <P>12.7 If the measurement of the peak response for benzidine is prevented by the presence of interferences, reduce the electrode potential to + 0.6 V and reanalyze. If the benzidine peak is still obscured by interferences, further cleanup is required.</P>
                        <HD SOURCE="HD2">13. Calculations</HD>
                        <P>13.1 Determine the concentration of individual compounds in the sample.</P>
                        <P>13.1.1 If the external standard calibration procedure is used, calculate the amount of material injected from the peak response using the calibration curve or calibration factor determined in Section 7.2.2. The concentration in the sample can be calculated from Equation 2.</P>
                        <MATH SPAN="1" DEEP="31">
                            <MID>EC15NO91.101</MID>
                        </MATH>
                        <FP SOURCE="FRP0">Equation 2</FP>
                        <FP>where:</FP>
                        <FP SOURCE="FP-2">A = Amount of material injected (ng).</FP>
                        <FP SOURCE="FP-2">
                            V
                            <E T="52">i</E>
                             = Volume of extract injected (µL).
                        </FP>
                        <FP SOURCE="FP-2">
                            V
                            <E T="52">t</E>
                             = Volume of total extract (µL).
                        </FP>
                        <FP SOURCE="FP-2">
                            V
                            <E T="52">s</E>
                             = Volume of water extracted (mL).
                        </FP>
                        <P>13.1.2 If the internal standard calibration procedure is used, calculate the concentration in the sample using the response factor (RF) determined in Section 7.3.2 and Equation 3.</P>
                        <MATH SPAN="1" DEEP="31">
                            <MID>EC15NO91.102</MID>
                        </MATH>
                        <FP SOURCE="FRP0">Equation 3</FP>
                        <FP>where:</FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">s</E>
                             = Response for the parameter to be measured.
                        </FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">is</E>
                             = Response for the internal standard.
                        </FP>
                        <FP SOURCE="FP-2">
                            I
                            <E T="52">s</E>
                             = Amount of internal standard added to each extract (µg).
                        </FP>
                        <FP SOURCE="FP-2">
                            V
                            <E T="52">o</E>
                             = Volume of water extracted (L).
                        </FP>
                        <P>13.2 Report results in µg/L without correction for recovery data. All QC data obtained should be reported with the sample results.</P>
                        <HD SOURCE="HD2">14. Method Performance</HD>
                        <P>
                            14.1 The method detection limit (MDL) is defined as the minimum concentration of a substance that can be measured and reported with 99% confidence that the value is above zero. 
                            <SU>1</SU>
                             The MDL concentrations listed in Table 1 were obtained using reagent water. 
                            <SU>10</SU>
                             Similar results were achieved using representative wastewaters. The MDL actually achieved in a given analysis will vary depending on instrument sensitivity and matrix effects.
                        </P>
                        <P>
                            14.2 This method has been tested for linearity of spike recovery from reagent water and has been demonstrated to be applicable over the concentration range from 7 × MDL to 3000 × MDL. 
                            <SU>10</SU>
                        </P>
                        <P>
                            14.3 This method was tested by 17 laboratories using reagent water, drinking water, surface water, and three industrial wastewaters spiked at six concentrations over the range 1.0 to 70 µg/L. 
                            <SU>11</SU>
                             Single operator precision, overall precision, and method accuracy were found to be directly related to the concentration of the parameter and essentially independent of the sample matrix. Linear equations to describe these relationships are presented in Table 3.
                        </P>
                        <HD SOURCE="HD2">References</HD>
                        <P>1. 40 CFR part 136, appendix B.</P>
                        <P>2. “Determination of Benzidines in Industrial and Muncipal Wastewaters,” EPA 600/4-82-022, National Technical Information Service, PB82-196320, Springfield, Virginia 22161, April 1982.</P>
                        <P>3. ASTM Annual Book of Standards, Part 31, D3694-78. “Standard Practices for Preparation of Sample Containers and for Preservation of Organic Constituents,” American Society for Testing and Materials, Philadelphia.</P>
                        <P>4. “Carcinogens—Working With Carcinogens,” Department of Health, Education, and Welfare, Public Health Service, Center for Disease Control, National Institute for Occupational Safety and Health, Publication No. 77-206, August 1977.</P>
                        <P>5. “OSHA Safety and Health Standards, General Industry,” (29 CFR part 1910), Occupational Safety and Health Administration, OSHA 2206 (Revised, January 1976).</P>
                        <P>6. “Safety in Academic Chemistry Laboratories,” American Chemical Society Publication, Committee on Chemical Safety, 3rd Edition, 1979.</P>
                        <P>
                            7. Provost, L.P., and Elder, R.S. “Interpretation of Percent Recovery Data,” 
                            <E T="03">American</E>
                             Laboratory, 15, 58-63 (1983). (The value 2.44 used in the equation in Section 8.3.3 is two times the value 1.22 derived in this report.)
                        </P>
                        <P>8. ASTM Annual Book of Standards, Part 31, D3370-76. “Standard Practices for Sampling Water,” American Society for Testing and Materials, Philadelphia.</P>
                        <P>9. “Methods 330.4 (Titrimetric, DPD-FAS) and 330.5 (Spectrophotometric, DPD) for Chlorine Total Residual,” Methods for Chemical Analysis of Water and Wastes, EPA-600/4-79-020, U.S. Environmental Protection Agency, Environmental Monitoring and Support Laboratory, Cincinnati, Ohio 45268, March 1979.</P>
                        <P>10. “EPA Method Study 15, Method 605 (Benzidines),” EPA 600/4-84-062, National Technical Information Service, PB84-211176, Springfield, Virginia 22161, June 1984.</P>
                        <P>
                            11. “EPA Method Validation Study 15, Method 605 (Benzidines),” Report for EPA Contract 68-03-2624 (In preparation).
                            <PRTPAGE P="134"/>
                        </P>
                        <GPOTABLE COLS="4" OPTS="L2" CDEF="s60,10,10,10">
                            <TTITLE>Table 1—Chromatographic Conditions and Method Detection Limits</TTITLE>
                            <BOXHD>
                                <CHED H="1">Parameter</CHED>
                                <CHED H="1">Retention time (min)</CHED>
                                <CHED H="1">Column capacity factor (k′)</CHED>
                                <CHED H="1">Method detection limit (µg/L)</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">Benzidine</ENT>
                                <ENT>6.1</ENT>
                                <ENT>1.44</ENT>
                                <ENT>0.08</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">3,3′-Dichlorobenzidine</ENT>
                                <ENT>12.1</ENT>
                                <ENT>3.84</ENT>
                                <ENT>0.13</ENT>
                            </ROW>
                            <TNOTE>HPLC Column conditions: Lichrosorb RP-2, 5 micron particle size, in a 25 cm × 4.6 mm ID stainless steel column. Mobile Phase: 0.8 mL/min of 50% acetonitrile/50% 0.1M pH 4.7 acetate buffer. The MDL were determined using an electrochemical detector operated at + 0.8 V.</TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="5" OPTS="L2" CDEF="s50,8,8,9,8">
                            <TTITLE>Table 2—QC Acceptance Criteria—Method 605</TTITLE>
                            <BOXHD>
                                <CHED H="1">Parameter</CHED>
                                <CHED H="1">Test conc. (µg/L)</CHED>
                                <CHED H="1">Limit for s (µg/L)</CHED>
                                <CHED H="1">
                                    Range for X
                                    <AC T="8"/>
                                     (µg/L)
                                </CHED>
                                <CHED H="1">
                                    Range for P, P
                                    <E T="52">s</E>
                                     (percent)
                                </CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">Benzidine</ENT>
                                <ENT>50</ENT>
                                <ENT>18.7</ENT>
                                <ENT>9.1-61.0</ENT>
                                <ENT>D-140</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">3.3′-Dichlorobenzidine</ENT>
                                <ENT>50</ENT>
                                <ENT>23.6</ENT>
                                <ENT>18.7-50.0</ENT>
                                <ENT>5-128</ENT>
                            </ROW>
                            <TNOTE>s = Standard deviation of four recovery measurements, in µg/L (Section 8.2.4).</TNOTE>
                            <TNOTE>
                                X
                                <AC T="8"/>
                                 = Average recovery for four recovery measurements, in µg/L (Section 8.2.4).
                            </TNOTE>
                            <TNOTE>
                                P, P
                                <E T="52">s</E>
                                 = Percent recovery measured (Section 8.3.2, Section 8.4.2).
                            </TNOTE>
                            <TNOTE>D = Detected; result must be greater than zero.</TNOTE>
                            <TNOTE>Note: These criteria are based directly upon the method performance data in Table 3. Where necessary, the limits for recovery have been broadened to assure applicability of the limits to concentrations below those used to develop Table 3.</TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="4" OPTS="L2" CDEF="s50,12,12,12">
                            <TTITLE>Table 3—Method Accuracy and Precision as Functions of Concentration—Method 605</TTITLE>
                            <BOXHD>
                                <CHED H="1">Parameter</CHED>
                                <CHED H="1">Accuracy, as recovery, X′(µg/L)</CHED>
                                <CHED H="1">
                                    Single analyst precision, s
                                    <E T="52">r</E>
                                    ′ (µg/L)
                                </CHED>
                                <CHED H="1">Overall precision, S′ (µg/L)</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">Benzidine</ENT>
                                <ENT>0.70C + 0.06</ENT>
                                <ENT>
                                    0.28X
                                    <AC T="8"/>
                                     + 0.19
                                </ENT>
                                <ENT>
                                    0.40X
                                    <AC T="8"/>
                                     + 0.18
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">3,3′-Dichlorobenzidine</ENT>
                                <ENT>0.66C + 0.23</ENT>
                                <ENT>
                                    0.39X
                                    <AC T="8"/>
                                    −0.05
                                </ENT>
                                <ENT>
                                    0.38X
                                    <AC T="8"/>
                                     + 0.02
                                </ENT>
                            </ROW>
                            <TNOTE>X′ = Expected recovery for one or more measurements of a sample containing a concentration of C, in µg/L.</TNOTE>
                            <TNOTE>
                                s
                                <E T="52">r</E>
                                ′ = Expected single analyst standard deviation of measurements at an average concentration found of X
                                <AC T="8"/>
                                , in µg/L.
                            </TNOTE>
                            <TNOTE>
                                S′ = Expected interlaboratory standard deviation of measurements at an average concentration found of X
                                <AC T="8"/>
                                , in µg/L.
                            </TNOTE>
                            <TNOTE>C = True value for the concentration, in µg/L.</TNOTE>
                            <TNOTE>
                                X
                                <AC T="8"/>
                                 = Average recovery found for measurements of samples containing a concentration of C, in µg/L.
                            </TNOTE>
                        </GPOTABLE>
                        <GPH SPAN="2" DEEP="470">
                            <PRTPAGE P="135"/>
                            <GID>EC02JY92.014</GID>
                        </GPH>
                        <PRTPAGE P="136"/>
                        <HD SOURCE="HD1">Method 606—Phthalate Ester</HD>
                        <EAR>Pt. 136, App. A, Meth. 606</EAR>
                        <HD SOURCE="HD2">1. Scope and Application</HD>
                        <P>1.1 This method covers the determination of certain phthalate esters. The following parameters can be determined by this method:</P>
                        <GPOTABLE COLS="3" OPTS="L2" CDEF="s10,6,9">
                            <BOXHD>
                                <CHED H="1">Parameter</CHED>
                                <CHED H="1">STORET No.</CHED>
                                <CHED H="1">CAS No.</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">Bis(2-ethylhexyl) phthalate</ENT>
                                <ENT>39100</ENT>
                                <ENT>117-81-7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Butyl benzyl phthalate</ENT>
                                <ENT>34292</ENT>
                                <ENT>85-68-7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Di-n-butyl phthalate</ENT>
                                <ENT>39110</ENT>
                                <ENT>84-74-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Diethyl phthalate</ENT>
                                <ENT>34336</ENT>
                                <ENT>84-66-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dimethyl phthalate</ENT>
                                <ENT>34341</ENT>
                                <ENT>131-11-3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Di-n-octyl phthalate</ENT>
                                <ENT>34596</ENT>
                                <ENT>117-84-0</ENT>
                            </ROW>
                        </GPOTABLE>
                        <P>1.2 This is a gas chromatographic (GC) method applicable to the determination of the compounds listed above in municipal and industrial discharges as provided under 40 CFR 136.1. When this method is used to analyze unfamiliar samples for any or all of the compounds above, compound identifications should be supported by at least one additional qualitative technique. This method describes analytical conditions for a second gas chromatographic column that can be used to confirm measurements made with the primary column. Method 625 provides gas chromatograph/mass spectrometer (GC/MS) conditions appropriate for the qualitative and quantitative confirmation of results for all of the parameters listed above, using the extract produced by this method.</P>
                        <P>
                            1.3 The method detection limit (MDL, defined in Section 14.1) 
                            <SU>1</SU>
                             for each parameter is listed in Table 1. The MDL for a specific wastewater may differ from those listed, depending upon the nature of interferences in the sample matrix.
                        </P>
                        <P>1.4 The sample extraction and concentration steps in this method are essentially the same as in Methods 608, 609, 611, and 612. Thus, a single sample may be extracted to measure the parameters included in the scope of each of these methods. When cleanup is required, the concentration levels must be high enough to permit selecting aliquots, as necessary, to apply appropriate cleanup procedures. The analyst is allowed the latitude, under Section 12, to select chromatographic conditions appropriate for the simultaneous measurement of combinations of these parameters.</P>
                        <P>1.5 Any modification of this method, beyond those expressly permitted, shall be considered as a major modification subject to application and approval of alternate test procedures under 40 CFR 136.4 and 136.5.</P>
                        <P>1.6 This method is restricted to use by or under the supervision of analysts experienced in the use of a gas chromatograph and in the interpretation of gas chromatograms. Each analyst must demonstrate the ability to generate acceptable results with this method using the procedure described in Section 8.2.</P>
                        <HD SOURCE="HD2">2. Summary of Method</HD>
                        <P>
                            2.1 A measured volume of sample, approximately 1-L, is extracted with methylene chloride using a separatory funnel. The methylene chloride extract is dried and exchanged to hexane during concentration to a volume of 10 mL or less. The extract is separated by gas chromatography and the phthalate esters are then measured with an electron capture detector. 
                            <SU>2</SU>
                        </P>
                        <P>2.2 Analysis for phthalates is especially complicated by their ubiquitous occurrence in the environment. The method provides Florisil and alumina column cleanup procedures to aid in the elimination of interferences that may be encountered.</P>
                        <HD SOURCE="HD2">3. Interferences</HD>
                        <P>3.1 Method interferences may be caused by contaminants in solvents, reagents, glassware, and other sample processing hardware that lead to discrete artifacts and/or elevated baselines in gas chromatograms. All of these materials must be routinely demonstrated to be free from interferences under the conditions of the analysis by running laboratory reagent blanks as described in Section 8.1.3.</P>
                        <P>
                            3.1.1 Glassware must be scrupulously cleaned. 
                            <SU>3</SU>
                             Clean all glassware as soon as possible after use by rinsing with the last solvent used in it. Solvent rinsing should be followed by detergent washing with hot water, and rinses with tap water and distilled water. The glassware should then be drained dry, and heated in a muffle furnace at 400 °C for 15 to 30 min. Some thermally stable materials, such as PCBs, may not be eliminated by this treatment. Solvent rinses with acetone and pesticide quality hexane may be substituted for the muffle furnace heating. Thorough rinsing with such solvents usually eliminates PCB interference. Volumetric ware should not be heated in a muffle furnace. After drying and cooling, glassware should be sealed and stored in a clean environment to prevent any accumulation of dust or other contaminants. Store inverted or capped with aluminum foil.
                        </P>
                        <P>3.1.2 The use of high purity reagents and solvents helps to minimize interference problems. Purification of solvents by distillation in all-glass systems may be required.</P>
                        <P>
                            3.2 Phthalate esters are contaminants in many products commonly found in the laboratory. It is particularly important to avoid the use of plastics because phthalates are commonly used as plasticizers and are easily extracted from plastic materials. Serious phthalate contamination can result at any time, if consistent quality control is not practiced. Great care must be experienced to prevent such contamination. Exhaustive cleanup of reagents and glassware may be required to eliminate background phthalate contamination. 
                            <SU>4 5</SU>
                            <PRTPAGE P="137"/>
                        </P>
                        <P>3.3 Matrix interferences may be caused by contaminants that are co-extracted from the sample. The extent of matrix interferences will vary considerably from source to source, depending upon the nature and diversity of the industrial complex or municipality being sampled. The cleanup procedures in Section 11 can be used to overcome many of these interferences, but unique samples may require additional cleanup approaches to achieve the MDL listed in Table 1.</P>
                        <HD SOURCE="HD2">4. Safety</HD>
                        <P>
                            4.1 The toxicity or carcinogenicity of each reagent used in this method has not been precisely defined; however, each chemical compound should be treated as a potential health hazard. From this viewpoint, exposure to these chemicals must be reduced to the lowest possible level by whatever means available. The laboratory is responsible for maintaining a current awareness file of OSHA regulations regarding the safe handling of the chemicals specified in this method. A reference file of material data handling sheets should also be made available to all personnel involved in the chemical analysis. Additional references to laboratory safety are available and have been identified 
                            <SU>6 8</SU>
                             for the information of the analyst.
                        </P>
                        <HD SOURCE="HD2">5. Apparatus and Materials</HD>
                        <P>5.1 Sampling equipment, for discrete or composite sampling.</P>
                        <P>5.1.1 Grab sample bottle—1-L or 1-qt, amber glass, fitted with a screw cap lined with Teflon. Foil may be substituted for Teflon if the sample is not corrosive. If amber bottles are not available, protect samples from light. The bottle and cap liner must be washed, rinsed with acetone or methylene chloride, and dried before use to minimize contamination.</P>
                        <P>5.1.2 Automatic sampler (optional)—The sampler must incorporate glass sample containers for the collection of a minimum of 250 mL of sample. Sample containers must be kept refrigerated at 4 °C and protected from light during compositing. If the sampler uses a peristaltic pump, a minimum length of compressible silicone rubber tubing may be used. Before use, however, the compressible tubing should be thoroughly rinsed with methanol, followed by repeated rinsings with distilled water to minimize the potential for contamination of the sample. An integrating flow meter is required to collect flow proportional composites.</P>
                        <P>5.2 Glassware (All specifications are suggested. Catalog numbers are included for illustration only).</P>
                        <P>5.2.1 Separatory funnel—2-L, with Teflon stopcock.</P>
                        <P>5.2.2 Drying column—Chromatographic column, approximately 400 mm long × 19 mm ID, with coarse frit filter disc.</P>
                        <P>5.2.3 Chromatographic column—300 mm long × 10 mm ID, with Teflon stopcock and coarse frit filter disc at bottom (Kontes K-420540-0213 or equivalent).</P>
                        <P>5.2.4 Concentrator tube, Kuderna-Danish—10-mL, graduated (Kontes K-570050-1025 or equivalent). Calibration must be checked at the volumes employed in the test. Ground glass stopper is used to prevent evaporation of extracts.</P>
                        <P>5.2.5 Evaporative flask, Kuderna-Danish—500-mL (Kontes K-570001-0500 or equivalent). Attach to concentrator tube with springs.</P>
                        <P>5.2.6 Snyder column, Kuderna-Danish—Three-ball macro (Kontes K-503000-0121 or equivalent).</P>
                        <P>5.2.7 Snyder column, Kuderna-Danish—Two-ball micro (Kontes K-569001-0219 or equivalent).</P>
                        <P>5.2.8 Vials—10 to 15-mL, amber glass, with Teflon-lined screw cap.</P>
                        <P>5.3 Boiling chips—Approximately 10/40 mesh. Heat to 400 °C for 30 min or Soxhlet extract with methylene chloride.</P>
                        <P>5.4 Water bath—Heated, with concentric ring cover, capable of temperature control (±2 °C). The bath should be used in a hood.</P>
                        <P>5.5 Balance—Analytical, capable of accurately weighing 0.0001 g.</P>
                        <P>5.6 Gas chromatograph—An analytical system complete with gas chromatograph suitable for on-column injection and all required accessories including syringes, analytical columns, gases, detector, and strip-chart recorder. A data system is recommended for measuring peak areas.</P>
                        <P>5.6.1 Column 1—1.8 m long × 4 mm ID glass, packed with 1.5% SP-2250/1.95% SP-2401 Supelcoport (100/120 mesh) or equivalent. This column was used to develop the method performance statemelts in Section 14. Guidelines for the use of alternate column packings are provided in Section 12.1.</P>
                        <P>5.6.2 Column 2—1.8 m long × 4 mm ID glass, packed with 3% OV-1 on Supelcoport (100/120 mesh) or equivalent.</P>
                        <P>5.6.3 Detector—Electron capture detector. This detector has proven effective in the analysis of wastewaters for the parameters listed in the scope (Section 1.1), and was used to develop the method performance statements in Section 14. Guidelines for the use of alternate detectors are provided in Section 12.1.</P>
                        <HD SOURCE="HD2">6. Reagents</HD>
                        <P>6.1 Reagent water—Reagent water is defined as a water in which an interferent is not observed at the MDL of the parameters of interest.</P>
                        <P>6.2 Acetone, hexane, isooctane, methylene chloride, methanol—Pesticide quality or equivalent.</P>
                        <P>6.3 Ethyl ether—nanograde, redistilled in glass if necessary.</P>
                        <P>
                            6.3.1 Ethyl ether must be shown to be free of peroxides before it is used as indicated by 
                            <PRTPAGE P="138"/>
                            EM Laboratories Quant test strips. (Available from Scientific Products Co., Cat. No. P1126-8, and other suppliers.)
                        </P>
                        <P>6.3.2 Procedures recommended for removal of peroxides are provided with the test strips. After cleanup, 20 mL of ethyl alcohol preservative must be added to each liter of ether.</P>
                        <P>6.4 Sodium sulfate—(ACS) Granular, anhydrous. Several levels of purification may be required in order to reduce background phthalate levels to an acceptable level: 1) Heat 4 h at 400 °C in a shallow tray, 2) Heat 16 h at 450 to 500 °C in a shallow tray, 3) Soxhlet extract with methylene chloride for 48 h.</P>
                        <P>6.5 Florisil—PR grade (60/100 mesh). Purchase activated at 1250 °F and store in the dark in glass containers with ground glass stoppers or foil-lined screw caps. To prepare for use, place 100 g of Florisil into a 500-mL beaker and heat for approximately 16 h at 40 °C. After heating transfer to a 500-mL reagent bottle. Tightly seal and cool to room temperature. When cool add 3 mL of reagent water. Mix thoroughly by shaking or rolling for 10 min and let it stand for at least 2 h. Keep the bottle sealed tightly.</P>
                        <P>6.6 Alumina—Neutral activity Super I, W200 series (ICN Life Sciences Group, No. 404583). To prepare for use, place 100 g of alumina into a 500-mL beaker and heat for approximately 16 h at 400 °C. After heating transfer to a 500-mL reagent bottle. Tightly seal and cool to room temperature. When cool add 3 mL of reagent water. Mix thoroughly by shaking or rolling for 10 min and let it stand for at least 2 h. Keep the bottle sealed tightly.</P>
                        <P>6.7 Stock standard solutions (1.00 µg/µL)—Stock standard solutions can be prepared from pure standard materials or purchased as certified solutions.</P>
                        <P>6.7.1 Prepare stock standard solutions by accurately weighing about 0.0100 g of pure material. Dissolve the material in isooctane and dilute to volume in a 10-mL volumetric flask. Larger volumes can be used at the convenience of the analyst. When compound purity is assayed to be 96% or greater, the weight can be used without correction to calculate the concentration of the stock standard. Commercially prepared stock standards can be used at any concentration if they are certified by the manufacturer or by an independent source.</P>
                        <P>6.7.2 Transfer the stock standard solutions into Teflon-sealed screw-cap bottles. Store at 4 °C and protect from light. Stock standard solutions should be checked frequently for signs of degradation or evaporation, especially just prior to preparing calibration standards from them.</P>
                        <P>6.7.3 Stock standard solutions must be replaced after six months, or sooner if comparison with check standards indicates a problem.</P>
                        <P>6.8 Quality control check sample concentrate—See Section 8.2.1.</P>
                        <HD SOURCE="HD2">7. Calibration</HD>
                        <P>7.1 Establish gas chromatograph operating conditions equivalent to those given in Table 1. The gas chromatographic system can be calibrated using the external standard technique (Section 7.2) or the internal standard technique (Section 7.3).</P>
                        <P>7.2 External standard calibration procedure:</P>
                        <P>7.2.1 Prepared calibration standards at a minimum of three concentration levels for each parameter of interest by adding volumes of one or more stock standards to a volumetric flask and diluting to volume with isooctane. One of the external standards should be at a concentration near, but above, the MDL (Table 1) and the other concentrations should correspond to the expected range of concentrations found in real samples or should define the working range of the detector.</P>
                        <P>7.2.2 Using injections of 2 to 5 µL, analyze each calibration standard according to Section 12 and tabulate peak height or area responses against the mass injected. The results can be used to prepare a calibration curve for each compound. Alternatively, if the ratio of response to amount injected (calibration factor) is a constant over the working range (&lt;10% relative standard deviation, RSD), linearity through the origin can be assumed and the average ratio or calibration factor can be used in place of a calibration curve.</P>
                        <P>7.3 Internal standard calibration procedure—To use this approach, the analyst must select one or more internal standards that are similar in analytical behavior to the compounds of interest. The analyst must further demonstrate that the measurement of the internal standard is not affected by method or matrix interferences. Because of these limitations, no internal standard can be suggested that is applicable to all samples.</P>
                        <P>
                            7.3.1 Prepare calibration standards at a minimum of three concentration levels for each parameter of interest by adding volumes of one or more stock standards to a volumetric flash. To each calibration standard, add a known constant amount of one or more internal standards, and dilute to volume with isooctane. One of the standards should be at a concentration near, but above, the MDL and the other concentrations should correspond to the expected range of concentrations found in real samples or should define the working range of the detector.
                            <PRTPAGE P="139"/>
                        </P>
                        <P>7.3.2 Using injections of 2 to 5 µL, analyze each calibration standard according to Section 12 and tabulate peak height or area responses against concentration for each compound and internal standard. Calculate response factors (RF) for each compound using Equation 1.</P>
                        <HD SOURCE="HD3">
                            RF = (A
                            <E T="52">s</E>
                            )(C
                            <E T="52">is</E>
                             (A
                            <E T="52">is</E>
                            )(C
                            <E T="52">s</E>
                            )
                        </HD>
                        <FP SOURCE="FRP">Equation 1</FP>
                        <FP>where:</FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">s</E>
                             = Response for the parameter to be measured.
                        </FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">is</E>
                             = Response for the internal standard.
                        </FP>
                        <FP SOURCE="FP-2">
                            C
                            <E T="52">is</E>
                             = Concentration of the internal standard (µg/L).
                        </FP>
                        <FP SOURCE="FP-2">
                            C
                            <E T="52">s</E>
                             = Concentration of the parameter to be measured (µg/L).
                        </FP>
                        <P>
                            If the RF value over the working range is a constant (&lt;10% RSD), the RF can be assumed to be invariant and the average RF can be used for calculations. Alternatively, the results can be used to plot a calibration curve of response ratios, A
                            <E T="52">s</E>
                            /A
                            <E T="52">is</E>
                            , vs. RF.
                        </P>
                        <P>7.4 The working calibration curve, calibration factor, or RF must be verified on each working day by the measurement of one or more calibration standards. If the response for any parameter varies from the predicted response by more than ±15%, a new calibration curve must be prepared for that compound.</P>
                        <P>7.5 Before using any cleanup procedure, the analyst must process a series of calibration standards through the procedure to validate elution patterns and the absence of interferences from the reagents.</P>
                        <HD SOURCE="HD2">8. Quality Control</HD>
                        <P>8.1 Each laboratory that uses this method is required to operate a formal quality control program. The minimum requirements of this program consist of an initial demonstration of laboratory capability and an ongoing analysis of spiked samples to evaluate and document data quality. The laboratory must maintain records to document the quality of data that is generated. Ongoing data quality checks are compared with established performance criteria to determine if the results of analyses meet the performance characteristics of the method. When results of sample spikes indicate atypical method performance, a quality control check standard must be analyzed to confirm that the measurements were performed in an in-control mode of operation.</P>
                        <P>8.1.1 The analyst must make an initial, one-time, demonstration of the ability to generate acceptable accuracy and precision with this method. This ability is established as described in Section 8.2.</P>
                        <P>8.1.2 In recognition of advances that are occurring in chromatography, the analyst is permitted certain options (detailed in Sections 10.4, 11.1, and 12.1) to improve the separations or lower the cost of measurements. Each time such a modification is made to the method, the analyst is required to repeat the procedure in Section 8.2.</P>
                        <P>8.1.3 Before processing any samples, the analyst must analyze a reagent water blank to demonstrate that interferences from the analytical system and glassware are under control. Each time a set of samples is extracted or reagents are changed, a reagent water blank must be processed as a safeguard against laboratory contamination.</P>
                        <P>8.1.4 The laboratory must, on an ongoing basis, spike and analyze a minimum of 10% of all samples to monitor and evaluate laboratory data quality. This procedure is described in Section 8.3.</P>
                        <P>8.1.5 The laboratory must, on an ongoing basis, demonstrate through the analyses of quality control check standards that the operation of the measurement system is in control. This procedure is described in Section 8.4. The frequency of the check standard analyses is equivalent to 10% of all samples analyzed but may be reduced if spike recoveries from samples (Section 8.3) meet all specified quality control criteria.</P>
                        <P>8.1.6 The laboratory must maintain performance records to document the quality of data that is generated. This procedure is described in Section 8.5.</P>
                        <P>8.2 To establish the ability to generate acceptable accuracy and precision, the analyst must perform the following operations.</P>
                        <P>8.2.1 A quality contrml (QC) check sample concentrate is required containing each parameter of interest at the following concentrations in acetone: butyl benzyl phthalate, 10 µg/mL; bis(2-ethylhexyl) phthalate, 50 µg/mL; di-n-octyl phthalate, 50 µg/mL; any other phthlate, 25 µg/mL. The QC check sample concentrate must be obtained from the U.S. Environmental Protection Agancy, Environmental Monitoring and Support Laboratory in Cincinnati, Ohio, if available. If not available from that source, the QC check sample concentrate must be obtained from another external source. If not available from either source above, the QC check sample concentrate must be prepared by the laboratory using stock standards prepared independently from those used for calibration.</P>
                        <P>8.2.2 Using a pipet, prepare QC check samples at the test concentrations shown in Table 2 by adding 1.00 mL of QC check sample concentrate to each of four 1-L aliquots of reagent water.</P>
                        <P>8.2.3 Analyze the well-mixed QC check samples according to the method beginning in Section 10.</P>
                        <P>
                            8.2.4 Calculate the average recovery (X
                            <AC T="8"/>
                            ) in µg/L, and the standard deviation of the recovery (s) in µg/L, for each parameter using the four results.
                        </P>
                        <P>
                            8.2.5 For each parameter compare s and X
                            <AC T="8"/>
                             with the corresponding acceptance criteria for precision and accuracy, respectively, 
                            <PRTPAGE P="140"/>
                            found in Table 2. If s and X
                            <AC T="8"/>
                             for all parameters of interest meet the acceptance criteria, the system performance is acceptable and analysis of actual samples can begin. If any individual s exceeds the precision limit or any individual X
                            <AC T="8"/>
                             falls outside the range for accuracy, the system performance is unacceptable for that parameter. Locate and correct the source of the problem and repeat the test for all parameters of interest beginning with Section 8.2.2.
                        </P>
                        <P>8.3 The laboratory must, on an ongoing basis, spike at least 10% of the samples from each sample site being monitored to assess accuracy. For laboratories analyzing one to ten samples per month, at least one spiked sample per month is required.</P>
                        <P>8.3.1 The concentration of the spike in the sample should be determined as follows:</P>
                        <P>8.3.1.1 If, as in compliance monitoring, the concentration of a specific parameter in the sample is being checked against a regulatory concentration limit, the spike should be at that limit or 1 to 5 times higher than the background concentration determined in Section 8.3.2, whichever concentration would be larger.</P>
                        <P>8.3.1.2 If the concentration of a specific parameter in the sample is not being checked against a limit specific to that parameter, the spike should be at the test concentration in Section 8.2.2 or 1 to 5 times higher than the background concentration determined in Section 8.3.2, whichever concentration would be larger.</P>
                        <P>8.3.1.3 If it is impractical to determine background levels before spiking (e.g., maximum holding times will be exceeded), the spike concentration should be (1) the regulatory concentration limit, if any; or, if none (2) the larger of either 5 times higher than the expected background concentration or the test concentration in Section 8.2.2.</P>
                        <P>8.3.2 Analyze one sample aliquot to determine the background concentration (B) of each parameter. If necessary, prepare a new QC check sample concentrate (Section 8.2.1) appropriate for the background concentrations in the sample. Spike a second sample aliquot with 1.0 mL of the QC check sample concentrate and analyze it to determine the concentration after spiking (A) of each parameter. Calculate each percent recovery (P) as 100(A-B)%/T, where T is the known true value of the spike.</P>
                        <P>
                            8.3.3 Compare the percent recovery (P) for each parameter with the corresponding QC acceptance criteria found in Table 2. These acceptance criteria were calculated to include an allowance for error in measurement of both the background and spike concentrations, assuming a spike to background ratio of 5:1. This error will be accounted for to the extent that the analyst's spike to background ratio approaches 5:1. 
                            <SU>9</SU>
                             If spiking was performed at a concentration lower than the test concentration in Section 8.2.2, the analyst must use either the QC acceptance criteria in Table 2, or optional QC acceptance criteria calculated for the specific spike concentration. To calculate optional acceptance criteria for the recovery of a parameter: (1) Calculate accuracy (X′) using the equation in Table 3, substituting the spike concentration (T) for C; (2) calculate overall precision (S′) using the equation in Table 3, substituting X′ for X
                            <AC T="8"/>
                            ; (3) calculate the range for recovery at the spike concentration as (100 X′/T)±2.44(100 S′/T)%. 
                            <SU>9</SU>
                        </P>
                        <P>8.3.4 If any individual P falls outside the designated range for recovery, that parameter has failed the acceptance criteria. A check standard containing each parameter that failed the criteria must be analyzed as described in Section 8.4.</P>
                        <P>8.4 If any parameter fails the acceptance criteria for recovery in Section 8.3, a QC check standard containing each parameter that failed must be prepared and analyzed.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>The frequency for the required analysis of a QC check standard will depend upon the number of parameters being simultaneously tested, the complexity of the sample matrix, and the performance of the laboratory.</P>
                        </NOTE>
                        <P>8.4.1 Prepare the QC check standard by adding 1.0 mL of QC check sample concentrate (Section 8.2.1 or 8.3.2) to 1 L of reagent water. The QC check standard needs only to contain the parameters that failed criteria in the test in Section 8.3.</P>
                        <P>
                            8.4.2 Analyze the QC check standard to determine the concentration measured (A) of each parameter. Calculate each percent recovery (P
                            <E T="52">s</E>
                            ) as 100 (A/T)%, where T is the true value of the standard concentration.
                        </P>
                        <P>
                            8.4.3 Compare the percent recovery (P
                            <E T="52">s</E>
                            ) for each parameter with the corresponding QC acceptance criteria found in Table 2. Only parameters that failed the test in Section 8.3 need to be compared with these criteria. If the recovery of any such parameter falls outside the designated range, the laboratory performance for that parameter is judged to be out of control, and the problem must be immediately identified and corrected. The analytical result for that parameter in the unspiked sample is suspect and may not be reported for regulatory compliance purposes.
                        </P>
                        <P>
                            8.5 As part of the QC program for the laboratory, method accuracy for wastewater samples must be assessed and records must be maintained. After the analysis of five spiked wastewater samples as in Section 8.3, calculate the average percent recovery (P
                            <AC T="8"/>
                            ) and the standard deviation of the percent recovery (s
                            <E T="52">p</E>
                            ). Express the accuracy assessment as a percent recovery interval from P
                            <AC T="8"/>
                            −2s
                            <E T="52">p</E>
                             to P
                            <AC T="8"/>
                             + 2s
                            <E T="52">p</E>
                            . If P
                            <AC T="8"/>
                             = 90% and s
                            <E T="52">p</E>
                             = 10%, for example, the accuracy interval is expressed as 70-110%. Update the accuracy assessment for each parameter on a regular basis (e.g. after each five to ten new accuracy measurements).
                            <PRTPAGE P="141"/>
                        </P>
                        <P>8.6 It is recommended that the laboratory adopt additional quality assurance practices for use with this method. The specific practices that are most productive depend upon the needs of the laboratory and the nature of the samples. Field duplicates may be analyzed to assess the precision of the environmental measurements. When doubt exists over the identification of a peak on the chromatogram, confirmatory techniques such as gas chromatography with a dissimilar column, specific element detector, or mass spectrometer must be used. Whenever possible, the laboratory should analyze standard reference materials and participate in relevant performance evaluation studies.</P>
                        <HD SOURCE="HD2">9. Sample Collection, Preservation, and Handling</HD>
                        <P>
                            9.1 Grab samples must be collected in glass containers. Conventional sampling practices 
                            <SU>10</SU>
                             should be followed, except that the bottle must not be prerinsed with sample before collection. Composite samples should be collected in refrigerated glass containers in accordance with the requirements of the program. Automatic sampling equipment must be as free as possible of Tygon tubing and other potential sources of contamination.
                        </P>
                        <P>9.2 All samples must be iced or refrigerated at 4 °C from the time of collection until extraction.</P>
                        <P>
                            9.3 All samples must be extracted within 7 days of collection and completely analyzed within 40 days of extraction. 
                            <SU>2</SU>
                        </P>
                        <HD SOURCE="HD2">10. Sample Extraction</HD>
                        <P>10.1 Mark the water meniscus on the side of the sample bottle for later determination of sample volume. Pour the entire sample into a 2-L separatory funnel.</P>
                        <P>10.2 Add 60 mL of methylene chloride to the sample bottle, seal, and shake 30 s to rinse the inner surface. Transfer the solvent to the separatory funnel and extract the sample by shaking the funnel for 2 min. with periodic venting to release excess pressure. Allow the organic layer to separate from the water phase for a minimum of 10 min. If the emulsion interface between layers is more than one-third the volume of the solvent layer, the analyst must employ mechanical techniques to complete the phrase separation. The optimum technique depends upon the sample, but may include stirring, filtration of the emulsion through glass wool, centrifugation, or other physical methods. Collect the methylene chloride extract in a 250-mL Erlenmeyer flask.</P>
                        <P>10.3 Add a second 60-mL volume of methylene chloride to the sample bottle and repeat the extraction procedure a second time, combining the extracts in the Erlenmeyer flask. Perform a third extraction in the same manner.</P>
                        <P>10.4 Assemble a Kuderna-Danish (K-D) concentrator by attaching a 10-mL concentrator tube to a 500-mL evaporative flask. Other concentrator devices or techniques may be used in place of the K-D concentrator if the requirements of Section 8.2 are met.</P>
                        <P>10.5 Pour the combined extract through a solvent-rinsed drying column containing about 10 cm of anhydrous sodium sulfate, and collect the extract in the K-D concentrator. Rinse the Erlenmeyer flask and column with 20 to 30 mL of methylene chloride to complete the quantitative transfer.</P>
                        <P>10.6 Add one or two clean boiling chips to the evaporative flask and attach a three-ball Snyder column. Prewet the Snyder column by adding about 1 mL of methylene chloride to the top. Place the K-D apparatus on a hot water bath (60 to 65 °C) so that the concentrator tube is partially immersed in the hot water, and the entire lower rounded surface of the flask is bathed with hot vapor. Adjust the vertical position of the apparatus and the water temperature as required to complete the concentration in 15 to 20 min. At the proper rate of distillation the balls of the column will actively chatter but the chambers will not flood with condensed solvent. When the apparent volume of liquid reaches 1 mL, remove the K-D apparatus and allow it to drain and cool for at least 10 min.</P>
                        <P>10.7 Increase the temperature of the hot water bath to about 80 °C. Momentarily remove the Snyder column, add 50 mL of hexane and a new boiling chip, and reattach the Snyder column. Concentrate the extract as in Section 10.6, except use hexane to prewet the column. The elapsed time of concentration should be 5 to 10 min.</P>
                        <P>10.8 Remove the Snyder column and rinse the flask and its lower joint into the concentrator tube with 1 to 2 mL of hexane. A 5-mL syringe is recommended for this operation. Adjust the extract volume to 10 mL. Stopper the concentrator tube and store refrigerated if further processing will not be performed immediately. If the extract will be stored longer than two days, it should be transferred to a Teflon-sealed screw-cap vial. If the sample extract requires no further cleanup, proceed with gas chromatographic analysis (Section 12). If the sample requires further cleanup, proceed to Section 11.</P>
                        <P>10.9 Determine the original sample volume by refilling the sample bottle to the mark and transferring the liquid to a 1000-mL graduated cylinder. Record the sample volume to the nearest 5 mL.</P>
                        <HD SOURCE="HD2">11. Cleanup and Separation</HD>
                        <P>
                            11. Cleanup procedures may not be necessary for a relatively clean sample matrix. If particular circumstances demand the use of a cleanup procedure, the analyst may use either procedure below or any other appropriate procedure. However, the analyst first must demonstrate that the requirements of 
                            <PRTPAGE P="142"/>
                            Section 8.2 can be met using the method as revised to incorporate the cleanup procedure.
                        </P>
                        <P>11.2 If the entire extract is to be cleaned up by one of the following procedures, it must be concentrated to 2.0 mL. To the concentrator tube in Section 10.8, add a clean boiling chip and attach a two-ball micro-Snyder column. Prewet the column by adding about 0.5 mL of hexane to the top. Place the micro-K-D apparatus on a hot water bath (80 °C) so that the concentrator tube is partially immersed in the hot water. Adjust the vertical position of the apparatus and the water temperature as required to complete the concentration in 5 to 10 min. At the proper rate of distillation the balls of the column will actively chatter but the chambers will not flood. When the apparent volume of liquid reaches about 0.5 mL, remove the K-D apparatus and allow it to drain and cool for at least 10 min. Remove the micro-Snyder column and rinse its lower joint into the concentrator tube with 0.2 mL of hexane. Adjust the final volume to 2.0 mL and proceed with one of the following cleanup procedures.</P>
                        <P>11.3 Florisil column cleanup for phthalate esters:</P>
                        <P>11.3.1 Place 10 g of Florisil into a chromatographic column. Tap the column to settle the Florisil and add 1 cm of anhydrous sodium sulfate to the top.</P>
                        <P>11.3.2 Preelute the column with 40 mL of hexane. The rate for all elutions should be about 2 mL/min. Discard the eluate and just prior to exposure of the sodium sulfate layer to the air, quantitatively transfer the 2-mL sample extract onto the column using an additional 2 mL of hexane to complete the transfer. Just prior to exposure of the sodium sulfate layer to the air, add 40 mL of hexane and continue the elution of the column. Discard this hexane eluate.</P>
                        <P>11.3.3 Next, elute the column with 100 mL of 20% ethyl ether in hexane (V/V) into a 500-mL K-D flask equipped with a 10-mL concentrator tube. Concentrate the collected fraction as in Section 10.6. No solvent exchange is necessary. Adjust the volume of the cleaned up extract to 10 mL in the concentrator tube and analyze by gas chromatography (Section 12).</P>
                        <P>11.4 Alumina column cleanup for phthalate esters:</P>
                        <P>11.4.1 Place 10 g of alumina into a chromatographic column. Tap the column to settle the alumina and add 1 cm of anhydrous sodium sulfate to the top.</P>
                        <P>11.4.2 Preelute the column with 40 mL of hexane. The rate for all elutions should be about 2 mL/min. Discard the eluate and just prior to exposure of the sodium sulfate layer to the air, quantitatively transfer the 2-mL sample extract onto the column using an additional 2 mL of hexane to complete the transfer. Just prior to exposure of the sodium sulfate layer to the air, add 35 mL of hexane and continue the elution of the column. Discard this hexane eluate.</P>
                        <P>11.4.3 Next, elute the column with 140 mL of 20% ethyl ether in hexane (V/V) into a 500-mL K-D flask equipped with a 10-mL concentrator type. Concentrate the collected fraction as in Section 10.6. No solvent exchange is necessary. Adjust the volume of the cleaned up extract to 10 mL in the concentrator tube and analyze by gas chromatography (Section 12).</P>
                        <HD SOURCE="HD2">12. Gas Chromatography</HD>
                        <P>12.1 Table 1 summarizes the recommended operating conditions for the gas chromatograph. Included in this table are retention times and MDL that can be achieved under these conditions. Examples of the separations achieved by Column 1 are shown in Figures 1 and 2. Other packed or capillary (open-tubular) columns, chromatographic conditions, or detectors may be used if the requirements of Section 8.2 are met.</P>
                        <P>12.2 Calibrate the system daily as described in Section 7.</P>
                        <P>12.3 If the internal standard calibration procedure is being used, the internal staldard must be added to the sample extract and mixed thoroughly immediately before injection into the gas chromatograph.</P>
                        <P>
                            12.4 Inject 2 to 5 µL of the sample extract or standard into the gas-chromatograph using the solvent-flush technique. 
                            <SU>11</SU>
                             Smaller (1.0 µL) volumes may be injected if automatic devices are employed. Record the volume injected to the nearest 0.05 µL, and the resulting peak size in area or peak height units.
                        </P>
                        <P>12.5 Identify the parameters in the sample by comparing the retention times of the peaks in the sample chromatogram with those of the peaks in standard chromatograms. The width of the retention time window used to make identifications should be based upon measurements of actual retention time variations of standards over the course of a day. Three times the standard deviation of a retention time for a compound can be used to calculate a suggested window size; however, the experience of the analyst should weigh heavily in the interpretation of chromatograms.</P>
                        <P>12.6 If the response for a peak exceeds the working range of the system, dilute the extract and reanalyze.</P>
                        <P>12.7 If the measurement of the peak response is prevented by the presence of interferences, further cleanup is required.</P>
                        <HD SOURCE="HD2">13. Calculations</HD>
                        <P>13.1 Determine the concentration of individual compounds in the sample.</P>
                        <P>
                            13.1.1 If the external standard calibration procedure is used, calculate the amount of material injected from the peak response using the calibration curve or calibration 
                            <PRTPAGE P="143"/>
                            factor determined in Section 7.2.2. The concentration in the sample can be calculated from Equation 2.
                        </P>
                        <MATH SPAN="1" DEEP="31">
                            <MID>EC15NO91.103</MID>
                        </MATH>
                        <FP SOURCE="FRP0">Equation 2</FP>
                        <FP>where:</FP>
                        <FP SOURCE="FP-2">A = Amount of material injected (ng).</FP>
                        <FP SOURCE="FP-2">
                            V
                            <E T="52">i</E>
                             = Volume of extract injected (µL).
                        </FP>
                        <FP SOURCE="FP-2">
                            V
                            <E T="52">t</E>
                             = Volume of total extract (µL).
                        </FP>
                        <FP SOURCE="FP-2">
                            V
                            <E T="52">s</E>
                             = Volume of water extracted (mL).
                        </FP>
                        <P>13.1.2 If the internal standard calibration procedure is used, calculate the concentration in the sample using the response factor (RF) determined in Section 7.3.2 and Equation 3.</P>
                        <MATH SPAN="1" DEEP="31">
                            <MID>EC15NO91.104</MID>
                        </MATH>
                        <FP SOURCE="FRP0">Equation 3</FP>
                        <FP>where:</FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">s</E>
                             = Response for the parameter to be measured.
                        </FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">is</E>
                             = Response for the internal standard.
                        </FP>
                        <FP SOURCE="FP-2">
                            I
                            <E T="52">s</E>
                             = Amount of internal standard added to each extract (µg).
                        </FP>
                        <FP SOURCE="FP-2">
                            V
                            <E T="52">o</E>
                             = Volume of water extracted (L).
                        </FP>
                        <P>13.2 Report results in µg/L without correction for recovery data. All QC data obtained should be reported with the sample results.</P>
                        <HD SOURCE="HD2">14. Method Performance</HD>
                        <P>
                            14.1 The method detection limit (MDL) is defined as the minimum concentration of a substance that can be measured and reported with 99% confidence that the value is above zero. 
                            <SU>1</SU>
                             The MDL concentrations listed in Table 1 were obtained using reagent water. 
                            <SU>12</SU>
                             Similar results were achieved using representative wastewaters. The MDL actually achieved in a given analysis will vary depending on instrument sensitivity and matrix effects.
                        </P>
                        <P>
                            14.2 This method has been tested for linearity of spike recovery from reagent water and has been demonstrated to be applicable over the concentration range from 5 × MDL to 1000 × MDL with the following exceptions: dimethyl and diethyl phthalate recoveries at 1000 × MDL were low (70%); bis-2-ethylhexyl and di-n-octyl phthalate recoveries at 5 × MDL were low (60%). 
                            <SU>12</SU>
                        </P>
                        <P>
                            14.3 This method was tested by 16 laboratories using reagent water, drinking water, surface water, and three industrial wastewaters spiked at six concentrations over the range 0.7 to 106 µg/L. 
                            <SU>13</SU>
                             Single operator precision, overall precision, and method accuracy were found to be directly related to the concentration of the parameter and essentially independent of the sample matrix. Linear equations to describe these relationships are presented in Table 3.
                        </P>
                        <HD SOURCE="HD2">References</HD>
                        <P>1. 40 CFR part 136, appendix B.</P>
                        <P>2. “Determination of Phthalates in Industrial and Muncipal Wastewaters,” EPA 600/4-81-063, National Technical Information Service, PB81-232167, Springfield, Virginia 22161, July 1981.</P>
                        <P>3. ASTM Annual Book of Standards, Part 31, D3694-78. “Standard Practices for Preparation of Sample Containers and for Preservation of Organic Constituents,” American Society for Testing and Materials, Philadelphia.</P>
                        <P>
                            4. Giam, C.S., Chan, H.S., and Nef, G.S. “Sensitive Method for Determination of Phthalate Ester Plasticizers in Open-Ocean Biota Samples,” 
                            <E T="03">Analytical Chemistry, 47,</E>
                             2225 (1975).
                        </P>
                        <P>5. Giam, C.S., and Chan, H.S. “Control of Blanks in the Analysis of Phthalates in Air and Ocean Biota Samples,” U.S. National Bureau of Standards, Special Publication 442, pp. 701-708, 1976.</P>
                        <P>6. “Carcinogens—Working with Carcinogens,” Department of Health, Education, and Welfare, Public Health Service, Center for Disease Control, National Institute for Occupational Safety and Health, Publication No. 77-206, August 1977.</P>
                        <P>7. “OSHA Safety and Health Standards, General Industry,” (29 CFR part 1910), Occupational Safety and Health Administration, OSHA 2206 (Revised, January 1976).</P>
                        <P>8. “Safety in Academic Chemistry Laboratories,” American Chemical Society Publication, Committee on Chemical Safety, 3rd Edition, 1979.</P>
                        <P>
                            9. Provost L.P., and Elder, R.S. “Interpretation of Percent Recovery Data,” 
                            <E T="03">American Laboratory, 15,</E>
                             58-63 (1983). (The value 2.44 used in the equation in Section 8.3.3 is two times the value 1.22 derived in this report.)
                        </P>
                        <P>10. ASTM Annual Book of Standards, Part 31, D3370-76. “Standard Practices for Sampling Water,” American Society for Testing and Materials, Philadelphia.</P>
                        <P>
                            11. Burke, J.A. “Gas Chromatography for Pesticide Residue Analysis; Some Practical Aspects,” 
                            <E T="03">Journal of the Association of Official Analytical Chemists, 48,</E>
                             1037 (1965).
                        </P>
                        <P>12. “Method Detection Limit and Analytical Curve Studies, EPA Methods 606, 607, and 608,” Special letter report for EPA Contract 68-03-2606, U.S. Environmental Protection Agency, Environmental Monitoring and Support Laboratory, Cincinnati, Ohio 45268, June 1980.</P>
                        <P>
                            13. “EPA Method Study 16 Method 606 (Phthalate Esters),” EPA 600/4-84-056, National Technical Information Service, PB84-211275, Springfield, Virginia 22161, June 1984.
                            <PRTPAGE P="144"/>
                        </P>
                        <GPOTABLE COLS="4" OPTS="L2" CDEF="s50,8.2,8.2,8.2">
                            <TTITLE>Table 1—Chromatographic Conditions and Method Detection Limits</TTITLE>
                            <BOXHD>
                                <CHED H="1">Parameter</CHED>
                                <CHED H="1">Retention time (min)</CHED>
                                <CHED H="2">Column 1</CHED>
                                <CHED H="2">Column 2</CHED>
                                <CHED H="1">Method detection limit (µg/L)</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">Dimethyl phthalate</ENT>
                                <ENT>2.03</ENT>
                                <ENT>0.95</ENT>
                                <ENT>0.29</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Diethyl phthalate</ENT>
                                <ENT>2.82</ENT>
                                <ENT>1.27</ENT>
                                <ENT>0.49</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Di-n-butyl phthalate</ENT>
                                <ENT>8.65</ENT>
                                <ENT>3.50</ENT>
                                <ENT>0.36</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Butyl benzyl phthalate</ENT>
                                <ENT>
                                    <SU>a</SU>
                                     6.94
                                </ENT>
                                <ENT>
                                    <SU>a</SU>
                                     5.11
                                </ENT>
                                <ENT>0.34</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Bis(2-ethylhexyl) phthalate</ENT>
                                <ENT>
                                    <SU>a</SU>
                                     8.92
                                </ENT>
                                <ENT>
                                    <SU>a</SU>
                                     10.5
                                </ENT>
                                <ENT>2.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Di-n-octyl phthalate</ENT>
                                <ENT>
                                    <SU>a</SU>
                                     16.2
                                </ENT>
                                <ENT>
                                    <SU>a</SU>
                                     18.0
                                </ENT>
                                <ENT>3.0</ENT>
                            </ROW>
                            <TNOTE>Column 1 conditions: Supelcoport (100/120 mesh) coated with 1.5% SP-2250/1.95% SP-2401 packed in a 1.8 m long × 4 mm ID glass column with 5% methane/95% argon carrier gas at 60 mL/min flow rate. Column temperature held isothermal at 180 °C, except where otherwise indicated.</TNOTE>
                            <TNOTE>Column 2 conditions: Supelcoport (100/120 mesh) coated with 3% OV-1 packed in a 1.8 m long × 4 mm ID glass column with 5% methane/95% argon carrier gas at 60 mL/min flow rate. Column temperature held isothermal at 200 °C, except where otherwise indicated.</TNOTE>
                            <TNOTE>
                                <SU>a</SU>
                                 220 °C column temperature.
                            </TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="5" OPTS="L2" CDEF="s50,8,8,9,8">
                            <TTITLE>Table 2—QC Acceptance Criteria—Method 606</TTITLE>
                            <BOXHD>
                                <CHED H="1">Parameter</CHED>
                                <CHED H="1">Test conc. (µg/L)</CHED>
                                <CHED H="1">Limit for s (µg/L)</CHED>
                                <CHED H="1">
                                    Range for X
                                    <AC T="8"/>
                                     (µg/L)
                                </CHED>
                                <CHED H="1">
                                    Range for P, P
                                    <E T="52">s</E>
                                     (percent)
                                </CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">Bis(2-ethylhexyl) phthalate</ENT>
                                <ENT>50</ENT>
                                <ENT>38.4</ENT>
                                <ENT>1.2-55.9</ENT>
                                <ENT>D-158</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Butyl benzyl phthalate</ENT>
                                <ENT>10</ENT>
                                <ENT>4.2</ENT>
                                <ENT>5.7-11.0</ENT>
                                <ENT>30-136</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Di-n-butyl phthalate</ENT>
                                <ENT>25</ENT>
                                <ENT>8.9</ENT>
                                <ENT>10.3-29.6</ENT>
                                <ENT>23-136</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Diethyl phthalate</ENT>
                                <ENT>25</ENT>
                                <ENT>9.0</ENT>
                                <ENT>1.9-33.4</ENT>
                                <ENT>D-149</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dimethyl phathalate</ENT>
                                <ENT>25</ENT>
                                <ENT>9.5</ENT>
                                <ENT>1.3-35.5</ENT>
                                <ENT>D-156</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Di-n-octyl phthalate</ENT>
                                <ENT>50</ENT>
                                <ENT>13.4</ENT>
                                <ENT>D-50.0</ENT>
                                <ENT>D-114</ENT>
                            </ROW>
                            <TNOTE>s = Standard deviation of four recovery measurements, in µg/L (Section 8.2.4).</TNOTE>
                            <TNOTE>
                                X
                                <AC T="8"/>
                                 = Average recovery for four recovery measurements, in µg/L (Section 8.2.4).
                            </TNOTE>
                            <TNOTE>
                                P, P
                                <E T="52">s</E>
                                 = Percent recovery measured (Section 8.3.2, Section 8.4.2).
                            </TNOTE>
                            <TNOTE>D = Detected; result must be greater than zero.</TNOTE>
                            <TNOTE>Note: These criteria are based directly upon the method performance data in Table 3. Where necessary, the limits for recovery have been broadened to assure applicability of the limits to concentrations below those used to develop Table 3.</TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="4" OPTS="L2" CDEF="s50,12,12,12">
                            <TTITLE>Table 3—Method Accuracy and Precision as Functions of Concentration—Method 606</TTITLE>
                            <BOXHD>
                                <CHED H="1">Parameter</CHED>
                                <CHED H="1">Accuracy, as recovery, X′ (µg/L)</CHED>
                                <CHED H="1">
                                    Single analyst precision, s
                                    <E T="52">r</E>
                                    ′ (µg/L)
                                </CHED>
                                <CHED H="1">Overall precision, S′ (µg/L)</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">Bis(2-ethylhexyl) phthalate</ENT>
                                <ENT>0.53C + 2.02</ENT>
                                <ENT>
                                    0.80X
                                    <AC T="8"/>
                                    −2.54
                                </ENT>
                                <ENT>
                                    0.73X
                                    <AC T="8"/>
                                    −0.17
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Butyl benzyl phthalate</ENT>
                                <ENT>0.82C + 0.13</ENT>
                                <ENT>
                                    0.26X
                                    <AC T="8"/>
                                     + 0.04
                                </ENT>
                                <ENT>
                                    0.25X
                                    <AC T="8"/>
                                     + 0.07
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Di-n-butyl phthalate</ENT>
                                <ENT>0.79C + 0.17</ENT>
                                <ENT>
                                    0.23X
                                    <AC T="8"/>
                                     + 0.20
                                </ENT>
                                <ENT>
                                    0.29X
                                    <AC T="8"/>
                                     + 0.06
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Diethyl phthalate</ENT>
                                <ENT>0.70C + 0.13</ENT>
                                <ENT>
                                    0.27X
                                    <AC T="8"/>
                                     + 0.05
                                </ENT>
                                <ENT>
                                    0.45X
                                    <AC T="8"/>
                                     + 0.11
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dimethyl phthalate</ENT>
                                <ENT>0.73C + 0.17</ENT>
                                <ENT>
                                    0.26X
                                    <AC T="8"/>
                                     + 0.14
                                </ENT>
                                <ENT>
                                    0.44X
                                    <AC T="8"/>
                                     + 0.31
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Di-n-octyl phthalate</ENT>
                                <ENT>0.35C−0.71</ENT>
                                <ENT>
                                    0.38X
                                    <AC T="8"/>
                                     + 0.71
                                </ENT>
                                <ENT>
                                    0.62X
                                    <AC T="8"/>
                                     + 0.34
                                </ENT>
                            </ROW>
                            <TNOTE>
                                X
                                <AC T="8"/>
                                ′ = Expected recovery for one or more measurements of a sample containing a concentration of C, in µg/L.
                            </TNOTE>
                            <TNOTE>
                                s
                                <E T="52">r</E>
                                ′ = Expected single analyst standard deviation of measurements at an average concentration found of X
                                <AC T="8"/>
                                , in µg/L.
                            </TNOTE>
                            <TNOTE>
                                S′ = Expected interlaboratory standard deviation of measurements at an average concentration found of X
                                <AC T="8"/>
                                , in µg/L.
                            </TNOTE>
                            <TNOTE>C = True value for the concentration, in µg/L.</TNOTE>
                            <TNOTE>
                                X
                                <AC T="8"/>
                                 = Average recovery found for measurements of samples containing a concentration of C, in µg/L.
                            </TNOTE>
                        </GPOTABLE>
                        <GPH SPAN="2" DEEP="448">
                            <PRTPAGE P="145"/>
                            <GID>EC02JY92.015</GID>
                        </GPH>
                        <GPH SPAN="2" DEEP="470">
                            <PRTPAGE P="146"/>
                            <GID>EC02JY92.016</GID>
                        </GPH>
                        <PRTPAGE P="147"/>
                        <HD SOURCE="HD1">Method 607—Nitrosamines</HD>
                        <EAR>Pt. 136, App. A, Meth. 607</EAR>
                        <HD SOURCE="HD2">1. Scope and Application</HD>
                        <P>1.1 This method covers the determination of certain nitrosamines. The following parameters can be determined by this method:</P>
                        <GPOTABLE COLS="3" OPTS="L2" CDEF="s10,10,10">
                            <BOXHD>
                                <CHED H="1">Parameter</CHED>
                                <CHED H="1">Storet No.</CHED>
                                <CHED H="1">CAS No.</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">N-Nitrosodimethylamine</ENT>
                                <ENT>34438</ENT>
                                <ENT>62-75-9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">N-Nitrosodiphenylamine</ENT>
                                <ENT>34433</ENT>
                                <ENT>86-30-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">N-Nitrosodi-n-propylamine</ENT>
                                <ENT>34428</ENT>
                                <ENT>621-64-7</ENT>
                            </ROW>
                        </GPOTABLE>
                        <P>
                            1.2 This is a gas chromatographic (GC) method applicable to the determination of the parameters listed above in municipal and industrial discharges as provided under 40 CFR 136.1. When this method is used to analyze unfamiliar samples for any or all of the compmunds above, compound identifications should be supported by at least one additional qualitative technique. This method describes analytical conditimns for a second gas chromatographic column that can be used to confirm measurements made with the primary column. Method 625 provides gas chromatograph/mass spectrometer (GC/MS) conditions appropriate for the qualitative and quantitative confirmation of results for N-nitrosodi-n-propylamine. In order to confirm the presence of N-nitrosodiphenylamine, the cleanup procedure specified in Section 11.3 or 11.4 must be used. In order to confirm the presence of N-nitrosodimethylamine by GC/MS, Column 1 of this method must be substituted for the column recommended in Method 625. Confirmation of these parameters using GC-high resolution mass spectrometry or a Thermal Energy Analyzer is also recommended. 
                            <SU>1 2</SU>
                        </P>
                        <P>
                            1.3 The method detection limit (MDL, defined in Section 14.1) 
                            <SU>3</SU>
                             for each parameter is listed in Table 1. The MDL for a specific wastewater may differ from those listed, depending upon the nature of interferences in the sample matrix.
                        </P>
                        <P>1.4 Any modification of this method, beyond those expressly permitted, shall be considered as a major modification subject to application and approval of alternate test procedures under 40 CFR 136.4 and 136.5.</P>
                        <P>1.5 This method is restricted to use by or under the supervision of analysts experienced in the use of a gas chromatograph and in the interpretation of gas chromatograms. Each analyst must demonstrate the ability to generate acceptable results with this method using the procedure described in Section 8.2.</P>
                        <HD SOURCE="HD2">2. Summary of Method</HD>
                        <P>
                            2.1 A measured volume of sample, approximately 1-L, is extracted with methylene chloride using a separatory funnel. The methylene chloride extract is washed with dilute hydrochloric acid to remove free amines, dried, and concentrated to a volume of 10 mL or less. After the extract has been exchanged to methanol, it is separated by gas chromatography and the parameters are then measured with a nitrogen-phosphorus detector. 
                            <SU>4</SU>
                        </P>
                        <P>2.2 The method provides Florisil and alumina column cleanup procedures to separate diphenylamine from the nitrosamines and to aid in the elimination of interferences that may be encountered.</P>
                        <HD SOURCE="HD2">3. Interferences</HD>
                        <P>3.1 Method interferences may be caused by contaminants in solvents, reagents, glassware, and other sample processing hardware that lead to discrete artifacts and/or elevated baselines in gas chromatograms. All of these materials must be routinely demonstrated to be free from interferences under the conditions of the analysis by running laboratory reagent blanks as described in Section 8.1.3.</P>
                        <P>
                            3.1.1 Glassware must be scrupulously cleaned. 
                            <SU>5</SU>
                             Clean all glassware as soon as possible after use by rinsing with the last solvent used in it. Solvent rinsing should be followed by detergent washing with hot water, and rinses with tap water and distilled water. The glassware should then be drained dry, and heated in a muffle furnace at 400 °C for 15 to 30 min. Solvent rinses with acetone and pesticide quality hexane may be substituted for the muffle furnace heating. Volumetric ware should not be heated in a muffle furnace. After drying and cooling, glassware should be sealed and stored in a clean environment to prevent any accumulation of dust or other contaminants. Store inverted or capped with aluminum foil.
                        </P>
                        <P>3.1.2 The use of high purity reagents and solvents helps to minimize interference problems. Purification of solvents by distillation in all-glass systems may be required.</P>
                        <P>3.2 Matrix interferences may be caused by contaminants that are co-extracted from the sample. The extent of matrix interferences will vary considerably from source to source, depending upon the nature and diversity of the industrial complex or municipality being sampled. The cleanup procedures in Section 11 can be used to overcome many of these interferences, but unique samples may require additional cleanup approaches to achieve the MDL listed in Table 1.</P>
                        <P>
                            3.3 N-Nitrosodiphenylamine is reported 
                            <SU>6-9</SU>
                             to undergo transnitrosation reactions. Care must be exercised in the heating or concentrating of solutions containing this compound in the presence of reactive amines.
                        </P>
                        <P>
                            3.4 The sensitive and selective Thermal Energy Analyzer and the reductive Hall detector may be used in place of the nitrogen-phosphorus detector when interferences are encountered. The Thermal Energy Analyzer offers the highest selectivity of the non-MS detectors.
                            <PRTPAGE P="148"/>
                        </P>
                        <HD SOURCE="HD2">4. Safety</HD>
                        <P>
                            4.1 The toxicity or carcinogenicity of each reagent used in this method has not been precisely defined; however, each chemical compound should be treated as a potential health hazard. From this viewpoint, exposure to these chemicals must be reduced to the lowest possible level by whatever means available. The laboratory is responsible for maintaining a current awareness file of OSHA regulations regarding the safe handling of the chemicals specified in this method. A reference file of material data handling sheets should also be made available to all personnel involved in the chemical analysis. Additional references to laboratory safety are available and have been identified 
                            <SU>10-12</SU>
                             for the information of the analyst.
                        </P>
                        <P>
                            4.2 These nitrosamines are known carcinogens, 
                            <SU>13-17</SU>
                             therefore, utmost care must be exercised in the handling of these materials. Nitrosamine reference standards and standard solutions should be handled and prepared in a ventilated glove box within a properly ventilated room.
                        </P>
                        <HD SOURCE="HD2">5. Apparatus and Materials</HD>
                        <P>5.1 Sampling equipment, for discrete or composite sampling.</P>
                        <P>5.1.1 Grab sample bottle—1-L or 1-qt, amber glass, fitted with a screw cap lined with Teflon. Foil may be substituted for Teflon if the sample is not corrosive. If amber bottles are not available, protect samples from light. The bottle and cap liner must be washed, rinsed with acetone or methylene chloride, and dried before use to minimize contamination.</P>
                        <P>5.1.2 Automatic sampler (optional)—The sampler must incorporate glass sample containers for the collection of a minimum of 250 mL of sample. Sample containers must be kept refrigerated at 4 °C and protected from light during compositing. If the sampler uses a peristaltic pump, a minimum length of compressible silicone rubber tubing may be used. Before use, however, the compressible tubing should be thoroughly rinsed with methanol, followed by repeated rinsings with distilled water to minimize the potential for contamination of the sample. An integrating flowmeter is required to collect flow proportional composites.</P>
                        <P>5.2 Glassware (All specifications are suggested. Catalog numbers are included for illustration only.):</P>
                        <P>5.2.1 Separatory funnels—2-L and 250-mL, with Teflon stopcock.</P>
                        <P>5.2.2 Drying column—Chromatographic column, approximately 400 mm long × 19 mm ID, with coarse frit filter disc.</P>
                        <P>5.2.3 Concentrator tube, Kuderna-Danish—10-mL, graduated (Kontes K-570050-1025 or equivalent). Calibration must be checked at the volumes employed in the test. Ground glass stopper is used to prevent evaporation of extracts.</P>
                        <P>5.2.4 Evaporative flask, Kuderna-Danish—500-mL (Kontes K-570001-0500 or equivalent). Attach to concentrator tube with springs.</P>
                        <P>5.2.5 Snyder column, Kuderna-Danish—Three-ball macro (Kontes K-503000-0121 or equivalent).</P>
                        <P>5.2.6 Snyder column, Kuderna-Danish—Two-ball micro (Kontes K-569001-0219 or equivalent).</P>
                        <P>5.2.7 Vials—10 to 15-mL, amber glass, with Teflon-lined screw cap.</P>
                        <P>5.2.8 Chromatographic column—Approximately 400 mm long × 22 mm ID, with Teflon stopcock and coarse frit filter disc at bottom (Kontes K-420540-0234 or equivalent), for use in Florisil column cleanup procedure.</P>
                        <P>5.2.9 Chromatographic column—Approximately 300 mm long × 10 mm ID, with Teflon stopcock and coarse frit filter disc at bottom (Kontes K-420540-0213 or equivalent), for use in alumina column cleanup procedure.</P>
                        <P>5.3 Boiling chips—Approximately 10/40 mesh. Heat to 400 °C for 30 min or Soxhlet extract with methylene chloride.</P>
                        <P>5.4 Water bath—Heated, with concentric ring cover, capable of temperature control (±2 °C). The bath should be used in a hood.</P>
                        <P>5.5 Balance—Analytical, capable of accurately weighing 0.0001 g.</P>
                        <P>5.6 Gas chromatograph—An analytical system complete with gas chromatograph suitable for on-column injection and all required accessories including syringes, analytical columns, gases, detector, and strip-chart recorder. A data system is recommended for measuring peak areas.</P>
                        <P>5.6.1 Column 1—1.8 m long × 4 mm ID glass, packed with 10% Carbowax 20 M/2% KOH on Chromosorb W-AW (80/100 mesh) or equivalent. This column was used to develop the method performance statements in Section 14. Guidelines for the use of alternate column packings are provided in Section 12.2.</P>
                        <P>5.6.2 Column 2—1.8 m long × 4 mm ID glass, packed with 10% SP-2250 on Supel-coport (100/120 mesh) or equivalent.</P>
                        <P>
                            5.6.3 Detector—Nitrogen-phosphorus, reductive Hall, or Thermal Energy Analyzer detector. 
                            <SU>1 2</SU>
                             These detectors have proven effective in the analysis of wastewaters for the parameters listed in the scope (Section 1.1). A nitrogen-phosphorus detector was used to develop the method performance statements in Section 14. Guidelines for the use of alternate detectors are provided in Section 12.2.
                        </P>
                        <HD SOURCE="HD2">6. Reagents</HD>
                        <P>6.1 Reagent water—Reagent water is defined as a water in which an interferent is not observed at the MDL of the parameters of interest.</P>
                        <P>
                            6.2 Sodium hydroxide solution (10 N)—Dissolve 40 g of NaOH (ACS) in reagent water and dilute to 100 ml.
                            <PRTPAGE P="149"/>
                        </P>
                        <P>6.3 Sodium thiosulfate—(ACS) Granular.</P>
                        <P>
                            6.4 Sulfuric acid (1 + 1)—Slowly, add 50 mL of H
                            <E T="52">2</E>
                            SO
                            <E T="52">4</E>
                             (ACS, sp. gr. 1.84) to 50 mL of reagent water.
                        </P>
                        <P>6.5 Sodium sulfate—(ACS) Granular, anhydrous. Purify by heating at 400 °C for 4 h in a shallow tray.</P>
                        <P>6.6 Hydrochloric acid (1 + 9)—Add one volume of concentrated HCl (ACS) to nine volumes of reagent water.</P>
                        <P>6.7 Acetone, methanol, methylene chloride, pentane—Pesticide quality or equivalent.</P>
                        <P>6.8 Ethyl ether—Nanograde, redistilled in glass if necessary.</P>
                        <P>6.8.1 Ethyl ether must be shown to be free of peroxides before it is used as indicated by EM Laboratories Quant test strips. (Available from Scientific Products Co., Cat No. P1126-8, and other suppliers.)</P>
                        <P>6.8.2 Procedures recommended for removal of peroxides are provided with the test strips. After cleanup, 20 mL of ethyl alcohol preservative must be added to each liter of ether.</P>
                        <P>6.9 Florisil—PR grade (60/100 mesh). Purchase activated at 1250 °F and store in the dark in glass containers with ground glass stoppers or foil-lined screw caps. Before use, activate each batch at least 16 h at 130 °C in a foil-covered glass container and allow to cool.</P>
                        <P>6.10 Alumina—Basic activity Super I, W200 series (ICN Life Sciences Group, No. 404571, or equivalent). To prepare for use, place 100 g of alumina into a 500-mL reagent bottle and add 2 mL of reagent water. Mix the alumina preparation thoroughly by shaking or rolling for 10 min and let it stand for at least 2 h. The preparation should be homogeneous before use. Keep the bottle sealed tightly to ensure proper activity.</P>
                        <P>6.11 Stock standard solutions (1.00 µg/µL)—Stock standard solutions can be prepared from pure standard materials or purchased as certified solutions.</P>
                        <P>6.11.1 Prepare stock standard solutions by accurately weighing about 0.0100 g of pure material. Dissolve the material in methanol and dilute to volume in a 10-mL volumetric flask. Larger volumes can be used at the convenience of the analyst. When compound purity is assayed to be 96% or greater, the weight can be used without correction to calculate the concentration of the stock standard. Commercially prepared stock standards can be used at any concentration if they are certified by the manufacturer or by an independent source.</P>
                        <P>6.11.2 Transfer the stock standard solutions into Teflon-sealed screw-cap bottles. Store at 4 °C and protect from light. Stock standard solutions should be checked frequently for signs of degradation or evaporation, especially just prior to preparing calibration standards from them.</P>
                        <P>6.11.3 Stock standard solutions must be replaced after six months, or sooner if comparison with check standards indicates a problem.</P>
                        <P>6.12 Quality control check sample concentrate—See Section 8.2.1.</P>
                        <HD SOURCE="HD2">7. Calibration</HD>
                        <P>7.1 Establish gas chromatographic operating conditions equivalent to those given in Table 1. The gas chromatographic system can be calibrated using the external standard technique (Section 7.2) or the internal standard technique (Section 7.3).</P>
                        <P>7.2 External standard calibration procedure:</P>
                        <P>7.2.1 Prepare calibration standards at a minimum of three concentration levels for each parameter of interest by adding volumes of one or more stock standards to a volumetric flask and diluting to volume with methanol. One of the external standards should be at a concentration near, but above, the MDL (Table 1) and the other concentrations should correspond to the expected range of concentrations found in real samples or should define the working range of the detector.</P>
                        <P>7.2.2 Using injections of 2 to 5 µL, analyze each calibration standard according to Section 12 and tabulate peak height or area responses against the mass injected. The results can be used to prepare a calibration curve for each compound. Alternatively, if the ratio of response to amount injected (calibration factor) is a constant over the working range (&lt;10% relative standard deviation, RSD), linearity through the origin can be assumed and the average ratio or calibration factor can be used in place of a calibration curve.</P>
                        <P>7.3 Internal standard calibration procedure—To use this approach, the analyst must select one or more internal standards that are similar in analytical behavior to the compounds of interest. The analyst must further demonstrate that the measurement of the internal standard is not affected by method or matrix interferences. Because of these limitations, no internal standard can be suggested that is applicable to all samples.</P>
                        <P>
                            7.3.1 Prepare calibration standards at a minimum of three concentration levels for each parameter of interest by adding volumes of one or more stock standards to a volumetric flask. To each calibration standard, add a known constant amount of one or more internal standards, and dilute to volume with methanol. One of the standards should be at a concentration near, but above, the MDL and the other concentrations should correspond to the expected range of concentrations found in real samples or should define the working range of the detector.
                            <PRTPAGE P="150"/>
                        </P>
                        <P>7.3.2 Using injections of 2 to 5 µL, analyze each calibration standard according to Section 12 and tabulate peak height or area responses against concentration for each compound and internal standard. Calculate response factors (RF) for each compound using Equation 1.</P>
                        <HD SOURCE="HD3">
                            RF = (A
                            <E T="52">s</E>
                            )(C
                            <E T="52">is</E>
                             (A
                            <E T="52">is</E>
                            )(C
                            <E T="52">s</E>
                            )
                        </HD>
                        <FP SOURCE="FRP">Equation 1</FP>
                        <FP>where:</FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">s</E>
                             = Response for the parameter to be measured.
                        </FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">is</E>
                             = Response for the internal standard.
                        </FP>
                        <FP SOURCE="FP-2">
                            C
                            <E T="52">is</E>
                             = Concentration of the internal standard (µg/L).
                        </FP>
                        <FP SOURCE="FP-2">
                            C
                            <E T="52">s</E>
                             = Concentration of the parameter to be measured (µg/L).
                        </FP>
                        <P>
                            If the RF value over the working range is a constant (&lt;10% RSD), the RF can be assumed to be invariant and the average RF can be used for calculations. Alternatively, the results can be used to plot a calibration curve of response ratios, A
                            <E T="52">s</E>
                            /A
                            <E T="52">is</E>
                            , vs. RF.
                        </P>
                        <P>7.4 The working calibration curve, calibration factor, or RF must be verified on each working day by the measurement of one or more calibration standards. If the response for any parameter varies from the predicted response by more than ±15%, a new calibration curve must be prepared for that compound.</P>
                        <P>7.5 Before using any cleanup procedure, the analyst must process a series of calibration standards through the procedure to validate elution patterns and the absence of interferences from the reagents.</P>
                        <HD SOURCE="HD2">8. Quality Control</HD>
                        <P>8.1 Each laboratory that uses this method is required to operate a formal quality control program. The minimum requirements of this program consist of an initial demonstration of laboratory capability and an ongoing analysis of spiked samples to evaluate and document data quality. The laboratory must maintain records to document the quality of data that is generated. Ongoing data quality checks are compared with established performance criteria to determine if the results of analyses meet the performance characteristics of the method. When results of sample spikes indicate atypical method performance, a quality control check standard must be analyzed to confirm that the measurements were performed in an in-control mode of operation.</P>
                        <P>8.1.1 The analyst must make an initial, one-time, demonstration of the ability to generate acceptable accuracy and precision with this method. This ability is established as described in Section 8.2.</P>
                        <P>8.1.2 In recognition of advances that are occurring in chromatography, the analyst is permitted certain options (detailed in Sections 10.4, 11.1, and 12.2) to improve the separations or lower the cost of measurements. Each time such a modification is made to the method, the analyst is required to repeat the procedure in Section 8.2.</P>
                        <P>8.1.3 Before processing any samples, the analyst must analyze a reagent water blank to demonstrate that interferences from the analytical system and glassware are under control. Each time a set of samples is extracted or reagents are changed, a reagent water blank must be processed as a safeguard against laboratory contamination.</P>
                        <P>8.1.4 The laboratory must, on an ongoing basis, spike and analyze a minimum of 10% of all samples to monitor and evaluate laboratory data quality. This procedure is described in Section 8.3.</P>
                        <P>8.1.5 The laboratory must, on an ongoing basis, demonstrate through the analyses of quality control check standards that the operation of the measurement system is in control. This procedure is described in Section 8.4. The frequency of the check standard analyses is equivalent to 10% of all samples analyzed but may be reduced if spike recoveries from samples (Section 8.3) meet all specified quality control criteria.</P>
                        <P>8.1.6 The laboratory must maintain performance records to document the quality of data that is generated. This procedure is described in Section 8.5.</P>
                        <P>8.2 To establish the ability to generate acceptable accuracy and precision, the analyst must perform the following operations.</P>
                        <P>8.2.1 A quality control (QC) check sample concentrate is required containing each parameter of interest at a concentration of 20 µg/mL in methanol. The QC check sample concentrate must be obtained from the U.S. Environmental Protection Agency, Environmental Monitoring and Support Laboratory in Cincinnati, Ohio, if available. If not available from that source, the QC check sample concentrate must be obtained from another external source. If not available from either source above, the QC check sample concentrate must be prepared by the laboratory using stock standards prepared independently from those used for calibration.</P>
                        <P>8.2.2 Using a pipet, prepare QC check samples at a concentration of 20 µg/L by adding 1.00 mL of QC check sample concentrate to each of four 1-L aliquots of reagent water.</P>
                        <P>8.2.3 Analyze the well-mixed QC check samples according to the method beginning in Section 10.</P>
                        <P>
                            8.2.4 Calculate the average recovery (X
                            <AC T="8"/>
                            ) in µg/L, and the standard deviation of the recovery (s) in µg/L, for each parameter using the four results.
                        </P>
                        <P>
                            8.2.5 For each parameter compare s and X
                            <AC T="8"/>
                             with the corresponding acceptance criteria for precision and accuracy, respectively, found in Table 2. If s and X
                            <AC T="8"/>
                             for all parameters of interest meet the acceptance criteria, the system performance is acceptable and analysis of actual samples can begin. If 
                            <PRTPAGE P="151"/>
                            any individual s exceeds the precision limit or any individual X
                            <AC T="8"/>
                             falls outside the range for accuracy, the system performance is unacceptable for that parameter. Locate and correct the source of the problem and repeat the test for all parameters of interest beginning with Section 8.2.2.
                        </P>
                        <P>8.3 The laboratory must, on an ongoing basis, spike at least 10% of the samples from each sample site being monitored to assess accuracy. For laboratories analyzing one to ten samples per month, at least one spiked sample per month is required.</P>
                        <P>8.3.1 The concentration of the spike in the sample should be determined as follows:</P>
                        <P>8.3.1.1 If, as in compliance monitoring, the concentration of a specific parameter in the sample is being checked against a regulatory concentration limit, the spike should be at that limit or 1 to 5 times higher than the background concentration determined in Section 8.3.2, whichever concentration would be larger.</P>
                        <P>8.3.1.2 If the concentration of a specific parameter in the sample is not being checked against a limit specific to that parameter, the spike should be at 20 µg/L or 1 to 5 times higher than the background concentration determined in Section 8.3.2, whichever concentration would be larger.</P>
                        <P>8.3.1.3 If it is impractical to determine background levels before spiking (e.g., maximum holding times will be exceeded), the spike concentration should be (1) the regulatory concentration limit, if any; or, if none (2) the larger of either 5 times higher than the expected background concentration or 20 µg/L.</P>
                        <P>8.3.2 Analyze one sample aliquot to determine the background concentration (B) of each parameter. If necessary, prepare a new QC check sample concentrate (Section 8.2.1) appropriate for the background concentrations in the sample. Spike a second sample aliquot with 1.0 mL of the QC check sample concentrate and analyze it to determine the concentration after spiking (A) of each parameter. Calculate each percent recovery (P) as 100(A−B)%/T, where T is the known true value of the spike.</P>
                        <P>
                            8.3.3 Compare the percent recovery (P) for each parameter with the corresponding QC acceptance criteria found in Table 2. These acceptance criteria were caluclated to include an allowance for error in measurement of both the background and spike concentrations, assuming a spike to background ratio of 5:1. This error will be accounted for to the extent that the analyst's spike to background ratio approaches 5:1. 
                            <SU>18</SU>
                             If spiking was performed at a concentration lower than 20 µg/L, the analyst must use either the QC acceptance criteria in Table 2, or optional QC acceptance criteria caluclated for the specific spike concentration. To calculate optional acceptance criteria for the recovery of a parameter: (1) Calculate accuracy (X′) using the equation in Table 3, substituting the spike concentration (T) for C; (2) calculate overall precision (S′) using the equation in Table 3, substituting X′ for X
                            <AC T="8"/>
                            ; (3) calculate the range for recovery at the spike concentration as (100 X′/T) ±2.44(100 S′/T)%. 
                            <SU>18</SU>
                        </P>
                        <P>8.3.4 If any individual P falls outside the designated range for recovery, that parameter has failed the acceptance criteria. A check standard containing each parameter that failed the criteria must be analyzed as described in Section 8.4.</P>
                        <P>8.4 If any parameter fails the acceptance criteria for recovery in Section 8.3, a QC check standard containing each parameter that failed must be prepared and analyzed.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>The frequency for the required analysis of a QC check standard will depend upon the number of parameters being simultaneously tested, the complexity of the sample matrix, and the performance of the laboratory.</P>
                        </NOTE>
                        <P>8.4.1 Prepare the QC check standard by adding 1.0 mL of QC check sample concentrate (Section 8.2.1 or 8.3.2) to 1 L of reagent water. The QC check standard needs only to contain the parameters that failed criteria in the test in Section 8.3.</P>
                        <P>
                            8.4.2 Analyze the QC check standard to determine the concentration measured (A) of each parameter. Calculate each percent recovery (P
                            <E T="52">s</E>
                            ) as 100 (A/T)%, where T is the true value of the standard concentration.
                        </P>
                        <P>
                            8.4.3 Compare the percent recovery (P
                            <E T="52">s</E>
                            ) for each parameter with the corresponding QC acceptance criteria found in Table 2. Only parameters that failed the test in Section 8.3 need to be compared with these criteria. If the recovery of any such parameter falls outside the designated range, the laboratory performance for that parameter is judged to be out of control, and the problem must be immediately identified and corrected. The analytical result for that parameter in the unspiked sample is suspect and may not be reported for regulatory compliance purposes.
                        </P>
                        <P>
                            8.5 As part of the QC program for the laboratory, method accuracy for wastewater samples must be assessed and records must be maintained. After the analysis of five spiked wastewater samples as in Section 8.3, calculate the average percent recovery (P
                            <AC T="8"/>
                            ) and the standard deviation of the percent recovery (s
                            <E T="52">p</E>
                            ). Express the accuracy assessment as a percent recovery interval from P
                            <AC T="8"/>
                            −2s
                            <E T="52">p</E>
                             to P
                            <AC T="8"/>
                             + 2s
                            <E T="52">p</E>
                            . If P
                            <AC T="8"/>
                             = 90% and s
                            <E T="52">p</E>
                             = 10%, for example, the accuracy interval is expressed as 70-110%. Update the accuracy assessment for each parameter on a regular basis (e.g. after each five to ten new accuracy measurements).
                        </P>
                        <P>
                            8.6 It is recommended that the laboratory adopt additional quality assurance practices for use with this method. The specific practices that are most productive depend upon the needs of the laboratory and the nature of 
                            <PRTPAGE P="152"/>
                            the samples. Field duplicates may be analyzed to assess the precision of the environmental measurements. When doubt exists over the identification of a peak on the chromatogram, confirmatory techniques such as gas chromatography with a dissimilar column, specific element detector, or mass spectrometer must be used. Whenever possible, the laboratory should analyze standard reference materials and participate in relevant performance evaluation studies.
                        </P>
                        <HD SOURCE="HD2">9. Sample Collection, Preservation, and Handling</HD>
                        <P>
                            9.1 Grab samples must be collected in glass containers. Conventional sampling practices 
                            <SU>19</SU>
                             should be followed, except that the bottle must not be prerinsed with sample before collection. Composite samples should be collected in refrigerated glass containers in accordance with the requirements of the program. Automatic sampling equipment must be as free as possible of Tygon tubing and other potential sources of contamination.
                        </P>
                        <P>
                            9.2 All samples must be iced or refrigerated at 4 °C from the time of collection until extraction. Fill the sample bottles and, if residual chlorine is present, add 80 mg of sodium thiosulfate per liter of sample and mix well. EPA Methods 330.4 and 330.5 may be used for measurement of residual chlorine. 
                            <SU>20</SU>
                             Field test kits are available for this purpose. If N-nitrosodiphenylamine is to be determined, adjust the sample pH to 7 to 10 with sodium hydroxide solution or sulfuric acid.
                        </P>
                        <P>
                            9.3 All samples must be extracted within 7 days of collection and completely analyzed within 40 days of extraction. 
                            <SU>4</SU>
                        </P>
                        <P>
                            9.4 Nitrosamines are known to be light sensitive. 
                            <SU>7</SU>
                             Samples should be stored in amber or foil-wrapped bottles in order to minimize photolytic decomposition.
                        </P>
                        <HD SOURCE="HD2">10. Sample Extraction</HD>
                        <P>10.1 Mark the water meniscus on the side of the sample bottle for later determination of sample volume. Pour the entire sample into a 2-L separatory funnel. Check the pH of the sample with wide-range pH paper and adjust to within the range of 5 to 9 with sodium hydroxide solution or sulfuric acid.</P>
                        <P>10.2 Add 60 mL of methylene chloride to the sample bottle, seal, and shake 30 s to rinse the inner surface. Transfer the solvent to the separatory funnel and extract the sample by shaking the funnel for 2 min with periodic venting to release excess pressure. Allow the organic layer to separate from the water phase for a minimum of 10 min. If the emulsion interface between layers is more than one-third the volume of the solvent layer, the analyst must employ mechanical techniques to complete the phase separation. The optimum technique depends upon the sample, but may include stirring, filtration of the emulsion through glass wool, centrifugation, or other physical methods. Collect the methylene chloride extract in a 250-mL Erlenmeyer flask.</P>
                        <P>10.3 Add a second 60-mL volume of methylene chloride to the sample bottle and repeat the extraction procedure a second time, combining the extracts in the Erlenmeyer flask. Perform a third extraction in the same manner.</P>
                        <P>10.4 Assemble a Kuderna-Danish (K-D) concentrator by attaching a 10-mL concentrator tube to a 500-mL evaporative flask. Other concentration devices or techniques may be used in place of the K-D concentrator if the requirements of Section 8.2 are met.</P>
                        <P>10.5 Add 10 mL of hydrochloric acid to the combined extracts and shake for 2 min. Allow the layers to separate. Pour the combined extract through a solvent-rinsed drying column containing about 10 cm of anhydrous sodium sulfate, and collect the extract in the K-D concentrator. Rinse the Erlenmeyer flask and column with 20 to 30 mL of methylene chloride to complete the quantitative transfer.</P>
                        <P>10.6 Add one or two clean boiling chips to the evaporative flask and attach a three-ball Snyder column. Prewet the Snyder column by adding about 1 mL of methylene chloride to the top. Place the K-D apparatus on a hot water bath (60 to 65 °C) so that the concentrator tube is partially immersed in the hot water, and the entire lower rounded surface of the flask is bathed with hot vapor. Adjust the vertical position of the apparatus and the water temperature as required to complete the concentration in 15 to 20 min. At the proper rate of distillation the balls of the column will actively chatter but the chambers will not flood with condensed solvent. When the apparent volume of liquid reaches 1 mL, remove the K-D apparatus and allow it to drain and cool for at least 10 min.</P>
                        <P>10.7 Remove the Snyder column and rinse the flask and its lower joint into the concentrator tube with 1 to 2 mL of methylene chloride. A 5-mL syringe is recommended for this operation. Stopper the concentrator tube and store refrigerated if further processing will not be performed immediately. If the extract will be stored longer than two days, it should be transferred to a Teflon-sealed screw-cap vial. If N-nitrosodiphenylamine is to be measured by gas chromatography, the analyst must first use a cleanup column to eliminate diphenylamine interference (Section 11). If N-nitrosodiphenylamine is of no interest, the analyst may proceed directly with gas chromatographic analysis (Section 12).</P>
                        <P>10.8 Determine the original sample volume by refilling the sample bottle to the mark and transferring the liquid to a 1000-</P>
                        <FP>
                            mL graduated cylinder. Record the sample volume to the nearest 5 mL.
                            <PRTPAGE P="153"/>
                        </FP>
                        <HD SOURCE="HD2">11. Cleanup and Separation</HD>
                        <P>11.1 Cleanup procedures may not be necessary for a relatively clean sample matrix. If particular circumstances demand the use of a cleanup procedure, the analyst may use either procedure below or any other appropriate procedure. However, the analyst first must demonstrate that the requirements of Section 8.2 can be met using the method as revised to incorporate the cleanup procedure. Diphenylamine, if present in the original sample extract, must be separated from the nitrosamines if N-nitrosodiphenylamine is to be determined by this method.</P>
                        <P>11.2 If the entire extract is to be cleaned up by one of the following procedures, it must be concentrated to 2.0 mL. To the concentrator tube in Section 10.7, add a clean boiling chip and attach a two-ball micro-Snyder column. Prewet the column by adding about 0.5 mL of methylene chloride to the top. Place the micr-K-D apparatus on a hot water bath (60 to 65 °C) so that the concentrator tube is partially immersed in the hot water. Adjust the vertical position of the apparatus and the water temperature as required to complete the concentration in 5 to 10 min. At the proper rate of distillation the balls of the column will actively chatter but the chambers will not flood. When the apparent volume of liquid reaches about 0.5 mL, remove the K-D apparatus and allow it to drain and cool for at least 10 min. Remove the micro-Snyder column and rinse its lower joint into the concentrator tube with 0.2 mL of methylene chloride. Adjust the final volume to 2.0 mL and proceed with one of the following cleanup procedures.</P>
                        <P>11.3 Florisil column cleanup for nitrosamines:</P>
                        <P>11.3.1 Place 22 g of activated Florisil into a 22-mm ID chromatographic column. Tap the column to settle the Florisil and add about 5 mm of anhydrous sodium sulfate to the top.</P>
                        <P>11.3.2 Preelute the column with 40 mL of ethyl ether/pentane (15 + 85)(V/V). Discard the eluate and just prior to exposure of the sodium sulfate layer to the air, quantitatively transfer the 2-mL sample extract onto the column using an additional 2 mL of pentane to complete the transfer.</P>
                        <P>11.3.3 Elute the column with 90 mL of ethyl ether/pentane (15 + 85)(V/V) and discard the eluate. This fraction will contain the diphenylamine, if it is present in the extract.</P>
                        <P>11.3.4 Next, elute the column with 100 mL of acetone/ethyl ether (5 + 95)(V/V) into a 500-mL K-D flask equipped with a 10-mL concentrator tube. This fraction will contain all of the nitrosamines listed in the scope of the method.</P>
                        <P>11.3.5 Add 15 mL of methanol to the collected fraction and concentrate as in Section 10.6, except use pentane to prewet the column and set the water bath at 70 to 75 °C. When the apparatus is cool, remove the Snyder column and rinse the flask and its lower joint into the concentrator tube with 1 to 2 mL of pentane. Analyze by gas chromatography (Section 12).</P>
                        <P>11.4 Alumina column cleanup for nitrosamines:</P>
                        <P>11.4.1 Place 12 g of the alumina preparation (Section 6.10) into a 10-mm ID chromatographic column. Tap the column to settle the alumina and add 1 to 2 cm of anhydrous sodium sulfate to the top.</P>
                        <P>11.4.2 Preelute the column with 10 mL of ethyl ether/pentane (3 + 7)(V/V). Discard the eluate (about 2 mL) and just prior to exposure of the sodium sulfate layer to the air, quantitatively transfer the 2 mL sample extract onto the column using an additional 2 mL of pentane to complete the transfer.</P>
                        <P>11.4.3 Just prior to exposure of the sodium sulfate layer to the air, add 70 mL of ethyl ether/pentane (3 + 7)(V/V). Discard the first 10 mL of eluate. Collect the remainder of the eluate in a 500-mL K-D flask equipped with a 10 mL concentrator tube. This fraction contains N-nitrosodiphenylamine and probably a small amount of N-nitrosodi-n-propylamine.</P>
                        <P>11.4.4 Next, elute the column with 60 mL of ethyl ether/pentane (1 + 1)(V/V), collecting the eluate in a second K-D flask equipped with a 10-mL concentrator tube. Add 15 mL of methanol to the K-D flask. This fraction will contain N-nitrosodimethylamine, most of the N-nitrosodi-n-propylamine and any diphenylamine that is present.</P>
                        <P>11.4.5 Concentrate both fractions as in Section 10.6, except use pentane to prewet the column. When the apparatus is cool, remove the Snyder column and rinse the flask and its lower joint into the concentrator tube with 1 to 2 mL of pentane. Analyze the fractions by gas chromatography (Section 12).</P>
                        <HD SOURCE="HD2">12. Gas Chromatography</HD>
                        <P>12.1 N-nitrosodiphenylamine completely reacts to form diphenylamine at the normal operating temperatures of a GC injection port (200 to 250 °C). Thus, N-nitrosodiphenylamine is chromatographed and detected as diphenylamine. Accurate determination depends on removal of diphenylamine that may be present in the original extract prior to GC analysis (See Section 11).</P>
                        <P>12.2 Table 1 summarizes the recommended operating conditions for the gas chromatograph. Included in this table are retention times and MDL that can be achieved under these conditions. Examples of the separations achieved by Column 1 are shown in Figures 1 and 2. Other packed or capillary (open-tubular) columns, chromatographic conditions, or detectors may be used if the requirements of Section 8.2 are met.</P>
                        <P>
                            12.3 Calibrate the system daily as described in Section 7.
                            <PRTPAGE P="154"/>
                        </P>
                        <P>12.4 If the extract has not been subjected to one of the cleanup procedures in Section 11, it is necessary to exchange the solvent from methylene chloride to methanol before the thermionic detector can be used. To a 1 to 10-mL volume of methylene chloride extract in a concentrator tube, add 2 mL of methanol and a clean boiling chip. Attach a two-ball micro-Snyder column to the concentrator tube. Prewet the column by adding about 0.5 mL of methylene chloride to the top. Place the micro-K-D apparatus on a boiling (100 °C) water bath so that the concentrator tube is partially immersed in the hot water. Adjust the vertical position of the apparatus and the water temperature as required to complete the concentration in 5 to 10 min. At the proper rate of distillation the balls of the column will actively chatter but the chambers will not flood. When the apparent volume of liquid reaches about 0.5 mL, remove the K-D apparatus and allow it to drain and cool for at least 10 min. Remove the micro-Snyder column and rinse its lower joint into the concentrator tube with 0.2 mL of methanol. Adjust the final volume to 2.0 mL.</P>
                        <P>12.5 If the internal standard calibration procedure is being used, the internal standard must be added to the sample extract and mixed thoroughly immediately before injection into the gas chromatograph.</P>
                        <P>
                            12.6 Inject 2 to 5 µL of the sample extract or standard into the gas chromatograph using the solvent-flush technique. 
                            <SU>21</SU>
                             Smaller (1.0 µL) volumes may be injected if automatic devices are employed. Record the volume injected to the nearest 0.05 µL, and the resulting peak size in area or peak height units.
                        </P>
                        <P>12.7 Identify the parameters in the sample by comparing the retention times of the peaks in the sample chromatogram with those of the peaks in standard chromatograms. The width of the retention time window used to make identifications should be based upon measurements of actual retention time variations of standards over the course of a day. Three times the standard deviation of a retention time for a compound can be used to calculate a suggested window size; however, the experience of the analyst should weigh heavily in the interpretation of chromatograms.</P>
                        <P>12.8 If the response for a peak exceeds the working range of the system, dilute the extract and reanalyze.</P>
                        <P>12.9 If the measurement of the peak response is prevented by the presence of interferences, further cleanup is required.</P>
                        <HD SOURCE="HD2">13. Calculations</HD>
                        <P>13.1 Determine the concentration of individual compounds in the sample.</P>
                        <P>13.1.1 If the external standard calibration procedure is used, calculate the amount of material injected from the peak response using the calibration curve or calibration factor determined in Section 7.2.2. The concentration in the sample can be calculated from Equation 2.</P>
                        <MATH SPAN="1" DEEP="31">
                            <MID>EC15NO91.105</MID>
                        </MATH>
                        <FP SOURCE="FRP0">Equation 2</FP>
                        <FP>where:</FP>
                        <FP SOURCE="FP-2">A = Amount of material injected (ng).</FP>
                        <FP SOURCE="FP-2">
                            V
                            <E T="52">i</E>
                             = Volume of extract injected (µL).
                        </FP>
                        <FP SOURCE="FP-2">
                            V
                            <E T="52">t</E>
                             = Volume of total extract (µL).
                        </FP>
                        <FP SOURCE="FP-2">
                            V
                            <E T="52">s</E>
                             = Volume of water extracted (mL).
                        </FP>
                        <P>13.1.2 If the internal standard calibration procedure is used, calculate the concentration in the sample using the response factor (RF) determined in Section 7.3.2 and Equation 3.</P>
                        <MATH SPAN="1" DEEP="31">
                            <MID>EC15NO91.106</MID>
                        </MATH>
                        <FP SOURCE="FRP0">Equation 3</FP>
                        <FP>where:</FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">s</E>
                             = Response for the parameter to be measured.
                        </FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">is</E>
                             = Response for the internal standard.
                        </FP>
                        <FP SOURCE="FP-2">
                            I
                            <E T="52">s</E>
                             = Amount of internal standard added to each extract (µg).
                        </FP>
                        <FP SOURCE="FP-2">
                            V
                            <E T="52">o</E>
                             = Volume of water extracted (L).
                        </FP>
                        <P>13.2 Report results in µg/L without correction for recovery data. All QC data obtained should be reported with the sample results.</P>
                        <HD SOURCE="HD2">14. Method Performance</HD>
                        <P>
                            14.1 The method detection limit (MDL) is defined as the minimum concentration of a substance that can be measured and reported with 99% confidence that the value is above zero. 
                            <SU>3</SU>
                             The MDL concentrations listed in Table 1 were obtained using reagent water. 
                            <SU>22</SU>
                             Similar results were achieved using representative wastewaters. The MDL actually achieved in a given analysis will vary depending on instrument sensitivity and matrix effects.
                        </P>
                        <P>
                            14.2 This method has been tested for linearity of spike recovery from reagent water and has been demonstrated to be applicable over the concentration range from 4 × MDL to 1000 × MDL. 
                            <SU>22</SU>
                        </P>
                        <P>
                            14.3 This method was tested by 17 laboratories using reagent water, drinking water, surface water, and three industrial wastewaters spiked at six concentrations over the range 0.8 to 55 µg/L. 
                            <SU>23</SU>
                             Single operator precision, overall precision, and method accuracy were found to be directly related to the concentration of the parameter and essentially independent of the sample matrix. Linear equations to describe these relationships are presented in Table 3.
                            <PRTPAGE P="155"/>
                        </P>
                        <HD SOURCE="HD2">References</HD>
                        <P>
                            1. Fine, D.H., Lieb, D., and Rufeh, R. “Principle of Operation of the Thermal Energy Analyzer for the Trace Analysis of Volatile and Non-volatile N-nitroso Compounds,” 
                            <E T="03">Journal of Chromatography, 107,</E>
                             351 (1975).
                        </P>
                        <P>2. Fine, D.H., Hoffman, F., Rounbehler, D.P., and Belcher, N.M. “Analysis of N-nitroso Compounds by Combined High Performance Liquid Chromatography and Thermal Energy Analysis,” Walker, E.A., Bogovski, P. and Griciute, L., Editors, N-nitroso Compounds—Analysis and Formation, Lyon, International Agency for Research on Cancer (IARC Scientific Publications No. 14), pp. 43-50 (1976).</P>
                        <P>3. 40 CFR part 136, appendix B.</P>
                        <P>4. “Determination of Nitrosamines in Industrial and Municipal Wastewaters,” EPA 600/4-82-016, National Technical Information Service, PB82-199621, Springfield, Virginia 22161, April 1982.</P>
                        <P>5. ASTM Annual Book of Standards, Part 31, D3694-78. “Standard Practices for Preparation of Sample Containers and for Preservation of Organic Constituents,” American Society for Testing and Materials, Philadelphia.</P>
                        <P>6. Buglass, A.J., Challis, B.C., and Osborn, M.R. “Transnitrosation and Decomposition of Nitrosamines,” Bogovski, P. and Walker, E.A., Editors, N-nitroso Compounds in the Environment, Lyon, International Agency for Research on Cancer (IARC Scientific Publication No. 9), pp. 94-100 (1974).</P>
                        <P>
                            7. Burgess, E.M., and Lavanish, J.M. “Photochemical Decomposition of N-nitrosamines,” 
                            <E T="03">Tetrahedon Letters,</E>
                             1221 (1964)
                        </P>
                        <P>
                            8. Druckrey, H., Preussmann, R., Ivankovic, S., and Schmahl, D. “Organotrope Carcinogene Wirkungen bei 65 Verschiedenen N-NitrosoVerbindungen an BD-Ratten,” 
                            <E T="03">Z. Krebsforsch.</E>
                            , 
                            <E T="03">69,</E>
                             103 (1967).
                        </P>
                        <P>
                            9. Fiddler, W. “The Occurrence and Determination of N-nitroso Compounds,” 
                            <E T="03">Toxicol. Appl. Pharmacol., 31,</E>
                             352 (1975).
                        </P>
                        <P>10. “Carcinogens—Working With Carcinogens,” Department of Health, Education, and Welfare, Public Health Service, Center for Disease Control, National Institute for Occupational Safety and Health, Publication No. 77-206, August 1977.</P>
                        <P>11. “OSHA Safety and Health Standards, General Industry,” (29 CFR Part 1910), Occupational Safety and Health Administration, OSHA 2206 (Revised, January 1976).</P>
                        <P>12. “Safety in Academic Chemistry Laboratories,” American Chemical Society Publication, Committee on Chemical Safety, 3rd Edition, 1979.</P>
                        <P>
                            13. Lijinsky, W. “How Nitrosamines Cause Cancer,” 
                            <E T="03">New Scientist, 73,</E>
                             216 (1977).
                        </P>
                        <P>
                            14. Mirvish, S.S. “N-Nitroso compounds: Their Chemical and in vivo Formation and Possible Importance as Environmental Carcinogens,” 
                            <E T="03">J. Toxicol. Environ. Health, 3,</E>
                             1267 (1977).
                        </P>
                        <P>15. “Reconnaissance of Environmental Levels of Nitrosamines in the Central United States,” EPA-330/1-77-001, National Enforcement Investigations Center, U.S. Environmental Protection Agency (1977).</P>
                        <P>16. “Atmospheric Nitrosamine Assessment Report,” Office of Air Quality Planning and Standards, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina (1976).</P>
                        <P>17. “Scientific and Technical Assessment Report on Nitrosamines,” EPA-660/6-7-001, Office of Research and Development, U.S. Environmental Protection Agency (1976).</P>
                        <P>
                            18. Provost, L.P., and Elder, R.S. “Interpretation of Percent Recovery Data,” 
                            <E T="03">American Laboratory, 15,</E>
                             58-63 (1983). (The value 2.44 used in the equation in Section 8.3.3 is two times the value of 1.22 derived in this report.)
                        </P>
                        <P>19. ASTM Annual Book of Standards, Part 31, D3370-76. “Standard Practices for Sampling Water,” American Society for Testing and Materials, Philadelphia.</P>
                        <P>20. “Methods 330.4 (Titrimetric, DPD-FAS) and 330.5 (Spectrophotometric, DPD) for Chlorine, Total Residual,” Methods for Chemical Analysis of Water and Wastes, EPA-600/4-79-020, U.S. Environmental Protection Agency, Environmental Monitoring and Support Laboratory, Cincinnati, Ohio 45268, March 1979.</P>
                        <P>
                            21. Burke, J. A. “Gas Chromatography for Pesticide Residue Analysis; Some Practical Aspects,” 
                            <E T="03">Journal of the Association of Official Analytical Chemists, 48,</E>
                             1037 (1965).
                        </P>
                        <P>22. “Method Detection Limit and Analytical Curve Studies EPA Methods 606, 607, and 608,” Special letter report for EPA Contract 68-03-2606, U.S. Environmental Protection Agency, Environmental Monitoring and Support Laboratory, Cincinnati, Ohio 45268, June 1980.</P>
                        <P>23. “EPA Method Study 17 Method 607—Nitrosamines,” EPA 600/4-84-051, National Technical Information Service, PB84-207646, Springfield, Virginia 22161, June 1984.</P>
                        <GPOTABLE COLS="4" OPTS="L2" CDEF="s50,10,10,10">
                            <TTITLE>Table 1—Chromatographic Conditions and Method Detection Limits</TTITLE>
                            <BOXHD>
                                <CHED H="1">Parameter</CHED>
                                <CHED H="1">Retention time (min)</CHED>
                                <CHED H="2">Column 1</CHED>
                                <CHED H="2">Column 2</CHED>
                                <CHED H="1">Method detection limit (µg/L)</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">N-Nitrosodimethylamine</ENT>
                                <ENT>4.1</ENT>
                                <ENT>0.88</ENT>
                                <ENT>0.15</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">N-Nitrosodi-n-propylamine</ENT>
                                <ENT>12.1</ENT>
                                <ENT>4.2</ENT>
                                <ENT>.46</ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="156"/>
                                <ENT I="01">
                                    N-Nitrosodiphenylamine 
                                    <SU>a</SU>
                                </ENT>
                                <ENT>
                                    <SU>b</SU>
                                     12.8
                                </ENT>
                                <ENT>
                                    <SU>c</SU>
                                     6.4
                                </ENT>
                                <ENT>.81</ENT>
                            </ROW>
                            <TNOTE>Column 1 conditions: Chromosorb W-AW (80/100 mesh) coated with 10% Carbowax 20 M/2% KOH packed in a 1.8 m long × 4mm ID glass column with helium carrier gas at 40 mL/min flow rate. Column temperature held isothermal at 110 °C, except where otherwise indicated.</TNOTE>
                            <TNOTE>Column 2 conditions: Supelcoport (100/120 mesh) coated with 10% SP-2250 packed in a 1.8 m long × 4 mm ID glass column with helium carrier gas at 40 mL/min flow rate. Column temperature held isothermal at 120 °C, except where otherwise indicated.</TNOTE>
                            <TNOTE>
                                <SU>a</SU>
                                 Measured as diphenylamine.
                            </TNOTE>
                            <TNOTE>
                                <SU>b</SU>
                                 220 °C column temperature.
                            </TNOTE>
                            <TNOTE>
                                <SU>c</SU>
                                 210 °C column temperature.
                            </TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="5" OPTS="L2" CDEF="s50,10,10,10,10">
                            <TTITLE>Table 2—QC Acceptance Criteria—Method 607</TTITLE>
                            <BOXHD>
                                <CHED H="1">Parameter</CHED>
                                <CHED H="1">Test conc. (µg/L)</CHED>
                                <CHED H="1">Limit for s (µg/L)</CHED>
                                <CHED H="1">
                                    Range for X
                                    <AC T="8"/>
                                     (µg/L)
                                </CHED>
                                <CHED H="1">
                                    Range for P, P
                                    <E T="52">s</E>
                                     (percent)
                                </CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">N-Nitrosodimethylamine</ENT>
                                <ENT>20</ENT>
                                <ENT>3.4</ENT>
                                <ENT>4.6-20.0</ENT>
                                <ENT>13-109</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">N-Nitrosodiphenyl</ENT>
                                <ENT>20</ENT>
                                <ENT>6.1</ENT>
                                <ENT>2.1-24.5</ENT>
                                <ENT>D-139</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">N-Nitrosodi-n-propylamine</ENT>
                                <ENT>20</ENT>
                                <ENT>5.7</ENT>
                                <ENT>11.5-26.8</ENT>
                                <ENT>45-146</ENT>
                            </ROW>
                            <TNOTE>s = Standard deviation for four recovery measurements, in µg/L (Section 8.2.4).</TNOTE>
                            <TNOTE>
                                X
                                <AC T="8"/>
                                 = Average recovery for four recovery measurements, in µg/L (Section 8.2.4).
                            </TNOTE>
                            <TNOTE>
                                P, P
                                <E T="52">s</E>
                                 = Percent recovery measured (Section 8.3.2, Section 8.4.2).
                            </TNOTE>
                            <TNOTE>D = Detected; result must be greater than zero.</TNOTE>
                            <TNOTE>
                                <E T="04">Note:</E>
                                 These criteria are based directly upon the method performance data in Table 3. Where necessary, the limits for recovery have been broadened to assure applicability of the limits to concentrations below those used to develop Table 3.
                            </TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="4" OPTS="L2" CDEF="s50,12,12,12">
                            <TTITLE>Table 3—Method Accuracy and Precision as Functions of Concentration—Method 607</TTITLE>
                            <BOXHD>
                                <CHED H="1">Parameter</CHED>
                                <CHED H="1">Accuracy, as recovery, X′ (µg/L)</CHED>
                                <CHED H="1">
                                    Single analyst precision, s
                                    <E T="52">r</E>
                                    ′ (µg/L)
                                </CHED>
                                <CHED H="1">Overall precision, S′ (µg/L)</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">N-Nitrosodimethylamine</ENT>
                                <ENT>0.37C + 0.06</ENT>
                                <ENT>
                                    0.25X
                                    <AC T="8"/>
                                    −0.04
                                </ENT>
                                <ENT>
                                    0.25X
                                    <AC T="8"/>
                                     + 0.11
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">N-Nitrosodiphenylamine</ENT>
                                <ENT>0.64C + 0.52</ENT>
                                <ENT>
                                    0.36X
                                    <AC T="8"/>
                                    −1.53
                                </ENT>
                                <ENT>
                                    0.46X
                                    <AC T="8"/>
                                    −0.47
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">N-Nitrosodi-n-propylamine</ENT>
                                <ENT>0.96C−0.07</ENT>
                                <ENT>
                                    0.15X
                                    <AC T="8"/>
                                     + 0.13
                                </ENT>
                                <ENT>
                                    0.21X
                                    <AC T="8"/>
                                     + 0.15
                                </ENT>
                            </ROW>
                            <TNOTE>X′ = Expected recovery for one or more measurements of a sample containing a concentration of C, in µg/L.</TNOTE>
                            <TNOTE>
                                s
                                <E T="52">r</E>
                                ′ = Expected single analyst standard deviation of measurements at an average concentration found of X
                                <AC T="8"/>
                                , in µg/L.
                            </TNOTE>
                            <TNOTE>
                                S′ = Expected interlaboratory standard deviation of measurements at an average concentration found of X
                                <AC T="8"/>
                                , in µg/L.
                            </TNOTE>
                            <TNOTE>C = True value for the concentration, in µg/L.</TNOTE>
                            <TNOTE>
                                X
                                <AC T="8"/>
                                 = Average recovery found for measurements of samples containing a concentration of C, in µg/L.
                            </TNOTE>
                        </GPOTABLE>
                        <GPH SPAN="2" DEEP="470">
                            <PRTPAGE P="157"/>
                            <GID>EC02JY92.017</GID>
                        </GPH>
                        <GPH SPAN="2" DEEP="470">
                            <PRTPAGE P="158"/>
                            <GID>EC02JY92.018</GID>
                        </GPH>
                        <PRTPAGE P="159"/>
                        <EAR>Pt. 136, App. A, Meth. 608.3</EAR>
                        <HD SOURCE="HD1">Method 608.3—Organochlorine Pesticides And PCBs By GC/HSD</HD>
                        <HD SOURCE="HD2">1. Scope and Application</HD>
                        <P>1.1 This method is for determination of organochlorine pesticides and polychlorinated biphenyls (PCBs) in industrial discharges and other environmental samples by gas chromatography (GC) combined with a halogen-specific detector (HSD; e.g., electron capture, electrolytic conductivity), as provided under 40 CFR 136.1. This revision is based on a previous protocol (Reference 1), on the revision promulgated October 26, 1984, on an inter-laboratory method validation study (Reference 2), and on EPA Method 1656 (Reference 16). The analytes that may be qualitatively and quantitatively determined using this method and their CAS Registry numbers are listed in Table 1.</P>
                        <P>1.2 This method may be extended to determine the analytes listed in Table 2. However, extraction or gas chromatography challenges for some of these analytes may make quantitative determination difficult.</P>
                        <P>1.3 When this method is used to analyze unfamiliar samples for an analyte listed in Table 1 or Table 2, analyte identification must be supported by at least one additional qualitative technique. This method gives analytical conditions for a second GC column that can be used to confirm and quantify measurements. Additionally, Method 625.1 provides gas chromatograph/mass spectrometer (GC/MS) conditions appropriate for the qualitative confirmation of results for the analytes listed in Tables 1 and 2 using the extract produced by this method, and Method 1699 (Reference 18) provides high resolution GC/MS conditions for qualitative confirmation of results using the original sample. When such methods are used to confirm the identifications of the target analytes, the quantitative results should be derived from the procedure with the calibration range and sensitivity that are most appropriate for the intended application.</P>
                        <P>1.4 The large number of analytes in Tables 1 and 2 makes testing difficult if all analytes are determined simultaneously. Therefore, it is necessary to determine and perform quality control (QC) tests for the “analytes of interest” only. The analytes of interest are those required to be determined by a regulatory/control authority or in a permit, or by a client. If a list of analytes is not specified, the analytes in Table 1 must be determined, at a minimum, and QC testing must be performed for these analytes. The analytes in Table 1 and some of the analytes in Table 2 have been identified as Toxic Pollutants (40 CFR 401.15), expanded to a list of Priority Pollutants (40 CFR part 423, appendix A).</P>
                        <P>1.5 In this revision to Method 608, Chlordane has been listed as the alpha- and gamma- isomers in Table 1. Reporting may be by the individual isomers, or as the sum of the concentrations of these isomers, as requested or required by a regulatory/control authority or in a permit. Technical Chlordane is listed in Table 2 and may be used in cases where historical reporting has only been the Technical Chlordane. Toxaphene and the PCBs have been moved from Table 1 to Table 2 (Additional Analytes) to distinguish these analytes from the analytes required in quality control tests (Table 1). QC acceptance criteria for Toxaphene and the PCBs have been retained in Table 4 and may continue to be applied if desired, or if these analytes are requested or required by a regulatory/control authority or in a permit. Method 1668C (Reference 17) may be useful for determination of PCBs as individual chlorinated biphenyl congeners, and Method 1699 (Reference 18) may be useful for determination of the pesticides listed in this method. However, at the time of writing of this revision, Methods 1668C and 1699 had not been approved for use at 40 CFR part 136.</P>
                        <P>1.6 Method detection limits (MDLs; Reference 3) for the analytes in Tables 1 and some of the analytes in Table 2 are listed in those tables. These MDLs were determined in reagent water (Reference 3). Advances in analytical technology, particularly the use of capillary (open-tubular) columns, allowed laboratories to routinely achieve MDLs for the analytes in this method that are 2-10 times lower than those in the version promulgated in 1984. The MDL for an analyte in a specific wastewater may differ from those listed, depending upon the nature of interferences in the sample matrix.</P>
                        <P>1.6.1 EPA has promulgated this method at 40 CFR part 136 for use in wastewater compliance monitoring under the National Pollutant Discharge Elimination System (NPDES). The data reporting practices described in section 15.6 are focused on such monitoring needs and may not be relevant to other uses of the method.</P>
                        <P>1.6.2 This method includes “reporting limits” based on EPA's “minimum level” (ML) concept (see the glossary in section 23). Tables 1 and 2 contain MDL values and ML values for many of the analytes.</P>
                        <P>1.7 The separatory funnel and continuous liquid-liquid sample extraction and concentration steps in this method are essentially the same as those steps in Methods 606, 609, 611, and 612. Thus, a single sample may be extracted to measure the analytes included in the scope of each of these methods. Samples may also be extracted using a disk-based solid-phase extraction (SPE) procedure developed by the 3M Corporation and approved by EPA as an Alternate Test Procedure (ATP) for wastewater analyses in 1995 (Reference 20).</P>
                        <P>
                            1.8 This method is performance-based. It may be modified to improve performance (e.g., to overcome interferences or improve 
                            <PRTPAGE P="160"/>
                            the accuracy of results) provided all performance requirements are met.
                        </P>
                        <P>1.8.1 Examples of allowed method modifications are described at 40 CFR 136.6. Other examples of allowed modifications specific to this method are described in section 8.1.2.</P>
                        <P>1.8.2 Any modification beyond those expressly permitted at 40 CFR 136.6 or in section 8.1.2 of this method shall be considered a major modification subject to application and approval of an alternate test procedure under 40 CFR 136.4 and 136.5.</P>
                        <P>1.8.3 For regulatory compliance, any modification must be demonstrated to produce results equivalent or superior to results produced by this method when applied to relevant wastewaters (section 8.1.2).</P>
                        <P>1.9 This method is restricted to use by or under the supervision of analysts experienced in the use of GC/HSD. The laboratory must demonstrate the ability to generate acceptable results with this method using the procedure in section 8.2.</P>
                        <P>1.10 Terms and units of measure used in this method are given in the glossary at the end of the method.</P>
                        <HD SOURCE="HD3">2. Summary of Method</HD>
                        <P>2.1 A measured volume of sample, the amount required to meet an MDL or reporting limit (nominally 1-L), is extracted with methylene chloride using a separatory funnel, a continuous liquid/liquid extractor, or disk-based solid-phase extraction equipment. The extract is dried and concentrated for cleanup, if required. After cleanup, or if cleanup is not required, the extract is exchanged into an appropriate solvent and concentrated to the volume necessary to meet the required compliance or detection limit, and analyzed by GC/HSD.</P>
                        <P>2.2 Qualitative identification of an analyte in the extract is performed using the retention times on dissimilar GC columns. Quantitative analysis is performed using the peak areas or peak heights for the analyte on the dissimilar columns with either the external or internal standard technique.</P>
                        <P>2.3 Florisil®, alumina, a C18 solid-phase cleanup, and an elemental sulfur cleanup procedure are provided to aid in elimination of interferences that may be encountered. Other cleanup procedures may be used if demonstrated to be effective for the analytes in a wastewater matrix.</P>
                        <HD SOURCE="HD3">3. Contamination and Interferences</HD>
                        <P>3.1 Solvents, reagents, glassware, and other sample processing lab ware may yield artifacts, elevated baselines, or matrix interferences causing misinterpretation of chromatograms. All materials used in the analysis must be demonstrated free from contamination and interferences by running blanks initially and with each extraction batch (samples started through the extraction process in a given 24-hour period, to a maximum of 20 samples—see Glossary for detailed definition), as described in section 8.5. Specific selection of reagents and purification of solvents by distillation in all-glass systems may be required. Where possible, labware is cleaned by extraction or solvent rinse, or baking in a kiln or oven.</P>
                        <P>3.2 Glassware must be scrupulously cleaned (Reference 4). Clean all glassware as soon as possible after use by rinsing with the last solvent used in it. Solvent rinsing should be followed by detergent washing with hot water, and rinses with tap water and reagent water. The glassware should then be drained dry, and heated at 400 °C for 15-30 minutes. Some thermally stable materials, such as PCBs, may require higher temperatures and longer baking times for removal. Solvent rinses with pesticide quality acetone, hexane, or other solvents may be substituted for heating. Do not heat volumetric labware above 90 °C. After drying and cooling, store inverted or capped with solvent-rinsed or baked aluminum foil in a clean environment to prevent accumulation of dust or other contaminants.</P>
                        <P>3.3 Interferences by phthalate esters can pose a major problem in pesticide analysis when using the electron capture detector. The phthalate esters generally appear in the chromatogram as large late eluting peaks, especially in the 15 and 50% fractions from Florisil®. Common flexible plastics contain varying amounts of phthalates that may be extracted or leached from such materials during laboratory operations. Cross contamination of clean glassware routinely occurs when plastics are handled during extraction steps, especially when solvent-wetted surfaces are handled. Interferences from phthalates can best be minimized by avoiding use of non-fluoropolymer plastics in the laboratory. Exhaustive cleanup of reagents and glassware may be required to eliminate background phthalate contamination (References 5 and 6). Interferences from phthalate esters can be avoided by using a microcoulometric or electrolytic conductivity detector.</P>
                        <P>
                            3.4 Matrix interferences may be caused by contaminants co-extracted from the sample. The extent of matrix interferences will vary considerably from source to source, depending upon the nature and diversity of the industrial complex or municipality being sampled. Interferences extracted from samples high in total organic carbon (TOC) may result in elevated baselines, or by enhancing or suppressing a signal at or near the retention time of an analyte of interest. Analyses of the matrix spike and matrix spike duplicate (Section 8.3) may be useful in identifying matrix interferences, and the cleanup procedures in Section 11 may aid in eliminating these interferences. EPA has provided guidance that may aid in overcoming matrix 
                            <PRTPAGE P="161"/>
                            interferences (Reference 7); however, unique samples may require additional cleanup approaches to achieve the MDLs listed in Tables 1 and 2.
                        </P>
                        <HD SOURCE="HD3">4. Safety</HD>
                        <P>4.1 Hazards associated with each reagent used in this method have not been precisely defined; however, each chemical compound should be treated as a potential health hazard. From this viewpoint, exposure to these chemicals must be reduced to the lowest possible level by whatever means available. The laboratory is responsible for maintaining a current awareness file of OSHA regulations regarding the safe handling of the chemicals specified in this method. A reference file of safety data sheets (SDSs, OSHA, 29 CFR 1910.12009(g)) should also be made available to all personnel involved in sample handling and chemical analysis. Additional references to laboratory safety are available and have been identified (References 8 and 9) for the information of the analyst.</P>
                        <P>4.2 The following analytes covered by this method have been tentatively classified as known or suspected human or mammalian carcinogens: 4,4′-DDT, 4,4′-DDD, the BHCs, and the PCBs. Primary standards of these toxic analytes should be prepared in a chemical fume hood, and a NIOSH/MESA approved toxic gas respirator should be worn when high concentrations are handled.</P>
                        <P>4.3 This method allows the use of hydrogen as a carrier gas in place of helium (section 5.8.2). The laboratory should take the necessary precautions in dealing with hydrogen, and should limit hydrogen flow at the source to prevent buildup of an explosive mixture of hydrogen in air.</P>
                        <HD SOURCE="HD3">5. Apparatus and Materials</HD>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>Brand names and suppliers are for illustration purposes only. No endorsement is implied. Equivalent performance may be achieved using equipment and materials other than those specified here. Demonstrating that the equipment and supplies used in the laboratory achieve the required performance is the responsibility of the laboratory. Suppliers for equipment and materials in this method may be found through an on-line search. Please do not contact EPA for supplier information.</P>
                        </NOTE>
                        <P>5.1 Sampling equipment, for discrete or composite sampling.</P>
                        <P>5.1.1 Grab sample bottle—Amber glass bottle large enough to contain the necessary sample volume (nominally 1 L), fitted with a fluoropolymer-lined screw cap. Foil may be substituted for fluoropolymer if the sample is not corrosive. If amber bottles are not available, protect samples from light. Unless pre-cleaned, the bottle and cap liner must be washed, rinsed with acetone or methylene chloride, and dried before use to minimize contamination.</P>
                        <P>5.1.2 Automatic sampler (optional)—The sampler must use a glass or fluoropolymer container and tubing for sample collection. If the sampler uses a peristaltic pump, a minimum length of compressible silicone rubber tubing may be used. Before use, rinse the compressible tubing thoroughly with methanol, followed by repeated rinsing with reagent water to minimize the potential for sample contamination. An integrating flow meter is required to collect flow proportional composites. The sample container must be kept refrigerated at ≤6 °C and protected from light during compositing.</P>
                        <P>5.2. Lab ware.</P>
                        <P>5.2.1 Extraction.</P>
                        <P>5.2.1.1 pH measurement.</P>
                        <P>5.2.1.1.1 pH meter, with combination glass electrode.</P>
                        <P>5.2.1.1.2 pH paper, wide range (Hydrion Papers, or equivalent).</P>
                        <P>5.2.1.2 Separatory funnel—Size appropriate to hold the sample and extraction solvent volumes, equipped with fluoropolymer stopcock.</P>
                        <P>5.2.1.3 Continuous liquid-liquid extractor—Equipped with fluoropolymer or glass connecting joints and stopcocks requiring no lubrication. (Hershberg-Wolf Extractor, Ace Glass Company, Vineland, NJ, or equivalent.)</P>
                        <P>5.2.1.3.1 Round-bottom flask, 500-mL, with heating mantle.</P>
                        <P>5.2.1.3.2 Condenser, Graham, to fit extractor.</P>
                        <P>5.2.1.4 Solid-phase extractor—90-mm filter apparatus (Figure 2) or multi-position manifold.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>The approved ATP for solid-phase extraction is limited to disk-based extraction media and associated peripheral equipment.</P>
                        </NOTE>
                        <P>5.2.1.4.1 Vacuum system—Capable of achieving 0.1 bar (25 inch) Hg (house vacuum, vacuum pump, or water aspirator), equipped with shutoff valve and vacuum gauge.</P>
                        <P>5.2.1.4.2 Vacuum trap—Made from 500-mL sidearm flask fitted with single-hole rubber stopper and glass tubing.</P>
                        <P>5.2.2 Filtration.</P>
                        <P>5.2.2.1 Glass powder funnel, 125- to 250-mL.</P>
                        <P>5.2.2.2 Filter paper for above, Whatman 41, or equivalent.</P>
                        <P>5.2.2.3 Prefiltering aids—90-mm 1-µm glass fiber filter or Empore® Filter Aid 400.</P>
                        <P>5.2.3 Drying column.</P>
                        <P>5.2.3.1 Chromatographic column—Approximately 400 mm long x 15 mm ID, with fluoropolymer stopcock and coarse frit filter disc (Kontes or equivalent).</P>
                        <P>
                            5.2.3.2 Glass wool—Pyrex, extracted with methylene chloride or baked at 450 °C for 1 hour minimum.
                            <PRTPAGE P="162"/>
                        </P>
                        <P>5.2.4 Column for Florisil® or alumina cleanup—Approximately 300 mm long x 10 mm ID, with fluoropolymer stopcock. (This column is not required if cartridges containing Florisil® are used.)</P>
                        <P>5.2.5 Concentration/evaporation.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>Use of a solvent recovery system with the K-D or other solvent evaporation apparatus is strongly recommended.</P>
                        </NOTE>
                        <P>5.2.5.1 Kuderna-Danish concentrator.</P>
                        <P>5.2.5.1.1 Concentrator tube, Kuderna-Danish—10-mL, graduated (Kontes or equivalent). Calibration must be checked at the volumes employed for extract volume measurement. A ground-glass stopper is used to prevent evaporation of extracts.</P>
                        <P>5.2.5.1.2 Evaporative flask, Kuderna-Danish—500-mL (Kontes or equivalent). Attach to concentrator tube with connectors.</P>
                        <P>5.2.5.1.3 Snyder column, Kuderna/Danish—Three-ball macro (Kontes or equivalent).</P>
                        <P>5.2.5.1.4 Snyder column—Two-ball micro (Kontes or equivalent).</P>
                        <P>5.2.5.1.5 Water bath—Heated, with concentric ring cover, capable of temperature control (±2 °C), installed in a hood using appropriate engineering controls to limit exposure to solvent vapors.</P>
                        <P>5.2.5.2 Nitrogen evaporation device—Equipped with heated bath that can be maintained at an appropriate temperature for the solvent and analytes. (N-Evap, Organomation Associates, Inc., or equivalent).</P>
                        <P>5.2.5.3 Rotary evaporator—Buchi/Brinkman-American Scientific or equivalent, equipped with a variable temperature water bath, vacuum source with shutoff valve at the evaporator, and vacuum gauge.</P>
                        <P>5.2.5.3.1 A recirculating water pump and chiller are recommended, as use of tap water for cooling the evaporator wastes large volumes of water and can lead to inconsistent performance as water temperatures and pressures vary.</P>
                        <P>5.2.5.3.2 Round-bottom flask—100-mL and 500-mL or larger, with ground-glass fitting compatible with the rotary evaporator</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>This equipment is used to prepare copper foil or copper powder for removing sulfur from sample extracts (see Section 6.7.4).</P>
                        </NOTE>
                        <P>5.2.5.4 Automated concentrator—Equipped with glassware sufficient to concentrate 3-400 mL extract to a final volume of 1-10 mL under controlled conditions of temperature and nitrogen flow (Turbovap, or equivalent). Follow manufacturer's directions and requirements.</P>
                        <P>5.2.5.5 Boiling chips—Glass, silicon carbide, or equivalent, approximately 10/40 mesh. Heat at 400 °C for 30 minutes, or solvent rinse or Soxhlet extract with methylene chloride.</P>
                        <P>5.2.6 Solid-phase extraction disks—90-mm extraction disks containing 2 g of 8-µm octadecyl (C18) bonded silica uniformly enmeshed in a matrix of inert PTFE fibrils (3M Empore® or equivalent). The disks should not contain any organic compounds, either from the PTFE or the bonded silica, which will leach into the methylene chloride eluant. One liter of reagent water should pass through the disks in 2-5 minutes, using a vacuum of at least 25 inches of mercury.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>
                                Extraction disks from other manufacturers may be used in this procedure, provided that they use the same solid-phase materials (
                                <E T="03">i.e.,</E>
                                 octadecyl bonded silica). Disks of other diameters also may be used, but may adversely affect the flow rate of the sample through the disk.
                            </P>
                        </NOTE>
                        <P>5.3 Vials.</P>
                        <P>5.3.1 Extract storage—10- to 15-mL, amber glass, with fluoropolymer-lined screw cap.</P>
                        <P>5.3.2 GC autosampler—1- to 5-mL, amber glass, with fluoropolymer-lined screw- or crimp-cap, to fit GC autosampler.</P>
                        <P>5.4 Balances.</P>
                        <P>5.4.1 Analytical—Capable of accurately weighing 0.1 mg.</P>
                        <P>5.4.2 Top loading—Capable of weighing 10 mg.</P>
                        <P>5.5 Sample cleanup.</P>
                        <P>5.5.1 Oven—For baking and storage of adsorbents, capable of maintaining a constant temperature (±5 °C) in the range of 105-250 °C.</P>
                        <P>5.5.2 Muffle furnace—Capable of cleaning glassware or baking sodium sulfate in the range of 400-450 °C.</P>
                        <P>5.5.3 Vacuum system and cartridges for solid-phase cleanup (see Section 11.2).</P>
                        <P>5.5.3.1 Vacuum system—Capable of achieving 0.1 bar (25 in.) Hg (house vacuum, vacuum pump, or water aspirator), equipped with shutoff valve and vacuum gauge.</P>
                        <P>5.5.3.2 VacElute Manifold (Analytichem International, or equivalent).</P>
                        <P>5.5.3.3 Vacuum trap—Made from 500-mL sidearm flask fitted with single-hole rubber stopper and glass tubing.</P>
                        <P>5.5.3.4 Rack for holding 50-mL volumetric flasks in the manifold.</P>
                        <P>5.5.3.5 Cartridge—Mega Bond Elute, Non-polar, C18 Octadecyl, 10 g/60 mL (Analytichem International or equivalent), used for solid-phase cleanup of sample extracts (see Section 11.2).</P>
                        <P>5.5.4 Sulfur removal tube—40- to 50-mL bottle, test tube, or Erlenmeyer flask with fluoropolymer-lined screw cap.</P>
                        <P>5.6 Centrifuge apparatus.</P>
                        <P>5.6.1 Centrifuge—Capable of rotating 500-mL centrifuge bottles or 15-mL centrifuge tubes at 5,000 rpm minimum.</P>
                        <P>5.6.2 Centrifuge bottle—500-mL, with screw cap, to fit centrifuge.</P>
                        <P>5.6.3 Centrifuge tube—15-mL, with screw cap, to fit centrifuge.</P>
                        <P>
                            5.7 Miscellaneous lab ware—Graduated cylinders, pipettes, beakers, volumetric flasks, vials, syringes, and other lab ware 
                            <PRTPAGE P="163"/>
                            necessary to support the operations in this method.
                        </P>
                        <P>5.8 Gas chromatograph—Dual-column with simultaneous split/splitless, temperature programmable split/splitless (PTV), or on-column injection; temperature program with isothermal holds, and all required accessories including syringes, analytical columns, gases, and detectors. An autosampler is highly recommended because it injects volumes more reproducibly than manual injection techniques. Alternatively, two separate single-column gas chromatographic systems may be employed.</P>
                        <P>5.8.1 Example columns and operating conditions.</P>
                        <P>5.8.1.1 DB-608 (or equivalent), 30-m long x 0.53-mm ID fused-silica capillary, 0.83-µm film thickness.</P>
                        <P>5.8.1.2 DB-1701 (or equivalent), 30-m long x 0.53-mm ID fused-silica capillary, 1.0-µm film thickness.</P>
                        <P>5.8.1.3 Suggested operating conditions used to meet the retention times shown in Table 3 are:</P>
                        <P>(a) Carrier gas flow rate: Approximately 7 mL/min,</P>
                        <P>(b) Initial temperature: 150 °C for 0.5 minute,</P>
                        <P>(c) Temperature program: 150-270 °C at 5 °C/min, and</P>
                        <P>
                            (d) Final temperature: 270 °C, until 
                            <E T="03">trans</E>
                            -Permethrin elutes.
                        </P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>Other columns, internal diameters, film thicknesses, and operating conditions may be used, provided that the performance requirements in this method are met. However, the column pair chosen must have dissimilar phases/chemical properties in order to separate the compounds of interest in different retention time order. Columns that only differ in the length, ID, or film thickness, but use the same stationary phase do not qualify as “dissimilar.”</P>
                        </NOTE>
                        <P>5.8.2 Carrier gas—Helium or hydrogen. Data in the tables in this method were obtained using helium carrier gas. If hydrogen is used, analytical conditions may need to be adjusted for optimum performance, and calibration and all QC tests must be performed with hydrogen carrier gas. See Section 4.3 for precautions regarding the use of hydrogen as a carrier gas.</P>
                        <P>5.8.3 Detector—Halogen-specific detector (electron capture detector [ECD], electrolytic conductivity detector [ELCD], or equivalent). The ECD has proven effective in the analysis of wastewaters for the analytes listed in Tables 1 and 2, and was used to develop the method performance data in Section 17 and Tables 4 and 5.</P>
                        <P>5.8.4 Data system—A computer system must be interfaced to the GC that allows continuous acquisition and storage of data from the detectors throughout the chromatographic program. The computer must have software that allows searching GC data for specific analytes, and for plotting responses versus time. Software must also be available that allows integrating peak areas or peak heights in selected retention time windows and calculating concentrations of the analytes.</P>
                        <HD SOURCE="HD3">6. Reagents and Standards</HD>
                        <P>6.1 pH adjustment.</P>
                        <P>6.1.1 Sodium hydroxide solutions.</P>
                        <P>6.1.1.1 Concentrated (10 M)—Dissolve 40 g of NaOH (ACS) in reagent water and dilute to 100 mL.</P>
                        <P>6.1.1.2 Dilute (1 M)—Dissolve 40 g NaOH in 1 L of reagent water.</P>
                        <P>
                            6.1.2 Sulfuric acid (1+1)—Slowly add 50 mL of H
                            <E T="52">2</E>
                            SO
                            <E T="52">4</E>
                             (ACS, sp. gr. 1.84) to 50 mL of reagent water.
                        </P>
                        <P>6.1.3 Hydrochloric acid—Reagent grade, 6 N.</P>
                        <P>6.2 Sodium thiosulfate—(ACS) granular.</P>
                        <P>6.3 Sodium sulfate—Sodium sulfate, reagent grade, granular anhydrous (Baker or equivalent), rinsed with methylene chloride, baked in a shallow tray at 450 °C for 1 hour minimum, cooled in a desiccator, and stored in a pre-cleaned glass bottle with screw cap which prevents moisture from entering. If, after heating, the sodium sulfate develops a noticeable grayish cast (due to the presence of carbon in the crystal matrix), that batch of reagent is not suitable for use and should be discarded. Extraction with methylene chloride (as opposed to simple rinsing) and baking at a lower temperature may produce sodium sulfate suitable for use.</P>
                        <P>6.4 Reagent water—Reagent water is defined as water in which the analytes of interest and interfering compounds are not observed at the MDLs of the analytes in this method.</P>
                        <P>6.5 Solvents—Methylene chloride, acetone, methanol, hexane, acetonitrile, and isooctane, high purity pesticide quality, or equivalent, demonstrated to be free of the analytes and interferences (section 3). Purification of solvents by distillation in all-glass systems may be required.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>The standards and final sample extracts must be prepared in the same final solvent.</P>
                        </NOTE>
                        <P>6.6 Ethyl ether—Nanograde, redistilled in glass if necessary. Ethyl ether must be shown to be free of peroxides before use, as indicated by EM Laboratories Quant test strips (available from Scientific Products Co. and other suppliers). Procedures recommended for removal of peroxides are provided with the test strips. After removal of peroxides, add 20 mL of ethyl alcohol preservative to each liter of ether.</P>
                        <P>6.7 Materials for sample cleanup.</P>
                        <P>
                            6.7.1 Florisil®—PR grade (60/100 mesh), activated at 650-700 °C, stored in the dark in a glass container with fluoropolymer-lined 
                            <PRTPAGE P="164"/>
                            screw cap. Activate each batch immediately prior to use for 16 hours minimum at 130 °C in a foil-covered glass container and allow to cool. Alternatively, 500 mg cartridges (J.T. Baker, or equivalent) may be used.
                        </P>
                        <P>6.7.1.1 Cartridge certification—Each cartridge lot must be certified to ensure recovery of the analytes of interest and removal of 2,4,6-trichlorophenol. To make the test mixture, add the trichlorophenol solution (section 6.7.1.3) to the same standard used to prepare the Quality Control Check Sample (section 6.8.3). Transfer the mixture to the column and dry the column. Pre-elute with three 10-mL portions of elution solvent, drying the column between elutions. Elute the cartridge with 10 mL each of methanol and water, as in section 11.2.3.3.</P>
                        <P>6.7.1.2 Concentrate the eluant to per section 10.3.3, exchange to isooctane or hexane per section 10.3.3, and inject 1.0 µL of the concentrated eluant into the GC using the procedure in section 12. The recovery of all analytes (including the unresolved GC peaks) shall be within the ranges for calibration verification (section 13.6 and Table 4), the recovery of trichlorophenol shall be less than 5%, and no peaks interfering with the target analytes shall be detected. Otherwise the Florisil cartridge is not performing properly and the cartridge lot shall be rejected.</P>
                        <P>6.7.1.3 Florisil cartridge calibration solution—2,4,6-Trichlorophenol, 0.1 µg/mL in acetone.</P>
                        <P>6.7.2 SPE elution solvent—Methylene chloride:acetonitrile:hexane (50:3:47).</P>
                        <P>6.7.3 Alumina, neutral, Brockman Activity I, 80-200 mesh (Fisher Scientific certified, or equivalent). Heat in a glass bottle for 16 hours at 400 to 450 °C. Seal and cool to room temperature. Add 7% (w/w) reagent water and mix for 10 to 12 hours. Keep bottle tightly sealed.</P>
                        <P>6.7.4 Sulfur removal.</P>
                        <P>6.7.4.1 Copper foil or powder—Fisher, Alfa Aesar, or equivalent. Cut copper foil into approximately 1-cm squares. Copper must be activated before it may be used, as described below.</P>
                        <P>6.7.4.1.1 Place the quantity of copper needed for sulfur removal (section 11.5.1.3) in a ground-glass-stoppered Erlenmeyer flask or bottle. Cover the foil or powder with methanol.</P>
                        <P>6.7.4.1.2 Add HCl dropwise (0.5-1.0 mL) while swirling, until the copper brightens.</P>
                        <P>6.7.4.1.3 Pour off the methanol/HCl and rinse 3 times with reagent water to remove all traces of acid, then 3 times with acetone, then 3 times with hexane.</P>
                        <P>6.7.4.1.4 For copper foil, cover with hexane after the final rinse. Store in a stoppered flask under nitrogen until used. For the powder, dry on a rotary evaporator. Store in a stoppered flask under nitrogen until used. Inspect the copper foil or powder before each use. It must have a bright, non-oxidized appearance to be effective. Copper foil or powder that has oxidized may be reactivated using the procedure described above.</P>
                        <P>6.7.4.2 Tetrabutylammonium sulfite (TBA sulfite)—Prepare as described below.</P>
                        <P>
                            6.7.4.2.1 Tetrabutylammonium hydrogen sulfate, [CH
                            <E T="52">3</E>
                            (CH
                            <E T="52">2</E>
                            )
                            <E T="52">3</E>
                            ]
                            <E T="52">4</E>
                            NHSO
                            <E T="52">4.</E>
                        </P>
                        <P>
                            6.7.4.2.2 Sodium sulfite, Na
                            <E T="52">2</E>
                            SO
                            <E T="52">3.</E>
                        </P>
                        <P>6.7.4.2.3 Dissolve approximately 3 g tetrabutylammonium hydrogen sulfate in 100 mL of reagent water in an amber bottle with fluoropolymer-lined screw cap. Extract with three 20-mL portions of hexane and discard the hexane extracts.</P>
                        <P>6.7.4.2.4 Add 25 g sodium sulfite to produce a saturated solution. Store at room temperature. Replace after 1 month.</P>
                        <P>6.7.5 Sodium chloride—Reagent grade, prepare at 5% (w/v) solution in reagent water.</P>
                        <P>6.8 Stock standard solutions—Stock standard solutions may be prepared from pure materials, or purchased as certified solutions. Traceability must be to the National Institute of Standards and Technology (NIST) or other national or international standard, when available. Stock solution concentrations alternative to those below may be used. Because of the toxicity of some of the compounds, primary dilutions should be prepared in a hood, and a NIOSH/MESA approved toxic gas respirator should be worn when high concentrations of neat materials are handled. The following procedure may be used to prepare standards from neat materials.</P>
                        <P>6.8.1 Accurately weigh about 0.0100 g of pure material in a 10-mL volumetric flask. Dilute to volume in pesticide quality hexane, isooctane, or other suitable solvent. Larger volumes may be used at the convenience of the laboratory. When compound purity is assayed to be 96% or greater, the weight may be used without correction to calculate the concentration of the stock standard. Commercially prepared stock standards may be used at any concentration if they are certified by the manufacturer or by an independent source.</P>
                        <P>6.8.1.1 Unless stated otherwise in this method, store non-aqueous standards in fluoropolymer-lined screw-cap, or heat-sealed, glass containers, in the dark at −20 to −10 °C. Store aqueous standards; e.g., the aqueous LCS (section 8.4), in the dark at ≤6 °C, but do not freeze.</P>
                        <P>
                            6.8.1.2 Standards prepared by the laboratory may be stored for up to one year, except when comparison with QC check standards indicates that a standard has degraded or become more concentrated due to evaporation, or unless the laboratory has data on file to prove stability for a longer period. Commercially prepared standards may be stored until the expiration date provided by the vendor, except when comparison with QC check standards indicates that a standard 
                            <PRTPAGE P="165"/>
                            has degraded or become more concentrated due to evaporation, or unless the laboratory has data from the vendor on file to prove stability for a longer period.
                        </P>
                        <P>6.8.2 Calibration solutions—It is necessary to prepare calibration solutions for the analytes of interest (section 1.4) only using an appropriate solvent (isooctane or hexane may be used). Whatever solvent is used, both the calibration standards and the final sample extracts must use the same solvent. Other analytes may be included as desired.</P>
                        <P>
                            6.8.2.1 Prepare calibration standards for the single-component analytes of interest and surrogates at a minimum of three concentration levels (five are suggested) by adding appropriate volumes of one or more stock standards to volumetric flasks. One of the calibration standards should be at a concentration at or below the ML specified in Table 1, or 2, or as specified by a regulatory/control authority or in a permit. The ML value may be rounded to a whole number that is more convenient for preparing the standard, but must not exceed the ML value listed in Tables 1 or 2 for those analytes which list ML values. Alternatively, the laboratory may establish an ML for each analyte based on the concentration of the lowest calibration standard in a series of standards produced by the laboratory or obtained from a commercial vendor, again, provided that the ML does not exceed the ML in Table 1 and 2, and provided that the resulting calibration meets the acceptance criteria in section 7.5.2 based on the RSD, RSE, or R
                            <SU>2</SU>
                            .
                        </P>
                        <P>
                            (a) The other concentrations should correspond to the expected range of concentrations found in real samples or should define the working range of the GC system. A minimum of six concentration levels is required for a second order, non-linear (e.g., quadratic; ax
                            <SU>2</SU>
                             + bx + c = 0) calibration (section 7.5.2 or 7.6.2). Calibrations higher than second order are not allowed. A separate standard near the MDL may be analyzed as a check on sensitivity, but should not be included in the linearity assessment. The solvent for the standards must match the final solvent for the sample extracts (e.g., isooctane or hexane).
                        </P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>The option for non-linear calibration may be necessary to address specific instrumental techniques. However, it is not EPA's intent to allow non-linear calibration to be used to compensate for detector saturation or to avoid proper instrument maintenance.</P>
                        </NOTE>
                        <P>(b) Given the number of analytes included in this method, it is highly likely that some will coelute on one or both of the GC columns used for the analysis. Divide the analytes into two or more groups and prepare separate calibration standards for each group, at multiple concentrations (e.g., a five-point calibration will require ten solutions to cover two groups of analytes). Table 7 provides information on dividing the target analytes into separate calibration mixtures that should minimize or eliminate co-elutions. This table is provided solely as guidance, based on the GC columns suggested in this method. If an analyte listed in Table 7 is not an analyte of interest in a given laboratory setting, then it need not be included in a calibration mixture.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>Many commercially available standards are divided into separate mixtures to address this issue.</P>
                        </NOTE>
                        <P>(c) If co-elutions occur in analysis of a sample, a co-elution on one column is acceptable so long as effective separation of the co-eluting compounds can be achieved on the second column.</P>
                        <P>6.8.2.2 Multi-component analytes (e.g., PCBs as Aroclors, and Toxaphene).</P>
                        <P>6.8.2.2.1 A standard containing a mixture of Aroclor 1016 and Aroclor 1260 will include many of the peaks represented in the other Aroclor mixtures. As a result, a multi-point initial calibration employing a mixture of Aroclors 1016 and 1260 at three to five concentrations should be sufficient to demonstrate the linearity of the detector response without the necessity of performing multi-point initial calibrations for each of the seven Aroclors. In addition, such a mixture can be used as a standard to demonstrate that a sample does not contain peaks that represent any one of the Aroclors. This standard can also be used to determine the concentrations of either Aroclor 1016 or Aroclor 1260, should they be present in a sample. Therefore, prepare a minimum of three calibration standards containing equal concentrations of both Aroclor 1016 and Aroclor 1260 by dilution of the stock standard with isooctane or hexane. The concentrations should correspond to the expected range of concentrations found in real samples and should bracket the linear range of the detector.</P>
                        <P>6.8.2.2.2 Single standards of each of the other five Aroclors are required to aid the analyst in pattern recognition. Assuming that the Aroclor 1016/1260 standards described in Section 6.8.2.2.1 have been used to demonstrate the linearity of the detector, these single standards of the remaining five Aroclors also may be used to determine the calibration factor for each Aroclor. Prepare a standard for each of the other Aroclors. The concentrations should generally correspond to the mid-point of the linear range of the detector, but lower concentrations may be employed at the discretion of the analyst based on project requirements.</P>
                        <P>
                            6.8.2.2.3 For Toxaphene, prepare a minimum of three calibration standards containing Toxaphene by dilution of the stock 
                            <PRTPAGE P="166"/>
                            standard with isooctane or hexane. The concentrations should correspond to the expected range of concentrations found in real samples and should bracket the linear range of the detector.
                        </P>
                        <P>6.8.3 Quality Control (QC) Check Sample Concentrate—Prepare one or more mid-level standard mixtures (concentrates) in acetone (or other water miscible solvent). The concentrate is used as the spiking solution with which to prepare the Demonstration of Capabilities (DOC) samples, the Laboratory Control Sample (LCS), and Matrix Spike (MS) and Matrix Spike Duplicate (MSD) samples described in section 8. If prepared by the laboratory (as opposed the purchasing it from a commercial supplier), the concentrate must be prepared independently from the standards used for calibration, but may be prepared from the same source as the second-source standard used for calibration verification (section 7.7). Regardless of the source, the concentrate must be in a water-miscible solvent, as noted above. The concentrate is used to prepare the DOC and LCS (sections 8.2.1 and 8.4) and MS/MSD samples (section 8.3). Depending on the analytes of interest for a given sample (see Section 1.4), multiple solutions and multiple LCS or MS/MSD samples may be required to account for co-eluting analytes. However, a co-elution on one column is acceptable so long as effective separation of the co-eluting compounds can be achieved on the second column. In addition, the concentrations of the MS/MSD samples should reflect any relevant compliance limits for the analytes of interest, as described in section 8.3.1. If a custom spiking solution is required for a specific discharge (section 8.3.1), prepare it separately from the DOC and LCS solution.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>Some commercially available standards are divided into separate mixtures to address the co-elution issue.</P>
                        </NOTE>
                        <P>6.8.4 Calibration Verification Standards—In order to verify the results of the initial calibration standards, prepare one or more mid-level standard mixtures in isooctane or hexane, using standards obtained from a second source (different manufacturer or different certified lot from the calibration standards). These standards will be analyzed to verify the accuracy of the calibration (sections 7.7 and 13.6.2). As with the QC sample concentrate in section 6.8.3, multiple solutions may be required to address co-elutions among all of the analytes.</P>
                        <P>
                            6.8.5 Internal standard solution—If the internal standard calibration technique is to be used, prepare pentachloronitrobenzene (PCNB) at a concentration of 10 µg/mL in ethyl acetate. Alternative and multiple internal standards; e.g., tetrachloro-
                            <E T="03">m</E>
                            -xylene, 4,4′-dibromobiphenyl, and/or decachlorobiphenyl may be used provided that the laboratory performs all QC tests and meets all QC acceptance criteria with the alternative or additional internal standard(s) as an integral part of this method.
                        </P>
                        <P>
                            6.8.6 Surrogate solution—Prepare a solution containing one or more surrogates at a concentration of 2 µg/mL in acetone. Potential surrogates include: dibutyl chlorendate (DBC), tetrachloro-
                            <E T="03">m</E>
                            -xylene (TCMX), 4,4′-dibromobiphenyl, or decachlorobiphenyl. Alternative surrogates and concentrations may be used, provided the laboratory performs all QC tests and meets all QC acceptance criteria with the alternative surrogate(s) as an integral part of this method. If the internal standard calibration technique is used, do not use the internal standard as a surrogate.
                        </P>
                        <P>6.8.7 DDT and endrin decomposition (breakdown) solution—Prepare a solution containing endrin at a concentration of 50 ng/mL and 4,4'-DDT at a concentration of 100 ng/mL, in isooctane or hexane. A 1-µL injection of this standard will contain 50 picograms (pg) of endrin and 100 pg of DDT. The concentration of the solution may be adjusted by the laboratory to accommodate other injection volumes such that the same masses of the two analytes are introduced into the instrument.</P>
                        <HD SOURCE="HD3">7. Calibration</HD>
                        <P>7.1 Establish gas chromatographic operating conditions equivalent to those in Section 5.8.1 and Footnote 2 to Table 3. Alternative temperature program and flow rate conditions may be used. The system may be calibrated using the external standard technique (section 7.5) or the internal standard technique (section 7.6). It is necessary to calibrate the system for the analytes of interest (section 1.4) only.</P>
                        <P>7.2 Separately inject the mid-level calibration standard for each calibration mixture. Store the retention time on each GC column.</P>
                        <P>7.3 Injection of calibration solutions—Inject a constant volume in the range of 0.5 to 2.0 µL of each calibration solution into the GC column/detector pairs. An alternative volume (see Section 12.3) may be used provided all requirements in this method are met. Beginning with the lowest level mixture and proceeding to the highest level mixture may limit the risk of carryover from one standard to the next, but other sequences may be used. An instrument blank should be analyzed after the highest standard to demonstrate that there is no carry-over within the system for this calibration range.</P>
                        <P>
                            7.4 For each analyte, compute, record, and store, as a function of the concentration injected, the retention time and peak area on each column/detector system. If multi-component analytes are to be analyzed, store the retention time and peak area for the three to five exclusive (unique large) peaks 
                            <PRTPAGE P="167"/>
                            for each PCB or technical chlordane. Use four to six peaks for toxaphene.
                        </P>
                        <P>7.5 External standard calibration.</P>
                        <P>7.5.1 From the calibration data (Section 7.4), calculate the calibration factor (CF) for each analyte at each concentration according to the following equation:</P>
                        <GPH SPAN="2" DEEP="28">
                            <GID>ER28AU17.000</GID>
                        </GPH>
                        <FP SOURCE="FP-2">Where:</FP>
                        <FP SOURCE="FP-2">
                            C
                            <E T="52">s</E>
                             = Concentration of the analyte in the standard (ng/mL)
                        </FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">s</E>
                             = Peak height or area
                        </FP>
                        <P>For multi-component analytes, choose a series of characteristic peaks for each analyte (3 to 5 for each Aroclor, 4 to 6 for toxaphene) and calculate individual calibration factors for each peak. Alternatively, for toxaphene, sum the areas of all of the peaks in the standard chromatogram and use the summed area to determine the calibration factor. (If this alternative is used, the same approach must be used to quantitate the analyte in the samples.)</P>
                        <P>
                            7.5.2 Calculate the mean (average) and relative standard deviation (RSD) of the calibration factors. If the RSD is less than 20%, linearity through the origin can be assumed and the average CF can be used for calculations. Alternatively, the results can be used to fit a linear or quadratic regression of response, A
                            <E T="52">s</E>
                            , vs. concentration C
                            <E T="52">s</E>
                            . If used, the regression must be weighted inversely proportional to concentration. The coefficient of determination (R
                            <SU>2</SU>
                            ) of the weighted regression must be greater than 0.920. Alternatively, the relative standard error (Reference 10) may be used as an acceptance criterion. As with the RSD, the RSE must be less than 20%. If an RSE less than 20% cannot be achieved for a quadratic regression, system performance is unacceptable and the system must be adjusted and re-calibrated.
                        </P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>Regression calculations are not included in this method because the calculations are cumbersome and because many GC/ECD data systems allow selection of weighted regression for calibration and calculation of analyte concentrations.</P>
                        </NOTE>
                        <P>7.6 Internal standard calibration.</P>
                        <P>7.6.1 From the calibration data (Section 7.4), calculate the response factor (RF) for each analyte at each concentration according to the following equation:</P>
                        <GPH SPAN="2" DEEP="29">
                            <GID>ER28AU17.001</GID>
                        </GPH>
                        <FP SOURCE="FP-2">Where:</FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">s</E>
                             = Response for the analyte to be measured.
                        </FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">is</E>
                             = Response for the internal standard.
                        </FP>
                        <FP SOURCE="FP-2">
                            C
                            <E T="52">is</E>
                             = Concentration of the internal standard (ng/mL)
                        </FP>
                        <FP SOURCE="FP-2">
                            C
                            <E T="52">s</E>
                             = Concentration of the analyte to be measured (ng/mL).
                        </FP>
                        <P>
                            7.6.2 Calculate the mean (average) and relative standard deviation (RSD) of the response factors. If the RSD is less than 15%, linearity through the origin can be assumed and the average RF can be used for calculations. Alternatively, the results can be used to prepare a calibration curve of response ratios, A
                            <E T="52">s</E>
                            /A
                            <E T="52">is</E>
                            , vs. concentration ratios, C
                            <E T="52">s</E>
                            /C
                            <E T="52">is</E>
                            , for the analyte. A minimum of six concentration levels is required for a non-linear (e.g., quadratic) regression. If used, the regression must be weighted inversely proportional to concentration, and the coefficient of determination of the weighted regression must be greater than 0.920. Alternatively, the relative standard error (Reference 10) may be used as an acceptance criterion. As with the RSD, the RSE must be less than 15%. If an RSE less than 15% cannot be achieved for a quadratic regression, system performance is unacceptable and the system must be adjusted and re-calibrated.
                        </P>
                        <P>
                            7.7 The working calibration curve, CF, or RF must be verified immediately after calibration and at the beginning and end of each 24-hour shift by the analysis of a mid-level calibration standard. The calibration verification standard(s) must be obtained from a second manufacturer or a manufacturer's batch prepared independently from the batch used for calibration (Section 6.8.4). Requirements for calibration verification are given in Section 13.6 and Table 4. Alternatively, calibration verification may be performed after a set number of injections 
                            <PRTPAGE P="168"/>
                            (e.g., every 20 injections), to include injection of extracts of field samples, QC samples, instrument blanks, etc. (
                            <E T="03">i.e.,</E>
                             it is based on the number of injections performed, not sample extracts). The time for the injections may not exceed 24 hours.
                        </P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>The 24-hour shift begins after analysis of the combined QC standard (calibration verification) and ends 24 hours later. The ending calibration verification standard is run immediately after the last sample run during the 24-hour shift, so the beginning and ending calibration verifications are outside of the 24-hour shift. If calibration verification is based on the number of injections instead of time, then the ending verification standard for one group of injections may be used as the beginning verification for the next group of injections.</P>
                        </NOTE>
                        <P>7.8 Florisil® calibration—The column cleanup procedure in Section 11.3 utilizes Florisil column chromatography. Florisil® from different batches or sources may vary in adsorptive capacity. To standardize the amount of Florisil® which is used, use of the lauric acid value (Reference 11) is suggested. The referenced procedure determines the adsorption from a hexane solution of lauric acid (mg) per g of Florisil®. The amount of Florisil® to be used for each column is calculated by dividing 110 by this ratio and multiplying by 20 g. If cartridges containing Florisil® are used, then this step is not necessary.</P>
                        <HD SOURCE="HD3">8. Quality Control</HD>
                        <P>8.1 Each laboratory that uses this method is required to operate a formal quality assurance program. The minimum requirements of this program consist of an initial demonstration of laboratory capability and ongoing analysis of spiked samples and blanks to evaluate and document data quality. The laboratory must maintain records to document the quality of data generated. Ongoing data quality checks are compared with established performance criteria to determine if the results of analyses meet performance requirements of this method. A quality control check standard (LCS, section 8.4) must be prepared and analyzed with each batch of samples to confirm that the measurements were performed in an in-control mode of operation. A laboratory may develop its own performance criteria (as QC acceptance criteria), provided such criteria are as or more restrictive than the criteria in this method.</P>
                        <P>8.1.1 The laboratory must make an initial demonstration of the capability (IDC) to generate acceptable precision and recovery with this method. This demonstration is detailed in Section 8.2. On a continuing basis, the laboratory must repeat demonstration of capability (DOC) at least annually.</P>
                        <P>8.1.2 In recognition of advances that are occurring in analytical technology, and to overcome matrix interferences, the laboratory is permitted certain options (section 1.8 and 40 CFR 136.6(b) [Reference 12]) to improve separations or lower the costs of measurements. These options may include alternative extraction (e.g., other solid-phase extraction materials and formats), concentration, and cleanup procedures, and changes in GC columns (Reference 12). Alternative determinative techniques, such as the substitution of spectroscopic or immunoassay techniques, and changes that degrade method performance, are not allowed. If an analytical technique other than the techniques specified in this method is used, that technique must have a specificity equal to or greater than the specificity of the techniques in this method for the analytes of interest. The laboratory is also encouraged to participate in performance evaluation studies (see section 8.8).</P>
                        <P>8.1.2.1 Each time a modification listed above is made to this method, the laboratory is required to repeat the procedure in section 8.2. If the detection limit of the method will be affected by the change, the laboratory is required to demonstrate that the MDLs (40 CFR part 136, appendix B) are lower than one-third the regulatory compliance limit or as low as the MDLs in this method, whichever are greater. If calibration will be affected by the change, the instrument must be recalibrated per section 7. Once the modification is demonstrated to produce results equivalent or superior to results produced by this method as written, that modification may be used routinely thereafter, so long as the other requirements in this method are met (e.g., matrix spike/matrix spike duplicate recovery and relative percent difference).</P>
                        <P>
                            8.1.2.1.1 If an allowed method modification, is to be applied to a specific discharge, the laboratory must prepare and analyze matrix spike/matrix spike duplicate (MS/MSD) samples (section 8.3) and LCS samples (section 8.4). The laboratory must include surrogates (Section 8.7) in each of the samples. The MS/MSD and LCS samples must be fortified with the analytes of interest (section 1.4). If the modification is for nationwide use, MS/MSD samples must be prepared from a minimum of nine different discharges (See section 8.1.2.1.2), and all QC acceptance criteria in this method must be met. This evaluation only needs to be performed once other than for the routine QC required by this method (for example it could be performed by the vendor of an alternative material) but any laboratory using that specific material must have the results of the study available. This includes a full data package with the raw data that will allow an independent reviewer to verify each determination and calculation performed by the laboratory (see section 8.1.2.2.5, items (a)-(q)).
                            <PRTPAGE P="169"/>
                        </P>
                        <P>8.1.2.1.2 Sample matrices on which MS/MSD tests must be performed for nationwide use of an allowed modification:</P>
                        <P>(a) Effluent from a publicly owned treatment works (POTW).</P>
                        <P>(b) ASTM D5905 Standard Specification for Substitute Wastewater.</P>
                        <P>(c) Sewage sludge, if sewage sludge will be in the permit.</P>
                        <P>(d) ASTM D1141 Standard Specification for Substitute Ocean Water, if ocean water will be in the permit.</P>
                        <P>
                            (e) Untreated and treated wastewaters up to a total of nine matrix types (see 
                            <E T="03">https://www.epa.gov/eg/industrial-effluent-guidelines</E>
                             for a list of industrial categories with existing effluent guidelines).
                        </P>
                        <P>(i) At least one of the above wastewater matrix types must have at least one of the following characteristics:</P>
                        <P>(A) Total suspended solids greater than 40 mg/L.</P>
                        <P>(B) Total dissolved solids greater than 100 mg/L.</P>
                        <P>(C) Oil and grease greater than 20 mg/L.</P>
                        <P>(D) NaCl greater than 120 mg/L.</P>
                        <P>
                            (E) CaCO
                            <E T="52">3</E>
                             greater than 140 mg/L.
                        </P>
                        <P>(ii) The interim acceptance criteria for MS, MSD recoveries that do not have recovery limits in Table 4 or developed in section 8.3.3, and for surrogates that do not have recovery limits developed in section 8.6, must be no wider than 60-140%, and the relative percent difference (RPD) of the concentrations in the MS and MSD that do not have RPD limits in Table 4 or developed in section 8.3.3, must be less than 30%. Alternatively, the laboratory may use the laboratory's in-house limits if they are tighter.</P>
                        <P>(f) A proficiency testing (PT) sample from a recognized provider, in addition to tests of the nine matrices (section 8.1.2.1.1).</P>
                        <P>8.1.2.2 The laboratory must maintain records of modifications made to this method. These records include the following, at a minimum:</P>
                        <P>8.1.2.2.1 The names, titles, and business street addresses, telephone numbers, and email addresses, of the analyst(s) that performed the analyses and modification, and of the quality control officer that witnessed and will verify the analyses and modifications.</P>
                        <P>8.1.2.2.2 A list of analytes, by name and CAS Registry number.</P>
                        <P>8.1.2.2.3 A narrative stating reason(s) for the modifications.</P>
                        <P>8.1.2.2.4 Results from all quality control (QC) tests comparing the modified method to this method, including:</P>
                        <P>(a) Calibration (section 7).</P>
                        <P>(b) Calibration verification (section 13.6).</P>
                        <P>(c) Initial demonstration of capability (section 8.2).</P>
                        <P>(d) Analysis of blanks (section 8.5).</P>
                        <P>(e) Matrix spike/matrix spike duplicate analysis (section 8.3).</P>
                        <P>(f) Laboratory control sample analysis (section 8.4).</P>
                        <P>8.1.2.2.5 Data that will allow an independent reviewer to validate each determination by tracing the instrument output (peak height, area, or other signal) to the final result. These data are to include:</P>
                        <P>(a) Sample numbers and other identifiers.</P>
                        <P>(b) Extraction dates.</P>
                        <P>(c) Analysis dates and times.</P>
                        <P>(d) Analysis sequence/run chronology.</P>
                        <P>(e) Sample weight or volume (section 10).</P>
                        <P>(f) Extract volume prior to each cleanup step (sections 10 and 11).</P>
                        <P>(g) Extract volume after each cleanup step (section 11).</P>
                        <P>(h) Final extract volume prior to injection (sections 10 and 12).</P>
                        <P>(i) Injection volume (sections 12.3 and 13.2).</P>
                        <P>(j) Sample or extract dilution (section 15.4).</P>
                        <P>(k) Instrument and operating conditions.</P>
                        <P>(l) Column (dimensions, material, etc.).</P>
                        <P>(m) Operating conditions (temperatures, flow rates, etc.).</P>
                        <P>(n) Detector (type, operating conditions, etc.).</P>
                        <P>(o) Chromatograms and other recordings of raw data.</P>
                        <P>(p) Quantitation reports, data system outputs, and other data to link the raw data to the results reported.</P>
                        <P>(q) A written Standard Operating Procedure (SOP).</P>
                        <P>8.1.2.2.6 Each individual laboratory wishing to use a given modification must perform the start-up tests in section 8.1.2 (e.g., DOC, MDL), with the modification as an integral part of this method prior to applying the modification to specific discharges. Results of the DOC must meet the QC acceptance criteria in Table 5 for the analytes of interest (section 1.4), and the MDLs must be equal to or lower than the MDLs in Tables 1 and 2 for the analytes of interest.</P>
                        <P>8.1.3 Before analyzing samples, the laboratory must analyze a blank to demonstrate that interferences from the analytical system, lab ware, and reagents, are under control. Each time a batch of samples is extracted or reagents are changed, a blank must be extracted and analyzed as a safeguard against laboratory contamination. Requirements for the blank are given in section 8.5.</P>
                        <P>8.1.4 The laboratory must, on an ongoing basis, spike and analyze samples to monitor and evaluate method and laboratory performance on the sample matrix. The procedure for spiking and analysis is given in section 8.3.</P>
                        <P>
                            8.1.5 The laboratory must, on an ongoing basis, demonstrate through analysis of a quality control check sample (laboratory control sample, LCS; on-going precision and 
                            <PRTPAGE P="170"/>
                            recovery sample, OPR) that the measurement system is in control. This procedure is described in Section 8.4.
                        </P>
                        <P>8.1.6 The laboratory should maintain performance records to document the quality of data that is generated. This procedure is given in section 8.7.</P>
                        <P>8.1.7 The large number of analytes tested in performance tests in this method present a substantial probability that one or more will fail acceptance criteria when all analytes are tested simultaneously, and a re-test (reanalysis) is allowed if this situation should occur. If, however, continued re-testing results in further repeated failures, the laboratory should document the failures and either avoid reporting results for the analytes that failed or report the problem and failures with the data. A QC failure does not relieve a discharger or permittee of reporting timely results.</P>
                        <P>8.2 Demonstration of capability (DOC)—To establish the ability to generate acceptable recovery and precision, the laboratory must perform the DOC in sections 8.2.1 through 8.2.6 for the analytes of interest initially and in an on-going manner at least annually. The laboratory must also establish MDLs for the analytes of interest using the MDL procedure at 40 CFR part 136, appendix B. The laboratory's MDLs must be equal to or lower than those listed in Tables 1 or 2, or lower than one-third the regulatory compliance limit, whichever is greater. For MDLs not listed in Tables 1 or 2, the laboratory must determine the MDLs using the MDL procedure at 40 CFR part 136, appendix B under the same conditions used to determine the MDLs for the analytes listed in Tables 1 and 2. When analyzing the PCBs as Aroclors, it is only necessary to establish an MDL for one of the multi-component analytes (e.g., PCB 1254), or the mixture of Aroclors 1016 and 1260 may be used to establish MDLs for all of the Aroclors. Similarly, MDLs for other multi-component analytes (e.g., Chlordanes) may be determined using only one of the major components. All procedures used in the analysis, including cleanup procedures, must be included in the DOC.</P>
                        <P>8.2.1 For the DOC, a QC check sample concentrate containing each analyte of interest (section 1.4) is prepared in a water-miscible solvent using the solution in section 6.8.3.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>QC check sample concentrates are no longer available from EPA.</P>
                        </NOTE>
                        <P>8.2.2 Using a pipet or syringe, prepare four QC check samples by adding an appropriate volume of the concentrate and of the surrogate(s) to each of four 1-L aliquots of reagent water. Swirl or stir to mix.</P>
                        <P>8.2.3 Extract and analyze the well-mixed QC check samples according to the method beginning in section 10.</P>
                        <P>
                            8.2.4 Calculate the average percent recovery (
                            <E T="7501">X</E>
                            ) and the standard deviation (s) of the percent recovery for each analyte using the four results.
                        </P>
                        <P>
                            8.2.5 For each analyte, compare s and 
                            <E T="7501">X</E>
                             with the corresponding acceptance criteria for precision and recovery in Table 4. For analytes in Table 2 that are not listed in Table 4, QC acceptance criteria must be developed by the laboratory. EPA has provided guidance for development of QC acceptance criteria (References 12 and 13). If s and 
                            <E T="7501">X</E>
                             for all analytes of interest meet the acceptance criteria, system performance is acceptable and analysis of blanks and samples can begin. If any individual s exceeds the precision limit or any individual 
                            <E T="7501">X</E>
                             falls outside the range for recovery, system performance is unacceptable for that analyte.
                        </P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>The large number of analytes in Tables 1 and 2 present a substantial probability that one or more will fail at least one of the acceptance criteria when many or all analytes are determined simultaneously.</P>
                        </NOTE>
                        <P>8.2.6 When one or more of the analytes tested fail at least one of the acceptance criteria, repeat the test for only the analytes that failed. If results for these analytes pass, system performance is acceptable and analysis of samples and blanks may proceed. If one or more of the analytes again fail, system performance is unacceptable for the analytes that failed the acceptance criteria. Correct the problem and repeat the test (section 8.2). See section 8.1.7 for disposition of repeated failures.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>To maintain the validity of the test and re-test, system maintenance and/or adjustment is not permitted between this pair of tests.</P>
                        </NOTE>
                        <P>8.3 Matrix spike and matrix spike duplicate (MS/MSD)—The purpose of the MS/MSD requirement is to provide data that demonstrate the effectiveness of the method as applied to the samples in question by a given laboratory, and both the data user (discharger, permittee, regulated entity, regulatory/control authority, customer, other) and the laboratory share responsibility for provision of such data. The data user should identify the sample and the analytes of interest (section 1.4) to be spiked and provide sufficient sample volume to perform MS/MSD analyses. The laboratory must, on an ongoing basis, spike at least 5% of the samples in duplicate from each discharge being monitored to assess accuracy (recovery and precision). If direction cannot be obtained from the data user, the laboratory must spike at least one sample in duplicate per extraction batch of up to 20 samples with the analytes in Table 1. Spiked sample results should be reported only to the data user whose sample was spiked, or as requested or required by a regulatory/control authority, or in a permit.</P>
                        <P>
                            8.3.1. If, as in compliance monitoring, the concentration of a specific analyte will be 
                            <PRTPAGE P="171"/>
                            checked against a regulatory concentration limit, the concentration of the spike should be at that limit; otherwise, the concentration of the spike should be one to five times higher than the background concentration determined in section 8.3.2, at or near the midpoint of the calibration range, or at the concentration in the LCS (section 8.4) whichever concentration would be larger. When no information is available, the mid-point of the calibration may be used.
                        </P>
                        <P>
                            8.3.2 Analyze one sample aliquot to determine the background concentration (B) of the each analyte of interest. If necessary to meet the requirement in section 8.3.1, prepare a new check sample concentrate (section 8.2.1) appropriate for the background concentration. Spike and analyze two additional sample aliquots of the same volume as the original sample, and determine the concentrations after spiking (A
                            <E T="52">1</E>
                             and A
                            <E T="52">2</E>
                            ) of each analyte. Calculate the percent recoveries (P
                            <E T="52">1</E>
                             and P
                            <E T="52">2</E>
                            ) as:
                        </P>
                        <GPH SPAN="2" DEEP="25">
                            <GID>ER28AU17.002</GID>
                        </GPH>
                        <FP>where T is the known true value of the spike.</FP>
                        <P>
                            Also calculate the relative percent difference (RPD) between the concentrations (A
                            <E T="52">1</E>
                             and A
                            <E T="52">2</E>
                            ):
                        </P>
                        <GPH SPAN="2" DEEP="38">
                            <GID>ER28AU17.003</GID>
                        </GPH>
                        <P>
                            8.3.3 Compare the percent recoveries (P
                            <E T="52">1</E>
                             and P
                            <E T="52">2</E>
                            ) and the RPD for each analyte in the MS/MSD aliquots with the corresponding QC acceptance criteria for recovery (P) and RPD in Table 4.
                        </P>
                        <P>(a) If any individual P falls outside the designated range for recovery in either aliquot, or the RPD limit is exceeded, the result for the analyte in the unspiked sample is suspect and may not be reported or used for permitting or regulatory compliance. See section 8.1.7 for disposition of failures.</P>
                        <P>(b) For analytes in Table 2 not listed in Table 4, QC acceptance criteria must be developed by the laboratory. EPA has provided guidance for development of QC acceptance criteria (References 12 and 13).</P>
                        <P>8.3.4 After analysis of a minimum of 20 MS/MSD samples for each target analyte and surrogate, and if the laboratory chooses to develop and apply optional in-house QC limits, the laboratory should calculate and apply the optional in-house QC limits for recovery and RPD of future MS/MSD samples (Section 8.3). The optional in-house QC limits for recovery are calculated as the mean observed recovery ±3 standard deviations, and the upper QC limit for RPD is calculated as the mean RPD plus 3 standard deviations of the RPDs. The in-house QC limits must be updated at least every two years and re-established after any major change in the analytical instrumentation or process. At least 80% of the analytes tested in the MS/MSD must have in-house QC acceptance criteria that are tighter than those in Table 4 and the remaining analytes (those not included in the 80%) must meet the acceptance criteria in Table 4. If an in-house QC limit for the RPD is greater than the limit in Table 4, then the limit in Table 4 must be used. Similarly, if an in-house lower limit for recovery is below the lower limit in Table 4, then the lower limit in Table 4 must be used, and if an in-house upper limit for recovery is above the upper limit in Table 4, then the upper limit in Table 4 must be used. The laboratory must evaluate surrogate recovery data in each sample against its in-house surrogate recovery limits. The laboratory may use 60 -140% as interim acceptance criteria for surrogate recoveries until in-house limits are developed. Alternatively, surrogate recovery limits may be developed from laboratory control charts. In-house QC acceptance criteria must be updated at least every two years.</P>
                        <P>
                            8.4 Laboratory control sample (LCS)—A QC check sample (laboratory control sample, LCS; on-going precision and recovery sample, OPR) containing each single-component analyte of interest (section 1.4) must be extracted, concentrated, and analyzed with each extraction batch of up to 20 samples (section 3.1) to demonstrate acceptable recovery of the analytes of interest from a 
                            <PRTPAGE P="172"/>
                            clean sample matrix. If multi-peak analytes are required, extract and prepare at least one as an LCS for each batch. Alternatively, the laboratory may set up a program where multi-peak LCS is rotated with a single-peak LCS.
                        </P>
                        <P>8.4.1 Prepare the LCS by adding QC check sample concentrate (sections 6.8.3 and 8.2.1) to reagent water. Include all analytes of interest (section 1.4) in the LCS. The volume of reagent water must be the same as the nominal volume used for the sample, the DOC (Section 8.2), the blank (section 8.5), and the MS/MSD (section 8.3). Also add a volume of the surrogate solution (section 6.8.6).</P>
                        <P>8.4.2 Analyze the LCS prior to analysis of samples in the extraction batch (Section 3.1). Determine the concentration (A) of each analyte. Calculate the percent recovery as:</P>
                        <GPH SPAN="2" DEEP="25">
                            <GID>ER28AU17.004</GID>
                        </GPH>
                        <FP>where T is the true value of the concentration in the LCS.</FP>
                        <P>8.4.3 For each analyte, compare the percent recovery (P) with its corresponding QC acceptance criterion in Table 4. For analytes of interest in Table 2 not listed in Table 4, use the QC acceptance criteria developed for the MS/MSD (section 8.3.3.2), or limits based on laboratory control charts. If the recoveries for all analytes of interest fall within the designated ranges, analysis of blanks and field samples may proceed. If any individual recovery falls outside the range, proceed according to section 8.4.4.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>The large number of analytes in Tables 1 and 2 present a substantial probability that one or more will fail the acceptance criteria when all analytes are tested simultaneously. Because a re-test is allowed in event of failure (sections 8.1.7 and 8.4.4), it may be prudent to extract and analyze two LCSs together and evaluate results of the second analysis against the QC acceptance criteria only if an analyte fails the first test.</P>
                        </NOTE>
                        <P>8.4.4 Repeat the test only for those analytes that failed to meet the acceptance criteria (P). If these analytes now pass, system performance is acceptable and analysis of blanks and samples may proceed. Repeated failure, however, will confirm a general problem with the measurement system. If this occurs, repeat the test using a fresh LCS (section 8.2.1) or an LCS prepared with a fresh QC check sample concentrate (section 8.2.1), or perform and document system repair. Subsequent to analysis of the LCS prepared with a fresh sample concentrate, or to system repair, repeat the LCS test (Section 8.4). If failure of the LCS indicates a systemic problem with samples in the batch, re-extract and re-analyze the samples in the batch. See Section 8.1.7 for disposition of repeated failures.</P>
                        <P>8.4.5 After analysis of 20 LCS samples, and if the laboratory chooses to develop and apply optional in-house QC limits, the laboratory should calculate and apply the optional in-house QC limits for recovery of future LCS samples (section 8.4). Limits for recovery in the LCS should be calculated as the mean recovery ±3 standard deviations. A minimum of 80% of the analytes tested for in the LCS must have QC acceptance criteria tighter than those in Table 4, and the remaining analytes (those not included in the 80%) must meet the acceptance criteria in Table 4. If an in-house lower limit for recovery is lower than the lower limit in Table 4, the lower limit in Table 4 must be used, and if an in-house upper limit for recovery is higher than the upper limit in Table 4, the upper limit in Table 4 must be used. Many of the analytes and surrogates do not contain acceptance criteria. The laboratory should use 60-140% as interim acceptance criteria for recoveries of spiked analytes and surrogates that do not have recovery limits specified in Table 4, and at least 80% of the surrogates must meet the 60-140% interim criteria until in-house LCS and surrogate limits are developed. Alternatively, acceptance criteria for analytes that do not have recovery limits in Table 4 may be based on laboratory control charts. In-house QC acceptance criteria must be updated at least every two years.</P>
                        <P>8.5 Blank—Extract and analyze a blank with each extraction batch (section 3.1) to demonstrate that the reagents and equipment used for preparation and analysis are free from contamination.</P>
                        <P>8.5.1 Prepare the blank from reagent water and spike it with the surrogates. The volume of reagent water must be the same as the volume used for samples, the DOC (section 8.2), the LCS (section 8.4), and the MS/MSD (section 8.3). Extract, concentrate, and analyze the blank using the same procedures and reagents used for the samples, LCS, and MS/MSD in the batch. Analyze the blank immediately after analysis of the LCS (section 8.4) and prior to analysis of the MS/MSD and samples to demonstrate freedom from contamination.</P>
                        <P>
                            8.5.2 If any analyte of interest is found in the blank at a concentration greater than the MDL for the analyte, at a concentration 
                            <PRTPAGE P="173"/>
                            greater than one-third the regulatory compliance limit, or at a concentration greater than one-tenth the concentration in a sample in the batch (section 3.1), whichever is greatest, analysis of samples must be halted and samples in the batch must be re-extracted and the extracts reanalyzed. Samples in a batch must be associated with an uncontaminated blank before the results for those samples may be reported or used for permitting or regulatory compliance purposes. If re-testing of blanks results in repeated failures, the laboratory should document the failures and report the problem and failures with the data.
                        </P>
                        <P>8.6 Surrogate recovery—The laboratory must spike all samples with the surrogate standard spiking solution (section 6.8.6) per section 10.2.2 or 10.4.2, analyze the samples, and calculate the percent recovery of each surrogate. QC acceptance criteria for surrogates must be developed by the laboratory (section 8.4). If any recovery fails its criterion, attempt to find and correct the cause of the failure, and if sufficient volume is available, re-extract another aliquot of the affected sample; otherwise, see section 8.1.7 for disposition of repeated failures.</P>
                        <P>
                            8.7 As part of the QC program for the laboratory, it is suggested but not required that method accuracy for wastewater samples be assessed and records maintained. After analysis of five or more spiked wastewater samples as in Section 8.3, calculate the average percent recovery (
                            <E T="7501">X</E>
                            ) and the standard deviation of the percent recovery (sp). Express the accuracy assessment as a percent interval from 
                            <E T="7501">X</E>
                            −2sp to 
                            <E T="7501">X</E>
                            +2sp. For example, if 
                            <E T="7501">X</E>
                             = 90% and sp = 10%, the accuracy interval is expressed as 70-110%. Update the accuracy assessment for each analyte on a regular basis to ensure process control (e.g., after each 5-10 new accuracy measurements). If desired, statements of accuracy for laboratory performance, independent of performance on samples, may be developed using LCSs.
                        </P>
                        <P>8.8 It is recommended that the laboratory adopt additional quality assurance practices for use with this method. The specific practices that are most productive depend upon the needs of the laboratory and the nature of the samples. Field duplicates may be analyzed to assess the precision of environmental measurements. When doubt exists over the identification of a peak on the chromatogram, confirmatory techniques such as gas chromatography with another dissimilar column, specific element detector, or mass spectrometer must be used. Whenever possible, the laboratory should analyze standard reference materials and participate in relevant performance evaluation studies.</P>
                        <HD SOURCE="HD3">9. Sample Collection, Preservation, and Handling</HD>
                        <P>9.1 Collect samples as grab samples in glass bottles, or in refrigerated bottles using automatic sampling equipment. Collect 1-L of ambient waters, effluents, and other aqueous samples. If high concentrations of the analytes of interest are expected (e.g., for untreated effluents or in-process waters), collect a smaller volume (e.g., 250 mL), but not less than 100 mL, in addition to the 1-L sample. Follow conventional sampling practices, except do not pre-rinse the bottle with sample before collection. Automatic sampling equipment must be as free as possible of polyvinyl chloride or other tubing or other potential sources of contamination. If needed, collect additional sample(s) for the MS/MSD (section 8.3).</P>
                        <P>9.2 Ice or refrigerate the sample at ≤6 °C from the time of collection until extraction, but do not freeze. If aldrin is to be determined and residual chlorine is present, add 80 mg/L of sodium thiosulfate but do not add excess. Any method suitable for field use may be employed to test for residual chlorine (Reference 14). If sodium thiosulfate interferes in the determination of the analytes, an alternative preservative (e.g., ascorbic acid or sodium sulfite) may be used.</P>
                        <P>9.3 Extract all samples within seven days of collection and completely analyze within 40 days of extraction (Reference 1). If the sample will not be extracted within 72 hours of collection, adjust the sample pH to a range of 5.0-9.0 with sodium hydroxide solution or sulfuric acid. Record the volume of acid or base used.</P>
                        <HD SOURCE="HD3">10. Sample Extraction</HD>
                        <P>10.1 This section contains procedures for separatory funnel liquid-liquid extraction (SFLLE, section 10.2), continuous liquid-liquid extraction (CLLE, section 10.4), and disk-based solid-phase extraction (SPE, section 10.5). SFLLE is faster, but may not be as effective as CLLE for extracting polar analytes. SFLLE is labor intensive and may result in formation of emulsions that are difficult to break. CLLE is less labor intensive, avoids emulsion formation, but requires more time (18-24 hours), more hood space, and may require more solvent. SPE can be faster, unless the particulate load in an aqueous sample is so high that it slows the filtration process. If an alternative extraction scheme to those detailed in this method is used, all QC tests must be performed and all QC acceptance criteria must be met with that extraction scheme as an integral part of this method.</P>
                        <P>10.2 Separatory funnel liquid-liquid extraction (SFLLE).</P>
                        <P>
                            10.2.1 The SFLLE procedure below assumes a sample volume of 1 L. When a different sample volume is extracted, adjust the volume of methylene chloride accordingly.
                            <PRTPAGE P="174"/>
                        </P>
                        <P>10.2.2 Mark the water meniscus on the side of the sample bottle for later determination of sample volume. Pour the entire sample into the separatory funnel. Pipet the surrogate standard spiking solution (section 6.8.6) into the separatory funnel. If the sample will be used for the LCS or MS or MSD, pipet the appropriate QC check sample concentrate (section 8.3 or 8.4) into the separatory funnel. Mix well. If the sample arrives in a larger sample bottle, 1 L may be measured in a graduated cylinder, then added to the separatory funnel.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>Instances in which the sample is collected in an oversized bottle should be reported by the laboratory to the data user. Of particular concern is that fact that this practice precludes rinsing the empty bottle with solvent as described below, which could leave hydrophobic pesticides on the wall of the bottle, and underestimate the actual sample concentrations.</P>
                        </NOTE>
                        <P>10.2.3 Add 60 mL of methylene chloride to the sample bottle, seal, and shake for 30 seconds to rinse the inner surface. Transfer the solvent to the separatory funnel and extract the sample by shaking the funnel for two minutes with periodic venting to release excess pressure. Allow the organic layer to separate from the water phase for a minimum of 10 minutes. If an emulsion forms and the emulsion interface between the layers is more than one-third the volume of the solvent layer, employ mechanical techniques to complete the phase separation. The optimum technique depends upon the sample, but may include stirring, filtration of the emulsion through glass wool, use of phase-separation paper, centrifugation, salting, freezing, or other physical methods. Collect the methylene chloride extract in a flask. If the emulsion cannot be broken (recovery of less than 80% of the methylene chloride, corrected for the water solubility of methylene chloride), transfer the sample, solvent, and emulsion into the extraction chamber of a continuous extractor and proceed as described in section 10.4.</P>
                        <P>10.2.4 Add a second 60-mL volume of methylene chloride to the sample bottle and repeat the extraction procedure a second time, combining the extracts in the flask. Perform a third extraction in the same manner. Proceed to macro-concentration (section 10.3.1).</P>
                        <P>10.2.5 Determine the original sample volume by refilling the sample bottle to the mark and transferring the liquid to an appropriately sized graduated cylinder. Record the sample volume to the nearest 5 mL. Sample volumes may also be determined by weighing the container before and after extraction or filling to the mark with water.</P>
                        <P>10.3 Concentration.</P>
                        <P>10.3.1 Macro concentration.</P>
                        <P>10.3.1.1 Assemble a Kuderna-Danish (K-D) concentrator by attaching a 10-mL concentrator tube to a 500-mL evaporative flask. Other concentration devices or techniques may be used in place of the K-D concentrator so long as the requirements of section 8.2 are met.</P>
                        <P>10.3.1.2 Pour the extract through a solvent-rinsed drying column containing about 10 cm of anhydrous sodium sulfate, and collect the extract in the K-D concentrator. Rinse the flask and column with 20-30 mL of methylene chloride to complete the quantitative transfer.</P>
                        <P>10.3.1.3 If no cleanup is to be performed on the sample, add 500 µL (0.5 mL) of isooctane to the extract to act as a keeper during concentration.</P>
                        <P>10.3.1.4 Add one or two clean boiling chips and attach a three-ball Snyder column to the K-D evaporative flask. Pre-wet the Snyder column by adding about 1 mL of methylene chloride to the top. Place the K-D apparatus on a hot water bath (60-65 °C) so that the concentrator tube is partially immersed in the hot water, and the entire lower rounded surface of the flask is bathed with hot vapor. Adjust the vertical position of the apparatus and the water temperature as required to complete the concentration in 15-20 minutes. At the proper rate of evaporation the balls of the column will actively chatter but the chambers will not flood with condensed solvent. When the apparent volume of liquid reaches 1 mL or other determined amount, remove the K-D apparatus from the water bath and allow it to drain and cool for at least 10 minutes.</P>
                        <P>10.3.1.5 If the extract is to be cleaned up by sulfur removal or acid back extraction, remove the Snyder column and rinse the flask and its lower joint into the concentrator tube with 1 to 2 mL of methylene chloride. A 5-mL syringe is recommended for this operation. Adjust the final volume to 10 mL in methylene chloride and proceed to sulfur removal (section 11.5) or acid back extraction (section 11.6). If the extract is to cleaned up using one of the other cleanup procedures or is to be injected into the GC, proceed to Kuderna-Danish micro-concentration (section 10.3.2) or nitrogen evaporation and solvent exchange (section 10.3.3).</P>
                        <P>
                            10.3.2 Kuderna-Danish micro concentration—Add another one or two clean boiling chips to the concentrator tube and attach a two-ball micro-Snyder column. Pre-wet the Snyder column by adding about 0.5 mL of methylene chloride to the top. Place the K-D apparatus on a hot water bath (60-65 °C) so that the concentrator tube is partially immersed in hot water. Adjust the vertical position of the apparatus and the water temperature as required to complete the concentration in 5-10 minutes. At the proper rate of distillation the balls of the column will actively chatter but the chambers will not flood with condensed solvent. When the 
                            <PRTPAGE P="175"/>
                            apparent volume of liquid reaches approximately 1 mL or other required amount, remove the K-D apparatus from the water bath and allow it to drain and cool for at least 10 minutes. Remove the Snyder column and rinse the flask and its lower joint into the concentrator tube with approximately 0.2 mL of methylene chloride, and proceed to section 10.3.3 for nitrogen evaporation and solvent exchange.
                        </P>
                        <P>10.3.3 Nitrogen evaporation and solvent exchange—Extracts to be subjected to solid-phase cleanup (SPE) are exchanged into 1.0 mL of the SPE elution solvent (section 6.7.2.2). Extracts to be subjected to Florisil® or alumina cleanups are exchanged into hexane. Extracts that have been cleaned up and are ready for analysis are exchanged into isooctane or hexane, to match the solvent used for the calibration standards.</P>
                        <P>10.3.3.1 Transfer the vial containing the sample extract to the nitrogen evaporation (blowdown) device (section 5.2.5.2). Lower the vial into a 50-55 °C water bath and begin concentrating. During the solvent evaporation process, do not allow the extract to become dry. Adjust the flow of nitrogen so that the surface of the solvent is just visibly disturbed. A large vortex in the solvent may cause analyte loss.</P>
                        <P>10.3.3.2 Solvent exchange.</P>
                        <P>10.3.3.2.1 When the volume of the liquid is approximately 500 µL, add 2 to 3 mL of the desired solvent (SPE elution solvent for SPE cleanup, hexane for Florisil or alumina, or isooctane for final injection into the GC) and continue concentrating to approximately 500 µL. Repeat the addition of solvent and concentrate once more.</P>
                        <P>10.3.3.3.2 Adjust the volume of an extract to be cleaned up by SPE, Florisil®, or alumina to 1.0 mL. Proceed to extract cleanup (section 11).</P>
                        <P>10.3.3.3 Extracts that have been cleaned up and are ready for analysis—Adjust the final extract volume to be consistent with the volume extracted and the sensitivity desired. The goal is for a full-volume sample (e.g., 1-L) to have a final extract volume of 10 mL, but other volumes may be used.</P>
                        <P>10.3.4 Transfer the concentrated extract to a vial with fluoropolymer-lined cap. Seal the vial and label with the sample number. Store in the dark at room temperature until ready for GC analysis. If GC analysis will not be performed on the same day, store the vial in the dark at ≤6 °C. Analyze the extract by GC per the procedure in section 12.</P>
                        <P>10.4 Continuous liquid/liquid extraction (CLLE).</P>
                        <P>10.4.1 Use CLLE when experience with a sample from a given source indicates an emulsion problem, or when an emulsion is encountered using SFLLE. CLLE may be used for all samples, if desired.</P>
                        <P>10.4.2 Mark the water meniscus on the side of the sample bottle for later determination of sample volume. Transfer the sample to the continuous extractor and, using a pipet, add surrogate standard spiking solution. If the sample will be used for the LCS, MS, or MSD, pipet the appropriate check sample concentrate (section 8.2.1 or 8.3.2) into the separatory funnel. Mix well. Add 60 mL of methylene chloride to the sample bottle, seal, and shake for 30 seconds to rinse the inner surface. Transfer the solvent to the extractor.</P>
                        <P>10.4.3 Repeat the sample bottle rinse with two additional 50-100 mL portions of methylene chloride and add the rinses to the extractor.</P>
                        <P>10.4.4 Add a suitable volume of methylene chloride to the distilling flask (generally 200-500 mL) and sufficient reagent water to ensure proper operation of the extractor, and extract the sample for 18-24 hours. A shorter or longer extraction time may be used if all QC acceptance criteria are met. Test and, if necessary, adjust the pH of the water to a range of 5.0-9.0 during the second or third hour of the extraction. After extraction, allow the apparatus to cool, then detach the distilling flask. Dry, concentrate, solvent exchange, and transfer the extract to a vial with fluoropolymer-lined cap, per Section 10.3.</P>
                        <P>10.4.5 Determine the original sample volume by refilling the sample bottle to the mark and transferring the liquid to an appropriately sized graduated cylinder. Record the sample volume to the nearest 5 mL. Sample volumes may also be determined by weighing the container before and after extraction or filling to the mark with water.</P>
                        <P>10.5 Solid-phase extraction of aqueous samples. The steps in this section address the extraction of aqueous field samples using disk-based solid-phase extraction (SPE) media, based on an ATP approved by EPA in 1995 (Reference 20). This application of SPE is distinct from that used in this method for the cleanup of sample extracts in section 11.2. Analysts must be careful not to confuse the equipment, supplies, or the procedural steps from these two different uses of SPE.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>Changes to the extraction conditions described below may be made by the laboratory under the allowance for method flexibility described in section 8.1, provided that the performance requirements in section 8.2 are met. However, changes in SPE materials, formats, and solvents must meet the requirements in section 8.1.2 and its subsections.</P>
                        </NOTE>
                        <P>10.5.1 Mark the water meniscus on the side of the sample bottle for later determination of sample volume. If the sample contains particulates, let stand to settle out the particulates before extraction.</P>
                        <P>10.5.2 Extract the sample as follows:</P>
                        <P>
                            10.5.2.1 Place a 90-mm standard filter apparatus on a vacuum filtration flask or manifold and attach to a vacuum source. The vacuum gauge must read at least 25 in. of 
                            <PRTPAGE P="176"/>
                            mercury when all valves are closed. Position a 90-mm C18 extraction disk onto the filter screen. Wet the entire disk with methanol. To aid in filtering samples with particulates, a 1-µm glass fiber filter or Empore® Filter Aid 400 can be placed on the top of the disk and wetted with methanol. Install the reservoir and clamp. Resume vacuum to dry the disk. Interrupt the vacuum. Wash the disk and reservoir with 20 mL of methylene chloride. Resume the vacuum briefly to pull methylene chloride through the disk. Interrupt the vacuum and allow the disk to soak for about a minute. Resume vacuum and completely dry the disk.
                        </P>
                        <P>10.5.2.2 Condition the disk with 20 mL of methanol. Apply vacuum until nearly all the solvent has passed through the disk, interrupting it while solvent remains on the disk. Allow the disk to soak for about a minute. Resume vacuum to pull most of the methanol through, but interrupting it to leave a layer of methanol on the surface of the disk. Do not allow disk to dry. For uniform flow and good recovery, it is critical the disk not be allowed to dry from now until the end of the extraction. Discard waste solvent. Rinse the disk with 20 mL of deionized water. Resume vacuum to pull most of the water through, but interrupt it to leave a layer of water on the surface of the disk. Do not allow the disk to dry. If disk does dry, recondition with methanol as above.</P>
                        <P>10.5.2.3 Add the water sample to the reservoir and immediately apply the vacuum. If particulates have settled in the sample, gently decant the clear layer into the apparatus until most of the sample has been processed. Then pour the remainder including the particulates into the reservoir. Empty the sample bottle completely. When the filtration is complete, dry the disk for three minutes. Turn off the vacuum.</P>
                        <P>10.5.3 Discard sample filtrate. Insert tube to collect the eluant. The tube should fit around the drip tip of the base. Reassemble the apparatus. Add 5.0 mL of acetone to the center of the disk, allowing it to spread evenly over the disk. Turn the vacuum on and quickly off when the filter surface nears dryness but still remains wet. Allow to soak for 15 seconds. Add 20 mL of methylene chloride to the sample bottle, seal and shake to rinse the inside of the bottle. Transfer the methylene chloride from the bottle to the filter. Resume the vacuum slowly so as to avoid splashing.</P>
                        <P>Interrupt the vacuum when the filter surface nears dryness but still remains wet. Allow disk to soak in solvent for 20 seconds. Rinse the reservoir glass and disk with 10 mL of methylene chloride. Resume vacuum slowly. Interrupt vacuum when disk is covered with solvent. Allow to soak for 20 seconds. Resume vacuum to dry the disk. Remove the sample tube.</P>
                        <P>10.5.4 Dry, concentrate, solvent exchange, and transfer the extract to a vial with fluoropolymer-lined cap, per section 10.3.</P>
                        <P>10.5.5 Determine the original sample volume by refilling the sample bottle to the mark and transferring the liquid to an appropriately sized graduated cylinder. Record the sample volume to the nearest 5 mL. Sample volumes may also be determined by weighing the container before and after extraction or filling to the mark with water.</P>
                        <HD SOURCE="HD3">11. Extract Cleanup</HD>
                        <P>11.1 Cleanup may not be necessary for relatively clean samples (e.g., treated effluents, groundwater, drinking water). If particular circumstances require the use of a cleanup procedure, the laboratory may use any or all of the procedures below or any other appropriate procedure (e.g., gel permeation chromatography). However, the laboratory must first repeat the tests in sections 8.2, 8.3, and 8.4 to demonstrate that the requirements of those sections can be met using the cleanup procedure(s) as an integral part of this method. This is particularly important when the target analytes for the analysis include any of the single component pesticides in Table 2, because some cleanups have not been optimized for all of those analytes.</P>
                        <P>11.1.1 The solid-phase cartridge (section 11.2) removes polar organic compounds such as phenols.</P>
                        <P>11.1.2 The Florisil® column (section 11.3) allows for selected fractionation of the organochlorine analytes and will also eliminate polar interferences.</P>
                        <P>11.1.3 Alumina column cleanup (section 11.4) also removes polar materials.</P>
                        <P>11.1.4 Elemental sulfur, which interferes with the electron capture gas chromatography of some of the pesticides, may be removed using activated copper, or TBA sulfite. Sulfur removal (section 11.5) is required when sulfur is known or suspected to be present. Some chlorinated pesticides which also contain sulfur may be removed by this cleanup.</P>
                        <P>11.1.5 Acid back extraction (section 11.6) may be useful for cleanup of PCBs and other compounds not adversely affected by sulfuric acid.</P>
                        <P>11.2 Solid-phase extraction (SPE) as a cleanup. In order to use the C18 SPE cartridge in section 5.5.3.5 as a cleanup procedure, the sample extract must be exchanged from methylene chloride to methylene chloride:acetonitrile:hexane (50:3:47). Follow the solvent exchange steps in section 10.3.3.2 prior to attempting solid-phase cleanup.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>This application of SPE is distinct from that used in this method for the extraction of aqueous samples in section 10.5. Analysts must be careful not to confuse the equipment, supplies, or procedural steps from these two different uses of SPE.</P>
                        </NOTE>
                        <PRTPAGE P="177"/>
                        <P>11.2.1 Setup.</P>
                        <P>11.2.1.1 Attach the VacElute Manifold (section 5.5.3.2) to a water aspirator or vacuum pump with the trap and gauge installed between the manifold and vacuum source.</P>
                        <P>11.2.1.2 Place the SPE cartridges in the manifold, turn on the vacuum source, and adjust the vacuum to 5 to 10 psi.</P>
                        <P>11.2.2 Cartridge washing—Pre-elute each cartridge prior to use sequentially with 10-mL portions each of hexane, methanol, and water using vacuum for 30 seconds after each eluting solvent. Follow this pre-elution with 1 mL methylene chloride and three 10-mL portions of the elution solvent (section 6.7.2.2) using vacuum for 5 minutes after each eluting solvent. Tap the cartridge lightly while under vacuum to dry between solvent rinses. The three portions of elution solvent may be collected and used as a cartridge blank, if desired. Finally, elute the cartridge with 10 mL each of methanol and water, using the vacuum for 30 seconds after each eluant.</P>
                        <P>11.2.3 Extract cleanup.</P>
                        <P>11.2.3.1 After cartridge washing (section 11.2.2), release the vacuum and place the rack containing the 50-mL volumetric flasks (section 5.5.3.4) in the vacuum manifold. Re-establish the vacuum at 5 to 10 psi.</P>
                        <P>11.2.3.2 Using a pipette or a 1-mL syringe, transfer 1.0 mL of extract to the SPE cartridge. Apply vacuum for five minutes to dry the cartridge. Tap gently to aid in drying.</P>
                        <P>11.2.3.3 Elute each cartridge into its volumetric flask sequentially with three 10-mL portions of the methylene chloride:acetonitrile:hexane (50:3:47) elution solvent (section 6.7.2.2), using vacuum for five minutes after each portion. Collect the eluants in the 50-mL volumetric flasks.</P>
                        <P>11.2.3.4 Release the vacuum and remove the 50-mL volumetric flasks.</P>
                        <P>11.2.3.5 Concentrate the eluted extracts per Section 10.3.</P>
                        <P>11.3 Florisil®. In order to use Florisil cleanup, the sample extract must be exchanged from methylene chloride to hexane. Follow the solvent exchange steps in section 10.3.3.2 prior to attempting Florisil® cleanup.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>Alternative formats for this cleanup may be used by the laboratory, including cartridges containing Florisil®. If an alternative format is used, consult the manufacturer's instructions and develop a formal documented procedure to replace the steps in section 11.3 of this method and demonstrate that the alternative meets the relevant quality control requirements of this method.</P>
                        </NOTE>
                        <P>11.3.1 If the chromatographic column does not contain a frit at the bottom, place a small plug of pre-cleaned glass wool in the column (section 5.2.4) to retain the Florisil®. Place the mass of Florisil® (nominally 20 g) predetermined by calibration (section 7.8 and Table 6) in a chromatographic column. Tap the column to settle the Florisil® and add 1 to 2 cm of granular anhydrous sodium sulfate to the top.</P>
                        <P>11.3.2 Add 60 mL of hexane to wet and rinse the sodium sulfate and Florisil®. Just prior to exposure of the sodium sulfate layer to the air, stop the elution of the hexane by closing the stopcock on the chromatographic column. Discard the eluant.</P>
                        <P>11.3.3 Transfer the concentrated extract (section 10.3.3) onto the column. Complete the transfer with two 1-mL hexane rinses, drawing the extract and rinses down to the level of the sodium sulfate.</P>
                        <P>11.3.4 Place a clean 500-mL K-D flask and concentrator tube under the column. Elute Fraction 1 with 200 mL of 6% (v/v) ethyl ether in hexane at a rate of approximately 5 mL/min. Remove the K-D flask and set it aside for later concentration. Elute Fraction 2 with 200 mL of 15% (v/v) ethyl ether in hexane into a second K-D flask. Elute Fraction 3 with 200 mL of 50% (v/v) ethyl ether in hexane into a third K-D flask. The elution patterns for the pesticides and PCBs are shown in Table 6.</P>
                        <P>11.3.5 Concentrate the fractions as in Section 10.3, except use hexane to prewet the column and set the water bath at about 85 °C. When the apparatus is cool, remove the Snyder column and rinse the flask and its lower joint into the concentrator tube with hexane. Adjust the volume of Fraction 1 to approximately 10 mL for sulfur removal (Section 11.5), if required; otherwise, adjust the volume of the fractions to 10 mL, 1.0 mL, or other volume needed for the sensitivity desired. Analyze the concentrated extract by gas chromatography (Section 12).</P>
                        <P>11.4 Alumina. The sample extract must be exchanged from methylene chloride to hexane. Follow the solvent exchange steps in section 10.3.3.2 prior to attempting alumina cleanup.</P>
                        <P>11.4.1 If the chromatographic column does not contain a frit at the bottom, place a small plug of pre-cleaned glass wool in the chromatographic column (section 5.2.4) to retain the alumina. Add 10 g of alumina (section 6.7.3) on top of the plug. Tap the column to settle the alumina. Place 1-2 g of anhydrous sodium sulfate on top of the alumina.</P>
                        <P>11.4.2 Close the stopcock and fill the column to just above the sodium sulfate with hexane. Add 25 mL of hexane. Open the stopcock and adjust the flow rate of hexane to approximately 2 mL/min. Do not allow the column to go dry throughout the elutions.</P>
                        <P>11.4.3 When the level of the hexane is at the top of the column, quantitatively transfer the extract to the column. When the level of the extract is at the top of the column, slowly add 25 mL of hexane and elute the column to the level of the sodium sulfate. Discard the hexane.</P>
                        <P>
                            11.4.4 Place a K-D flask (section 5.2.5.1.2) under the column and elute the pesticides 
                            <PRTPAGE P="178"/>
                            with approximately 150 mL of hexane:ethyl ether (80:20 v/v). It may be necessary to adjust the volume of elution solvent for slightly different alumina activities.
                        </P>
                        <P>11.4.5 Concentrate the extract per section 10.3.</P>
                        <P>11.5 Sulfur removal—Elemental sulfur will usually elute in Fraction 1 of the Florisil® column cleanup. If Florisil® cleanup is not used, or to remove sulfur from any of the Florisil® fractions, use one of the sulfur removal procedures below. These procedures may be applied to extracts in hexane, ethyl ether, or methylene chloride.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>Separate procedures using copper or TBA sulfite are provided in this section for sulfur removal. They may be used separately or in combination, if desired.</P>
                        </NOTE>
                        <P>11.5.1 Removal with copper (Reference 15).</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>Some of the analytes in Table 2 are not amenable to sulfur removal with copper (e.g., atrazine and diazinon). Therefore, before using copper to remove sulfur from an extract that will be analyzed for any of the non-PCB analytes in Table 2, the laboratory must demonstrate that the analytes can be extracted from an aqueous sample matrix that contains sulfur and recovered from an extract treated with copper. Acceptable performance can be demonstrated through the preparation and analysis of a matrix spike sample that meets the QC requirements for recovery.</P>
                        </NOTE>
                        <P>11.5.1.1 Quantitatively transfer the extract to a 40- to 50-mL flask or bottle. If there is evidence of water in the K-D or round-bottom flask after the transfer, rinse the flask with small portions of hexane:acetone (40:60) and add to the flask or bottle. Mark and set aside the concentration flask for future use.</P>
                        <P>11.5.1.2 Add 10-20 g of granular anhydrous sodium sulfate to the flask. Swirl to dry the extract.</P>
                        <P>11.5.1.3 Add activated copper (section 6.7.4.1.4) and allow to stand for 30-60 minutes, swirling occasionally. If the copper does not remain bright, add more and swirl occasionally for another 30-60 minutes.</P>
                        <P>11.5.1.4 After drying and sulfur removal, quantitatively transfer the extract to a nitrogen-evaporation vial or tube and proceed to section 10.3.3 for nitrogen evaporation and solvent exchange, taking care to leave the sodium sulfate and copper foil in the flask.</P>
                        <P>11.5.2 Removal with TBA sulfite.</P>
                        <P>11.5.2.1 Using small volumes of hexane, quantitatively transfer the extract to a 40- to 50-mL centrifuge tube with fluoropolymer-lined screw cap.</P>
                        <P>11.5.2.2 Add 1-2 mL of TBA sulfite reagent (section 6.7.4.2.4), 2-3 mL of 2-propanol, and approximately 0.7 g of sodium sulfite (section 6.7.4.2.2) crystals to the tube. Cap and shake for 1-2 minutes. If the sample is colorless or if the initial color is unchanged, and if clear crystals (precipitated sodium sulfite) are observed, sufficient sodium sulfite is present. If the precipitated sodium sulfite disappears, add more crystalline sodium sulfite in approximately 0.5-g portions until a solid residue remains after repeated shaking.</P>
                        <P>11.5.2.3 Add 5-10 mL of reagent water and shake for 1-2 minutes. Centrifuge to settle the solids.</P>
                        <P>11.5.2.4 Quantitatively transfer the hexane (top) layer through a small funnel containing a few grams of granular anhydrous sodium sulfate to a nitrogen-evaporation vial or tube and proceed to section 10.3.3 for micro-concentration and solvent exchange.</P>
                        <P>11.6 Acid back extraction (section 6.1.2).</P>
                        <P>11.6.1 Quantitatively transfer the extract (section 10.3.1.5) to a 250-mL separatory funnel.</P>
                        <P>11.6.2 Partition the extract against 50 mL of sulfuric acid solution (section 6.1.2). Discard the aqueous layer. Repeat the acid washing until no color is visible in the aqueous layer, to a maximum of four washings.</P>
                        <P>11.6.3 Partition the extract against 50 mL of sodium chloride solution (section 6.7.5). Discard the aqueous layer.</P>
                        <P>11.6.4 Proceed to section 10.3.3 for micro-concentration and solvent exchange.</P>
                        <HD SOURCE="HD3">12. Gas Chromatography</HD>
                        <P>12.1 Establish the same operating conditions used in section 7.1 for instrument calibration.</P>
                        <P>12.2 If the internal standard calibration procedure is used, add the internal standard solution (section 6.9.3) to the extract as close as possible to the time of injection to minimize the possibility of loss by evaporation, adsorption, or reaction. For example, add 1 µL of 10 µg/mL internal standard solution into the extract, assuming no dilutions. Mix thoroughly.</P>
                        <P>12.3 Simultaneously inject an appropriate volume of the sample extract or standard solution onto both columns, using split, splitless, solvent purge, large-volume, or on-column injection. Alternatively, if using a single-column GC configuration, inject an appropriate volume of the sample extract or standard solution onto each GC column independently. If the sample is injected manually, the solvent-flush technique should be used. The injection volume depends upon the technique used and the sensitivity needed to meet MDLs or reporting limits for regulatory compliance. Injection volumes must be the same for all extracts. Record the volume injected to the nearest 0.05 µL.</P>
                        <P>
                            12.4 Set the data system or GC control to start the temperature program upon sample injection, and begin data collection after the solvent peak elutes. Set the data system to stop data collection after the last analyte is expected to elute and to return the column to the initial temperature.
                            <PRTPAGE P="179"/>
                        </P>
                        <P>12.5 Perform all qualitative and quantitative measurements as described in Sections 14 and 15. When standards and extracts are not being used for analyses, store them refrigerated at &lt;6 °C, protected from light, in screw-cap vials equipped with un-pierced fluoropolymer-lined septa.</P>
                        <HD SOURCE="HD3">13. System and Laboratory Performance</HD>
                        <P>13.1 At the beginning of each shift during which standards or extracts are analyzed, GC system performance and calibration must be verified for all analytes and surrogates on both column/detector systems. Adjustment and/or recalibration (per section 7) are performed until all performance criteria are met. Only after all performance criteria are met may samples, blanks and other QC samples, and standards be analyzed.</P>
                        <P>13.2 Inject an aliquot of the calibration verification standard (section 6.8.4) on both columns. Inject an aliquot of each of the multi-component standards.</P>
                        <P>13.3 Retention times—The absolute retention times of the peak maxima shall be within ±2 seconds of the retention times in the calibration verification (section 7.8).</P>
                        <P>13.4 GC resolution—Resolution is acceptable if the valley height between two peaks (as measured from the baseline) is less than 40% of the shorter of the two peaks.</P>
                        <P>13.4.1 DB-608 column—DDT and endrin aldehyde</P>
                        <P>
                            13.4.2 DB-1701 column—
                            <E T="03">alpha</E>
                             and 
                            <E T="03">gamma</E>
                             chlordane
                        </P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>If using other GC columns or stationary phases, these resolution criteria apply to these four target analytes and any other closely eluting analytes on those other GC columns.</P>
                        </NOTE>
                        <P>13.5 Decomposition of DDT and endrin—If DDT, endrin, or their breakdown products are to be determined, this test must be performed prior to calibration verification (section 13.6). DDT decomposes to DDE and DDD. Endrin decomposes to endrin aldehyde and endrin ketone.</P>
                        <P>13.5.1 Inject 1 µL of the DDT and endrin decomposition solution (section 6.8.7). As noted in section 6.8.7, other injection volumes may be used as long as the concentrations of DDT and endrin in the solution are adjusted to introduce the masses of the two analytes into the instrument that are listed in section 6.8.7.</P>
                        <P>13.5.2 Measure the areas of the peaks for DDT, DDE, DDD, endrin, endrin aldehyde, and endrin ketone in the chromatogram and calculate the percent breakdown as shown in the equations below:</P>
                        <GPH SPAN="2" DEEP="76">
                            <GID>ER28AU17.005</GID>
                        </GPH>
                        <P>13.5.3 Both the % breakdown of DDT and of endrin must be less than 20%, otherwise the system is not performing acceptably for DDT and endrin. In this case, repair the GC column system that failed and repeat the performance tests (sections 13.2 to 13.6) until the specification is met.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>DDT and endrin decomposition are usually caused by accumulations of particulates in the injector and in the front end of the column. Cleaning and silanizing the injection port liner, and breaking off a short section of the front end of the column will usually eliminate the decomposition problem. Either of these corrective actions may affect retention times, GC resolution, and calibration linearity.</P>
                        </NOTE>
                        <P>13.6 Calibration verification.</P>
                        <P>13.6.1 Compute the percent recovery of each analyte and of the coeluting analytes, based on the initial calibration data (section 7.5 or 7.6).</P>
                        <P>
                            13.6.2 For each analyte or for coeluting analytes, compare the concentration with the limits for calibration verification in Table 4. For coeluting analytes, use the coeluting analyte with the least restrictive specification (the widest range). For analytes in Table 2 not listed in Table 4, QC acceptance criteria must be developed by the laboratory. EPA has provided guidance for development of QC acceptance criteria (References 13 and 14). If the recoveries for all analytes meet the acceptance criteria, system performance is acceptable and analysis of blanks and samples may continue. If, however, any recovery falls outside the calibration verification range, system performance is unacceptable for that analyte. If this occurs, repair the system and repeat the test (section 13.6), or prepare a fresh calibration 
                            <PRTPAGE P="180"/>
                            standard and repeat the test, or recalibrate (section 7). See Section 8.1.7 for information on repeated test failures.
                        </P>
                        <P>13.7 Laboratory control sample.</P>
                        <P>13.7.1 Analyze the extract of the LCS (section 6.8.3) extracted with each sample batch (Section 8.4). See Section 8.4 for criteria acceptance of the LCS.</P>
                        <P>13.7.2 It is suggested, but not required, that the laboratory update statements of data quality. Add results that pass the specifications in section 13.7.3 to initial (section 8.7) and previous ongoing data. Update QC charts to form a graphic representation of continued laboratory performance. Develop a statement of laboratory data quality for each analyte by calculating the average percent recovery (R) and the standard deviation of percent recovery, sr. Express the accuracy as a recovery interval from R − 2sr to R + 2sr. For example, if R = 95% and sr = 5%, the accuracy is 85 to 105%.</P>
                        <P>
                            13.8 Internal standard response—If internal standard calibration is used, verify that detector sensitivity has not changed by comparing the response (area or height) of each internal standard in the sample, blank, LCS, MS, and MSD to the response in calibration verification (section 6.8.3). The peak area or height of the internal standard should be within 50% to 200% (
                            <FR>1/2</FR>
                             to 2x) of its respective peak area or height in the verification standard. If the area or height is not within this range, compute the concentration of the analytes using the external standard method (section 7.5). If the analytes are affected, re-prepare and reanalyze the sample, blank, LCS, MS, or MSD, and repeat the pertinent test.
                        </P>
                        <HD SOURCE="HD3">14. Qualitative Identification</HD>
                        <P>14.1 Identification is accomplished by comparison of data from analysis of a sample, blank, or other QC sample with data from calibration verification (section 7.7.1 or 13.5), and with data stored in the retention-time and calibration libraries (section 7.7). The retention time window is determined as described in section 14.2. Identification is confirmed when retention time agrees on both GC columns, as described below. Alternatively, GC/MS identification may be used to provide another means of identification.</P>
                        <P>14.2 Establishing retention time windows.</P>
                        <P>14.2.1 Using the data from the multi-point initial calibration (section 7.4), determine the retention time in decimal minutes (not minutes:seconds) of each peak representing a single-component target analyte on each column/detector system. For the multi-component analytes, use the retention times of the five largest peaks in the chromatograms on each column/detector system.</P>
                        <P>14.2.2 Calculate the standard deviation of the retention times for each single-component analyte on each column/detector system and for the three to five exclusive (unique large) peaks for each multi-component analyte.</P>
                        <P>14.2.3 Define the width of the retention time window as three times that standard deviation. Establish the center of the retention time window for each analyte by using the absolute retention time for each analyte from the calibration verification standard at the beginning of the analytical shift. For samples run during the same shift as an initial calibration, use the retention time of the mid-point standard of the initial calibration. If the calculated RT window is less than 0.02 minutes, then use 0.02 minutes as the window.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>Procedures for establishing retention time windows from other sources may be employed provided that they are clearly documented and provide acceptable performance. Such performance may be evaluated using the results for the spiked QC samples described in this method, such as laboratory control samples and matrix spike samples.</P>
                        </NOTE>
                        <P>14.2.4 The retention time windows must be recentered when a new GC column is installed or if a GC column has been shortened during maintenance to a degree that the retention times of analytes in the calibration verification standard have shifted close to the lower limits of the established retention time windows.</P>
                        <P>14.2.5 RT windows should be checked periodically by examining the peaks in spiked samples such as the LCS or MS/MSD to confirm that peaks for known analytes are properly identified.</P>
                        <P>14.2.6 If the retention time of an analyte in the calibration (Section 7.4) varies by more than 5 seconds across the calibration range as a function of the concentration of the standard, using the standard deviation of the retention times (section 14.2.3) to set the width of the retention time window may not adequately serve to identify the analyte in question under routine conditions. In such cases, data from additional analyses of standards may be required to adequately model the chromatographic behavior of the analyte.</P>
                        <P>14.3 Identifying the analyte in a sample.</P>
                        <P>14.3.1 In order to identify a single-component analyte from analysis of a sample, blank, or other QC sample, the peak representing the analyte must fall within its respective retention time windows on both column/detector systems (as defined in section 14.2). That identification is further supported by the comparison of the numerical results on both columns, as described in section 15.7.</P>
                        <P>
                            14.3.2 In order to identify a multi-component analyte, pattern matching (fingerprinting) may be used, or the three to five exclusive (unique and largest) peaks for that analyte must fall within their respective retention time windows on both column/detector systems (as defined in section 14.2). 
                            <PRTPAGE P="181"/>
                            That identification is further supported by the comparison of the numerical results on both columns, as described in section 15.7. Alternatively, GC/MS identification may be used. Differentiation among some of the Aroclors may require evaluation of more than five peaks to ensure correct identification.
                        </P>
                        <P>14.4 GC/MS confirmation. When the concentration of an analyte is sufficient and the presence or identity is suspect, its presence should be confirmed by GC/MS. In order to match the sensitivity of the GC/ECD, confirmation would need to be by GC/MS-SIM, or the estimated concentration would need to be 100 times higher than the GC/ECD calibration range. The extract may be concentrated by an additional amount to allow a further attempt at GC/MS confirmation.</P>
                        <P>14.5 Additional information that may aid the laboratory in the identification of an analyte. The occurrence of peaks eluting near the retention time of an analyte of interest increases the probability of a false positive for the analyte. If the concentration is insufficient for confirmation by GC/MS, the laboratory may use the cleanup procedures in this method (section 11) on a new sample aliquot to attempt to remove the interferent. After attempts at cleanup are exhausted, the following steps may be helpful to assure that the substance that appears in the RT windows on both columns is the analyte of interest.</P>
                        <P>
                            14.5.1 Determine the consistency of the RT data for the analyte on each column. For example, if the RT is very stable (
                            <E T="03">i.e.,</E>
                             varies by no more than a few seconds) for the calibration, calibration verification, blank, LCS, and MS/MSD, the RT for the analyte of interest in the sample should be within this variation regardless of the window established in Section 14.2. If the analyte is not within this variation on both columns, it is likely not present.
                        </P>
                        <P>14.5.2 The possibility exists that the RT for the analyte in a sample could shift if extraneous materials are present. This possibility may be able to be confirmed or refuted by the behavior of the surrogates in the sample. If multiple surrogates are used that span the length of the chromatographic run, the RTs for the surrogates on both columns are consistent with their RTs in calibration, calibration verification, blank, LCS, and MS/MSD, it is unlikely that the RT for the analyte of interest has shifted.</P>
                        <P>14.5.3 If the RT for the analyte is shifted slightly later on one column and earlier on the other, and the surrogates have not shifted, it is highly unlikely that the analyte is present, because shifts nearly always occur in the same direction on both columns.</P>
                        <HD SOURCE="HD3">15. Quantitative Determination</HD>
                        <P>15.1 External standard quantitation—Calculate the concentration of the analyte in the extract using the calibration curve or average calibration factor determined in calibration (section 7.5.2) and the following equation:</P>
                        <GPH SPAN="2" DEEP="25">
                            <GID>ER28AU17.006</GID>
                        </GPH>
                        <FP SOURCE="FP-2">where:</FP>
                        <FP SOURCE="FP-2">
                            C
                            <E T="52">ex</E>
                             = Concentration of the analyte in the extract (ng/mL)
                        </FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">s</E>
                             = Peak height or area for the analyte in the standard or sample
                        </FP>
                        <FP SOURCE="FP-2">CF = Calibration factor, as defined in Section 7.5.1</FP>
                        <P>15.2 Internal standard quantitation—Calculate the concentration of the analyte in the extract using the calibration curve or average response factor determined in calibration (section 7.6.2) and the following equation:</P>
                        <GPH SPAN="2" DEEP="28">
                            <GID>ER28AU17.007</GID>
                        </GPH>
                        <FP SOURCE="FP-2">where:</FP>
                        <FP SOURCE="FP-2">
                            C
                            <E T="52">ex</E>
                             = Concentration of the analyte in the extract (ng/mL)
                        </FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">s</E>
                             = Peak height or area for the analyte in the standard or sample
                        </FP>
                        <FP SOURCE="FP-2">
                            C
                            <E T="52">is</E>
                             = Concentration of the internal standard (ng/mL)
                        </FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">is</E>
                             = Area of the internal standard
                        </FP>
                        <FP SOURCE="FP-2">RF = Response factor, as defined in section 7.6.1</FP>
                        <PRTPAGE P="182"/>
                        <P>15.3 Calculate the concentration of the analyte in the sample using the concentration in the extract, the extract volume, the sample volume, and the dilution factor, per the following equation:</P>
                        <GPH SPAN="2" DEEP="28">
                            <GID>ER28AU17.008</GID>
                        </GPH>
                        <FP SOURCE="FP-2">where:</FP>
                        <FP SOURCE="FP-2">
                            C
                            <E T="52">s</E>
                             = Concentration of the analyte in the sample (µg/L)
                        </FP>
                        <FP SOURCE="FP-2">
                            V
                            <E T="52">ex</E>
                             = Final extract volume (mL)
                        </FP>
                        <FP SOURCE="FP-2">
                            C
                            <E T="52">ex</E>
                             = Concentration in the extract (ng/mL)
                        </FP>
                        <FP SOURCE="FP-2">
                            V
                            <E T="52">s</E>
                             = Volume of sample (L)
                        </FP>
                        <FP SOURCE="FP-2">DF = Dilution factor</FP>
                        <FP>and the factor of 1,000 in the denominator converts the final units from ng/L to µg/L</FP>
                        <P>15.4 If the concentration of any target analyte exceeds the calibration range, either extract and analyze a smaller sample volume, or dilute and analyze the diluted extract.</P>
                        <P>15.5 Quantitation of multi-component analytes.</P>
                        <P>15.5.1 PCBs as Aroclors. Quantify an Aroclor by comparing the sample chromatogram to that of the most similar Aroclor standard as indicated in section 14.3.2. Compare the responses of 3 to 5 major peaks in the calibration standard for that Aroclor with the peaks observed in the sample extract. The amount of Aroclor is calculated using the individual calibration factor for each of the 3 to 5 characteristic peaks chosen in section 7.5.1. Determine the concentration of each of the characteristic peaks, using the average calibration factor calculated for that peak in section 7.5.2, and then those 3 to 5 concentrations are averaged to determine the concentration of that Aroclor.</P>
                        <P>15.5.2 Other multi-component analytes. Quantify any other multi-component analytes (technical chlordane or toxaphene) using the same peaks used to develop the average calibration factors in section 7.5.2. Determine the concentration of each of the characteristic peaks, and then the concentrations represented by those characteristic peaks are averaged to determine the concentration of the analyte. Alternatively, for toxaphene, the analyst may determine the calibration factor in section 7.5.2 by summing the areas of all of the peaks for the analyte and using the summed of the peak areas in the sample chromatogram to determine the concentration. However, the approach used for toxaphene must be the same for the calibration and the sample analyses.</P>
                        <P>15.6 Reporting of results. As noted in section 1.6.1, EPA has promulgated this method at 40 CFR part 136 for use in wastewater compliance monitoring under the National Pollutant Discharge Elimination System (NPDES). The data reporting practices described here are focused on such monitoring needs and may not be relevant to other uses of the method.</P>
                        <P>15.6.1 Report results for wastewater samples in µg/L without correction for recovery. (Other units may be used if required by in a permit.) Report all QC data with the sample results.</P>
                        <P>15.6.2 Reporting level. Unless specified otherwise by a regulatory authority or in a discharge permit, results for analytes that meet the identification criteria are reported down to the concentration of the ML established by the laboratory through calibration of the instrument (see section 7.5 or 7.6 and the glossary for the derivation of the ML). EPA considers the terms “reporting limit,” “quantitation limit,” and “minimum level” to be synonymous.</P>
                        <P>15.6.2.1 Report the lower result from the two columns (see section 15.7 below) for each analyte in each sample or QC standard at or above the ML to 3 significant figures. Report a result for each analyte in each sample or QC standard below the ML as “&lt;ML,” where “ML” is the concentration of the analyte at the ML (e.g., if the ML is 10 µg/L, then report the result as &lt;10 µg/L), or as required by the regulatory authority or permit. Report a result for each analyte in a blank at or above the MDL to 2 significant figures. Report a result for each analyte found in a blank below the MDL as “&lt;MDL,” where MDL is the concentration of the analyte at the MDL, or as required by the regulatory/control authority or permit.</P>
                        <P>15.6.2.2 In addition to reporting results for samples and blank(s) separately, the concentration of each analyte in a blank or field blank associated with that sample may be subtracted from the result for that sample, but only if requested or required by a regulatory authority or in a permit. In this case, both the sample result and the blank results must be reported together.</P>
                        <P>
                            15.6.2.3 Report the result for an analyte in a sample or extract that has been diluted at the least dilute level at which the peak area is within the calibration range (
                            <E T="03">i.e.,</E>
                             above the ML for the analyte) and the MS/MSD recovery and RPD are within their respective QC acceptance criteria (Table 4). This may require reporting results for some analytes 
                            <PRTPAGE P="183"/>
                            from different analyses. Results for each analyte in MS/MSD samples should be reported from the same GC column as used to report the results for that analyte in the unspiked sample. If the MS/MSD recoveries and RPDs calculated in this manner do not meet the acceptance criteria in Table 4, the analyst may use the results from the other GC column to determine if the MS/MSD results meet the acceptance criteria. If such a situation occurs, the results for the sample should be recalculated using the same GC column data as used for the MS/MSD samples, and reported with appropriate annotations that alert the data user of the issue.
                        </P>
                        <P>
                            15.6.2.4 Results from tests performed with an analytical system that is not in control (
                            <E T="03">i.e.,</E>
                             that does not meet acceptance criteria for all of QC tests in this method) must not be reported or otherwise used for permitting or regulatory compliance purposes, but do not relieve a discharger or permittee of reporting timely results. See section 8.1.7 for dispositions of failures. If the holding time would be exceeded for a re-analysis of the sample, the regulatory/control authority should be consulted for disposition.
                        </P>
                        <P>15.6.3 Analyze the sample by GC/MS or on a third column when analytes have co-eluted or interfere with determination on both columns.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>Dichlone and kepone do not elute from the DB-1701 column and must be confirmed on a DB-5 column, or by GC/MS.</P>
                        </NOTE>
                        <P>15.7 Quantitative information that may aid in the confirmation of the presence of an analyte.</P>
                        <P>15.7.1 As noted in Section 14.3, the relative agreement between the numerical results from the two GC columns may be used to support the identification of the target analyte by providing evidence that co-eluting interferences are not present at the retention time of the target analyte. Calculate the percent difference (%D) between the results for the analyte from both columns, as follows:</P>
                        <GPH SPAN="2" DEEP="28">
                            <GID>ER28AU17.009</GID>
                        </GPH>
                        <P>In general, if the %D of the two results is less than 50% (e.g., a factor of 2), then the pesticide is present. This %D is generous and allows for the pesticide that has the largest measurement error.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>Laboratories may employ metrics less than 50% for this comparison, including those specified in other analytical methods for these pesticides (e.g., CLP or SW-846).</P>
                        </NOTE>
                        <P>15.7.2 If the amounts do not agree, and the RT data indicate the presence of the analyte (per Section 14), it is likely that a positive interference is present on the column that yielded the higher result. That interferent may be represented by a separate peak on the other column that does not coincide with the retention time of any of the target analytes. If the interfering peak is evident on the other column, report the result from that column and advise the data user that the interference resulted in a %D value greater than 50%. If an interferent is not identifiable on the second column, then the results must be reported as “not detected” at the lower concentration. In this event, the pesticide is not confirmed and the reporting limit is elevated. See section 8.1.7 for disposition of problem results.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>The resulting elevation of the reporting limit may not meet the requirements for compliance monitoring and the use of additional cleanup procedures may be required.</P>
                        </NOTE>
                        <HD SOURCE="HD3">16. Analysis of Complex Samples</HD>
                        <P>16.1 Some samples may contain high levels (greater than 1 µg/L) of the analytes of interest, interfering analytes, and/or polymeric materials. Some samples may not concentrate to 1.0 mL (section 10.3.3.3.2); others may overload the GC column and/or detector.</P>
                        <P>16.2 When an interference is known or suspected to be present, the laboratory should attempt to clean up the sample extract using the SPE cartridge (section 11.2), by Florisil® (Section 11.3), Alumina (Section 11.4), sulfur removal (section 11.5), or another clean up procedure appropriate to the analytes of interest. If these techniques do not remove the interference, the extract is diluted by a known factor and reanalyzed (section 12). Dilution until the extract is lightly colored is preferable. Typical dilution factors are 2, 5, and 10.</P>
                        <P>
                            16.3 Recovery of surrogate(s)—In most samples, surrogate recoveries will be similar to those from reagent water. If surrogate recovery is outside the limits developed in Section 8.6, re-extract and reanalyze the sample if there is sufficient sample and if it is within the 7-day extraction holding time. If surrogate recovery is still outside this range, extract and analyze one-tenth the volume of sample to overcome any matrix interference problems. If a sample is highly colored or suspected to be high in concentration, a 1-L 
                            <PRTPAGE P="184"/>
                            sample aliquot and a 100-mL sample aliquot could be extracted simultaneously and still meet the holding time criteria, while providing information about a complex matrix.
                        </P>
                        <P>16.4 Recovery of the matrix spike and matrix spike duplicate (MS/MSD)—In most samples, MS/MSD recoveries will be similar to those from reagent water. If either the MS or MSD recovery is outside the range specified in Section 8.3.3, one-tenth the volume of sample is spiked and analyzed. If the matrix spike recovery is still outside the range, the result for the unspiked sample may not be reported or used for permitting or regulatory compliance purposes. See Section 8.1.7 for dispositions of failures. Poor matrix spike recovery does not relieve a discharger or permittee of reporting timely results.</P>
                        <HD SOURCE="HD3">17. Method Performance</HD>
                        <P>17.1 This method was tested for linearity of spike recovery from reagent water and has been demonstrated to be applicable over the concentration range from 4x MDL to 1000x MDL with the following exceptions: Chlordane recovery at 4x MDL was low (60%); Toxaphene recovery was demonstrated linear over the range of 10x MDL to 1000x MDL (Reference 3).</P>
                        <P>17.2 The 1984 version of this method was tested by 20 laboratories using reagent water, drinking water, surface water, and three industrial wastewaters spiked at six concentrations (Reference 2). Concentrations used in the study ranged from 0.5 to 30 µg/L for single-component pesticides and from 8.5 to 400 µg/L for multi-component analytes. These data are for a subset of analytes described in the current version of the method.</P>
                        <P>17.3 During the development of Method 1656, a similar EPA procedure for the organochlorine pesticides, single-operator precision, overall precision, and method accuracy were found to be directly related to the concentration of the analyte and essentially independent of the sample matrix. Linear equations to describe these relationships are presented in Table 5.</P>
                        <HD SOURCE="HD3">18. Pollution Prevention</HD>
                        <P>18.1 Pollution prevention encompasses any technique that reduces or eliminates the quantity or toxicity of waste at the point of generation. Many opportunities for pollution prevention exist in laboratory operations. EPA has established a preferred hierarchy of environmental management techniques that places pollution prevention as the management option of first choice. Whenever feasible, the laboratory should use pollution prevention techniques to address waste generation. When wastes cannot be reduced at the source, the Agency recommends recycling as the next best option.</P>
                        <P>18.2 The analytes in this method are used in extremely small amounts and pose little threat to the environment when managed properly. Standards should be prepared in volumes consistent with laboratory use to minimize the disposal of excess volumes of expired standards. This method utilizes significant quantities of methylene chloride. Laboratories are encouraged to recover and recycle this and other solvents during extract concentration.</P>
                        <P>18.3 For information about pollution prevention that may be applied to laboratories and research institutions, consult “Less is Better: Laboratory Chemical Management for Waste Reduction” (Reference 19), available from the American Chemical Society's Department of Governmental Relations and Science Policy, 1155 16th Street NW., Washington DC 20036, 202-872-4477.</P>
                        <HD SOURCE="HD3">19. Waste Management</HD>
                        <P>19.1 The laboratory is responsible for complying with all Federal, State, and local regulations governing waste management, particularly the hazardous waste identification rules and land disposal restrictions, and to protect the air, water, and land by minimizing and controlling all releases from fume hoods and bench operations. Compliance is also required with any sewage discharge permits and regulations. An overview of requirements can be found in Environmental Management Guide for Small Laboratories (EPA 233-B-98-001).</P>
                        <P>19.2 Samples at pH &lt;2, or pH &gt;12, are hazardous and must be handled and disposed of as hazardous waste, or neutralized and disposed of in accordance with all federal, state, and local regulations. It is the laboratory's responsibility to comply with all federal, state, and local regulations governing waste management, particularly the hazardous waste identification rules and land disposal restrictions. The laboratory using this method has the responsibility to protect the air, water, and land by minimizing and controlling all releases from fume hoods and bench operations. Compliance is also required with any sewage discharge permits and regulations. For further information on waste management, see “The Waste Management Manual for Laboratory Personnel,” also available from the American Chemical Society at the address in section 18.3.</P>
                        <P>19.3 Many analytes in this method decompose above 500 °C. Low-level waste such as absorbent paper, tissues, animal remains, and plastic gloves may be burned in an appropriate incinerator. Gross quantities of neat or highly concentrated solutions of toxic or hazardous chemicals should be packaged securely and disposed of through commercial or governmental channels that are capable of handling toxic wastes.</P>
                        <P>
                            19.4 For further information on waste management, consult The Waste Management Manual for Laboratory Personnel and 
                            <PRTPAGE P="185"/>
                            Less is Better-Laboratory Chemical Management for Waste Reduction, available from the American Chemical Society's Department of Government Relations and Science Policy, 1155 16th Street NW., Washington, DC 20036, 202-872-4477.
                        </P>
                        <HD SOURCE="HD3">20. References</HD>
                        <FP SOURCE="FP-2">1. “Determination of Pesticides and PCBs in Industrial and Municipal Wastewaters,” EPA 600/4-82-023, National Technical Information Service, PB82-214222, Springfield, Virginia 22161, April 1982.</FP>
                        <FP SOURCE="FP-2">2. “EPA Method Study 18 Method 608-Organochlorine Pesticides and PCBs,” EPA 600/4-84-061, National Technical Information Service, PB84-211358, Springfield, Virginia 22161, June 1984.</FP>
                        <FP SOURCE="FP-2">3. “Method Detection Limit and Analytical Curve Studies, EPA Methods 606, 607, and 608,” Special letter report for EPA Contract 68-03-2606, U.S. Environmental Protection Agency, Environmental Monitoring and Support Laboratory, Cincinnati, Ohio 45268, June 1980.</FP>
                        <FP SOURCE="FP-2">4. ASTM Annual Book of Standards, Part 31, D3694-78. “Standard Practice for Preparation of Sample Containers and for Preservation of Organic Constituents,” American Society for Testing and Materials, Philadelphia.</FP>
                        <FP SOURCE="FP-2">5. Giam, C.S., Chan, H.S., and Nef, G.S. “Sensitive Method for Determination of Phthalate Ester Plasticizers in Open-Ocean Biota Samples,” Analytical Chemistry, 47:2225 (1975).</FP>
                        <FP SOURCE="FP-2">6. Giam, C.S. and Chan, H.S. “Control of Blanks in the Analysis of Phthalates in Air and Ocean Biota Samples,” U.S. National Bureau of Standards, Special Publication 442, pp. 701-708, 1976.</FP>
                        <FP SOURCE="FP-2">7. Solutions to Analytical Chemistry Problems with Clean Water Act Methods, EPA 821-R-07-002, March 2007.</FP>
                        <FP SOURCE="FP-2">8. “Carcinogens-Working With Carcinogens,” Department of Health, Education, and Welfare, Public Health Service, Center for Disease Control, National Institute for Occupational Safety and Health, Publication No. 77-206, August 1977.</FP>
                        <FP SOURCE="FP-2">9. “Occupational Exposure to Hazardous Chemicals in Laboratories,” (29 CFR 1910.1450), Occupational Safety and Health Administration, OSHA.</FP>
                        <FP SOURCE="FP-2">10. 40 CFR 136.6(b)(4)(j).</FP>
                        <FP SOURCE="FP-2">11. Mills, P.A. “Variation of Florisil Activity: Simple Method for Measuring Absorbent Capacity and Its Use in Standardizing Florisil Columns,” Journal of the Association of Official Analytical Chemists, 51:29, (1968).</FP>
                        <FP SOURCE="FP-2">12. 40 CFR 136.6(b)(2)(i).</FP>
                        <FP SOURCE="FP-2">13. Protocol for EPA Approval of New Methods for Organic and Inorganic Analytes in Wastewater and Drinking Water (EPA-821-B-98-003) March 1999.</FP>
                        <FP SOURCE="FP-2">14. Methods 4500 Cl F and 4500 Cl G, Standard Methods for the Examination of Water and Wastewater, published jointly by the American Public Health Association, American Water Works Association, and Water Environment Federation, 1015 Fifteenth St., Washington, DC 20005, 20th Edition, 2000.</FP>
                        <FP SOURCE="FP-2">15. “Manual of Analytical Methods for the Analysis of Pesticides in Human and Environmental Samples,” EPA-600/8-80-038, U.S. Environmental Protection Agency, Health Effects Research Laboratory, Research Triangle Park, North Carolina.</FP>
                        <FP SOURCE="FP-2">16. USEPA, 2000, Method 1656 Organo-Halide Pesticides In Wastewater, Soil, Sludge, Sediment, and Tissue by GC/HSD, EPA-821-R-00-017, September 2000.</FP>
                        <FP SOURCE="FP-2">17. USEPA, 2010, Method 1668C Chlorinated Biphenyl Congeners in Water, Soil, Sediment, Biosolids, and Tissue by HRGC/HRMS, EPA-820-R-10-005, April 2010.</FP>
                        <FP SOURCE="FP-2">18. USEPA, 2007, Method 1699: Pesticides in Water, Soil, Sediment, Biosolids, and Tissue by HRGC/HRMS, EPA-821-R-08-001, December 2007.</FP>
                        <FP SOURCE="FP-2">
                            19. “Less is Better,” American Chemical Society on-line publication, 
                            <E T="03">http://www.acs.org/content/dam/acsorg/about/governance/committees/chemicalsafety/publications/less-is-better.pdf</E>
                            .
                        </FP>
                        <FP SOURCE="FP-2">
                            20. EPA Method 608 ATP 3M0222, An alternative test procedure for the measurement of organochlorine pesticides and polychlorinated biphenyls in waste water. 
                            <E T="04">Federal Register,</E>
                             Vol. 60, No. 148 August 2, 1995.
                        </FP>
                        <HD SOURCE="HD3">21. Tables</HD>
                        <GPOTABLE COLS="4" OPTS="L2" CDEF="s100,12,12,12">
                            <TTITLE>
                                Table 1—Pesticides 
                                <SU>1</SU>
                            </TTITLE>
                            <BOXHD>
                                <CHED H="1">Analyte</CHED>
                                <CHED H="1">CAS No.</CHED>
                                <CHED H="1">
                                    MDL 
                                    <SU>2</SU>
                                    <LI>(ng/L)</LI>
                                </CHED>
                                <CHED H="1">
                                    ML 
                                    <SU>3</SU>
                                    <LI>(ng/L)</LI>
                                </CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">Aldrin</ENT>
                                <ENT>309-00-2</ENT>
                                <ENT>4</ENT>
                                <ENT>12</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">alpha</E>
                                    -BHC
                                </ENT>
                                <ENT>319-84-6</ENT>
                                <ENT>3</ENT>
                                <ENT>9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">beta</E>
                                    -BHC
                                </ENT>
                                <ENT>319-85-7</ENT>
                                <ENT>6</ENT>
                                <ENT>18</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">delta</E>
                                    -BHC
                                </ENT>
                                <ENT>319-86-8</ENT>
                                <ENT>9</ENT>
                                <ENT>27</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">gamma</E>
                                    -BHC (Lindane)
                                </ENT>
                                <ENT>58-89-9</ENT>
                                <ENT>4</ENT>
                                <ENT>12</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">alpha</E>
                                    -Chlordane 
                                    <SU>4</SU>
                                </ENT>
                                <ENT>5103-71-9</ENT>
                                <ENT>14</ENT>
                                <ENT>42</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">gamma</E>
                                    -Chlordane 
                                    <SU>4</SU>
                                </ENT>
                                <ENT>5103-74-2</ENT>
                                <ENT>14</ENT>
                                <ENT>42</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4,4′-DDD</ENT>
                                <ENT>72-54-8</ENT>
                                <ENT>11</ENT>
                                <ENT>33</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4,4′-DDE</ENT>
                                <ENT>72-55-9</ENT>
                                <ENT>4</ENT>
                                <ENT>12</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4,4′-DDT</ENT>
                                <ENT>50-29-3</ENT>
                                <ENT>12</ENT>
                                <ENT>36</ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="186"/>
                                <ENT I="01">Dieldrin</ENT>
                                <ENT>60-57-1</ENT>
                                <ENT>2</ENT>
                                <ENT>6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Endosulfan I</ENT>
                                <ENT>959-98-8</ENT>
                                <ENT>14</ENT>
                                <ENT>42</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Endosulfan II</ENT>
                                <ENT>33213-65-9</ENT>
                                <ENT>4</ENT>
                                <ENT>12</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Endosulfan sulfate</ENT>
                                <ENT>1031-07-8</ENT>
                                <ENT>66</ENT>
                                <ENT>198</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Endrin</ENT>
                                <ENT>72-20-8</ENT>
                                <ENT>6</ENT>
                                <ENT>18</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Endrin aldehyde</ENT>
                                <ENT>7421-93-4</ENT>
                                <ENT>23</ENT>
                                <ENT>70</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Heptachlor</ENT>
                                <ENT>76-44-8</ENT>
                                <ENT>3</ENT>
                                <ENT>9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Heptachlor epoxide</ENT>
                                <ENT>1024-57-3</ENT>
                                <ENT>83</ENT>
                                <ENT>249</ENT>
                            </ROW>
                            <TNOTE>
                                <SU>1</SU>
                                 All analytes in this table are Priority Pollutants (40 CFR part 423, appendix A).
                            </TNOTE>
                            <TNOTE>
                                <SU>2</SU>
                                 40 CFR part 136, appendix B, June 30, 1986.
                            </TNOTE>
                            <TNOTE>
                                <SU>3</SU>
                                 ML = Minimum Level—see Glossary for definition and derivation, calculated as 3 times the MDL.
                            </TNOTE>
                            <TNOTE>
                                <SU>4</SU>
                                 MDL based on the MDL for Chlordane.
                            </TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="4" OPTS="L2" CDEF="s100,12,12,12">
                            <TTITLE>Table 2—Additional Analytes</TTITLE>
                            <BOXHD>
                                <CHED H="1">Analyte</CHED>
                                <CHED H="1">CAS No.</CHED>
                                <CHED H="1">
                                    MDL 
                                    <SU>3</SU>
                                    <LI>(ng/L)</LI>
                                </CHED>
                                <CHED H="1">
                                    ML 
                                    <SU>4</SU>
                                    <LI>(ng/L)</LI>
                                </CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">Acephate</ENT>
                                <ENT>30560-19-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Alachlor</ENT>
                                <ENT>15972-60-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Atrazine</ENT>
                                <ENT>1912-24-9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benfluralin (Benefin)</ENT>
                                <ENT>1861-40-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Bromacil</ENT>
                                <ENT>314-40-9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Bromoxynil octanoate</ENT>
                                <ENT>1689-99-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Butachlor</ENT>
                                <ENT>23184-66-9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Captafol</ENT>
                                <ENT>2425-06-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Captan</ENT>
                                <ENT>133-06-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Carbophenothion (Trithion)</ENT>
                                <ENT>786-19-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chlorobenzilate</ENT>
                                <ENT>510-15-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chloroneb (Terraneb)</ENT>
                                <ENT>2675-77-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chloropropylate (Acaralate)</ENT>
                                <ENT>5836-10-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chlorothalonil</ENT>
                                <ENT>1897-45-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Cyanazine</ENT>
                                <ENT>21725-46-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">DCPA (Dacthal)</ENT>
                                <ENT>1861-32-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4′-DDD</ENT>
                                <ENT>53-19-0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4′-DDE</ENT>
                                <ENT>3424-82-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4′-DDT</ENT>
                                <ENT>789-02-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Diallate (Avadex)</ENT>
                                <ENT>2303-16-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2-Dibromo-3-chloropropane (DBCP)</ENT>
                                <ENT>96-12-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dichlone</ENT>
                                <ENT>117-80-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dichloran</ENT>
                                <ENT>99-30-9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dicofol</ENT>
                                <ENT>115-32-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Endrin ketone</ENT>
                                <ENT>53494-70-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ethalfluralin (Sonalan)</ENT>
                                <ENT>55283-68-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Etridiazole</ENT>
                                <ENT>2593-15-9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Fenarimol (Rubigan)</ENT>
                                <ENT>60168-88-9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Hexachlorobenzene 
                                    <SU>1</SU>
                                </ENT>
                                <ENT>118-74-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Hexachlorocyclopentadiene 
                                    <SU>1</SU>
                                </ENT>
                                <ENT>77-47-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Isodrin</ENT>
                                <ENT>465-73-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Isopropalin (Paarlan)</ENT>
                                <ENT>33820-53-0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Kepone</ENT>
                                <ENT>143-50-0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Methoxychlor</ENT>
                                <ENT>72-43-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Metolachlor</ENT>
                                <ENT>51218-45-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Metribuzin</ENT>
                                <ENT>21087-64-9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Mirex</ENT>
                                <ENT>2385-85-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Nitrofen (TOK)</ENT>
                                <ENT>1836-75-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">cis</E>
                                    -Nonachlor
                                </ENT>
                                <ENT>5103-73-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">trans-Nonachlor</ENT>
                                <ENT>39765-80-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Norfluorazon</ENT>
                                <ENT>27314-13-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Octachlorostyrene</ENT>
                                <ENT>29082-74-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Oxychlordane</ENT>
                                <ENT>27304-13-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">PCNB (Pentachloronitrobenzene)</ENT>
                                <ENT>82-68-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Pendamethalin (Prowl)</ENT>
                                <ENT>40487-42-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">cis</E>
                                    -Permethrin
                                </ENT>
                                <ENT>61949-76-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">trans</E>
                                    -Permethrin
                                </ENT>
                                <ENT>61949-77-7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Perthane (Ethylan)</ENT>
                                <ENT>72-56-0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Propachlor</ENT>
                                <ENT>1918-16-7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Propanil</ENT>
                                <ENT>709-98-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Propazine</ENT>
                                <ENT>139-40-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Quintozene</ENT>
                                <ENT>82-68-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Simazine</ENT>
                                <ENT>122-34-9</ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="187"/>
                                <ENT I="01">Strobane</ENT>
                                <ENT>8001-50-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Technazene</ENT>
                                <ENT>117-18-0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Technical Chlordane 
                                    <SU>2</SU>
                                </ENT>
                                <ENT/>
                            </ROW>
                            <ROW>
                                <ENT I="01">Terbacil</ENT>
                                <ENT>5902-51-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Terbuthylazine</ENT>
                                <ENT>5915-41-3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Toxaphene 
                                    <SU>1</SU>
                                </ENT>
                                <ENT>8001-35-2</ENT>
                                <ENT>240</ENT>
                                <ENT>720</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Trifluralin</ENT>
                                <ENT>1582-09-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    PCB-1016 
                                    <SU>1</SU>
                                </ENT>
                                <ENT>12674-11-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    PCB-1221 
                                    <SU>1</SU>
                                </ENT>
                                <ENT>11104-28-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    PCB-1232 
                                    <SU>1</SU>
                                </ENT>
                                <ENT>11141-16-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    PCB-1242 
                                    <SU>1</SU>
                                </ENT>
                                <ENT>53469-21-9</ENT>
                                <ENT>65</ENT>
                                <ENT>95</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    PCB-1248 
                                    <SU>1</SU>
                                </ENT>
                                <ENT>12672-29-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    PCB-1254 
                                    <SU>1</SU>
                                </ENT>
                                <ENT>11097-69-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    PCB-1260 
                                    <SU>1</SU>
                                </ENT>
                                <ENT>11096-82-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">PCB-1268</ENT>
                                <ENT>11100-14-4</ENT>
                            </ROW>
                            <TNOTE>
                                <SU>1</SU>
                                 Priority Pollutants (40 CFR part 423, appendix A).
                            </TNOTE>
                            <TNOTE>
                                <SU>2</SU>
                                 Technical Chlordane may be used in cases where historical reporting has only been for this form of Chlordane.
                            </TNOTE>
                            <TNOTE>
                                <SU>3</SU>
                                 40 CFR part 136, appendix B, June 30, 1986.
                            </TNOTE>
                            <TNOTE>
                                <SU>4</SU>
                                 ML = Minimum Level—see Glossary for definition and derivation, calculated as 3 times the MDL.
                            </TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="3" OPTS="L2" CDEF="s100,12,12">
                            <TTITLE>
                                Table 3—Example Retention Times 
                                <SU>1</SU>
                            </TTITLE>
                            <BOXHD>
                                <CHED H="1">Analyte</CHED>
                                <CHED H="1">
                                    Retention time
                                    <LI>
                                        (min) 
                                        <SU>2</SU>
                                    </LI>
                                </CHED>
                                <CHED H="2">DB-608</CHED>
                                <CHED H="2">DB-1701</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">Acephate</ENT>
                                <ENT>5.03</ENT>
                                <ENT>
                                    (
                                    <SU>3</SU>
                                    )
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Trifluralin</ENT>
                                <ENT>5.16</ENT>
                                <ENT>6.79</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ethalfluralin</ENT>
                                <ENT>5.28</ENT>
                                <ENT>6.49</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benfluralin</ENT>
                                <ENT>5.53</ENT>
                                <ENT>6.87</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Diallate-A</ENT>
                                <ENT>7.15</ENT>
                                <ENT>6.23</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Diallate-B</ENT>
                                <ENT>7.42</ENT>
                                <ENT>6.77</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">alpha</E>
                                    -BHC
                                </ENT>
                                <ENT>8.14</ENT>
                                <ENT>7.44</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">PCNB</ENT>
                                <ENT>9.03</ENT>
                                <ENT>7.58</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Simazine</ENT>
                                <ENT>9.06</ENT>
                                <ENT>9.29</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Atrazine</ENT>
                                <ENT>9.12</ENT>
                                <ENT>9.12</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Terbuthylazine</ENT>
                                <ENT>9.17</ENT>
                                <ENT>9.46</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">gamma</E>
                                    -BHC (Lindane)
                                </ENT>
                                <ENT>9.52</ENT>
                                <ENT>9.91</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">beta</E>
                                    -BHC
                                </ENT>
                                <ENT>9.86</ENT>
                                <ENT>11.90</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Heptachlor</ENT>
                                <ENT>10.66</ENT>
                                <ENT>10.55</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chlorothalonil</ENT>
                                <ENT>10.66</ENT>
                                <ENT>10.96</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dichlone</ENT>
                                <ENT>10.80</ENT>
                                <ENT>
                                    (
                                    <SU>4</SU>
                                    )
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Terbacil</ENT>
                                <ENT>11.11</ENT>
                                <ENT>12.63</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">delta</E>
                                    -BHC
                                </ENT>
                                <ENT>11.20</ENT>
                                <ENT>12.98</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Alachlor</ENT>
                                <ENT>11.57</ENT>
                                <ENT>11.06</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Propanil</ENT>
                                <ENT>11.60</ENT>
                                <ENT>14.10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Aldrin</ENT>
                                <ENT>11.84</ENT>
                                <ENT>11.46</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">DCPA</ENT>
                                <ENT>12.18</ENT>
                                <ENT>12.09</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Metribuzin</ENT>
                                <ENT>12.80</ENT>
                                <ENT>11.68</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Triadimefon</ENT>
                                <ENT>12.99</ENT>
                                <ENT>13.57</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Isopropalin</ENT>
                                <ENT>13.06</ENT>
                                <ENT>13.37</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Isodrin</ENT>
                                <ENT>13.47</ENT>
                                <ENT>11.12</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Heptachlor epoxide</ENT>
                                <ENT>13.97</ENT>
                                <ENT>12.56</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Pendamethalin</ENT>
                                <ENT>14.21</ENT>
                                <ENT>13.46</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Bromacil</ENT>
                                <ENT>14.39</ENT>
                                <ENT>
                                    (
                                    <SU>3</SU>
                                    )
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">alpha</E>
                                    -Chlordane
                                </ENT>
                                <ENT>14.63</ENT>
                                <ENT>14.20</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Butachlor</ENT>
                                <ENT>15.03</ENT>
                                <ENT>15.69</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">gamma</E>
                                    -Chlordane
                                </ENT>
                                <ENT>15.24</ENT>
                                <ENT>14.36</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Endosulfan I</ENT>
                                <ENT>15.25</ENT>
                                <ENT>13.87</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4,4′-DDE</ENT>
                                <ENT>16.34</ENT>
                                <ENT>14.84</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dieldrin</ENT>
                                <ENT>16.41</ENT>
                                <ENT>15.25</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Captan</ENT>
                                <ENT>16.83</ENT>
                                <ENT>15.43</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chlorobenzilate</ENT>
                                <ENT>17.58</ENT>
                                <ENT>17.28</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Endrin</ENT>
                                <ENT>17.80</ENT>
                                <ENT>15.86</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Nitrofen (TOK)</ENT>
                                <ENT>17.86</ENT>
                                <ENT>17.47</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Kepone</ENT>
                                <ENT>17.92</ENT>
                                <ENT>
                                    (
                                    <SU>3 5</SU>
                                    )
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4,4′-DDD</ENT>
                                <ENT>18.43</ENT>
                                <ENT>17.77</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Endosulfan II</ENT>
                                <ENT>18.45</ENT>
                                <ENT>18.57</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Bromoxynil octanoate</ENT>
                                <ENT>18.85</ENT>
                                <ENT>18.57</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4,4′-DDT</ENT>
                                <ENT>19.48</ENT>
                                <ENT>18.32</ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="188"/>
                                <ENT I="01">Carbophenothion</ENT>
                                <ENT>19.65</ENT>
                                <ENT>18.21</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Endrin aldehyde</ENT>
                                <ENT>19.72</ENT>
                                <ENT>19.18</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Endosulfan sulfate</ENT>
                                <ENT>20.21</ENT>
                                <ENT>20.37</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Captafol</ENT>
                                <ENT>22.51</ENT>
                                <ENT>21.22</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Norfluorazon</ENT>
                                <ENT>20.68</ENT>
                                <ENT>22.01</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Mirex</ENT>
                                <ENT>22.75</ENT>
                                <ENT>19.79</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Methoxychlor</ENT>
                                <ENT>22.80</ENT>
                                <ENT>20.68</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Endrin ketone</ENT>
                                <ENT>23.00</ENT>
                                <ENT>21.79</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Fenarimol</ENT>
                                <ENT>24.53</ENT>
                                <ENT>23.79</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">cis</E>
                                    -Permethrin
                                </ENT>
                                <ENT>25.00</ENT>
                                <ENT>23.59</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">trans</E>
                                    -Permethrin
                                </ENT>
                                <ENT>25.62</ENT>
                                <ENT>23.92</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">PCB-1016</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">PCB-1221</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">PCB-1232</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">PCB-1242</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">PCB-1248</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">PCB-1254</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">PCB-1260 (5 peaks)</ENT>
                                <ENT>15.44</ENT>
                                <ENT>14.64</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>15.73</ENT>
                                <ENT>15.36</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>16.94</ENT>
                                <ENT>16.53</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>17.28</ENT>
                                <ENT>18.70</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>19.17</ENT>
                                <ENT>19.92</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Toxaphene (5 peaks)</ENT>
                                <ENT>16.60</ENT>
                                <ENT>16.60</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>17.37</ENT>
                                <ENT>17.52</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>18.11</ENT>
                                <ENT>17.92</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>19.46</ENT>
                                <ENT>18.73</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>19.69</ENT>
                                <ENT>19.00</ENT>
                            </ROW>
                            <TNOTE>
                                <SU>1</SU>
                                 Data from EPA Method 1656 (Reference 16).
                            </TNOTE>
                            <TNOTE>
                                <SU>2</SU>
                                 Columns: 30-m long x 0.53-mm ID fused-silica capillary; DB-608, 0.83 µm; and DB-1701, 1.0 µm.
                            </TNOTE>
                            <TNOTE>
                                Conditions suggested to meet retention times shown: 150 °C for 0.5 minute, 150-270 °C at 5 °C/min, and 270 °C until 
                                <E T="03">trans</E>
                                -Permethrin elutes.
                            </TNOTE>
                            <TNOTE>Carrier gas flow rates approximately 7 mL/min.</TNOTE>
                            <TNOTE>
                                <SU>3</SU>
                                 Does not elute from DB-1701 column at level tested.
                            </TNOTE>
                            <TNOTE>
                                <SU>4</SU>
                                 Not recovered from water at the levels tested.
                            </TNOTE>
                            <TNOTE>
                                <SU>5</SU>
                                 Dichlone and Kepone do not elute from the DB-1701 column and should be confirmed on DB-5.
                            </TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="7" OPTS="L2" CDEF="s50,12,12,12,12,12,12">
                            <TTITLE>Table 4—QC Acceptance Criteria</TTITLE>
                            <BOXHD>
                                <CHED H="1">Analyte</CHED>
                                <CHED H="1">
                                    Calibration verification
                                    <LI>(%)</LI>
                                </CHED>
                                <CHED H="1">
                                    Test
                                    <LI>concentration</LI>
                                    <LI>(µg/L)</LI>
                                </CHED>
                                <CHED H="1">
                                    Limit for s
                                    <LI>(% SD)</LI>
                                </CHED>
                                <CHED H="1">
                                    Range for 
                                    <E T="7501">X</E>
                                    <LI>(%)</LI>
                                </CHED>
                                <CHED H="1">
                                    Range for P
                                    <LI>(%)</LI>
                                </CHED>
                                <CHED H="1">
                                    Maximum
                                    <LI>MS/MSD</LI>
                                    <LI>RPD</LI>
                                    <LI>(%)</LI>
                                </CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">Aldrin</ENT>
                                <ENT>75-125</ENT>
                                <ENT>2.0</ENT>
                                <ENT>25</ENT>
                                <ENT>54-130</ENT>
                                <ENT>42-140</ENT>
                                <ENT>35</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">alpha</E>
                                    -BHC
                                </ENT>
                                <ENT>69-125</ENT>
                                <ENT>2.0</ENT>
                                <ENT>28</ENT>
                                <ENT>49-130</ENT>
                                <ENT>37-140</ENT>
                                <ENT>36</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">beta</E>
                                    -BHC
                                </ENT>
                                <ENT>75-125</ENT>
                                <ENT>2.0</ENT>
                                <ENT>38</ENT>
                                <ENT>39-130</ENT>
                                <ENT>17-147</ENT>
                                <ENT>44</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">delta</E>
                                    -BHC
                                </ENT>
                                <ENT>75-125</ENT>
                                <ENT>2.0</ENT>
                                <ENT>43</ENT>
                                <ENT>51-130</ENT>
                                <ENT>19-140</ENT>
                                <ENT>52</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">gamma</E>
                                    -BHC
                                </ENT>
                                <ENT>75-125</ENT>
                                <ENT>2.0</ENT>
                                <ENT>29</ENT>
                                <ENT>43-130</ENT>
                                <ENT>32-140</ENT>
                                <ENT>39</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">alpha</E>
                                    -Chlordane
                                </ENT>
                                <ENT>73-125</ENT>
                                <ENT>50.0</ENT>
                                <ENT>24</ENT>
                                <ENT>55-130</ENT>
                                <ENT>45-140</ENT>
                                <ENT>35</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">gamma</E>
                                    -Chlordane
                                </ENT>
                                <ENT>75-125</ENT>
                                <ENT>50.0</ENT>
                                <ENT>24</ENT>
                                <ENT>55-130</ENT>
                                <ENT>45-140</ENT>
                                <ENT>35</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4,4′-DDD</ENT>
                                <ENT>75-125</ENT>
                                <ENT>10.0</ENT>
                                <ENT>32</ENT>
                                <ENT>48-130</ENT>
                                <ENT>31-141</ENT>
                                <ENT>39</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4,4′-DDE</ENT>
                                <ENT>75-125</ENT>
                                <ENT>2.0</ENT>
                                <ENT>30</ENT>
                                <ENT>54-130</ENT>
                                <ENT>30-145</ENT>
                                <ENT>35</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4,4′-DDT</ENT>
                                <ENT>75-125</ENT>
                                <ENT>10.0</ENT>
                                <ENT>39</ENT>
                                <ENT>46-137</ENT>
                                <ENT>25-160</ENT>
                                <ENT>42</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dieldrin</ENT>
                                <ENT>48-125</ENT>
                                <ENT>2.0</ENT>
                                <ENT>42</ENT>
                                <ENT>58-130</ENT>
                                <ENT>36-146</ENT>
                                <ENT>49</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Endosulfan I</ENT>
                                <ENT>75-125</ENT>
                                <ENT>2.0</ENT>
                                <ENT>25</ENT>
                                <ENT>57-141</ENT>
                                <ENT>45-153</ENT>
                                <ENT>28</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Endosulfan II</ENT>
                                <ENT>75-125</ENT>
                                <ENT>10.0</ENT>
                                <ENT>63</ENT>
                                <ENT>22-171</ENT>
                                <ENT>D-202</ENT>
                                <ENT>53</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Endosulfan sulfate</ENT>
                                <ENT>70-125</ENT>
                                <ENT>10.0</ENT>
                                <ENT>32</ENT>
                                <ENT>38-132</ENT>
                                <ENT>26-144</ENT>
                                <ENT>38</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Endrin</ENT>
                                <ENT>5-125</ENT>
                                <ENT>10.0</ENT>
                                <ENT>42</ENT>
                                <ENT>51-130</ENT>
                                <ENT>30-147</ENT>
                                <ENT>48</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Heptachlor</ENT>
                                <ENT>75-125</ENT>
                                <ENT>2.0</ENT>
                                <ENT>28</ENT>
                                <ENT>43-130</ENT>
                                <ENT>34-140</ENT>
                                <ENT>43</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Heptachlor epoxide</ENT>
                                <ENT>75-125</ENT>
                                <ENT>2.0</ENT>
                                <ENT>22</ENT>
                                <ENT>57-132</ENT>
                                <ENT>37-142</ENT>
                                <ENT>26</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Toxaphene</ENT>
                                <ENT>68-134</ENT>
                                <ENT>50.0</ENT>
                                <ENT>30</ENT>
                                <ENT>56-130</ENT>
                                <ENT>41-140</ENT>
                                <ENT>41</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">PCB-1016</ENT>
                                <ENT>75-125</ENT>
                                <ENT>50.0</ENT>
                                <ENT>24</ENT>
                                <ENT>61-103</ENT>
                                <ENT>50-140</ENT>
                                <ENT>36</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">PCB-1221</ENT>
                                <ENT>75-125</ENT>
                                <ENT>50.0</ENT>
                                <ENT>50</ENT>
                                <ENT>44-150</ENT>
                                <ENT>15-178</ENT>
                                <ENT>48</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">PCB-1232</ENT>
                                <ENT>75-125</ENT>
                                <ENT>50.0</ENT>
                                <ENT>32</ENT>
                                <ENT>28-197</ENT>
                                <ENT>10-215</ENT>
                                <ENT>25</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">PCB-1242</ENT>
                                <ENT>75-125</ENT>
                                <ENT>50.0</ENT>
                                <ENT>26</ENT>
                                <ENT>50-139</ENT>
                                <ENT>39-150</ENT>
                                <ENT>29</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">PCB-1248</ENT>
                                <ENT>75-125</ENT>
                                <ENT>50.0</ENT>
                                <ENT>32</ENT>
                                <ENT>58-140</ENT>
                                <ENT>38-158</ENT>
                                <ENT>35</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">PCB-1254</ENT>
                                <ENT>75-125</ENT>
                                <ENT>50.0</ENT>
                                <ENT>34</ENT>
                                <ENT>44-130</ENT>
                                <ENT>29-140</ENT>
                                <ENT>45</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">PCB-1260</ENT>
                                <ENT>75-125</ENT>
                                <ENT>50.0</ENT>
                                <ENT>28</ENT>
                                <ENT>37-130</ENT>
                                <ENT>8-140</ENT>
                                <ENT>38</ENT>
                            </ROW>
                            <TNOTE>S = Standard deviation of four recovery measurements for the DOC (section 8.2.4).</TNOTE>
                            <TNOTE>
                                <E T="7501">X</E>
                                 = Average of four recovery measurements for the DOC (section 8.2.4).
                                <PRTPAGE P="189"/>
                            </TNOTE>
                            <TNOTE>P = Recovery for the LCS (section 8.4.3).</TNOTE>
                            <TNOTE>
                                <E T="02">Note:</E>
                                 These criteria were developed from data in Table 5 (Reference 2). Where necessary, limits for recovery have been broadened to assure applicability to concentrations below those in Table 5.
                            </TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="4" OPTS="L2" CDEF="s50,15,15,15">
                            <TTITLE>Table 5—Precision and Recovery as Functions of Concentration</TTITLE>
                            <BOXHD>
                                <CHED H="1">Analyte</CHED>
                                <CHED H="1">
                                    Recovery, X′
                                    <LI>(µg/L)</LI>
                                </CHED>
                                <CHED H="1">
                                    Single analyst
                                    <LI>
                                        precision, s
                                        <E T="0732">r</E>
                                        ′
                                    </LI>
                                    <LI>(µg/L)</LI>
                                </CHED>
                                <CHED H="1">
                                    Overall
                                    <LI>precision, S′</LI>
                                    <LI>(µg/L)</LI>
                                </CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">Aldrin</ENT>
                                <ENT>0.81C + 0.04</ENT>
                                <ENT>
                                    0.16(
                                    <E T="7501">X</E>
                                    ) − 0.04
                                </ENT>
                                <ENT>
                                    0.20(
                                    <E T="7501">X</E>
                                    ) − 0.01
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">alpha</E>
                                    -BHC
                                </ENT>
                                <ENT>0.84C + 0.03</ENT>
                                <ENT>
                                    0.13(
                                    <E T="7501">X</E>
                                    ) + 0.04
                                </ENT>
                                <ENT>
                                    0.23(
                                    <E T="7501">X</E>
                                    ) − 0.00
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">beta</E>
                                    -BHC
                                </ENT>
                                <ENT>0.81C + 0.07</ENT>
                                <ENT>
                                    0.22(
                                    <E T="7501">X</E>
                                    ) − 0.02
                                </ENT>
                                <ENT>
                                    0.33(
                                    <E T="7501">X</E>
                                    ) − 0.05
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">delta</E>
                                    -BHC
                                </ENT>
                                <ENT>0.81C + 0.07</ENT>
                                <ENT>
                                    0.18(
                                    <E T="7501">X</E>
                                    ) + 0.09
                                </ENT>
                                <ENT>
                                    0.25(
                                    <E T="7501">X</E>
                                    ) + 0.03
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">gamma</E>
                                    -BHC (Lindane)
                                </ENT>
                                <ENT>0.82C − 0.05</ENT>
                                <ENT>
                                    0.12(
                                    <E T="7501">X</E>
                                    ) + 0.06
                                </ENT>
                                <ENT>
                                    0.22(
                                    <E T="7501">X</E>
                                    ) + 0.04
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chlordane</ENT>
                                <ENT>0.82C − 0.04</ENT>
                                <ENT>
                                    0.13(
                                    <E T="7501">X</E>
                                    ) + 0.13
                                </ENT>
                                <ENT>
                                    0.18(
                                    <E T="7501">X</E>
                                    ) + 0.18
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4,4′-DDD</ENT>
                                <ENT>0.84C + 0.30</ENT>
                                <ENT>
                                    0.20(
                                    <E T="7501">X</E>
                                    ) − 0.18
                                </ENT>
                                <ENT>
                                    0.27(
                                    <E T="7501">X</E>
                                    ) − 0.14
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4,4′-DDE</ENT>
                                <ENT>0.85C + 0.14</ENT>
                                <ENT>
                                    0.13(
                                    <E T="7501">X</E>
                                    ) + 0.06
                                </ENT>
                                <ENT>
                                    0.28(
                                    <E T="7501">X</E>
                                    ) − 0.09
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4,4′-DDT</ENT>
                                <ENT>0.93C − 0.13</ENT>
                                <ENT>
                                    0.17(
                                    <E T="7501">X</E>
                                    ) + 0.39
                                </ENT>
                                <ENT>
                                    0.31(
                                    <E T="7501">X</E>
                                    ) − 0.21
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dieldrin</ENT>
                                <ENT>0.90C + 0.02</ENT>
                                <ENT>
                                    0.12(
                                    <E T="7501">X</E>
                                    ) + 0.19
                                </ENT>
                                <ENT>
                                    0.16(
                                    <E T="7501">X</E>
                                    ) + 0.16
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Endosulfan I</ENT>
                                <ENT>0.97C + 0.04</ENT>
                                <ENT>
                                    0.10(
                                    <E T="7501">X</E>
                                    ) + 0.07
                                </ENT>
                                <ENT>
                                    0.18(
                                    <E T="7501">X</E>
                                    ) + 0.08
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Endosulfan II</ENT>
                                <ENT>0.93C + 0.34</ENT>
                                <ENT>
                                    0.41(
                                    <E T="7501">X</E>
                                    ) − 0.65
                                </ENT>
                                <ENT>
                                    0.47(
                                    <E T="7501">X</E>
                                    ) − 0.20
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Endosulfan sulfate</ENT>
                                <ENT>0.89C − 0.37</ENT>
                                <ENT>
                                    0.13(
                                    <E T="7501">X</E>
                                    ) + 0.33
                                </ENT>
                                <ENT>
                                    0.24(
                                    <E T="7501">X</E>
                                    ) + 0.35
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Endrin</ENT>
                                <ENT>0.89C − 0.04</ENT>
                                <ENT>
                                    0.20(
                                    <E T="7501">X</E>
                                    ) + 0.25
                                </ENT>
                                <ENT>
                                    0.24(
                                    <E T="7501">X</E>
                                    ) + 0.25
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Heptachlor</ENT>
                                <ENT>0.69C + 0.04</ENT>
                                <ENT>
                                    0.06(
                                    <E T="7501">X</E>
                                    ) + 0.13
                                </ENT>
                                <ENT>
                                    0.16(
                                    <E T="7501">X</E>
                                    ) + 0.08
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Heptachlor epoxide</ENT>
                                <ENT>0.89C + 0.10</ENT>
                                <ENT>
                                    0.18(
                                    <E T="7501">X</E>
                                    ) − 0.11
                                </ENT>
                                <ENT>
                                    0.25(
                                    <E T="7501">X</E>
                                    ) − 0.08
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Toxaphene</ENT>
                                <ENT>0.80C + 1.74</ENT>
                                <ENT>
                                    0.09(
                                    <E T="7501">X</E>
                                    ) + 3.20
                                </ENT>
                                <ENT>
                                    0.20(
                                    <E T="7501">X</E>
                                    ) + 0.22
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">PCB-1016</ENT>
                                <ENT>0.81C + 0.50</ENT>
                                <ENT>
                                    0.13(
                                    <E T="7501">X</E>
                                    ) + 0.15
                                </ENT>
                                <ENT>
                                    0.15(
                                    <E T="7501">X</E>
                                    ) + 0.45
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">PCB-1221</ENT>
                                <ENT>0.96C + 0.65</ENT>
                                <ENT>
                                    0.29(
                                    <E T="7501">X</E>
                                    ) − 0.76
                                </ENT>
                                <ENT>
                                    0.35(
                                    <E T="7501">X</E>
                                    ) − 0.62
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">PCB-1232</ENT>
                                <ENT>0.91C + 10.8</ENT>
                                <ENT>
                                    0.21(
                                    <E T="7501">X</E>
                                    ) − 1.93
                                </ENT>
                                <ENT>
                                    0.31(
                                    <E T="7501">X</E>
                                    ) + 3.50
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">PCB-1242</ENT>
                                <ENT>0.93C + 0.70</ENT>
                                <ENT>
                                    0.11(
                                    <E T="7501">X</E>
                                    ) + 1.40
                                </ENT>
                                <ENT>
                                    0.21(
                                    <E T="7501">X</E>
                                    ) + 1.52
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">PCB-1248</ENT>
                                <ENT>0.97C + 1.06</ENT>
                                <ENT>
                                    0.17(
                                    <E T="7501">X</E>
                                    ) + 0.41
                                </ENT>
                                <ENT>
                                    0.25(
                                    <E T="7501">X</E>
                                    ) − 0.37
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">PCB-1254</ENT>
                                <ENT>0.76C + 2.07</ENT>
                                <ENT>
                                    0.15(
                                    <E T="7501">X</E>
                                    ) + 1.66
                                </ENT>
                                <ENT>
                                    0.17(
                                    <E T="7501">X</E>
                                    ) + 3.62
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">PCB-1260</ENT>
                                <ENT>0.66C + 3.76</ENT>
                                <ENT>
                                    0.22(
                                    <E T="7501">X</E>
                                    ) − 2.37
                                </ENT>
                                <ENT>
                                    0.39(
                                    <E T="7501">X</E>
                                    ) − 4.86
                                </ENT>
                            </ROW>
                            <TNOTE>X′ = Expected recovery for one or more measurements of a sample containing a concentration of C, in µg/L.</TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="4" OPTS="L2" CDEF="s50,12,12,12">
                            <TTITLE>Table 6—Distribution of Chlorinated Pesticides and PCBs Into Florisil® Column Fractions</TTITLE>
                            <BOXHD>
                                <CHED H="1">Analyte</CHED>
                                <CHED H="1">
                                    Percent Recovery by Fraction 
                                    <SU>1</SU>
                                </CHED>
                                <CHED H="2">1</CHED>
                                <CHED H="2">2</CHED>
                                <CHED H="2">3</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">Aldrin</ENT>
                                <ENT>100</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">alpha</E>
                                    -BHC
                                </ENT>
                                <ENT>100</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">beta</E>
                                    -BHC
                                </ENT>
                                <ENT>97</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">delta</E>
                                    -BHC
                                </ENT>
                                <ENT>98</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">gamma</E>
                                    -BHC (Lindane)
                                </ENT>
                                <ENT>100</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chlordane</ENT>
                                <ENT>100</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4,4′-DDD</ENT>
                                <ENT>99</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4,4′-DDE</ENT>
                                <ENT/>
                                <ENT>98</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4,4′-DDT</ENT>
                                <ENT>100</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dieldrin</ENT>
                                <ENT>0</ENT>
                                <ENT>100</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Endosulfan I</ENT>
                                <ENT>37</ENT>
                                <ENT>64</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Endosulfan II</ENT>
                                <ENT>0</ENT>
                                <ENT>7</ENT>
                                <ENT>91</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Endosulfan sulfate</ENT>
                                <ENT>0</ENT>
                                <ENT>0</ENT>
                                <ENT>106</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Endrin</ENT>
                                <ENT>4</ENT>
                                <ENT>96</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Endrin aldehyde</ENT>
                                <ENT>0</ENT>
                                <ENT>68</ENT>
                                <ENT>26</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Heptachlor</ENT>
                                <ENT>100</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Heptachlor epoxide</ENT>
                                <ENT>100</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Toxaphene</ENT>
                                <ENT>96</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">PCB-1016</ENT>
                                <ENT>97</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">PCB-1221</ENT>
                                <ENT>97</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">PCB-1232</ENT>
                                <ENT>95</ENT>
                                <ENT>4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">PCB-1242</ENT>
                                <ENT>97</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">PCB-1248</ENT>
                                <ENT>103</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">PCB-1254</ENT>
                                <ENT>90</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">PCB-1260</ENT>
                            </ROW>
                            <TNOTE>
                                <SU>1</SU>
                                 Eluant composition:
                            </TNOTE>
                            <TNOTE>Fraction 1—6% ethyl ether in hexane.</TNOTE>
                            <TNOTE>Fraction 2—15% ethyl ether in hexane.</TNOTE>
                            <TNOTE>Fraction 3—50% ethyl ether in hexane.</TNOTE>
                        </GPOTABLE>
                        <PRTPAGE P="190"/>
                        <GPOTABLE COLS="1" OPTS="L2" CDEF="s100">
                            <TTITLE>
                                Table 7—Suggested Calibration Groups 
                                <SU>1</SU>
                            </TTITLE>
                            <BOXHD>
                                <CHED H="1">Analyte</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="22">
                                    <E T="03">Calibration Group 1:</E>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">Acephate</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">Alachlor</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">Atrazine</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">
                                    <E T="03">beta</E>
                                    -BHC
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">Bromoxynil octanoate</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">Captafol</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">Diallate</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">Endosulfan sulfate</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">Endrin</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">Isodrin</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">Pendimethalin (Prowl)</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">
                                    <E T="03">trans</E>
                                    -Permethrin
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22">
                                    <E T="03">Calibration Group 2:</E>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">
                                    <E T="03">alpha</E>
                                    -BHC
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">DCPA</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">4,4′-DDE</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">4,4′-DDT</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">Dichlone</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">Ethalfluralin</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">Fenarimol</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">Methoxychlor</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">Metribuzin</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22">
                                    <E T="03">Calibration Group 3:</E>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">
                                    <E T="03">gamma</E>
                                    -BHC (Lindane)
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">
                                    <E T="03">gamma</E>
                                    -Chlordane
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">Endrin ketone</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">Heptachlor epoxide</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">Isopropalin</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">Nitrofen (TOK)</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">PCNB</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">
                                    <E T="03">cis</E>
                                    -Permethrin
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">Trifluralin</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22">
                                    <E T="03">Callibration Group 4:</E>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">Benfluralin</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">Chlorobenzilate</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">Dieldrin</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">Endosulfan I</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">Mirex</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">Terbacil</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">Terbuthylazine</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">Triadimefon</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22">
                                    <E T="03">Calibration Group 5:</E>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">
                                    <E T="03">alpha-</E>
                                    Chlordane
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">Captan</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">Chlorothalonil</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">4,4′-DDD</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">Norfluorazon</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">Simazine</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22">
                                    <E T="03">Calibration Group 6:</E>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">Aldrin</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">
                                    <E T="03">delta-</E>
                                    BHC
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">Bromacil</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">Butachlor</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">Endosulfan II</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">Heptachlor</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">Kepone</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22">
                                    <E T="03">Calibration Group 7:</E>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">Carbophenothion</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">Chloroneb</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">Chloropropylate</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">DBCP</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">Dicofol</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">Endrin aldehyde</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">Etridiazone</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">Perthane</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">Propachlor</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">Propanil</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">Propazine</ENT>
                            </ROW>
                            <TNOTE>
                                <SU>1</SU>
                                 The analytes may be organized in other calibration groups, provided that there are no coelution problems and that all QC requirements are met.
                            </TNOTE>
                        </GPOTABLE>
                        <HD SOURCE="HD3">22. Figures</HD>
                        <GPH SPAN="2" DEEP="267">
                            <PRTPAGE P="191"/>
                            <GID>ER28AU17.010</GID>
                        </GPH>
                        <GPH SPAN="2" DEEP="458">
                            <PRTPAGE P="192"/>
                            <GID>ER28AU17.011</GID>
                        </GPH>
                        <HD SOURCE="HD3">23. Glossary</HD>
                        <P>These definitions and purposes are specific to this method but have been conformed to common usage to the extent possible.</P>
                        <P>23.1 Units of weight and measure and their abbreviations.</P>
                        <P>23.1.1 Symbols.</P>
                        <FP SOURCE="FP-1"> °C degrees Celsius</FP>
                        <FP SOURCE="FP-1">
                            µg microgram
                            <PRTPAGE P="193"/>
                        </FP>
                        <FP SOURCE="FP-1">µL microliter</FP>
                        <FP SOURCE="FP-1">&lt; less than</FP>
                        <FP SOURCE="FP-1">≤ less than or equal to</FP>
                        <FP SOURCE="FP-1">&gt; greater than</FP>
                        <FP SOURCE="FP-1">% percent</FP>
                        <P>23.1.2 Abbreviations (in alphabetical order).</P>
                        <FP SOURCE="FP-1">cm centimeter</FP>
                        <FP SOURCE="FP-1">g gram</FP>
                        <FP SOURCE="FP-1">hr hour</FP>
                        <FP SOURCE="FP-1">ID inside diameter</FP>
                        <FP SOURCE="FP-1">in. inch</FP>
                        <FP SOURCE="FP-1">L liter</FP>
                        <FP SOURCE="FP-1">M molar solution—one mole or gram molecular weight of solute in one liter of solution</FP>
                        <FP SOURCE="FP-1">mg milligram</FP>
                        <FP SOURCE="FP-1">min minute</FP>
                        <FP SOURCE="FP-1">mL milliliter</FP>
                        <FP SOURCE="FP-1">mm millimeter</FP>
                        <FP SOURCE="FP-1">N Normality—one equivalent of solute in one liter of solution</FP>
                        <FP SOURCE="FP-1">ng nanogram</FP>
                        <FP SOURCE="FP-1">psia pounds-per-square inch absolute</FP>
                        <FP SOURCE="FP-1">psig pounds-per-square inch gauge</FP>
                        <FP SOURCE="FP-1">v/v volume per unit volume</FP>
                        <FP SOURCE="FP-1">w/v weight per unit volume</FP>
                        <P>23.2 Definitions and acronyms (in alphabetical order)</P>
                        <P>Analyte—A compound or mixture of compounds (e.g., PCBs) tested for by this method. The analytes are listed in Tables 1 and 2.</P>
                        <P>Analytical batch—The set of samples analyzed on a given instrument during a 24-hour period that begins and ends with calibration verification (sections 7.8 and 13). See also “Extraction batch.”</P>
                        <P>Blank (method blank; laboratory blank)—An aliquot of reagent water that is treated exactly as a sample including exposure to all glassware, equipment, solvents, reagents, internal standards, and surrogates that are used with samples. The blank is used to determine if analytes or interferences are present in the laboratory environment, the reagents, or the apparatus.</P>
                        <P>Calibration factor (CF)—See section 7.5.1.</P>
                        <P>Calibration standard—A solution prepared from stock solutions and/or a secondary standards and containing the analytes of interest, surrogates, and internal standards. This standard is used to model the response of the GC instrument against analyte concentration.</P>
                        <P>Calibration verification—The process of confirming that the response of the analytical system remains within specified limits of the calibration.</P>
                        <P>Calibration verification standard—The standard (section 6.8.4) used to verify calibration (sections 7.8 and 13.6).</P>
                        <P>Extraction Batch—A set of up to 20 field samples (not including QC samples) started through the extraction process in a given 24-hour shift. Each extraction batch of 20 or fewer samples must be accompanied by a blank (section 8.5), a laboratory control sample (LCS, section 8.4), a matrix spike and duplicate (MS/MSD; section 8.3), resulting in a minimum of five samples (1 field sample, 1 blank, 1 LCS, 1 MS, and 1 MSD) and a maximum of 24 samples (20 field samples, 1 blank, 1 LCS, 1 MS, and 1 MSD) for the batch. If greater than 20 samples are to be extracted in a 24-hour shift, the samples must be separated into extraction batches of 20 or fewer samples.</P>
                        <P>Field Duplicates—Two samples collected at the same time and place under identical conditions, and treated identically throughout field and laboratory procedures. Results of analyses the field duplicates provide an estimate of the precision associated with sample collection, preservation, and storage, as well as with laboratory procedures.</P>
                        <P>Field blank—An aliquot of reagent water or other reference matrix that is placed in a sample container in the field, and treated as a sample in all respects, including exposure to sampling site conditions, storage, preservation, and all analytical procedures. The purpose of the field blank is to determine if the field or sample transporting procedures and environments have contaminated the sample. See also “Blank.”</P>
                        <P>GC—Gas chromatograph or gas chromatography.</P>
                        <P>Gel-permeation chromatography (GPC)—A form of liquid chromatography in which the analytes are separated based on exclusion from the solid phase by size.</P>
                        <P>Internal standard—A compound added to an extract or standard solution in a known amount and used as a reference for quantitation of the analytes of interest and surrogates. Also see Internal standard quantitation.</P>
                        <P>Internal standard quantitation—A means of determining the concentration of an analyte of interest (Tables 1 and 2) by reference to a compound not expected to be found in a sample.</P>
                        <P>IDC—Initial Demonstration of Capability (section 8.2); four aliquots of a reference matrix spiked with the analytes of interest and analyzed to establish the ability of the laboratory to generate acceptable precision and recovery. An IDC is performed prior to the first time this method is used and any time the method or instrumentation is modified.</P>
                        <P>Laboratory Control Sample (LCS; laboratory fortified blank; section 8.4)—An aliquot of reagent water spiked with known quantities of the analytes of interest and surrogates. The LCS is analyzed exactly like a sample. Its purpose is to assure that the results produced by the laboratory remain within the limits specified in this method for precision and recovery.</P>
                        <P>Laboratory Fortified Sample Matrix—See Matrix spike.</P>
                        <P>
                            Laboratory reagent blank—See blank.
                            <PRTPAGE P="194"/>
                        </P>
                        <P>Matrix spike (MS) and matrix spike duplicate (MSD) (laboratory fortified sample matrix and duplicate)—Two aliquots of an environmental sample to which known quantities of the analytes of interest and surrogates are added in the laboratory. The MS/MSD are prepared and analyzed exactly like a field sample. Their purpose is to quantify any additional bias and imprecision caused by the sample matrix. The background concentrations of the analytes in the sample matrix must be determined in a separate aliquot and the measured values in the MS/MSD corrected for background concentrations.</P>
                        <P>May—This action, activity, or procedural step is neither required nor prohibited.</P>
                        <P>May not—This action, activity, or procedural step is prohibited.</P>
                        <P>Method detection limit (MDL)—A detection limit determined by the procedure at 40 CFR part 136, appendix B. The MDLs determined by EPA are listed in Tables 1 and 2. As noted in section 1.6, use the MDLs in Tables 1 and 2 in conjunction with current MDL data from the laboratory actually analyzing samples to assess the sensitivity of this procedure relative to project objectives and regulatory requirements (where applicable).</P>
                        <P>Minimum level (ML)—The term “minimum level” refers to either the sample concentration equivalent to the lowest calibration point in a method or a multiple of the method detection limit (MDL), whichever is higher. Minimum levels may be obtained in several ways: They may be published in a method; they may be based on the lowest acceptable calibration point used by a laboratory; or they may be calculated by multiplying the MDL in a method, or the MDL determined by a laboratory, by a factor of 3. For the purposes of NPDES compliance monitoring, EPA considers the following terms to be synonymous: “quantitation limit,” “reporting limit,” and “minimum level.”</P>
                        <P>MS—Mass spectrometer or mass spectrometry.</P>
                        <P>Must—This action, activity, or procedural step is required.</P>
                        <P>Preparation blank—See blank.</P>
                        <P>Reagent water—Water demonstrated to be free from the analytes of interest and potentially interfering substances at the MDLs for the analytes in this method.</P>
                        <P>Regulatory compliance limit—A limit on the concentration or amount of a pollutant or contaminant specified in a nationwide standard, in a permit, or otherwise established by a regulatory/control authority.</P>
                        <P>Relative standard deviation (RSD)—The standard deviation times 100 divided by the mean. Also termed “coefficient of variation.”</P>
                        <P>RF—Response factor. See section 7.6.2.</P>
                        <P>RPD—Relative percent difference.</P>
                        <P>RSD—See relative standard deviation.</P>
                        <P>Safety Data Sheet (SDS)—Written information on a chemical's toxicity, health hazards, physical properties, fire, and reactivity, including storage, spill, and handling precautions that meet the requirements of OSHA, 29 CFR 1910.1200(g) and appendix D to § 1910.1200. United Nations Globally Harmonized System of Classification and Labelling of Chemicals (GHS), third revised edition, United Nations, 2009.</P>
                        <P>Should—This action, activity, or procedural step is suggested but not required.</P>
                        <P>SPE—Solid-phase extraction; a sample extraction or extract cleanup technique in which an analyte is selectively removed from a sample or extract by passage over or through a material capable of reversibly adsorbing the analyte.</P>
                        <P>Stock solution—A solution containing an analyte that is prepared using a reference material traceable to EPA, the National Institute of Science and Technology (NIST), or a source that will attest to the purity and authenticity of the reference material.</P>
                        <P>Surrogate—A compound unlikely to be found in a sample, which is spiked into the sample in a known amount before extraction, and which is quantified with the same procedures used to quantify other sample components. The purpose of the surrogate is to monitor method performance with each sample.</P>
                        <HD SOURCE="HD1">Method 609—Nitroaromatics and Isophorone</HD>
                        <EAR>Pt. 136, App. A, Meth. 609</EAR>
                        <HD SOURCE="HD2">1. Scope and Application</HD>
                        <P>1.1 This method covers the determination of certain nitroaromatics and isophorone. The following parameters may be determined by this method:</P>
                        <GPOTABLE COLS="3" OPTS="L2" CDEF="s10,10,10">
                            <BOXHD>
                                <CHED H="1">Parameter</CHED>
                                <CHED H="1">STORET No.</CHED>
                                <CHED H="1">CAS No.</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">2,4-Dinitrotoluene</ENT>
                                <ENT>34611</ENT>
                                <ENT>121-14-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,6-Dinitrotoluene</ENT>
                                <ENT>34626</ENT>
                                <ENT>606-20-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Isophorone</ENT>
                                <ENT>34408</ENT>
                                <ENT>78-59-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Nitrobenzene</ENT>
                                <ENT>34447</ENT>
                                <ENT>98-95-3</ENT>
                            </ROW>
                        </GPOTABLE>
                        <P>
                            1.2 This is a gas chromatographic (GC) method applicable to the determination of the compounds listed above in municipal and industrial discharges as provided under 40 CFR 136.1. When this method is used to analyze unfamiliar samples for any or all of the compounds above, compound identifications should be supported by at least one additional qualitative technique. This method describes analytical conditions for a second gas chromatographic column that can be used to confirm measurements made with the primary column. Method 625 provides gas chromatograph/mass spectrometer (GC/MS) conditions appropriate for the qualitative and quantitative confirmation of results for all of the parameters listed above, using the extract produced by this method.
                            <PRTPAGE P="195"/>
                        </P>
                        <P>
                            1.3 The method detection limit (MDL, defined in Section 14.1) 
                            <SU>1</SU>
                             for each parameter is listed in Table 1. The MDL for a specific wastewater may differ from those listed, depending upon the nature of interferences in the sample matrix.
                        </P>
                        <P>1.4 The sample extraction and concentration steps in this method are essentially the same as in Methods 606, 608, 611, and 612. Thus, a single sample may be extracted to measure the parameters included in the scope of each of these methods. When cleanup is required, the concentration levels must be high enough to permit selecting aliquots, as necessary, to apply appropriate cleanup procedures. The analyst is allowed the latitude, under Section 12, to select chromatographic conditions appropriate for the simultaneous measurement of combinations of these parameters.</P>
                        <P>1.5 Any modification of this method, beyond those expressly permitted, shall be considered as a major modification subject to application and approval of alternate test procedures under 40 CFR 136.4 and 136.5.</P>
                        <P>1.6 This method is restricted to use by or under the supervision of analysts experienced in the use of a gas chromatograph and in the interpretation of gas chromatograms. Each analyst must demonstrate the ability to generate acceptable results with this method using the procedure described in Section 8.2.</P>
                        <HD SOURCE="HD2">2. Summary of Method</HD>
                        <P>
                            2.1 A measured volume of sample, approximately 1-L, is extracted with methylene chloride using a separatory funnel. The methylene chloride extract is dried and exchanged to hexane during concentration to a volume of 10 mL or less. Isophorone and nitrobenzene are measured by flame ionization detector gas chromatography (FIDGC). The dinitrotoluenes are measured by electron capture detector gas chromatography (ECDGC). 
                            <SU>2</SU>
                        </P>
                        <P>2.2 The method provides a Florisil column cleanup procedure to aid in the elimination of interferences that may be encountered.</P>
                        <HD SOURCE="HD2">3. Interferences</HD>
                        <P>3.1 Method interferences may be caused by contaminants in solvents, reagents, glassware, and other sample processing hardware that lead to discrete artifacts and/or elevated baseliles in gas chromatograms. All of these materials must be routinely demonstrated to be free from interferences under the conditions of the analysis by running laboratory reagent blanks as described in Section 8.1.3.</P>
                        <P>
                            3.1.1 Glassware must be scrupulously cleaned. 
                            <SU>3</SU>
                             Clean all glassware as soon as possible after use by rinsing with the last solvent used in it. Solvent rinsing should be followed by detergent washing with hot water, and rinses with tap water and distilled water. The glassware should then be drained dry, and heated in a muffle furnace at 400 °C for 15 to 30 min. Some thermally stable materials, such as PCBs, may not be eliminated by this treatment. Solvent rinses with acetone and pesticide quality hexane may be substituted for the muffle furnace heating. Thorough rinsing with such solvents usually eliminates PCB interference. Volumetric ware should not be heated in a muffle furnace. After drying and cooling, glassware should be sealed and stored in a clean environment to prevent any accumulation of dust or other contaminants. Store inverted or capped with aluminum foil.
                        </P>
                        <P>3.1.2 The use of high purity reagents and solvents helps to minimize interference problems. Purification of solvents by distillation in all-glass systems may be required.</P>
                        <P>3.2 Matrix interferences may be caused by contaminants that are co-extracted from the sample. The extent of matrix interferences will vary considerably from source to source, depending upon the nature and diversity of the industrial complex or municipality being sampled. The cleanup procedure in Section 11 can be used to overcome many of these interferences, but unique samples may require additional cleanup approaches to achieve the MDL listed in Table 1.</P>
                        <HD SOURCE="HD2">4. Safety</HD>
                        <P>
                            4.1 The toxicity or carcinogenicity of each reagent used in this method has not been precisely defined; however, each chemical compound should be treated as a potential health hazard. From this viewpoint, exposure to these chemicals must be reduced to the lowest possible level by whatever means available. The laboratory is responsible for maintaining a current awareness file of OSHA regulations regarding the safe handling of the chemicals specified in this method. A reference file of material data handling sheets should also be made available to all personnel involved in the chemical analysis. Additional references to laboratory safety are available and have been identified 
                            <SU>4-6</SU>
                             for the information of the analyst.
                        </P>
                        <HD SOURCE="HD2">5. Apparatus and Materials</HD>
                        <P>5.1 Sampling equipment, for discrete or composite sampling.</P>
                        <P>5.1.1 Grab sample bottle—1-L or 1-qt, amber glass, fitted with a screw cap lined with Teflon. Foil may be substituted for Teflon if the sample is not corrosive. If amber bottles are not available, protect samples from light. The bottle and cap liner must be washed, rinsed with acetone or methylene chloride, and dried before use to minimize contamination.</P>
                        <P>
                            5.1.2 Automatic sampler (optional)—The sampler must incorporate glass sample containers for the collection of a minimum of 
                            <PRTPAGE P="196"/>
                            250 mL of sample. Sample containers must be kept refrigerated at 4 °C and protected from light during compositing. If the sampler uses a peristaltic pump, a minimum length of compressible silicone rubber tubing may be used. Before use, however, the compressible tubing should be thoroughly rinsed with methanol, followed by repeated rinsings with distilled water to minimize the potential for contamination of the sample. An integrating flow meter is required to collect flow proportional composites.
                        </P>
                        <P>5.2 Glassware (All specifications are suggested. Catalog numbers are included for illustration only.):</P>
                        <P>5.2.1 Separatory funnel—2-L, with Teflon stopcock.</P>
                        <P>5.2.2 Drying column—Chromatographic column, approximately 400 mm long × 19 mm ID, with coarse frit filter disc.</P>
                        <P>5.2.3 Chromatographic column—100 mm long × 10 mm ID, with Teflon stopcock.</P>
                        <P>5.2.4 Concentrator tube, Kuderna-Danish—10-mL, graduated (Kontes K-570050-1025 or equivalent). Calibration must be checked at the volumes employed in the test. Ground glass stopper is used to prevent evaporation of extracts.</P>
                        <P>5.2.5 Evaporative flask, Kuderna-Danish—500-mL (Kontes K-570001-0500 or equivalent). Attach to concentrator tube with springs.</P>
                        <P>5.2.6 Snyder column, Kuderna-Danish—Three-ball macro (Kontes K-503000-0121 or equivalent).</P>
                        <P>5.2.7 Snyder column, Kuderna-Danish—Two-ball micro (Kontes K-569001-0219 or equivalent).</P>
                        <P>5.2.8 Vials—10 to 15-mL, amber glass, with Teflon-lined screw cap.</P>
                        <P>5.3 Boiling chips—Approximately 10/40 mesh. Heat to 400 °C for 30 min or Soxhlet extract with methylene chloride.</P>
                        <P>5.4 Water bath—Heated, with concentric ring cover, capable of temperature control (±2 °C). The bath should be used in a hood.</P>
                        <P>5.5 Balance—Analytical, capable of accurately weighing 0.0001 g.</P>
                        <P>5.6 Gas chromatograph—An analytical system complete with gas chromatograph suitable for on-column injection and all required accessories including syringes, analytical columns, gases, detector, and strip-chart recorder. A data system is recommended for measuring peak areas.</P>
                        <P>5.6.1 Column 1—1.2 m long × 2 or 4 mm ID glass, packed with 1.95% QF-1/1.5% OV-17 on Gas-Chrom Q (80/100 mesh) or equivalent. This column was used to develop the method performance statements given in Section 14. Guidelines for the use of alternate column packings are provided in Section 12.1.</P>
                        <P>5.6.2 Column 2—3.0 m long × 2 or 4 mm ID glass, packed with 3% OV-101 on Gas-Chrom Q (80/100 mesh) or equivalent.</P>
                        <P>5.6.3 Detectors—Flame ionization and electron capture detectors. The flame ionization detector (FID) is used when determining isophorone and nitrobenzene. The electron capture detector (ECD) is used when determining the dinitrotoluenes. Both detectors have proven effective in the analysis of wastewaters and were used in develop the method performance statements in Section 14. Guidelines for the use to alternate detectors are provided in Section 12.1.</P>
                        <HD SOURCE="HD2">6. Reagents</HD>
                        <P>6.1 Reagent water—Reagent water is defined as a water in which an interferent is not observed at the MDL of the parameters of interest.</P>
                        <P>6.2 Sodium hydroxide solution (10 N)—Dissolve 40 g of NaOH (ACS) in reagent water and dilute to 100 mL.</P>
                        <P>
                            6.3 Sulfuric acid (1 + 1)—Slowly, add 50 mL of H
                            <E T="52">2</E>
                            SO
                            <E T="52">4</E>
                             (ACS, sp. gr. 1.84) to 50 mL of reagent water.
                        </P>
                        <P>6.4 Acetone, hexane, methanol, methylene chloride—Pesticide quality or equivalent.</P>
                        <P>6.5 Sodium sulfate—(ACS) Granular, anhydrous. Purify by heating at 400 °C for 4 h in a shallow tray.</P>
                        <P>6.6 Florisil—PR grade (60/100 mesh). Purchase activated at 1250 °F and store in dark in glass containers with ground glass stoppers or foil-lined screw caps. Before use, activate each batch at least 16 h at 200 °C in a foil-covered glass container and allow to cool.</P>
                        <P>6.7 Stock standard solutions (1.00 µg/µL)—Stock standard solutions can be prepared from pure standard materials or purchased as certified solutions.</P>
                        <P>6.7.1 Prepare stock standard solutions by accurately weighing about 0.0100 g of pure material. Dissolve the material in hexane and dilute to volume in a 10-mL volumetric flask. Larger volumes can be used at the convenience of the analyst. When compound purity is assayed to be 96% or greater, the weight can be used without correction to calculate the concentration of the stock standard. Commercially prepared stock standards can be used at any concentration if they are certified by the manufacturer or by an independent source.</P>
                        <P>6.7.2 Transfer the stock standard solutions into Teflon-sealed screw-cap bottles. Store at 4 °C and protect from light. Stock standard solutions should be checked frequently for signs of degradation or evaporation, especially just prior to preparing calibration standards from them.</P>
                        <P>6.7.3 Stock standard solutions must be replaced after six months, or sooner if comparison with check standards indicates a problem.</P>
                        <P>6.8 Quality control check sample concentrate—See Section 8.2.1.</P>
                        <HD SOURCE="HD2">7. Calibration</HD>
                        <P>
                            7.1 Establish gas chromatographic operating conditions equivalent to those given in 
                            <PRTPAGE P="197"/>
                            Table 1. The gas chromatographic system can be calibrated using the external standard technique (Section 7.2) or the internal standard technique (Section 7.3).
                        </P>
                        <P>7.2 External standard calibration procedure:</P>
                        <P>7.2.1 Prepare calibration standards at a minimum of three concentration levels for each parameter of interest by adding volumes of one or more stock standards to a volumetric flask and diluting to volume with hexane. One of the external standards should be at a concentration near, but above, the MDL (Table 1) and the other concentrations should correspond to the expected range of concentrations found in real samples or should define the working range of the detector.</P>
                        <P>7.2.2 Using injections of 2 to 5 µL, analyze each calibration standard according to Section 12 and tabulate peak height or area responses against the mass injected. The results can be used to prepare a calibration curve for each compound. Alternatively, if the ratio of response to amount injected (calibration factor) is a constant over the working range (&lt;10% relative standard deviation, RSD) linearity through the origin can be assumed and the average ratio or calibration factor can be used in place of a calibration curve.</P>
                        <P>7.3 Internal standard calibration procedure—To use this approach, the analyst must select one or more internal standards that are similar in analytical behavior to the compounds of interest. The analyst must further demonstrate that the measurement of the internal standard is not affected by method or matrix interferences. Because of these limitations, no internal standard can be suggested that is applicable to all samples.</P>
                        <P>7.3.1 Prepare calibration standards at a minimum of three concentration levels for each parameter of interest by adding volumes of one or more stock standards to a volumetric flash. To each calibration standard, add a known constant amount of one or more internal standards, and dilute to volume with hexane. One of the standards should be at a concentration near, but above, the MDL and the other concentrations should correspond to the expected range of concentrations found in real samples or should define the working range of the detector.</P>
                        <P>7.3.2 Using injections of 2 to 5 µL, analyze each calibration standard according to Section 12 and tabulate peak height or area responses against concentration for each compound and internal standard. Calculate response factors (RF) for each compound using Equation 1.</P>
                        <P>Equation 1.</P>
                        <MATH SPAN="1" DEEP="31">
                            <MID>EC15NO91.110</MID>
                        </MATH>
                        <FP>where:</FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">s</E>
                             = Response for the parameter to be measured.
                        </FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">is</E>
                             = Response for the internal standard.
                        </FP>
                        <FP SOURCE="FP-2">
                            C
                            <E T="52">is</E>
                             = Concentration of the internal standard (µg/L).
                        </FP>
                        <FP SOURCE="FP-2">
                            C
                            <E T="52">s</E>
                             = Concentration of the parameter to be measured (µg/L).
                        </FP>
                        <P>
                            If the RF value over the working range is a constant (&lt;10% RSD), the RF can be assumed to be invariant and the average RF can be used for calculations. Alternatively, the results can be used to plot a calibration curve of response ratios, A
                            <E T="52">s</E>
                            /A
                            <E T="52">is</E>
                            , vs. RF.
                        </P>
                        <P>7.4 The working calibration curve, calibration factor, or RF must be verified on each working day by the measurement of one or more calibration standards. If the response for any parameter varies from the predicted response by more than ±15%, a new calibration curve must be prepared for that compound.</P>
                        <P>7.5 Before using any cleanup procedure, the analyst must process a series of calibration standards through the procedure to validate elution patterns and the absence of interferences from the reagents.</P>
                        <HD SOURCE="HD2">8. Quality Control</HD>
                        <P>8.1 Each laboratory that uses this method is required to operate a formal quality control program. The minimum requirements of this program consist of an initial demonstration of laboratory capability and an ongoing analysis of spiked samples to evaluate and document data quality. The laboratory must maintain records to document the quality of data that is generated. Ongoing data quality checks are compared with established performance criteria to determine if the results of analyses meet the performance characteristics of the method. When results of sample spikes indicate atypical method performance, a quality control check standard must be analyzed to confirm that the measurements were performed in an in-control mode of operation.</P>
                        <P>8.1.1 The analyst must make an initial, one-time, demonstration of the ability to generate acceptable accuracy and precision with this method. This ability is established as described in Section 8.2.</P>
                        <P>
                            8.1.2 In recognition of advances that are occurring in chromatography, the analyst is permitted certain options (detailed in Sections 10.4, 11.1, and 12.1) to improve the separations or lower the cost of measurements. Each time such a modification is made to the method, the analyst is required to repeat the procedure in Section 8.2.
                            <PRTPAGE P="198"/>
                        </P>
                        <P>8.1.3 Before processing any samples, the analyst must analyze a reagent water blank to demonstrate that interferences from the analytical system and glassware are under control. Each time a set of samples is extracted or reagents are changed, a reagent water blank must be processed as a safeguard against laboratory contamination.</P>
                        <P>8.1.4 The laboratory must, on an ongoing basis, spike and analyze a minimum of 10% of all samples to monitor and evaluate laboratory data quality. This procedure is described in Section 8.3.</P>
                        <P>8.1,5 The laboratory must, on an ongoing basis, demonstrate through the analyses of quality control check standards that the operation of the measurement system is in control. This procedure is described in Section 8.4. The frequency of the check standard analyses is equivalent to 10% of all samples analyzed but may be reduced if spike recoveries from samples (Section 8.3) meet all specified quality control criteria.</P>
                        <P>8.1.6 The laboratory must maintain performance records to document the quality of data that is generated. This procedure is described in Section 8.5.</P>
                        <P>8.2 To establish the ability to generate acceptable accuracy and precision, the analyst must perform the following operations.</P>
                        <P>8.2.1 A quality control (QC) check sample concentrate is required containing each parameter of interest in acetone at a concentration of 20 µg/mL for each dinitrotoluene and 100 µg/mL for isophorone and nitrobenzene. The QC check sample concentrate must be obtained from the U.S. Environmental Protection Agency, Environmental Monitoring and Support Laboratory in Cincinnati, Ohio, if available. If not available from that source, the QC check sample concentrate must be obtained from another external source. If not available from either source above, the QC check sample concentrate must be prepared by the laboratory using stock standards prepared independently from those used for calibration.</P>
                        <P>8.2.2 Using a pipet, prepare QC check samples at the test concentrations shown in Table 2 by adding 1.00 mL of QC check sample concentrate to each of four 1-L aliquots of reagent water.</P>
                        <P>8.2.3 Analyze the well-mixed QC check samples according to the method beginning in Section 10.</P>
                        <P>
                            8.2.4 Calculate the average recovery (X
                            <AC T="8"/>
                            ) in µg/L, and the standard deviation of the recovery (s) in µg/L, for each parameter using the four results.
                        </P>
                        <P>
                            8.2.5 For each parameter compare s and X
                            <AC T="8"/>
                             with the corresponding acceptance criteria for precision and accuracy, respectively, found in Table 2. If s and X
                            <AC T="8"/>
                             for all parameters of interest meet the acceptance criteria, the system performance is acceptable and analysis of actual samples can begin. If any individual s exceeds the precision limit or any individual X
                            <AC T="8"/>
                             falls outside the range for accuracy, the system performance is unacceptable for that parameter. Locate and correct the source of the problem and repeat the test for all parameters of interest beginning with Section 8.2.2.
                        </P>
                        <P>8.3 The laboratory must, on an ongoing basis, spike at least 10% of the samples from each sample site being monitored to assess accuracy. For laboratories analyzing one to ten samples per month, at least one spiked sample per month is required.</P>
                        <P>8.3.1 The concentration of the spike in the sample should be determined as follows:</P>
                        <P>8.3.1.1 If, as in compliance monitoring, the concentration of a specific parameter in the sample is being checked against a regulatory concentration limit, the spike should be at that limit or 1 to 5 times higher than the background concentration determined in Section 8.3.2, whichever concentration would be larger.</P>
                        <P>8.3.1.2 If the concentration of a specific parameter in the sample is not being checked against a limit specific to that parameter, the spike should be at the test concentration in Section 8.2.2 or 1 to 5 times higher than the background concentration determined in Section 8.3.2, whichever concentration would be larger.</P>
                        <P>8.3.1.3 If it is impractical to determile background levels before spiking (e.g., maximum holding times will be exceeded), the spike concentration should be (1) the regulatory concentration limit, if any; or, if none (2) the larger of either 5 times higher than the expected background concentration or the test concentration in Section 8.2.2.</P>
                        <P>8.3.2 Analyze one sample aliquot to determine the background concentration (B) of each parameter. If necessary, prepare a new QC check sample concentrate (Section 8.2.1) appropriate for the background concentrations in the sample. Spike a second sample aliquot with 1.0 mL of the QC check sample concentrate and analyze it to determine the concentration after spiking (A) of each parameter. Calculate each percent recovery (P) as 100 (A−B)%/T, where T is the known true value of the spike.</P>
                        <P>
                            8.3.3 Compare the percent recovery (P) for each parameter with the corresponding QC acceptance criteria found in Table 2. These acceptance criteria were calculated to include an allowance for error in measurement of both the background and spike concentrations, assuming a spike to background ratio of 5:1. This error will be accounted for to the extent that the analyst's spike to background ratio approaches 5:1. 
                            <SU>7</SU>
                             If spiking was performed at a concentration lower than the test concentration in Section 8.2.2, the analyst must use either the QC acceptance criteria in Table 2, or optional QC acceptance criteria calculated for the specific spike concentration. To calculate optional acceptance criteria for the recovery of a parameter: (1) 
                            <PRTPAGE P="199"/>
                            Calculate accuracy (X′) using the equation in Table 3, substituting the spike concentration (T) for C; (2) calculate overall precision (S′) using the equation in Table 3, substituting X′ for X
                            <AC T="8"/>
                            8; (3) calculate the range for recovery at the spike concentration as (100 X′/T) ±2.44 (100 S′/T)%. 
                            <SU>7</SU>
                        </P>
                        <P>8.3.4 If any individual P falls outside the designated range for recovery, that parameter has failed the acceptance criteria. A check standard containing each parameter that failed the criteria must be analyzed as described in Section 8.4.</P>
                        <P>8.4. If any parameter fails the acceptance criteria for recovery in Section 8.3, a QC check standard containing each parameter that failed must be prepared and analyzed.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>The frequency for the required analysis of a QC check standard will depend upon the number of parameters being simultaneously tested, the complexity of the sample matrix, and the performance of the laboratory.</P>
                        </NOTE>
                        <P>8.4.1 Prepare the QC check standard by adding 1.0 mL of QC check sample concentrate (Section 8.2.1 or 8.3.2) to 1 L of reagent water. The QC check standard needs only to contain the parameters that failed criteria in the test in Section 8.3.</P>
                        <P>
                            8.4.2 Analyze the QC check standard to determine the concentration measured (A) of each parameter. Calculate each percent recovery (P
                            <E T="52">s</E>
                            ) as 100 (A/T)%, where T is the true value of the standard concentration.
                        </P>
                        <P>
                            8.4.3 Compare the percent recovery (P
                            <E T="52">s</E>
                            ) for each parameter with the corresponding QC acceptance criteria found in Table 2. Only parameters that failed the test in Section 8.3 need to be compared with these criteria. If the recovery of any such parameter falls outside the designated range, the laboratory performance for that parameter is judged to be out of control, and the problem must be immediately identified and corrected. The analytical result for that parameter in the unspiked sample is suspect and may not be reported for regulatory compliance purposes.
                        </P>
                        <P>
                            8.5 As part of QC program for the laboratory, method accuracy for wastewater samples must be assessed and records must be maintained. After the analysis of five spiked wastewater samples as in Section 8.3, calculate the average percent recovery (P
                            <AC T="8"/>
                            ) and the standard deviation of the percent recovery (s
                            <E T="52">p</E>
                            ). Express the accuracy assessment as a percent recovery interval from P
                            <AC T="8"/>
                            −2s
                            <E T="52">p</E>
                             to P
                            <AC T="8"/>
                             + 2s
                            <E T="52">p</E>
                            . If P
                            <AC T="8"/>
                             = 90% and s
                            <E T="52">p</E>
                             = 10%, for example, the accuracy interval is expressed as 70-110%. Update the accuracy assessment for each parameter on a regular basis (e.g. after each five to ten new accuracy measurements).
                        </P>
                        <P>8.6 It is recommended that the laboratory adopt additional quality assurance practices for use with this method. The specific practices that are most productive depend upon the needs of the laboratory and the nature of the samples. Field duplicates may be analyzed to assess the precision of the environmental measurements. When doubt exists over the identification of a peak on the chromatogram, confirmatory techniques such as gas chromatography with a dissimilar column, specific element detector, or mass spectrometer must be used. Whenever possible, the laboratory should analyze standard reference materials and participate in relevant performance evaluation studies.</P>
                        <HD SOURCE="HD2">9. Sample Collection, Preservation, and Handling</HD>
                        <P>
                            9.1 Grab samples must be collected in glass containers. Conventional sampling practices 
                            <SU>8</SU>
                             should be followed, except that the bottle must not be prerinsed with sample before collection. Composite samples should be collected in refrigerated glass containers in accordance with the requirements of the program. Automatic sampling equipment must be as free as possible of Tygon tubing and other potential sources of contamination.
                        </P>
                        <P>9.2 All samples must be iced or refrigerated at 4 °C from the time of collection until extraction.</P>
                        <P>
                            9.3 All samples must be extracted within 7 days of collection and completely analyzed within 40 days of extraction. 
                            <SU>2</SU>
                        </P>
                        <HD SOURCE="HD2">10. Sample Extraction</HD>
                        <P>10.1 Mark the water meniscus on the side of the sample bottle for later determination of sample volume. Pour the entire sample into a 2-L separatory funnel. Check the pH of the sample with wide-range pH paper and adjust to within the range of 5 to 9 with sodium hydroxide solution or sulfuric acid.</P>
                        <P>10.2 Add 60 mL of methylene chloride to the sample bottle, seal, and shake 30 s to rinse the inner surface. Transfer the solvent to the separatory funnel and extract the sample by shaking the funnel for 2 min. with periodic venting to release excess pressure. Allow the organic layer to separate from the water phase for a minimum of 10 min. If the emulsion interface between layers is more than one-third the volume of the solvent layer, the analyst must employ mechanical techniques to complete the phase separation. The optimum technique depends upon the sample, but may include stirring, filtration of the emulsion through glass wool, centrifugation, or other physical methods. Collect the methylene chloride extract in a 250-mL Erlenmeyer flask.</P>
                        <P>
                            10.3 Add a second 60-mL volume of methylene chloride to the sample bottle and repeat the extraction procedure a second time, combining the extracts in the Erlenmeyer flask. Perform a third extraction in the same manner.
                            <PRTPAGE P="200"/>
                        </P>
                        <P>10.4 Assemble a Kuderna-Danish (K-D) concentrator by attaching a 10-mL concentrator tube to a 500-mL evaporative flask. Other concentration devices or techniques may be used in place of the K-D concentrator if the requirements of Section 8.2 are met.</P>
                        <P>10.5 Pour the combined extract through a solvent-rinsed drying column containing about 10 cm of anhydrous sodium sulfate, and collect the extract in the K-D concentrator. Rinse the Erlenmeyer flask and column with 20 to 30 mL of methylene chloride to complete the quantitative transfer.</P>
                        <P>10.6 Sections 10.7 and 10.8 describe a procedure for exchanging the methylene chloride solvent to hexane while concentrating the extract volume to 1.0 mL. When it is not necessary to achieve the MDL in Table 2, the solvent exchange may be made by the addition of 50 mL of hexane and concentration to 10 mL as described in Method 606, Sections 10.7 and 10.8.</P>
                        <P>10.7 Add one or two clean boiling chips to the evaporative flask and attach a three-ball Snyder column. Prewet the Snyder column by adding about 1 mL of methylene chloride to the top. Place the K-D apparatus on a hot water bath (60 to 65 °C) so that the concentrator tube is partially immersed in the hot water, and the entire lower rounded surface of the flask is bathed with hot vapor. Adjust the vertical position of the apparatus and the water temperature as required to complete the concentration in 15 to 20 min. At the proper rate of distillation the balls of the column will actively chatter but the chambers will not flood with condensed solvent. When the apparent volume of liquid reaches 1 mL, remove the K-D apparatus and allow it to drain and cool for at least 10 min.</P>
                        <P>10.8 Remove the Snyder column and rinse the flask and its lower joint into the concentrator tube with 1 to 2 mL of methylene chloride. A 5-mL syringe is recommended for this operation. Add 1 to 2 mL of hexane and a clean boiling chip to the concentrator tube and attach a two-ball micro-Snyder column. Prewet the column by adding about 0.5 mL of hexane to the top. Place the micro-K-D apparatus on a hot water bath (60 to 65 °C) so that the concentrator tube is partially immersed in the hot water. Adjust the vertical position of the apparatus and the water temperature as required to complete the concentration in 5 to 10 min. At the proper rate of distillation the balls of the column will actively chatter but the chambers will not flood. When the apparent volume of liquid reaches 0.5 mL, remove the K-D apparatus and allow it to drain and cool for at least 10 min.</P>
                        <P>10.9 Remove the micro-Snyder column and rinse its lower joint into the concentrator tube with a minimum amount of hexane. Adjust the extract volume to 1.0 mL. Stopper the concentrator tube and store refrigerated if further processing will not be performed immediately. If the extract will be stored longer than two days, it should be transferred to a Teflon-sealed screw-cap vial. If the sample extract requires no further cleanup, proceed with gas chromatographic analysis (Section 12). If the sample requires further cleanup, proceed to Section 11.</P>
                        <P>10.10 Determine the original sample volume by refilling the sample bottle to the mark and transferring the liquid to a 1000-mL graduated cylinder. Record the sample volume to the nearest 5 mL.</P>
                        <HD SOURCE="HD2">11. Cleanup and Separation</HD>
                        <P>11.1 Cleanup procedures may not be necessary for a relatively clean sample matrix. If particular circumstances demand the use of a cleanup procedure, the analyst may use the procedure below or any other appropriate procedure. However, the analyst first must demonstrate that the requirements of Section 8.2 can be met using the method as revised to incorporate the cleanup procedure.</P>
                        <P>11.2 Florisil column cleanup:</P>
                        <P>11.2.1 Prepare a slurry of 10 g of activated Florisil in methylene chloride/hexane (1 + 9)(V/V) and place the Florisil into a chromatographic column. Tap the column to settle the Florisil and add 1 cm of anhydrous sodium sulfate to the top. Adjust the elution rate to about 2 mL/min.</P>
                        <P>11.2.2 Just prior to exposure of the sodium sulfate layer to the air, quantitatively transfer the sample extract onto the column using an additional 2 mL of hexane to complete the transfer. Just prior to exposure of the sodium sulfate layer to the air, add 30 mL of methylene chloride/hexane (1 + 9)(V/V) and continue the elution of the column. Discard the eluate.</P>
                        <P>11.2.3 Next, elute the column with 30 mL of acetone/methylene chloride (1 + 9)(V/V) into a 500-mL K-D flask equipped with a 10-mL concentrator tube. Concentrate the collected fraction as in Sections 10.6, 10.7, 10.8, and 10.9 including the solvent exchange to 1 mL of hexane. This fraction should contain the nitroaromatics and isophorone. Analyze by gas chromatography (Section 12).</P>
                        <HD SOURCE="HD2">12. Gas Chromatography</HD>
                        <P>12.1 Isophorone and nitrobenzene are analyzed by injection of a portion of the extract into an FIDGC. The dinitrotoluenes are analyzed by a separate injection into an ECDGC. Table 1 summarizes the recommended operating conditions for the gas chromatograph. Included in this table are retention times and MDL that can be achieved under these conditions. Examples of the separations achieved by Column 1 are shown in Figures 1 and 2. Other packed or capillary (open-tubular) columns, chromatographic conditions, or detectors may be used if the requirements of Section 8.2 are met.</P>
                        <P>
                            12.2 Calibrate the system daily as described in Section 7.
                            <PRTPAGE P="201"/>
                        </P>
                        <P>12.3 If the internal standard calibration procedure is being used, the internal standard must be added to the same extract and mixed thoroughly immediately before injection into the gas chromatograph.</P>
                        <P>
                            12.4 Inject 2 to 5 µL of the sample extract or standard into the gas chromatograph using the solvent-flush technique. 
                            <SU>9</SU>
                             Smaller (1.0 µL) volumes may be injected if automatic devices are employed. Record the volume injected to the nearest 0.05 µL, the total extract volume, and the resulting peak size in area or peak height units.
                        </P>
                        <P>12.5 Identify the parameters in the sample by comparing the retention times of the peaks in the sample chromatogram with those of the peaks in standard chromatograms. The width of the retention time window used to make identifications should be based upon measurements of actual retention time variations of standards over the course of a day. Three times the standard deviation of a retention time for a compound can be used to calculate a suggested window size; however, the experience of the analyst should weigh heavily in the interpretation of chromatograms.</P>
                        <P>12.6 If the response for a peak exceeds the working range of the system, dilute the extract and reanalyze.</P>
                        <P>12.7 If the measurement of the peak response is prevented by the presence of interferences, further cleanup is required.</P>
                        <HD SOURCE="HD2">13. Calculations</HD>
                        <P>13.1 Determine the concentration of individual compounds in the sample.</P>
                        <P>13.1.1 If the external standard calibration procedure is used, calculate the amount of material injected from the peak response using the calibration curve or calibration factor determined in Section 7.2.2. The concentration in the sample can be calculated from Equation 2.</P>
                        <MATH SPAN="1" DEEP="31">
                            <MID>EC15NO91.111</MID>
                        </MATH>
                        <FP SOURCE="FRP0">Equation 2</FP>
                        <FP>where:</FP>
                        <FP SOURCE="FP-2">A = Amount of material injected (ng).</FP>
                        <FP SOURCE="FP-2">
                            V
                            <E T="52">i</E>
                             = Volume of extract injected (µL).
                        </FP>
                        <FP SOURCE="FP-2">
                            V
                            <E T="52">t</E>
                             = Volume of total extract (µL).
                        </FP>
                        <FP SOURCE="FP-2">
                            V
                            <E T="52">s</E>
                             = Volume of water extracted (mL).
                        </FP>
                        <P>13.1.2 If the internal standard calibration procedure is used, calculate the concentration in the sample using the response factor (RF) determined in Section 7.3.2 and Equation 3.</P>
                        <MATH SPAN="1" DEEP="31">
                            <MID>EC15NO91.112</MID>
                        </MATH>
                        <FP SOURCE="FRP0">Equation 3</FP>
                        <FP>where:</FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">s</E>
                             = Response for the parameter to be measured.
                        </FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">is</E>
                             = Response for the internal standard.
                        </FP>
                        <FP SOURCE="FP-2">
                            I
                            <E T="52">s</E>
                             = Amount of internal standard added to each extract (µg).
                        </FP>
                        <FP SOURCE="FP-2">
                            V
                            <E T="52">o</E>
                             = Volume of water extracted (L).
                        </FP>
                        <P>13.2 Report results in µg/L without correction for recovery data. All QC data obtained should be reported with the sample results.</P>
                        <HD SOURCE="HD2">14. Method Performance</HD>
                        <P>
                            14.1 The method detection limit (MDL) is defined as the minimum concentration of a substance that can be measured and reported with 99% confidence that the value is above zero. 
                            <SU>1</SU>
                             The MDL concentrations listed in Table 1 were obtained using reagent water. 
                            <SU>10</SU>
                             Similar results were achieved using representative wastewaters. The MDL actually achieved in a given analysis will vary depending on instrument sensitivity and matrix effects.
                        </P>
                        <P>
                            14.2 This method has been tested for linearity of spike recovery from reagent water and has been demonstrated to be applicable over the concentration range from 7 × MDL to 1000 × MDL. 
                            <SU>10</SU>
                        </P>
                        <P>
                            14.3 This method was tested by 18 laboratories using reagent water, drinking water, surface water, and three industrial wastewaters spiked at six concentrations over the range 1.0 to 515 µg/L. 
                            <SU>11</SU>
                             Single operator precision, overall precision, and method accuracy were found to be directly related to the concentration of the parameter and essentially independent of the sample matrix. Linear equations to describe these relationships are presented in Table 3.
                        </P>
                        <HD SOURCE="HD1">References</HD>
                        <P>1. 40 CFR part 136, appendix B.</P>
                        <P>2. “Determination of Nitroaromatic Compounds and Isophorone in Industrial and Municipal Wastewaters,” EPA 600/ 4-82-024, National Technical Information Service, PB82-208398, Springfield, Virginia 22161, May 1982.</P>
                        <P>3. ASTM Annual Book of Standards, Part 31, D3694-78. “Standard Practices for Preparation of Sample Containers and for Preservation of Organic Constituents,” American Society for Testing and Materials, Philadelphia.</P>
                        <P>4. “Carcinogens—Working With Carcinogens,” Department of Health, Education, and Welfare, Public Health Service, Center for Disease Control, National Institute for Occupational Safety and Health, Publication No. 77-206, August 1977.</P>
                        <P>
                            5. “OSHA Safety and Health Standards, General Industry,” (29 CFR part 1910), Occupational Safety and Health Administration, OSHA 2206 (Revised, January 1976).
                            <PRTPAGE P="202"/>
                        </P>
                        <P>6. “Safety in Academic Chemistry Laboratories,” American Chemical Society Publication, Committee on Chemical Safety, 3rd Edition, 1979.</P>
                        <P>
                            7. Provost, L.P., and Elder, R.S. “Interpretation of Percent Recovery Data,” 
                            <E T="03">American Laboratory, 15,</E>
                             58-63 (1983). (The value 2.44 used in the equation in Section 8.3.3 is two times the value 1.22 derived in this report.)
                        </P>
                        <P>8. ASTM Annual Book of Standards, Part 31, D3370-76. “Standard Practices for Sampling Water,” American Society for Testing and Materials, Philadelphia.</P>
                        <P>
                            9. Burke, J.A. “Gas Chromatography for Pesticide Residue Analysis; Some Practical Aspects,” 
                            <E T="03">Journal of the Association of Official Analytical Chemists, 48,</E>
                             1037 (1965).
                        </P>
                        <P>10. “Determination of Method Detection Limit and Analytical Curve for EPA Method 609—Nitroaromatics and Isophorone,” Special letter report for EPA Contract 68-03-2624, U.S. Environmental Protection Agency, Environmental Monitoring and Support Laboratory, Cincinnati, Ohio 45268, June 1980.</P>
                        <P>11. “EPA Method Study 19, Method 609 (Nitroaromatics and Isophorone),” EPA 600/4-84-018, National Technical Information Service, PB84-176908, Springfield, Virginia 22161, March 1984.</P>
                        <GPOTABLE COLS="5" OPTS="L2" CDEF="s25,6.4,6.4,6.4,6.4">
                            <TTITLE>Table 1—Chromatographic Conditions and Method Detection Limits</TTITLE>
                            <BOXHD>
                                <CHED H="1">Parameter</CHED>
                                <CHED H="1">Retention time (min)</CHED>
                                <CHED H="2">Col. 1</CHED>
                                <CHED H="2">Col. 2</CHED>
                                <CHED H="1">Method detection limit (µg/L)</CHED>
                                <CHED H="2">ECDGC</CHED>
                                <CHED H="2">FIDGC</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">Nitrobenzene</ENT>
                                <ENT>3.31</ENT>
                                <ENT>4.31</ENT>
                                <ENT>13.7</ENT>
                                <ENT>3.6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,6-Dinitrotoluene</ENT>
                                <ENT>3.52</ENT>
                                <ENT>4.75</ENT>
                                <ENT>0.01</ENT>
                                <ENT>−</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Isophorone</ENT>
                                <ENT>4.49</ENT>
                                <ENT>5.72</ENT>
                                <ENT>15.7</ENT>
                                <ENT>5.7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4-Dinitrotoluene</ENT>
                                <ENT>5.35</ENT>
                                <ENT>6.54</ENT>
                                <ENT>0.02</ENT>
                                <ENT>−</ENT>
                            </ROW>
                            <TNOTE>Column 1 conditions: Gas-Chrom Q (80/100 mesh) coated with 1.95% QF-1/1.5% OV-17 packed in a 1.2 m long × 2 mm or 4 mm ID glass column. A 2 mm ID column and nitrogen carrier gas at 44 mL/min flow rate were used when determining isophorone and nitrobenzene by FIDGC. The column temperature was held isothermal at 85 °C. A 4 mm ID column and 10% methane/90% argon carrier gas at 44 mL/min flow rate were used when determining the dinitrotoluenes by ECDGC. The column temperature was held isothermal at 145 °C.</TNOTE>
                            <TNOTE>Column 2 conditions: Gas-Chrom Q (80/100 mesh) coated with 3% OV-101 packed in a 3.0 m long × 2 mm or 4 mm ID glass column. A 2 mm ID column and nitrogen carrier gas at 44 mL/min flow rate were used when determining isophorone and nitrobenzene by FIDGC. The column temperature was held isothermal at 100 °C. A 4 mm ID column and 10% methane/90% argon carrier gas at 44 mL/min flow rate were used when determining the dinitrotoluenes by ECDGC. The column temperature was held isothermal at 150 °C.</TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="5" OPTS="L2" CDEF="s100,10,9.1,5-5,10">
                            <TTITLE>Table 2—QC Acceptance Criteria—Method 609</TTITLE>
                            <BOXHD>
                                <CHED H="1">Parameter</CHED>
                                <CHED H="1">Test Conc. (µg/L)</CHED>
                                <CHED H="1">Limit for s (µg/L)</CHED>
                                <CHED H="1">
                                    Range for X
                                    <AC T="8"/>
                                     (µg/L)
                                </CHED>
                                <CHED H="1">
                                    Range for P, P
                                    <E T="52">s</E>
                                     (%)
                                </CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">2,4-Dinitrotoluene</ENT>
                                <ENT>20</ENT>
                                <ENT>5.1</ENT>
                                <ENT>3.6-22.8</ENT>
                                <ENT>6-125</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,6-Dinitrotoluene</ENT>
                                <ENT>20</ENT>
                                <ENT>4.8</ENT>
                                <ENT>3.8-23.0</ENT>
                                <ENT>8-126</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Isophorone</ENT>
                                <ENT>100</ENT>
                                <ENT>32.3</ENT>
                                <ENT>8.0-100.0</ENT>
                                <ENT>D-117</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Nitrobenzene</ENT>
                                <ENT>100</ENT>
                                <ENT>33.3</ENT>
                                <ENT>25.7-100.0</ENT>
                                <ENT>6-118</ENT>
                            </ROW>
                            <TNOTE>s = Standard deviation of four recovery measurements, in µg/L (Section 8.2.4).</TNOTE>
                            <TNOTE>
                                X
                                <AC T="8"/>
                                 = Average recovery for four recovery measurements, in µg/L (Section 8.2.4).
                            </TNOTE>
                            <TNOTE>
                                P, P
                                <E T="52">s</E>
                                 = Percent recovery measured (Section 8.3.2, Section 8.4.2).
                            </TNOTE>
                            <TNOTE>D = Detected; result must be greater than zero.</TNOTE>
                            <TNOTE>
                                <E T="04">Note:</E>
                                 These criteria are based directly upon the method performance data in Table 3. Where necessary, the limits for recovery have been broadened to assure applicability of the limits to concentrations below those used to develop Table 3.
                            </TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="4" OPTS="L2" CDEF="s50,15,15,15">
                            <TTITLE>Table 3—Method Accuracy and Precision as Functions of Concentration—Method 609</TTITLE>
                            <BOXHD>
                                <CHED H="1">Parameter</CHED>
                                <CHED H="1">Accuracy, as recovery, X′ (µg/L)</CHED>
                                <CHED H="1">
                                    Single analyst precision, s
                                    <E T="52">r</E>
                                    ′ (µg/L)
                                </CHED>
                                <CHED H="1">Overall precision, S′ (µg/L)</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="11">2,4-Dinitro-</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01"> toluene</ENT>
                                <ENT>0.65C + 0.22</ENT>
                                <ENT>
                                    0.20X
                                    <AC T="8"/>
                                     + 0.08
                                </ENT>
                                <ENT>
                                    0.37X
                                    <AC T="8"/>
                                    −0.07
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="11">2,6-Dinitro-</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01"> toluene</ENT>
                                <ENT>0.66C + 0.20</ENT>
                                <ENT>
                                    0.19X
                                    <AC T="8"/>
                                     + 0.06
                                </ENT>
                                <ENT>
                                    0.36X
                                    <AC T="8"/>
                                    −0.00
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Isophorone</ENT>
                                <ENT>0.49C + 2.93</ENT>
                                <ENT>
                                    0.28X
                                    <AC T="8"/>
                                     + 2.77
                                </ENT>
                                <ENT>
                                    0.46X
                                    <AC T="8"/>
                                     + 0.31
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Nitrobenzene</ENT>
                                <ENT>0.60C + 2.00</ENT>
                                <ENT>
                                    0.25X
                                    <AC T="8"/>
                                     + 2.53
                                </ENT>
                                <ENT>
                                    0.37X
                                    <AC T="8"/>
                                    −0.78
                                </ENT>
                            </ROW>
                            <TNOTE>X′ = Expected recovery for one or more measurements of a sample containing a concentration of C, in µg/L.</TNOTE>
                            <TNOTE>
                                s
                                <E T="52">r</E>
                                ′ = Expected single analyst standard deviation of measurements at an average concentration found of X
                                <AC T="8"/>
                                , in µg/L.
                            </TNOTE>
                            <TNOTE>
                                S′ = Expected interlaboratory standard deviation of measurements at an average concentration found of X
                                <AC T="8"/>
                                , in µg/L.
                            </TNOTE>
                            <TNOTE>C = True value for the concentration, in µg/L.</TNOTE>
                            <TNOTE>
                                X
                                <AC T="8"/>
                                 = Average recovery found for measurements of samples containing a concentration of C, in µg/L.
                            </TNOTE>
                        </GPOTABLE>
                        <GPH SPAN="2" DEEP="470">
                            <PRTPAGE P="203"/>
                            <GID>EC02JY92.029</GID>
                        </GPH>
                        <GPH SPAN="2" DEEP="470">
                            <PRTPAGE P="204"/>
                            <GID>EC02JY92.030</GID>
                        </GPH>
                        <PRTPAGE P="205"/>
                        <HD SOURCE="HD1">Method 610—Polynuclear Aromatic Hydrocarbons</HD>
                        <EAR>Pt. 136, App. A, Meth. 610</EAR>
                        <HD SOURCE="HD2">1. Scope and Application</HD>
                        <P>1.1 This method covers the determination of certain polynuclear aromatic hydrocarbons (PAH). The following parameters can be determined by this method:</P>
                        <GPOTABLE COLS="3" OPTS="L2" CDEF="s10,11,11">
                            <BOXHD>
                                <CHED H="1">Parameter</CHED>
                                <CHED H="1">STORET No.</CHED>
                                <CHED H="1">CAS No.</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">Acenaphthene</ENT>
                                <ENT>34205</ENT>
                                <ENT>83-32-9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Acenaphthylene</ENT>
                                <ENT>34200</ENT>
                                <ENT>208-96-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Anthracene</ENT>
                                <ENT>34220</ENT>
                                <ENT>120-12-7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzo(a)anthracene</ENT>
                                <ENT>34526</ENT>
                                <ENT>56-55-3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzo(a)pyrene</ENT>
                                <ENT>34247</ENT>
                                <ENT>50-32-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzo(b)fluoranthene</ENT>
                                <ENT>34230</ENT>
                                <ENT>205-99-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzo(ghi)perylene</ENT>
                                <ENT>34521</ENT>
                                <ENT>191-24-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzo(k)fluoranthene</ENT>
                                <ENT>34242</ENT>
                                <ENT>207-08-9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chrysene</ENT>
                                <ENT>34320</ENT>
                                <ENT>218-01-9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dibenzo(a,h)anthracene</ENT>
                                <ENT>34556</ENT>
                                <ENT>53-70-3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Fluoranthene</ENT>
                                <ENT>34376</ENT>
                                <ENT>206-44-0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Fluorene</ENT>
                                <ENT>34381</ENT>
                                <ENT>86-73-7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Indeno(1,2,3-cd)pyrene</ENT>
                                <ENT>34403</ENT>
                                <ENT>193-39-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Naphthalene</ENT>
                                <ENT>34696</ENT>
                                <ENT>91-20-3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Phenanthrene</ENT>
                                <ENT>34461</ENT>
                                <ENT>85-01-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Pyrene</ENT>
                                <ENT>34469</ENT>
                                <ENT>129-00-0</ENT>
                            </ROW>
                        </GPOTABLE>
                        <P>1.2 This is a chromatographic method applicable to the determination of the compounds listed above in municipal and industrial discharges as provided under 40 CFR 136.1. When this method is used to analyze unfamiliar samples for any or all of the compounds above, compound identifications should be supported by at least one additional qualitative technique. Method 625 provides gas chromatograph/mass spectrometer (GC/MS) conditions appropriate for the qualitative and quantitative confirmation of results for many of the parameters listed above, using the extract produced by this method.</P>
                        <P>1.3 This method provides for both high performance liquid chromatographic (HPLC) and gas chromatographic (GC) approaches for the determination of PAHs. The gas chromatographic procedure does not adequately resolve the following four pairs of compounds: Anthracene and phenanthrene; chrysene and benzo(a)anthracene; benzo(b)fluoranthene and benzo(k)fluoranthene; and dibenzo(a,h) anthracene and indeno (1,2,3-cd)pyrene. Unless the purpose for the analysis can be served by reporting the sum of an unresolved pair, the liquid chromatographic approach must be used for these compounds. The liquid chromatographic method does resolve all 16 of the PAHs listed.</P>
                        <P>
                            1.4 The method detection limit (MDL, defined in Section 15.1) 
                            <SU>1</SU>
                             for each parameter is listed in Table 1. The MDL for a specific wastewater may differ from those listed, depending upon the nature of interferences in the sample matrix.
                        </P>
                        <P>1.5 The sample extraction and concentration steps in this method are essentially the same as in Methods 606, 608, 609, 611, and 612. Thus, a single sample may be extracted to measure the parameters included in the scope of each of these methods. When cleanup is required, the concentration levels must be high enough to permit selecting aliquots, as necessary, to apply appropriate cleanup procedures. Selection of the aliquots must be made prior to the solvent exchange steps of this method. The analyst is allowed the latitude, under Sections 12 and 13, to select chromatographic conditions appropriate for the simultaneous measurement of combinations of these parameters.</P>
                        <P>1.6 Any modification of this method, beyond those expressly permitted, shall be considered as a major modification subject to application and approval of alternate test procedures under 40 CFR 136.4 and 136.5.</P>
                        <P>1.7 This method is restricted to use by or under the supervision of analysts experienced in the use of HPLC and GC systems and in the interpretation of liquid and gas chromatograms. Each analyst must demonstrate the ability to generate acceptable results with this method using the procedure described in Section 8.2.</P>
                        <HD SOURCE="HD2">2. Summary of Method</HD>
                        <P>
                            2.1 A measured volume of sample, approximately 1-L, is extracted with methylene chloride using a separatory funnel. The methylene chloride extract is dried and concentrated to a volume of 10 mL or less. The extract is then separated by HPLC or GC. Ultraviolet (UV) and fluorescence detectors are used with HPLC to identify and measure the PAHs. A flame ionization detector is used with GC. 
                            <SU>2</SU>
                        </P>
                        <P>2.2 The method provides a silica gel column cleanup procedure to aid in the elimination of interferences that may be encountered.</P>
                        <HD SOURCE="HD2">3. Interferences</HD>
                        <P>3.1 Method interferences may be caused by contaminants in solvents, reagents, glassware, and other sample processing hardward that lead to discrete artifacts and/or elevated baselines in the chromatograms. All of these materials must be routinely demonstrated to be free from interferences under the conditions of the analysis by running laboratory reagent blanks as described in Section 8.1.3.</P>
                        <P>
                            3.1.1 Glassware must be scrupulously cleaned. 
                            <SU>3</SU>
                             Clean all glassware as soon as possible after use by rinsing with the last solvent used in it. Solvent rinsing should be followed by detergent washing with hot water, and rinses with tap water and distilled water. The glassware should then be drained dry, and heated in a muffle furnace at 400 °C for 15 to 30 min. Some thermally stable materials, such as PCBs, may not be eliminated by this treatment. Solvent rinses with acetone and pesticide quality hexane may be 
                            <PRTPAGE P="206"/>
                            substituted for the muffle furnace heating. Thorough rinsing with such solvents usually eliminates PCB interference. Volumetric ware should not be heated in a muffle furnace. After drying and cooling, glassware should be sealed and stored in a clean environment to prevent any accumulation of dust or other contaminants. Store inverted or capped with aluminum foil.
                        </P>
                        <P>3.1.2 The use of high purity reagents and solvents helps to minimize interference problems. Purification of solvents by distillation in all-glass systems may be required.</P>
                        <P>3.2 Matrix interferences may be caused by contaminants that are co-extracted from the sample. The extent of matrix interferences will vary considerably from source to source, depending upon the nature and diversity of the industrial complex or municipality being sampled. The cleanup procedure in Section 11 can be used to overcome many of these interferences, but unique samples may require additional cleanup approaches to achieve the MDL listed in Table 1.</P>
                        <P>3.3 The extent of interferences that may be encountered using liquid chromatographic techniques has not been fully assessed. Although the HPLC conditions described allow for a unique resolution of the specific PAH compounds covered by this method, other PAH compounds may interfere.</P>
                        <HD SOURCE="HD2">4. Safety</HD>
                        <P>
                            4.1 The toxicity or carcinogenicity of each reagent used in this method have not been precisely defined; however, each chemical compound should be treated as a potential health hazard. From this viewpoint, exposure to these chemicals must be reduced to the lowest possible level by whatever means available. The laboratory is responsible for maintaining a current awareness file of OSHA regulations regarding the safe handling of the chemicals specified in this method. A reference file of material data handling sheets should also be made available to all personnel involved in the chemical analysis. Additional references to laboratory safety are available and have been identified 
                            <SU>4-6</SU>
                             for the information of the analyst.
                        </P>
                        <P>4.2 The following parameters covered by this method have been tentatively classified as known or suspected, human or mammalian carcinogens: benzo(a)anthracene, benzo(a)pyrene, and dibenzo(a,h)-anthracene. Primary standards of these toxic compounds should be prepared in a hood. A NIOSH/MESA approved toxic gas respirator should be worn when the analyst handles high concentrations of these toxic compounds.</P>
                        <HD SOURCE="HD2">5. Apparatus and Materials</HD>
                        <P>5.1 Sampling equipment, for discrete or composite sampling.</P>
                        <P>5.1.1 Grab sample bottle—1-L or 1-qt, amber glass, fitted with a screw cap lined with Teflon. Foil may be substituted for Teflon if the sample is not corrosive. If amber bottles are not available, protect samples from light. The bottle and cap liner must be washed, rinsed with acetone or methylene chloride, and dried before use to minimize contamination.</P>
                        <P>5.1.2 Automatic sampler (optional)—The sampler must incorporate glass sample containers for the collection of a minimum of 250 mL of sample. Sample containers must be kept refrigerated at 4 °C and protected from light during compositing. If the sampler uses a peristaltic pump, a minimum length of compressible silicone rubber tubing may be used. Before use, however, the compressible tubing should be thoroughly rinsed with methanol, followed by repeated rinsings with distilled water to minimize the potential for contamination of the sample. An integrating flow meter is required to collect flow proportional composites.</P>
                        <P>5.2 Glassware (All specifications are suggested. Catalog numbers are included for illustration only.):</P>
                        <P>5.2.1 Separatory funnel—2-L, with Teflon stopcock.</P>
                        <P>5.2.2 Drying column—Chromatographic column, approximately 400 mm long × 19 mm ID, with coarse frit filter disc.</P>
                        <P>5.2.3 Concentrator tube, Kuderna-Danish—10-mL, graduated (Kontes K-570050-1025 or equivalent). Calibration must be checked at the volumes employed in the test. Ground glass stopper is used to prevent evaporation of extracts.</P>
                        <P>5.2.4 Evaporative flask, Kuderna-Danish—500-mL (Kontes K-570001-0500 or equivalent). Attach to concentrator tube with springs.</P>
                        <P>5.2.5 Snyder column, Kuderna-Danish—Three-ball macro (Kontes K-503000-0121 or equivalent).</P>
                        <P>5.2.6 Snyder column, Kuderna-Danish—Two-ball micro (Kontes K-569001-0219 or equivalent).</P>
                        <P>5.2.7 Vials—10 to 15-mL, amber glass, with Teflon-lined screw cap.</P>
                        <P>5.2.8 Chromatographic column—250 mm long × 10 mm ID, with coarse frit filter disc at bottom and Teflon stopcock.</P>
                        <P>5.3 Boiling chips—Approximately 10/40 mesh. Heat to 400 °C for 30 min or Soxhlet extract with methylene chloride.</P>
                        <P>5.4 Water bath—Heated, with concentric ring cover, capable of temperature control (±2 °C). The bath should be used in a hood.</P>
                        <P>5.5 Balance—Analytical, capable of accurately weighing 0.0001 g.</P>
                        <P>5.6 High performance liquid chromatograph (HPLC)—An analytical system complete with column supplies, high pressure syringes, detectors, and compatible strip-chart recorder. A data system is recommended for measuring peak areas and retention times.</P>
                        <P>
                            5.6.1 Gradient pumping system—Constant flow.
                            <PRTPAGE P="207"/>
                        </P>
                        <P>5.6.2 Reverse phase column—HC-ODS Sil-X, 5 micron particle diameter, in a 25 cm × 2.6 mm ID stainless steel column (Perkin Elmer No. 089-0716 or equivalent). This column was used to develop the method performance statements in Section 15. Guidelines for the use of alternate column packings are provided in Section 12.2.</P>
                        <P>5.6.3 Detectors—Fluorescence and/or UV detectors. The fluorescence detector is used for excitation at 280 nm and emission greater than 389 nm cutoff (Corning 3-75 or equivalent). Fluorometers should have dispersive optics for excitation and can utilize either filter or dispersive optics at the emission detector. The UV detector is used at 254 nm and should be coupled to the fluorescence detector. These detectors were used to develop the method performance statements in Section 15. Guidelines for the use of alternate detectors are provided in Section 12.2.</P>
                        <P>5.7 Gas chromatograph—An analytical system complete with temperature programmable gas chromatograph suitable for on-column or splitless injection and all required accessories including syringes, analytical columns, gases, detector, and strip-chart recorder. A data system is recommended for measuring peak areas.</P>
                        <P>5.7.1 Column—1.8 m long × 2 mm ID glass, packed with 3% OV-17 on Chromosorb W-AW-DCMS (100/120 mesh) or equivalent. This column was used to develop the retention time data in Table 2. Guidelines for the use of alternate column packings are provided in Section 13.3.</P>
                        <P>5.7.2 Detector—Flame ionization detector. This detector has proven effective in the analysis of wastewaters for the parameters listed in the scope (Section 1.1), excluding the four pairs of unresolved compounds listed in Section 1.3. Guidelines for the use of alternate detectors are provided in Section 13.3.</P>
                        <HD SOURCE="HD2">6. Reagents</HD>
                        <P>6.1 Reagent water—Reagent water is defined as a water in which an interferent is not observed at the MDL of the parameters of interest.</P>
                        <P>6.2 Sodium thiosulfate—(ACS) Granular.</P>
                        <P>6.3 Cyclohexane, methanol, acetone, methylene chloride, pentane—Pesticide quality or equivalent.</P>
                        <P>6.4 Acetonitrile—HPLC quality, distilled in glass.</P>
                        <P>6.5 Sodium sulfate—(ACS) Granular, anhydrous. Purify by heating at 400 °C for 4 h in a shallow tray.</P>
                        <P>6.6 Silica gel—100/200 mesh, desiccant, Davison, grade-923 or equivalent. Before use, activate for at least 16 h at 130 °C in a shallow glass tray, loosely covered with foil.</P>
                        <P>6.7 Stock standard solutions (1.00 µg/µL)—Stock standard solutions can be prepared from pure standard materials or purchased as certified solutions.</P>
                        <P>6.7.1 Prepare stock standard solutions by accurately weighing about 0.0100 g of pure material. Dissolve the material in acetonitrile and dilute to volume in a 10-mL volumetric flask. Larger volumes can be used at the convenience of the analyst. When compound purity is assayed to be 96% or greater, the weight can be used without correction to calculate the concentration of the stock standard. Commercially prepared stock standards can be used at any concentration if they are certified by the manufacturer or by an independent source.</P>
                        <P>6.7.2 Transfer the stock standard solutions into Teflon-sealed screw-cap bottles. Store at 4 °C and protect from light. Stock standard solutions should be checked frequently for signs of degradation or evaporation, especially just prior to preparing calibration standards from them.</P>
                        <P>6.7.3 Stock standard solutions must be replaced after six months, or sooner if comparison with check standards indicates a problem.</P>
                        <P>6.8 Quality control check sample concentrate—See Section 8.2.1.</P>
                        <HD SOURCE="HD2">7. Calibration</HD>
                        <P>7.1 Establish liquid or gas chromatographic operating conditions equivalent to those given in Table 1 or 2. The chromatographic system can be calibrated using the external standard technique (Section 7.2) or the internal standard technique (Section 7.3).</P>
                        <P>7.2 External standard calibration procedure:</P>
                        <P>7.2.1 Prepare calibration standards at a minimum of three concentration levels for each parameter of interest by adding volumes of one or more stock standards to a volumetric flask and diluting to volume with acetonitrile. One of the external standards should be at a concentration near, but above, the MDL (Table 1) and the other concentrations should correspond to the expected range of concentrations found in real samples or should define the working range of the detector.</P>
                        <P>7.2.2 Using injections of 5 to 25 µL for HPLC and 2 to 5 µL for GC, analyze each calibration standard according to Section 12 or 13, as appropriate. Tabulate peak height or area responses against the mass injected. The results can be used to prepare a calibration curve for each compound. Alternatively, if the ratio of response to amount injected (calibration factor) is a constant over the working range (&lt;10% relative standard deviation, RSD), linearity through the origin can be assumed and the average ratio or calibration factor can be used in place of a calibration curve.</P>
                        <P>
                            7.3 Internal standard calibration procedure—To use this approach, the analyst must select one or more internal standards that are similar in analytical behavior to the 
                            <PRTPAGE P="208"/>
                            compounds of interest. The analyst must further demonstrate that the measurement of the internal standard is not affected by method or matrix interferences. Because of these limitations, no internal standard can be suggested that is applicable to all samples.
                        </P>
                        <P>7.3.1 Prepare calibration standards at a minimum of three concentration levels for each parameter of interest by adding volumes of one or more stock standards to a volumetric flask. To each calibration standard, add a known constant amount of one or more internal standards, and dilute to volume with acetonitrile. One of the standards should be at a concentration near, but above, the MDL and the other concentrations should correspond to the expected range of concentrations found in real samples or should define the working range of the detector.</P>
                        <P>7.3.2 Using injections of 5 to 25 µL for HPLC and 2 to 5 µL for GC, analyze each calibration standard according to Section 12 or 13, as appropriate. Tabulate peak height or area responses against concentration for each compound and internal standard. Calculate response factors (RF) for each compound using Equation 1.</P>
                        <MATH SPAN="1" DEEP="31">
                            <MID>EC15NO91.113</MID>
                        </MATH>
                        <FP SOURCE="FRP0">Equation 1</FP>
                        <FP>where:</FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">s</E>
                             = Response for the parameter to be measured.
                        </FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">is</E>
                             = Response for the internal standard.
                        </FP>
                        <FP SOURCE="FP-2">
                            C
                            <E T="52">is</E>
                             = Concentration of the internal standard (µg/L).
                        </FP>
                        <FP SOURCE="FP-2">
                            C
                            <E T="52">s</E>
                             = Concentration of the parameter to be measured (µg/L).
                        </FP>
                        <FP>
                            If the RF value over the working range is a constant (&lt;10% RSD), the RF can be assumed to be invariant and the average RF can be used for calculations. Alternatively, the results can be used to plot a calibration curve of response ratios, A
                            <E T="52">s</E>
                            /A
                            <E T="52">is</E>
                            , vs. RF.
                        </FP>
                        <P>7.4 The working calibration curve, calibration factor, or RF must be verified on each working day by the measurement of one or more calibration standards. If the response for any parameter varies from the predicted response by more than ±15%, the test must be repeated using a fresh calibration standard. Alternatively, a new calibration curve must be prepared for that compound.</P>
                        <P>7.5 Before using any cleanup procedure, the analyst must process a series of calibration standards through the procedure to validate elution patterns and the absence of interferences from the reagents.</P>
                        <HD SOURCE="HD2">8. Quality Control</HD>
                        <P>8.1 Each laboratory that uses this method is required to operate a formal quality control program. The minimum requirements of this program consist of an initial demonstration of laboratory capability and an ongoing analysis of spiked samples to evaluate and document data quality. The laboratory must maintain records to document the quality of data that is generated. Ongoing data quality checks are compared with established performance criteria to determine if the results of analyses meet the performance characteristics of the method. When results of sample spikes indicate atypical method performance, a quality control check standard must be analyzed to confirm that the measurements were performed in an in-control mode of operation.</P>
                        <P>8.1.1 The analyst must make an initial, one-time, demonstration of the ability to generate acceptable accuracy and precision with this method. This ability is established as described in Section 8.2.</P>
                        <P>8.1.2 In recognition of advances that are occurring in chromatography, the analyst is permitted certain options (detailed in Sections 10.4, 11.1, 12.2, and 13.3) to improve the separations or lower the cost of measurements. Each time such a modification is made to the method, the analyst is required to repeat the procedure in Section 8.2.</P>
                        <P>8.1.3 Before processing any samples the analyst must analyze a reagent water blank to demonstrate that interferences from the analytical system and glassware are under control. Each time a set of samples is extracted or reagents are changed a reagent water blank must be processed as a safeguard against laboratory contamination.</P>
                        <P>8.1.4 The laboratory must, on an ongoing basis, spike and analyze a minimum of 10% of all samples to monitor and evaluate laboratory data quality. This procedure is described in Section 8.3.</P>
                        <P>8.1.5 The laboratory must, on an ongoing basis, demonstrate through the analyses of quality control check standards that the operation of the measurement system is in control. This procedure is described in Section 8.4. The frequency of the check standard analyses is equivalent to 10% of all samples analyzed but may be reduced if spike recoveries from samples (Section 8.3) meet all specified quality control criteria.</P>
                        <P>8.1.6 The laboratory must maintain performance records to document the quality of data that is generated. This procedure is described in Section 8.5.</P>
                        <P>8.2 To establish the ability to generate acceptable accuracy and precision, the analyst must perform the following operations.</P>
                        <P>
                            8.2.1 A quality control (QC) check sample concentrate is required containing each parameter of interest at the following concentrations in acetonitrile: 100 µg/mL of any 
                            <PRTPAGE P="209"/>
                            of the six early-eluting PAHs (naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, and anthracene); 5 µg/mL of benzo(k)fluoranthene; and 10 µg/mL of any of the other PAHs. The QC check sample concentrate must be obtained from the U.S. Environmental Protection Agency, Environmental Monitoring and Support Laboratory in Cincinnati, Ohio, if available. If not available from that source, the QC check sample concentrate must be obtained from another external source. If not available from either source above, the QC check sample concentrate must be prepared by the laboratory using stock standards prepared independently from those used for calibration.
                        </P>
                        <P>8.2.2 Using a pipet, prepare QC check samples at the test concentrations shown in Table 3 by adding 1.00 mL of QC check sample concentrate to each of four 1-L aliquots of reagent water.</P>
                        <P>8.2.3 Analyze the well-mixed QC check samples according to the method beginning in Section 10.</P>
                        <P>
                            8.2.4 Calculate the average recovery (X
                            <AC T="8"/>
                            ) in µg/L, and the standard deviation of the recovery (s) in µg/L, for each parameter using the four results.
                        </P>
                        <P>
                            8.2.5 For each parameter compare s and X
                            <AC T="8"/>
                             with the corresponding acceptance criteria for precision and accuracy, respectively, found in Table 3. If s and X
                            <AC T="8"/>
                             for all parameters of interest meet the acceptance criteria, the system performance is acceptable and analysis of actual samples can begin. If any individual s exceeds the precision limit or any individual X
                            <AC T="8"/>
                             falls outside the range for accuracy, the system performance is unacceptable for that parameter.
                        </P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>The large number of parameters in Table 3 present a substantial probability that one or more will fail at least one of the acceptance criteria when all parameters are analyzed.</P>
                        </NOTE>
                        <P>8.2.6 When one or more of the parameters tested fail at least one of the acceptance criteria, the analyst must proceed according to Section 8.2.6.1 or 8.2.6.2.</P>
                        <P>8.2.6.1 Locate and correct the source of the problem and repeat the test for all parameters of interest beginning with Section 8.2.2.</P>
                        <P>8.2.6.2 Beginning with Section 8.2.2, repeat the test only for those parameters that failed to meet criteria. Repeated failure, however, will confirm a general problem with the measurement system. If this occurs, locate and correct the source of the problem and repeat the test for all compounds of interest beginning with Section 8.2.2.</P>
                        <P>8.3 The laboratory must, on an ongoing basis, spike at least 10% of the samples from each sample site being monitored to assess accuracy. For laboratories analyzing one to ten samples per month, at least one spiked sample per month is required.</P>
                        <P>8.3.1 The concentration of the spike in the sample should be determined as follows:</P>
                        <P>8.3.1.1 If, as in compliance monitoring, the concentration of a specific parameter in the sample is being checked against a regulatory concentration limit, the spike should be at that limit or 1 to 5 times higher than the background concentration determined in Section 8.3.2, whichever concentration would be larger.</P>
                        <P>8.3.1.2 If the concentration of a specific parameter in the sample is not being checked against a limit specific to that parameter, the spike should be at the test concentration in Section 8.2.2 or 1 to 5 times higher than the background concentration determined in Section 8.3.2, whichever concentration would be larger.</P>
                        <P>8.3.1.3 If it is impractical to determine background levels before spiking (e.g., maximum holding times will be exceeded), the spike concentration should be (1) the regulatory concentration limit, if any; or, if none, (2) the larger of either 5 times higher than the expected background concentration or the test concentration in Section 8.2.2.</P>
                        <P>8.3.2 Analyze one sample aliquot to determine the background concentration (B) of each parameter. If necessary, prepare a new QC check sample concentrate (Section 8.2.1) appropriate for the background concentrations in the sample. Spike a second sample aliquot with 1.0 mL of the QC check sample concentrate and analyze it to determine the concentration after spiking (A) of each parameter. Calculate each percent recovery (P) as 100 (A−B)%/T, where T is the known true value of the spike.</P>
                        <P>
                            8.3.3 Compare the percent recovery (P) for each parameter with the corresponding QC acceptance criteria found in Table 3. These acceptance criteria were calculated to include an allowance for error in measurement of both the background and spike concentrations, assuming a spike to background ratio of 5:1. This error will be accounted for to the extent that the analyst's spike to background ratio approaches 5:1. 
                            <SU>7</SU>
                             If spiking was performed at a concentration lower than the test concentration in Section 8.2.2, the analyst must use either the QC acceptance criteria in Table 3, or optional QC acceptance criteria calculated for the specific spike concentration. To calculate optional acceptance criteria for the recovery of a parameter: (1) Calculate accuracy (X′) using the equation in Table 4, substituting the spike concentration (T) for C; (2) calculate overall precision (S′) using the equation in Table 4, substituting X′ for X
                            <AC T="8"/>
                            ; (3) calculate the range for recovery at the spike concentration as (100 X′/T)±2.44(100 S′/T)%. 
                            <SU>7</SU>
                        </P>
                        <P>
                            8.3.4 If any individual P falls outside the designated range for recovery, that parameter has failed the acceptance criteria. A check standard containing each parameter 
                            <PRTPAGE P="210"/>
                            that failed the critiera must be analyzed as described in Section 8.4.
                        </P>
                        <P>8.4 If any parameter fails the acceptance criteria for recovery in Section 8.3, a QC check standard containing each parameter that failed must be prepared and analyzed.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>The frequency for the required analysis of a QC check standard will depend upon the number of parameters being simultaneously tested, the complexity of the sample matrix, and the performance of the laboratory. If the entire list of parameters in Table 3 must be measured in the sample in Section 8.3, the probability that the analysis of a QC check standard will be required is high. In this case the QC check standard should be routinely analyzed with the spike sample.</P>
                        </NOTE>
                        <P>8.4.1 Prepare the QC check standard by adding 1.0 mL of QC check sample concentrate (Section 8.2.1 or 8.3.2) to 1 L of reagent water. The QC check standard needs only to contain the parameters that failed criteria in the test in Section 8.3.</P>
                        <P>
                            8.4.2 Analyze the QC check standard to determine the concentration measured (A) of each parameter. Calculate each percent recovery (P
                            <E T="52">s</E>
                            ) as 100 (A/T)%, where T is the true value of the standard concentration.
                        </P>
                        <P>
                            8.4.3 Compare the percent recovery (P
                            <E T="52">s</E>
                            ) for each parameter with the corresponding QC acceptance criteria found in Table 3. Only parameters that failed the test in Section 8.3 need to be compared with these criteria. If the recovery of any such parameter falls outside the designated range, the laboratory performance for that parameter is judged to be out of control, and the problem must be immediately identified and corrected. The analytical result for that parameter in the unspiked sample is suspect and may not be reported for regulatory compliance purposes.
                        </P>
                        <P>
                            8.5 As part of the QC program for the laboratory, method accuracy for wastewater samples must be assessed and records must be maintained. After the analysis of five spiked wastewater samples as in Section 8.3, calculate the average percent recovery (P
                            <AC T="8"/>
                            ) and the standard deviation of the percent recovery (s
                            <E T="52">p</E>
                            ). Express the accuracy assessment as a percent recovery interval from P
                            <AC T="8"/>
                            -2s
                            <E T="52">p</E>
                             to P
                            <AC T="8"/>
                             + 2s
                            <E T="52">p</E>
                            . If P
                            <AC T="8"/>
                             = 90% and s
                            <E T="52">p</E>
                             = 10%, for example, the accuracy interval is expressed as 70-110%. Update the accuracy assessment for each parameter on a regular basis (e.g. after each five to ten new accuracy measurements).
                        </P>
                        <P>8.6 It is recommended that the laboratory adopt additional quality assurance practices for use with this method. The specific practices that are most productive depend upon the needs of the laboratory and the nature of the samples. Field duplicates may be analyzed to assess the precision of the environmental measurements. When doubt exists over the identification of a peak on the chromatogram, confirmatory techniques such as gas chromatography with a dissimilar column, specific element detector, or mass spectrometer must be used. Whenever possible, the laboratory should analyze standard reference materials and participate in relevant performance evaluation studies.</P>
                        <HD SOURCE="HD2">9. Sample Collection, Preservation, and Handling</HD>
                        <P>
                            9.1 Grab samples must be collected in glass containers. Conventional sampling practices 
                            <SU>8</SU>
                             should be followed, except that the bottle must not be prerinsed with sample before collection. Composite samples should be collected in refrigerated glass containers in accordance with the requirements of the program. Automatic sampling equipment must be as free as possible of Tygon tubing and other potential sources of contamination.
                        </P>
                        <P>
                            9.2 All samples must be iced or refrigerated at 4 °C from the time of collection until extraction. PAHs are known to be light sensitive; therefore, samples, extracts, and standards should be stored in amber or foil-wrapped bottles in order to minimize photolytic decomposition. Fill the sample bottles and, if residual chlorine is present, add 80 mg of sodium thiosulfate per liter of sample and mix well. EPA Methods 330.4 and 330.5 may be used for measurement of residual chlorine. 
                            <SU>9</SU>
                             Field test kits are available for this purpose.
                        </P>
                        <P>
                            9.3 All samples must be extracted within 7 days of collection and completely analyzed within 40 days of extraction. 
                            <SU>2</SU>
                        </P>
                        <HD SOURCE="HD2">10. Sample Extraction</HD>
                        <P>10.1 Mark the water meniscus on the side of the sample bottle for later determination of sample volume. Pour the entire sample into a 2-L separatory funnel.</P>
                        <P>10.2 Add 60 mL of methylene chloride to the sample bottle, seal, and shake 30 s to rinse the inner surface. Transfer the solvent to the separatory funnel and extract the sample by shaking the funnel for 2 min. with periodic venting to release excess pressure. Allow the organic layer to separate from the water phase for a minimum of 10 min. If the emulsion interface between layers is more than one-third the volume of the solvent layer, the analyst must employ mechanical techniques to complete the phase separation. The optimum technique depends upon the sample, but may include stirring, filtration of the emulsion through glass wool, centrifugation, or other physical methods. Collect the methylene chloride extract in a 250-mL Erlenmeyer flask.</P>
                        <P>
                            10.3 Add a second 60-mL volume of methylene chloride to the sample bottle and repeat the extraction procedure a second time, combining the extracts in the Erlenmeyer flask. Perform a third extraction in the same manner.
                            <PRTPAGE P="211"/>
                        </P>
                        <P>10.4 Assemble a Kuderna-Danish (K-D) concentrator by attaching a 10-mL concentrator tube to a 500-mL evaporative flask. Other concentration devices or techniques may be used in place of the K-D concentrator if the requirements of Section 8.2 are met.</P>
                        <P>10.5 Pour the combined extract through a solvent-rinsed drying column containing about 10 cm of anhydrous sodium sulfate, and collect the extract in the K-D concentrator. Rinse the Erlenmeyer flask and column with 20 to 30 mL of methylene chloride to complete the quantitative transfer.</P>
                        <P>10.6 Add one or two clean boiling chips to the evaporative flask and attach a three-ball Snyder column. Prewet the Snyder column by adding about 1 mL of methylene chloride to the top. Place the K-D apparatus on a hot water bath (60 to 65 °C) so that the concentrator tube is partially immersed in the hot water, and the entire lower rounded surface of the flask is bathed with hot vapor. Adjust the vertical position of the apparatus and the water temperature as required to complete the concentration in 15 to 20 min. At the proper rate of distillation the balls of the column will actively chatter but the chambers will not flood with condensed solvent. When the apparent volume of liquid reaches 1 mL, remove the K-D apparatus and allow it to drain and cool for at least 10 min.</P>
                        <P>10.7 Remove the Snyder column and rinse the flask and its lower joint into the concentrator tube with 1 to 2 mL of methylene chloride. A 5-mL syringe is recommended for this operation. Stopper the concentrator tube and store refrigerated if further processing will not be performed immediately. If the extract will be stored longer than two days, it should be transferred to a Teflon-sealed screw-cap vial and protected from light. If the sample extract requires no further cleanup, proceed with gas or liquid chromatographic analysis (Section 12 or 13). If the sample requires further cleanup, proceed to Section 11.</P>
                        <P>10.8 Determine the original sample volume by refilling the sample bottle to the mark and transferring the liquid to a 1000-mL graduated cylinder. Record the sample volume to the nearest 5 mL.</P>
                        <HD SOURCE="HD2">11. Cleanup and Separation</HD>
                        <P>11.1 Cleanup procedures may not be necessary for a relatively clean sample matrix. If particular circumstances demand the use of a cleanup procedure, the analyst may use the procedure below or any other appropriate procedure. However, the analyst first must demonstrate that the requirements of Section 8.2 can be met using the methods as revised to incorporate the cleanup procedure.</P>
                        <P>11.2 Before the silica gel cleanup technique can be utilized, the extract solvent must be exchanged to cyclohexane. Add 1 to 10 mL of the sample extract (in methylene chloride) and a boiling chip to a clean K-D concentrator tube. Add 4 mL of cyclohexane and attach a two-ball micro-Snyder column. Prewet the column by adding 0.5 mL of methylene chloride to the top. Place the micro-K-D apparatus on a boiling (100 °C) water bath so that the concentrator tube is partially immersed in the hot water. Adjust the vertical position of the apparatus and the water temperature as required to complete concentration in 5 to 10 min. At the proper rate of distillation the balls of the column will actively chatter but the chambers will not flood. When the apparent volume of the liquid reaches 0.5 mL, remove the K-D apparatus and allow it to drain and cool for at least 10 min. Remove the micro-Snyder column and rinse its lower joint into the concentrator tube with a minimum amount of cyclohexane. Adjust the extract volume to about 2 mL.</P>
                        <P>11.3 Silica gel column cleanup for PAHs:</P>
                        <P>11.3.1 Prepare a slurry of 10 g of activiated silica gel in methylene chloride and place this into a 10-mm ID chromatographic column. Tap the column to settle the silica gel and elute the methylene chloride. Add 1 to 2 cm of anhydrous sodium sulfate to the top of the silica gel.</P>
                        <P>11.3.2 Preelute the column with 40 mL of pentane. The rate for all elutions should be about 2 mL/min. Discard the eluate and just prior to exposure of the sodium sulfate layer to the air, transfer the 2-mL cyclohexane sample extract onto the column using an additional 2 mL cyclohexane to complete the transfer. Just prior to exposure of the sodium sulfate layer to the air, add 25 mL of pentane and continue the elution of the column. Discard this pentane eluate.</P>
                        <P>11.3.3 Next, elute the column with 25 mL of methylene chloride/pentane (4 + 6)(V/V) into a 500-mL K-D flask equipped with a 10-mL concentrator tube. Concentrate the collected fraction to less than 10 mL as in Section 10.6. When the apparatus is cool, remove the Snyder column and rinse the flask and its lower joint with pentane. Proceed with HPLC or GC analysis.</P>
                        <HD SOURCE="HD2">12. High Performance Liquid Chromatography</HD>
                        <P>12.1 To the extract in the concentrator tube, add 4 mL of acetonitrile and a new boiling chip, then attach a two-ball micro-Snyder column. Concentrate the solvent as in Section 10.6, except set the water bath at 95 to 100 °C. When the apparatus is cool, remove the micro-Snyder column and rinse its lower joint into the concentrator tube with about 0.2 mL of acetonitrile. Adjust the extract volume to 1.0 mL.</P>
                        <P>
                            12.2 Table 1 summarizes the recommended operating conditions for the HPLC. Included in this table are retention times, capacity factors, and MDL that can be achieved under these conditions. The UV detector is recommended for the determination of naphthalene, acenaphthylene, acenapthene, and 
                            <PRTPAGE P="212"/>
                            fluorene and the fluorescence detector is recommended for the remaining PAHs. Examples of the separations achieved by this HPLC column are shown in Figures 1 and 2. Other HPLC columns, chromatographic conditions, or detectors may be used if the requirements of Section 8.2 are met.
                        </P>
                        <P>12.3 Calibrate the system daily as described in Section 7.</P>
                        <P>12.4 If the internal standard calibration procedure is being used, the internal standard must be added to the sample extract and mixed thoroughly immediately before injection into the instrument.</P>
                        <P>12.5 Inject 5 to 25 µL of the sample extract or standard into the HPLC using a high pressure syringe or a constant volume sample injection loop. Record the volume injected to the nearest 0.1 µL, and the resulting peak size in area or peak height units. Re-equilibrate the HPLC column at the initial gradient conditions for at least 10 min between injections.</P>
                        <P>12.6 Identify the parameters in the sample by comparing the retention time of the peaks in the sample chromatogram with those of the peaks in standard chromatograms. The width of the retention time window used to make identifications should be based upon measurements of actual retention time variations of standards over the course of a day. Three times the standard deviation of a retention time for a compound can be used to calculate a suggested window size; however, the experience of the analyst should weigh heavily in the interpretation of chromatograms.</P>
                        <P>12.7 If the response for a peak exceeds the working range of the system, dilute the extract with acetonitrile and reanalyze.</P>
                        <P>12.8 If the measurement of the peak response is prevented by the presence of interferences, further cleanup is required.</P>
                        <HD SOURCE="HD2">13. Gas Chromatography</HD>
                        <P>13.1 The packed column GC procedure will not resolve certain isomeric pairs as indicated in Section 1.3 and Table 2. The liquid chromatographic procedure (Section 12) must be used for these parameters.</P>
                        <P>13.2 To achieve maximum sensitivity with this method, the extract must be concentrated to 1.0 mL. Add a clean boiling chip to the methylene chloride extract in the concentrator tube. Attach a two-ball micro-Snyder column. Prewet the micro-Snyder column by adding about 0.5 mL of methylene chloride to the top. Place the micro-K-D apparatus on a hot water bath (60 to 65 °C) so that the concentrator tube is partially immersed in the hot water. Adjust the vertical position of the apparatus and the water temperature as required to complete the concentration in 5 to 10 min. At the proper rate of distillation the balls will actively chatter but the chambers will not flood. When the apparent volume of liquid reaches 0.5 mL, remove the K-D apparatus and allow it to drain and cool for at least 10 min. Remove the micro-Snyder column and rinse its lower joint into the concentrator tube with a minimum amount of methylene chloride. Adjust the final volume to 1.0 mL and stopper the concentrator tube.</P>
                        <P>13.3 Table 2 summarizes the recommended operating conditions for the gas chromatograph. Included in this table are retention times that were obtained under these conditions. An example of the separations achieved by this column is shown in Figure 3. Other packed or capillary (open-tubular) columns, chromatographic conditions, or detectors may be used if the requirements of Section 8.2 are met.</P>
                        <P>13.4 Calibrate the gas chromatographic system daily as described in Section 7.</P>
                        <P>13.5 If the internal standard calibration procedure is being used, the internal standard must be added to the sample extract and mixed thoroughly immediately before injection into the gas chromatograph.</P>
                        <P>
                            13.6 Inject 2 to 5 µL of the sample extract or standard into the gas chromatograph using the solvent-flush technique. 
                            <SU>10</SU>
                             Smaller (1.0 µL) volumes may be injected if automatic devices are employed. Record the volume injected to the nearest 0.05 µL, and the resulting peak size in area or peak height units.
                        </P>
                        <P>13.7 Identify the parameters in the sample by comparing the retention times of the peaks in the sample chromatogram with those of the peaks in standard chromatograms. The width of the retention time window used to make identifications should be based upon measurements of actual retention time variations of standards over the course of a day. Three times the standard deviation of a retention time for a compound can be used to calculate a suggested window size; however, the experience of the analyst should weigh heavily in the interpretation of chromatograms.</P>
                        <P>13.8 If the response for a peak exceeds the working range of the system, dilute the extract and reanalyze.</P>
                        <P>13.9 If the measurement of the peak response is prevented by the presence of interferences, further cleanup is required.</P>
                        <HD SOURCE="HD2">14. Calculations</HD>
                        <P>14.1 Determine the concentration of individual compounds in the sample.</P>
                        <P>14.1.1 If the external standard calibration procedure is used, calculate the amount of material injected from the peak response using the calibration curve or calibration factor determined in Section 7.2.2. The concentration in the sample can be calculated from Equation 2.</P>
                        <MATH SPAN="1" DEEP="31">
                            <PRTPAGE P="213"/>
                            <MID>EC15NO91.114</MID>
                        </MATH>
                        <FP SOURCE="FRP0">Equation 2</FP>
                        <FP>where:</FP>
                        <FP SOURCE="FP-2">A = Amount of material injected (ng).</FP>
                        <FP SOURCE="FP-2">
                            V
                            <E T="52">i</E>
                             = Volume of extract injected (µL).
                        </FP>
                        <FP SOURCE="FP-2">
                            V
                            <E T="52">t</E>
                             = Volume of total extract (µL).
                        </FP>
                        <FP SOURCE="FP-2">
                            V
                            <E T="52">s</E>
                             = Volume of water extracted (mL).
                        </FP>
                        <P>13.1.2 If the internal standard calibration procedure is used, calculate the concentration in the sample using the response factor (RF) determined in Section 7.3.2 and Equation 3.</P>
                        <MATH SPAN="1" DEEP="31">
                            <MID>EC15NO91.115</MID>
                        </MATH>
                        <FP SOURCE="FRP0">Equation 3</FP>
                        <FP>where:</FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">s</E>
                             = Response for the parameter to be measured.
                        </FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">is</E>
                             = Response for the internal standard.
                        </FP>
                        <FP SOURCE="FP-2">
                            I
                            <E T="52">s</E>
                             = Amount of internal standard added to each extract (µg).
                        </FP>
                        <FP SOURCE="FP-2">
                            V
                            <E T="52">o</E>
                             = Volume of water extracted (L).
                        </FP>
                        <P>14.2 Report results in µg/L without correction for recovery data. All QC data obtained should be reported with the sample results.</P>
                        <HD SOURCE="HD2">15. Method Performance</HD>
                        <P>
                            15.1 The method detection limit (MDL) is defined as the minimum concentration of a substance that can be measured and reported with 99% confidence that the value is above zero. 
                            <SU>1</SU>
                             The MDL concentrations listed in Table 1 were obtained using reagent water. 
                            <SU>11</SU>
                             Similar results were achieved using representative wastewaters. MDL for the GC approach were not determined. The MDL actually achieved in a given analysis will vary depending on instrument sensitivity and matrix effects.
                        </P>
                        <P>
                            15.2 This method has been tested for linearity of spike recovery from reagent water and has been demonstrated to be applicable over the concentration range from 8 × MDL to 800 × MDL 
                            <SU>11</SU>
                             with the following exception: benzo(ghi)perylene recovery at 80 × and 800 × MDL were low (35% and 45%, respectively).
                        </P>
                        <P>
                            15.3 This method was tested by 16 laboratories using reagent water, drinking water, surface water, and three industrial wastewaters spiked at six concentrations over the range 0.1 to 425 µg/L. 
                            <SU>12</SU>
                             Single operator precision, overall precision, and method accuracy were found to be directly related to the concentration of the parameter and essentially independent of the sample matrix. Linear equations to describe these relationships are presented in Table 4.
                        </P>
                        <HD SOURCE="HD1">References</HD>
                        <P>1. 40 CFR part 136, appendix B.</P>
                        <P>2. “Determination of Polynuclear Aromatic Hydrocarbons in Industrial and Municipal Wastewaters,” EPA 600/4-82-025, National Technical Information Service, PB82-258799, Springfield, Virginia 22161, June 1982.</P>
                        <P>3. ASTM Annual Book of Standards, Part 31, D3694-78. “Standard Practices for Preparation of Sample Containers and for Preservation of Organic Constituents,” American Society for Testing and Materials, Philadelphia.</P>
                        <P>4. “Carcinogens—Working With Carcinogens,” Department of Health, Education, and Welfare, Public Health Service, Center for Disease Control, National Institute for Occupational Safety and Health, Publication No. 77-206, August 1977.</P>
                        <P>5. “OSHA Safety and Health Standards, General Industry,” (29 CFR part 1910), Occupational Safety and Health Administration, OSHA 2206 (Revised, January 1976).</P>
                        <P>6. “Safety in Academic Chemistry Laboratories,” American Chemical Society Publication, Committee on Chemical Safety, 3rd Edition, 1979.</P>
                        <P>
                            7. Provost, L.P., and Elder, R.S. “Interpretation of Percent Recovery Data,” 
                            <E T="03">American Laboratory, 15,</E>
                             58-63 (1983). (The value 2.44 used in the equation in Section 8.3.3 is two times the value 1.22 derived in this report.)
                        </P>
                        <P>8. ASTM Annual Book of Standards, Part 31, D3370-76. “Standard Practices for Sampling Water,” American Society for Testing and Materials, Philadelphia.</P>
                        <P>9. “Methods 330.4 (Titrimetric, DPD-FAS) and 330.5 (Spectrophotometric, DPD) for Chlorine, Total Residual,” Methods for Chemical Analysis of Water and Wastes, EPA-600/4-79-020, U.S. Environmental Protection Agency, Environmental Monitoring and Support Laboratory, Cincinnati, Ohio 45268, March 1979.</P>
                        <P>
                            10. Burke, J.A. “Gas Chromatography for Pesticide Residue Analysis; Some Practical Aspects,” 
                            <E T="03">Journal of the Association of Official Analytical Chemists, 48,</E>
                             1037 (1965).
                        </P>
                        <P>11. Cole, T., Riggin, R., and Glaser, J. “Evaluation of Method Detection Limits and Analytical Curve for EPA Method 610—PNAs,” International Symposium on Polynuclear Aromatic Hydrocarbons, 5th, Battelle's Columbus Laboratories, Columbus, Ohio (1980).</P>
                        <P>
                            12. “EPA Method Study 20, Method 610 (PNA's),” EPA 600/4-84-063, National Technical Information Service, PB84-211614, Springfield, Virginia 22161, June 1984.
                            <PRTPAGE P="214"/>
                        </P>
                        <GPOTABLE COLS="4" OPTS="L2" CDEF="s70,6.1,6.1,5.3">
                            <TTITLE>Table 1—High Performance Liquid Chromatography Conditions and Method Detection Limits</TTITLE>
                            <BOXHD>
                                <CHED H="1">Parameter</CHED>
                                <CHED H="1">Retention time (min)</CHED>
                                <CHED H="1">Column capacity factor (k′)</CHED>
                                <CHED H="1">
                                    Method detection limit (µg/L) 
                                    <SU>a</SU>
                                </CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">Naphthalene</ENT>
                                <ENT>16.6</ENT>
                                <ENT>12.2</ENT>
                                <ENT>1.8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Acenaphthylene</ENT>
                                <ENT>18.5</ENT>
                                <ENT>13.7</ENT>
                                <ENT>2.3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Acenaphthene</ENT>
                                <ENT>20.5</ENT>
                                <ENT>15.2</ENT>
                                <ENT>1.8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Fluorene</ENT>
                                <ENT>21.2</ENT>
                                <ENT>15.8</ENT>
                                <ENT>0.21</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Phenanthrene</ENT>
                                <ENT>22.1</ENT>
                                <ENT>16.6</ENT>
                                <ENT>0.64</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Anthracene</ENT>
                                <ENT>23.4</ENT>
                                <ENT>17.6</ENT>
                                <ENT>0.66</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Fluoranthene</ENT>
                                <ENT>24.5</ENT>
                                <ENT>18.5</ENT>
                                <ENT>0.21</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Pyrene</ENT>
                                <ENT>25.4</ENT>
                                <ENT>19.1</ENT>
                                <ENT>0.27</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzo(a)anthracene</ENT>
                                <ENT>28.5</ENT>
                                <ENT>21.6</ENT>
                                <ENT>0.013</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chrysene</ENT>
                                <ENT>29.3</ENT>
                                <ENT>22.2</ENT>
                                <ENT>0.15</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzo(b)fluoranthene</ENT>
                                <ENT>31.6</ENT>
                                <ENT>24.0</ENT>
                                <ENT>0.018</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzo(k)fluoranthene</ENT>
                                <ENT>32.9</ENT>
                                <ENT>25.1</ENT>
                                <ENT>0.017</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzo(a)pyrene</ENT>
                                <ENT>33.9</ENT>
                                <ENT>25.9</ENT>
                                <ENT>0.023</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dibenzo(a,h)anthracene</ENT>
                                <ENT>35.7</ENT>
                                <ENT>27.4</ENT>
                                <ENT>0.030</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzo(ghi)perylene</ENT>
                                <ENT>36.3</ENT>
                                <ENT>27.8</ENT>
                                <ENT>0.076</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Indeno(1,2,3-cd)pyrene</ENT>
                                <ENT>37.4</ENT>
                                <ENT>28.7</ENT>
                                <ENT>0.043</ENT>
                            </ROW>
                            <TNOTE>HPLC column conditions: Reverse phase HC-ODS Sil-X, 5 micron particle size, in a 25 cm × 2.6 mm ID stainless steel column. Isocratic elution for 5 min. using acetonitrile/water (4 + 6), then linear gradient elution to 100% acetonitrile over 25 min. at 0.5 mL/min flow rate. If columns having other internal diameters are used, the flow rate should be adjusted to maintain a linear velocity of 2 mm/sec.</TNOTE>
                            <TNOTE>
                                <SU>a</SU>
                                 The MDL for naphthalene, acenaphthylene, acenaphthene, and fluorene were determined using a UV detector. All others were determined using a fluorescence detector.
                            </TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="2" OPTS="L2" CDEF="s100,7.1">
                            <TTITLE>Table 2—Gas Chromatographic Conditions and Retention Times</TTITLE>
                            <BOXHD>
                                <CHED H="1">Parameter</CHED>
                                <CHED H="1">Retention time (min)</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">Naphthalene</ENT>
                                <ENT>4.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Acenaphthylene</ENT>
                                <ENT>10.4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Acenaphthene</ENT>
                                <ENT>10.8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Fluorene</ENT>
                                <ENT>12.6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Phenanthrene</ENT>
                                <ENT>15.9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Anthracene</ENT>
                                <ENT>15.9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Fluoranthene</ENT>
                                <ENT>19.8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Pyrene</ENT>
                                <ENT>20.6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzo(a)anthracene</ENT>
                                <ENT>24.7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chrysene</ENT>
                                <ENT>24.7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzo(b)fluoranthene</ENT>
                                <ENT>28.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzo(k)fluoranthene</ENT>
                                <ENT>28.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzo(a)pyrene</ENT>
                                <ENT>29.4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dibenzo(a,h)anthracene</ENT>
                                <ENT>36.2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Indeno(1,2,3-cd)pyrene</ENT>
                                <ENT>36.2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzo(ghi)perylene</ENT>
                                <ENT>38.6</ENT>
                            </ROW>
                            <TNOTE>GC Column conditions: Chromosorb W-AW-DCMS (100/120 mesh) coated with 3% OV-17 packed in a 1.8 × 2 mm ID glass column with nitrogen carrier gas at 40 mL/min. flow rate. Column temperature was held at 100 °C for 4 min., then programmed at 8 °C/min. to a final hold at 280 °C.</TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="5" OPTS="L2" CDEF="s50,10,10,10,10">
                            <TTITLE>Table 3—QC Acceptance Criteria—Method 610</TTITLE>
                            <BOXHD>
                                <CHED H="1">Parameter</CHED>
                                <CHED H="1">Test conc. (µg/L)</CHED>
                                <CHED H="1">Limit for s (µg/L)</CHED>
                                <CHED H="1">
                                    Range for X
                                    <AC T="8"/>
                                     (µg/L)
                                </CHED>
                                <CHED H="1">
                                    Range for P, P
                                    <E T="52">s</E>
                                     (%)
                                </CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">Acenaphthene</ENT>
                                <ENT>100</ENT>
                                <ENT>40.3</ENT>
                                <ENT>D-105.7</ENT>
                                <ENT>D-124</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Acenaphthylene</ENT>
                                <ENT>100</ENT>
                                <ENT>45.1</ENT>
                                <ENT>22.1-112.1</ENT>
                                <ENT>D-139</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Anthracene</ENT>
                                <ENT>100</ENT>
                                <ENT>28.7</ENT>
                                <ENT>11.2-112.3</ENT>
                                <ENT>D-126</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzo(a)anthracene</ENT>
                                <ENT>10</ENT>
                                <ENT>4.0</ENT>
                                <ENT>3.1-11.6</ENT>
                                <ENT>12-135</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzo(a)pyrene</ENT>
                                <ENT>10</ENT>
                                <ENT>4.0</ENT>
                                <ENT>0.2-11.0</ENT>
                                <ENT>D-128</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzo(b)fluor-anthene</ENT>
                                <ENT>10</ENT>
                                <ENT>3.1</ENT>
                                <ENT>1.8-13.8</ENT>
                                <ENT>6-150</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzo(ghi)perylene</ENT>
                                <ENT>10</ENT>
                                <ENT>2.3</ENT>
                                <ENT>D-10.7</ENT>
                                <ENT>D-116</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzo(k)fluo-ranthene</ENT>
                                <ENT>5</ENT>
                                <ENT>2.5</ENT>
                                <ENT>D-7.0</ENT>
                                <ENT>D-159</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chrysene</ENT>
                                <ENT>10</ENT>
                                <ENT>4.2</ENT>
                                <ENT>D-17.5</ENT>
                                <ENT>D-199</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dibenzo(a,h)an-thracene</ENT>
                                <ENT>10</ENT>
                                <ENT>2.0</ENT>
                                <ENT>0.3-10.0</ENT>
                                <ENT>D-110</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Fluoranthene</ENT>
                                <ENT>10</ENT>
                                <ENT>3.0</ENT>
                                <ENT>2.7-11.1</ENT>
                                <ENT>14-123</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Fluorene</ENT>
                                <ENT>100</ENT>
                                <ENT>43.0</ENT>
                                <ENT>D-119</ENT>
                                <ENT>D-142</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Indeno(1,2,3-cd)pyrene</ENT>
                                <ENT>10</ENT>
                                <ENT>3.0</ENT>
                                <ENT>1.2-10.0</ENT>
                                <ENT>D-116</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Naphthalene</ENT>
                                <ENT>100</ENT>
                                <ENT>40.7</ENT>
                                <ENT>21.5-100.0</ENT>
                                <ENT>D-122</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Phenanthrene</ENT>
                                <ENT>100</ENT>
                                <ENT>37.7</ENT>
                                <ENT>8.4-133.7</ENT>
                                <ENT>D-155</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Pyrene</ENT>
                                <ENT>10</ENT>
                                <ENT>3.4</ENT>
                                <ENT>1.4-12.1</ENT>
                                <ENT>D-140</ENT>
                            </ROW>
                            <TNOTE>s = Standard deviation of four recovery measurements, in µg/L (Section 8.2.4).</TNOTE>
                            <TNOTE>
                                X
                                <AC T="8"/>
                                 = Average recovery for four recovery measurements, in µg/L (Section 8.2.4).
                            </TNOTE>
                            <TNOTE>
                                P, P
                                <E T="52">s</E>
                                 = Percent recovery measured (Section 8.3.2, Section 8.4.2).
                            </TNOTE>
                            <TNOTE>D = Detected; result must be greater than zero.</TNOTE>
                            <TNOTE>
                                <E T="04">Note:</E>
                                 These criteria are based directly upon the method performance data in Table 4. Where necessary, the limits for recovery have been broadened to assure applicability of the limits to concentrations below those used to develop Table 4.
                            </TNOTE>
                        </GPOTABLE>
                        <PRTPAGE P="215"/>
                        <GPOTABLE COLS="4" OPTS="L2" CDEF="s50,12,12,12">
                            <TTITLE>Table 4—Method Accuracy and Precision as Functions of Concentration—Method 610</TTITLE>
                            <BOXHD>
                                <CHED H="1">Parameter</CHED>
                                <CHED H="1">Accuracy, as recovery, X′ (µg/L)</CHED>
                                <CHED H="1">
                                    Single analyst precision, s
                                    <E T="52">r</E>
                                    ′ (µg/L)
                                </CHED>
                                <CHED H="1">
                                    Overall precision, S′
                                    <LI>(µg/L)</LI>
                                </CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">Acenaphthene</ENT>
                                <ENT>0.52C + 0.54</ENT>
                                <ENT>
                                    0.39X
                                    <AC T="8"/>
                                     + 0.76
                                </ENT>
                                <ENT>
                                    0.53X
                                    <AC T="8"/>
                                     + 1.32
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Acenaphthylene</ENT>
                                <ENT>0.69C − 1.89</ENT>
                                <ENT>
                                    0.36X
                                    <AC T="8"/>
                                     + 0.29
                                </ENT>
                                <ENT>
                                    0.42X
                                    <AC T="8"/>
                                     + 0.52
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Anthracene</ENT>
                                <ENT>0.63C − 1.26</ENT>
                                <ENT>
                                    0.23X
                                    <AC T="8"/>
                                     + 1.16
                                </ENT>
                                <ENT>
                                    0.41X
                                    <AC T="8"/>
                                     + 0.45
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzo(a)anthracene</ENT>
                                <ENT>0.73C + 0.05</ENT>
                                <ENT>
                                    0.28X
                                    <AC T="8"/>
                                     + 0.04
                                </ENT>
                                <ENT>
                                    0.34X
                                    <AC T="8"/>
                                     + 0.02
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzo(a)pyrene</ENT>
                                <ENT>0.56C + 0.01</ENT>
                                <ENT>
                                    0.38X
                                    <AC T="8"/>
                                     − 0.01
                                </ENT>
                                <ENT>
                                    0.53X
                                    <AC T="8"/>
                                     − 0.01
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzo(b)fluoranthene</ENT>
                                <ENT>0.78C + 0.01</ENT>
                                <ENT>
                                    0.21X
                                    <AC T="8"/>
                                     + 0.01
                                </ENT>
                                <ENT>
                                    0.38X
                                    <AC T="8"/>
                                     − 0.00
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzo(ghi)perylene</ENT>
                                <ENT>0.44C + 0.30</ENT>
                                <ENT>
                                    0.25X
                                    <AC T="8"/>
                                     + 0.04
                                </ENT>
                                <ENT>
                                    0.58X
                                    <AC T="8"/>
                                     + 0.10
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzo(k)fluoranthene</ENT>
                                <ENT>0.59C + 0.00</ENT>
                                <ENT>
                                    0.44X
                                    <AC T="8"/>
                                     − 0.00
                                </ENT>
                                <ENT>
                                    0.69X
                                    <AC T="8"/>
                                     + 0.01
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chrysene</ENT>
                                <ENT>0.77C − 0.18</ENT>
                                <ENT>
                                    0.32X
                                    <AC T="8"/>
                                     − 0.18
                                </ENT>
                                <ENT>
                                    0.66X
                                    <AC T="8"/>
                                     − 0.22
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dibenzo(a,h)anthracene</ENT>
                                <ENT>0.41C + 0.11</ENT>
                                <ENT>
                                    0.24X
                                    <AC T="8"/>
                                     + 0.02
                                </ENT>
                                <ENT>
                                    0.45X
                                    <AC T="8"/>
                                     + 0.03
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Fluoranthene</ENT>
                                <ENT>0.68C + 0.07</ENT>
                                <ENT>
                                    0.22X
                                    <AC T="8"/>
                                     + 0.06
                                </ENT>
                                <ENT>
                                    0.32X
                                    <AC T="8"/>
                                     + 0.03
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Fluorene</ENT>
                                <ENT>0.56C − 0.52</ENT>
                                <ENT>
                                    0.44X
                                    <AC T="8"/>
                                     − 1.12
                                </ENT>
                                <ENT>
                                    0.63X
                                    <AC T="8"/>
                                     − 0.65
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Indeno(1,2,3-cd)pyrene</ENT>
                                <ENT>0.54C + 0.06</ENT>
                                <ENT>
                                    0.29X
                                    <AC T="8"/>
                                     + 0.02
                                </ENT>
                                <ENT>
                                    0.42X
                                    <AC T="8"/>
                                     + 0.01
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Naphthalene</ENT>
                                <ENT>0.57C − 0.70</ENT>
                                <ENT>
                                    0.39X
                                    <AC T="8"/>
                                     − 0.18
                                </ENT>
                                <ENT>
                                    0.41X
                                    <AC T="8"/>
                                     + 0.74
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Phenanthrene</ENT>
                                <ENT>0.72C − 0.95</ENT>
                                <ENT>
                                    0.29X
                                    <AC T="8"/>
                                     + 0.05
                                </ENT>
                                <ENT>
                                    0.47X
                                    <AC T="8"/>
                                     − 0.25
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Pyrene</ENT>
                                <ENT>0.69C − 0.12</ENT>
                                <ENT>
                                    0.25X
                                    <AC T="8"/>
                                     + 0.14
                                </ENT>
                                <ENT>
                                    0.42X
                                    <AC T="8"/>
                                     − 0.00
                                </ENT>
                            </ROW>
                            <TNOTE>X′ = Expected recovery for one or more measurements of a sample containing a concentration of C, in µg/L.</TNOTE>
                            <TNOTE>
                                s
                                <E T="52">r</E>
                                ′ = Expected single analyst standard deviation of measurements at an average concentration found of X
                                <AC T="8"/>
                                , in µg/L.
                            </TNOTE>
                            <TNOTE>
                                S′ = Expected interlaboratory standard deviation of measurements at an average concentration found of X
                                <AC T="8"/>
                                , in µg/L.
                            </TNOTE>
                            <TNOTE>C = True value for the concentration, in µg/L.</TNOTE>
                            <TNOTE>
                                X
                                <AC T="8"/>
                                 = Average recovery found for measurements of samples containing a concentration of C, in µg/L.
                            </TNOTE>
                        </GPOTABLE>
                        <GPH SPAN="2" DEEP="298">
                            <GID>EC02JY92.031</GID>
                        </GPH>
                        <GPH SPAN="2" DEEP="228">
                            <PRTPAGE P="216"/>
                            <GID>EC02JY92.032</GID>
                        </GPH>
                        <GPH SPAN="2" DEEP="308">
                            <PRTPAGE P="217"/>
                            <GID>EC02JY92.033</GID>
                        </GPH>
                        <HD SOURCE="HD1">Method 611—Haloethers</HD>
                        <EAR>Pt. 136, App. A, Meth. 611</EAR>
                        <HD SOURCE="HD2">1. Scope and Application</HD>
                        <P>1.1 This method covers the determination of certain haloethers. The following parameters can be determined by this method:</P>
                        <GPOTABLE COLS="3" OPTS="L2" CDEF="s30,7,10">
                            <BOXHD>
                                <CHED H="1">Parameter</CHED>
                                <CHED H="1">STORET No.</CHED>
                                <CHED H="1">CAS No.</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">Bis(2-chloroethyl) ether</ENT>
                                <ENT>34273</ENT>
                                <ENT>111-44-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Bis(2-chloroethoxy) methane</ENT>
                                <ENT>34278</ENT>
                                <ENT>111-91-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2, 2′-oxybis (1-chloropropane)</ENT>
                                <ENT>34283</ENT>
                                <ENT>108-60-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4-Bromophenyl phenyl ether</ENT>
                                <ENT>34636</ENT>
                                <ENT>101-55-3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4-Chlorophenyl phenyl ether</ENT>
                                <ENT>34641</ENT>
                                <ENT>7005-72-3</ENT>
                            </ROW>
                        </GPOTABLE>
                        <P>1.2 This is a gas chromatographic (GC) method applicable to the determination of the compounds listed above in municipal and industrial discharges as provided under 40 CFR 136.1. When this method is used to analyze unfamiliar samples for any or all of the compounds above, compound identifications should be supported by at least one additional qualitative technique. This method describes analytical conditions for a second gas chromatographic column that can be used to confirm measurements made with the primary column. Method 625 provides gas chromatograph/mass spectrometer (GC/MS) conditions appropriate for the qualitative and quantitative confirmation of results for all of the parameters listed above, using the extract produced by this method.</P>
                        <P>
                            1.3 The method detection limit (MDL, defined in Section 14.1) 
                            <SU>1</SU>
                             for each parameter is listed in Table 1. The MDL for a specific wastewater may differ from those listed, depending upon the nature of interferences in the sample matrix.
                        </P>
                        <P>
                            1.4 The sample extraction and concentration steps in this method are essentially the same as in Methods 606, 608, 609, and 612. Thus, a single sample may be extracted to measure the parameters included in the scope of each of these methods. When cleanup is required, the concentration levels must be high enough to permit selecting aliquots, as necessary, to apply appropriate cleanup procedures. The analyst is allowed the latitude, under Section 12, to select 
                            <PRTPAGE P="218"/>
                            chromatographic conditions appropriate for the simultaneous measurement of combinations of these parameters.
                        </P>
                        <P>1.5 Any modification of this method, beyond those expressly permitted, shall be considered as a major modification subject to application and approval of alternate test procedures under 40 CFR 136.4 and 136.5.</P>
                        <P>1.6 This method is restricted to use by or under the supervision of analysts experienced in the use of a gas chromatograph and in the interpretation of gas chromatograms. Each analyst must demonstrate the ability to generate acceptable results with this method using the procedure described in Section 8.2.</P>
                        <HD SOURCE="HD2">2. Summary of Method</HD>
                        <P>
                            2.1 A measured volume of sample, approximately 1-L, is extracted with methylene chloride using a separatory funnel. The methylene chloride extract is dried and exchanged to hexane during concentration to a volume of 10 mL or less. The extract is separated by gas chromatography and the parameters are then measured with a halide specific detector. 
                            <SU>2</SU>
                        </P>
                        <P>2.2 The method provides a Florisil column cleanup procedure to aid in the elimination of interferences that may be encountered.</P>
                        <HD SOURCE="HD2">3. Interferences</HD>
                        <P>3.1 Method interferences may be caused by contaminants in solvents, reagents, glassware, and other sample processing hardware that lead to discrete artifacts and/or elevated baselines in gas chromatograms. All of these materials must be routinely demonstrated to be free from interferences under the conditions of the analysis by running laboratory reagent blanks as described in Section 8.1.3.</P>
                        <P>
                            3.1.1 Glassware must be scrupulously cleaned. 
                            <SU>3</SU>
                             Clean all glassware as soon as possible after use by rinsing with the last solvent used in it. Solvent rinsing should be followed be detergent washing with hot water, and rinses with tap water and distilled water. The glassware should then be drained dry, and heated in a muffle furnace at 400 °C for 15 to 30 min. Some thermally stable materials, such a PCBs, may not be eliminated by this treatment. Solvent rinses with acetone and pesticide quality hexane may be substituted for the muffle furnace heating. Thorough rinsing with such solvents usually eliminates PCB interference. Volumetric ware should not be heated in a muffle furnace. After drying and cooling, glassware should be sealed and stored in a clean environment to prevent any accumulation of dust or other contaminants. Store inverted or capped with aluminum foil.
                        </P>
                        <P>3.1.2 The use of high purity reagents and solvents helps to minimize interference problems. Purification of solvents by distillation in all-glass systems may be required.</P>
                        <P>3.2 Matrix interferences may be caused by contaminants that are co-extracted from the sample. The extent of matrix interferences will vary considerably from source to source, depending upon the nature and diversity of the industrial complex or municipality being sampled. The cleanup procedure in Section 11 can be used to overcome many of these interferences, but unique samples may require additional cleanup approaches to achieve the MDL listed in Table 1.</P>
                        <P>3.3 Dichlorobenzenes are known to coelute with haloethers under some gas chromatographic conditions. If these materials are present together in a sample, it may be necessary to analyze the extract with two different column packings to completely resolve all of the compounds.</P>
                        <HD SOURCE="HD2">4. Safety</HD>
                        <P>
                            4.1 The toxicity or carcinogenicity of each reagent used in this method has not been precisely defined; however, each chemical compound should be treated as a potential health hazard. From this viewpoint, exposure to these chemicals must be reduced to the lowest possible level by whatever means available. The laboratory is responsible for maintaining a current awareness file of OSHA regulations regarding the safe handling of the chemicals specified in this method. A reference file of material data handling sheets should also be made available to all personnel involved in the chemical analysis. Additional references to laboratory safety are available and have been identified 
                            <SU>4-6</SU>
                             for the information of the analyst.
                        </P>
                        <HD SOURCE="HD2">5. Apparatus and Materials</HD>
                        <P>5.1 Sampling equipment, for discrete or composite sampling.</P>
                        <P>5.1.1 Grab sample bottle—1-L or 1-qt, amber glass, fitted with a screw cap lined with Teflon. Foil may be substituted for Teflon if the sample is not corrosive. If amber bottles are not available, protect samples from light. The bottle and cap liner must be washed, rinsed with acetone or methylene chloride, and dried before use to minimize contamination.</P>
                        <P>
                            5.1.2 Automatic sampler (optional)—The sampler must incorporate glass sample containers for the collection of a minimum of 250 mL of sample. Sample containers must be kept refrigerated at 4 °C and protected from light during compositing. If the sampler uses a peristaltic pump, a minimum length of compressible silicone rubber tubing may be used. Before use, however, the compressible tubing should be thoroughly rinsed with methanol, followed by repeated rinsings with distilled water to minimize the potential for contamination of the sample. An integrating 
                            <PRTPAGE P="219"/>
                            flow meter is required to collect flow proportional composites.
                        </P>
                        <P>5.2 Glassware (All specifications are suggested. Catalog numbers are included for illustration only.):</P>
                        <P>5.2.1 Separatory funnel—2-L, with Teflon stopcock.</P>
                        <P>5.2.2 Drying column—Chromatographic column, approximately 400 mm long × 19 mm ID, with coarse frit filter disc.</P>
                        <P>5.2.3 Chromatographic column—400 mm long × 19 mm ID, with Teflon stopcock and coarse frit filter disc at bottom (Kontes K-420540-0224 or equivalent).</P>
                        <P>5.2.4 Concentrator tube, Kuderna-Danish—10-mL, graduated (Kontes K-570050-1025 or equivalent). Calibration must be checked at the volumes employed in the test. Ground glass stopper is used to prevent evaporation of extracts.</P>
                        <P>5.2.5 Evaporative flask, Kuderna-Danish—500-mL (Kontes K-570001-0500 or equivalent). Attach to concentrator tube with springs.</P>
                        <P>5.2.6 Snyder column, Kuderna-Danish—Three-ball macro (Kontes K-503000-0121 or equivalent).</P>
                        <P>5.2.7 Vials—10 to 15-mL, amber glass, with Teflon-lined screw cap.</P>
                        <P>5.3 Boiling chips—Approximately 10/40 mesh. Heat to 400 °C for 30 min or Soxhlet extract with methylene chloride.</P>
                        <P>5.4 Water bath—Heated, with concentric ring cover, capable of temperature control (±2 °C). The bath should be used in a hood.</P>
                        <P>5.5 Balance—Analytical, capable of accurately weighing 0.0001 g.</P>
                        <P>5.6 Gas chromatograph—An analytical system complete with temperature programmable gas chromatograph suitable for on-column injection and all required accessories including syringes, analytical columns, gases, detector, and strip-chart recorder. A data system is recommended for measuring peak areas.</P>
                        <P>5.6.1 Column 1—1.8 m long × 2 mm ID glass, packed with 3% SP-1000 on Supelcoport (100/120 mesh) or equivalent. This column was used to develop the method performance statements in Section 14. Guidelines for the use of alternate column packings are provided in Section 12.1.</P>
                        <P>5.6.2 Column 2—1.8 m long × 2 mm ID glass, packed with 2,6-diphenylene oxide polymer (60/80 mesh), Tenax, or equivalent.</P>
                        <P>5.6.3 Detector—Halide specific detector: electrolytic conductivity or microcoulometric. These detectors have proven effective in the analysis of wastewaters for the parameters listed in the scope (Section 1.1). The Hall conductivity detector was used to develop the method performance statements in Section 14. Guidelines for the use of alternate detectors are provided in Section 12.1. Although less selective, an electron capture detector is an acceptable alternative.</P>
                        <HD SOURCE="HD2">6. Reagents</HD>
                        <P>6.1 Reagent water—Reagent water is defined as a water in which an interferent is not observed at the MDL of the parameters of interest.</P>
                        <P>6.2 Sodium thiosulfate—(ACS) Granular.</P>
                        <P>6.3 Acetone, hexane, methanol, methylene chloride, petroleum ether (boiling range 30-60 °C)—Pesticide quality or equivalent.</P>
                        <P>6.4 Sodium sulfate—(ACS) Granular, anhydrous. Purify by heating at 400 °C for 4 h in a shallow tray.</P>
                        <P>6.5 Florisil—PR Grade (60/100 mesh). Purchase activated at 1250 °F and store in the dark in glass containers with ground glass stoppers or foil-lined screw caps. Before use, activate each batch at least 16 h at 130 °C in a foil-covered glass container and allow to cool.</P>
                        <P>6.6 Ethyl ether—Nanograde, redistilled in glass if necessary.</P>
                        <P>6.6.1 Ethyl ether must be shown to be free of peroxides before it is used as indicated by EM Laboratories Quant test strips. (Available from Scientific Products Co., Cat. No. P1126-8, and other suppliers.)</P>
                        <P>6.6.2 Procedures recommended for removal of peroxides are provided with the test strips. After cleanup, 20 mL of ethyl alcohol preservative must be added to each liter of ether.</P>
                        <P>6.7 Stock standard solutions (1.00 µg/µL)—Stock standard solutions can be prepared from pure standard materials or purchased as certified solutions.</P>
                        <P>6.7.1 Prepare stock standard solutions by accurately weighing about 0.0100 g of pure material. Dissolve the material in acetone and dilute to volume in a 10-mL volumetric flask. Larger volumes can be used at the convenience of the analyst. When compound purity is assayed to be 96% or greater, the weight can be used without correction to calculate the concentration of the stock standard. Commercially prepared stock standards can be used at any concentration if they are certified by the manufacturer or by an independent source.</P>
                        <P>6.7.2 Transfer the stock standard solutions into Teflon-sealed screw-cap bottles. Store at 4 °C and protect from light. Stock standard solutions should be checked frequently for signs of degradation or evaporation, especially just prior to preparing calibration standards from them.</P>
                        <P>6.7.3 Stock standard solutions must be replaced after six months, or sooner if comparison with check standards indicates a problem.</P>
                        <P>6.8 Quality control check sample concentrate—See Section 8.2.1.</P>
                        <HD SOURCE="HD2">7. Calibration</HD>
                        <P>
                            7.1 Establish gas chromatographic operating conditions equivalent to those given in Table 1. The gas chromatographic system 
                            <PRTPAGE P="220"/>
                            can be calibrated using the external standard technique (Section 7.2) or the internal standard technique (Section 7.3).
                        </P>
                        <P>7.2 External standard calibration procedure:</P>
                        <P>7.2.1 Prepare calibration standards at a minimum of three concentration levels for each parameter of interest by adding volumes of one or more stock standards to a volumetric flask and diluting to volume with hexane. One of the external standards should be at a concentration near, but above, the MDL (Table 1) and the other concentrations should correspond to the expected range of concentrations found in real samples or should define the working range of the detector.</P>
                        <P>7.2.2 Using injections of 2 to 5 µL, analyze each calibration standard according to Section 12 and tabulate peak height or area responses against the mass injected. The results can be used to prepare a calibration curve for each compound. Alternatively, if the ratio of response to amount injected (calibration factor) is a constant over the working range (&lt;10% relative standard deviation, RSD), linearity through the origin can be assumed and the average ratio or calibration factor can be used in place of a calibration curve.</P>
                        <P>7.3 Internal standard calibration procedure—To use this approach, the analyst must select one or more internal standards that are similar in analytical behavior to the compounds of interest. The analyst must further demonstrate that the measurement of the internal standard is not affected by method or matrix interferences. Because of these limitations, no internal standard can be suggested that is applicable to all samples.</P>
                        <P>7.3.1 Prepare calibration standards at a minimum of three concentration levels for each parameter of interest by adding volumes of one or more stock standards to a volumetric flask. To each calibration standard, add a known constant amount of one or more internal standards, and dilute to volume with hexane. One of the standards should be at a concentration near, but above, the MDL and the other concentrations should correspond to the expected range of concentrations found in real samples or should define the working range of the detector.</P>
                        <P>7.3.2 Using injections of 2 to 5 µL, analyze each calibration standard according to Section 12 and tabulate peak height or area responses against concentration for each compound and internal standard. Calculate response factors (RF) for each compound using Equation 1.</P>
                        <MATH SPAN="1" DEEP="31">
                            <MID>EC15NO91.116</MID>
                        </MATH>
                        <FP SOURCE="FRP0">Equation 1</FP>
                        <FP>where:</FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">s</E>
                             = Response for the parameter to be measured.
                        </FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">is</E>
                             = Response for the internal standard.
                        </FP>
                        <FP SOURCE="FP-2">
                            C
                            <E T="52">is</E>
                             = Concentration of the internal standard (µg/L).
                        </FP>
                        <FP SOURCE="FP-2">
                            C
                            <E T="52">s</E>
                             = Concentration of the parameter to be measured (µg/L).
                        </FP>
                        <FP>
                            If the RF value over the working range is a constant (&lt;10% RSD), the RF can be assumed to be invariant and the average RF can be used for calculations. Alternatively, the results can be used to plot a calibration curve of response ratios, A
                            <E T="52">s</E>
                            /A
                            <E T="52">is</E>
                            , vs. RF.
                        </FP>
                        <P>7.4 The working calibration curve, calibration factor, or RF must be verified on each working day by the measurement of one or more calibration standards. If the response for any parameter varies from the predicted response by more than ±15%, a new calibration curve must be prepared for that compound.</P>
                        <P>
                            7.5 The cleanup procedure in Section 11 utilizes Florisil column chromatography. Florisil from different batches or sources may vary in adsorptive capacity. To standardize the amount of Florisil which is used, the use of lauric acid value 
                            <SU>7</SU>
                             is suggested. The referenced procedure determines the adsorption from hexane solution of lauric acid (mg) per g of Florisil. The amount of Florisil to be used for each column is calculated by dividing 110 by this ratio and multiplying by 20 g.
                        </P>
                        <P>7.6 Before using any cleanup procedure, the analyst must process a series of calibration standards through the procedure to validate elution patterns and the absence of interferences from the reagents.</P>
                        <HD SOURCE="HD2">8. Quality Control</HD>
                        <P>8.1 Each laboratory that uses this method is required to operate a formal quality control program. The minimum requirements of this program consist of an initial demonstration of laboratory capability and an ongoing analysis of spiked samples to evaluate and document data quality. The laboratory must maintain records to document the quality of data that is generated. Ongoing data quality checks are compared with established performance criteria to determine if the results of analyses meet the performance characteristics of the method. When results of sample spikes indicate atypical method performance, a quality control check standard must be analyzed to confirm that the measurements were performed in an in-control mode of operation.</P>
                        <P>
                            8.1.1 The analyst must make an initial, one-time, demonstration of the ability to generate acceptable accuracy and precision with this method. This ability is established as described in Section 8.2.
                            <PRTPAGE P="221"/>
                        </P>
                        <P>8.1.2 In recognition of advances that are occurring in chromatography, the analyst is permitted certain options (detailed in Sections 10.4, 11.1, and 12.1) to improve the separations or lower the cost of measurements. Each time such a modification is made to the method, the analyst is required to repeat the procedure in Section 8.2.</P>
                        <P>8.1.3 Before processing any samples, the analyst must analyze a reagent water blank to demonstrate that interferences from the analytical system and glassware are under control. Each time a set of samples is extracted or reagents are changed, a reagent water blank must be processed as a safeguard against laboratory contamination.</P>
                        <P>8.1.4 The laboratory must, on an ongoing basis, spike and analyze a minimum of 10% of all samples to monitor and evaluate laboratory data quality. This procedure is described in Section 8.3.</P>
                        <P>8.1.5 The laboratory must, on an ongoing basis, demonstrate through the analyses of quality control check standards that the operation of the measurement system is in control. This procedure is described in Section 8.4. The frequency of the check standard analyses is equivalent to 10% of all samples analyzed but may be reduced if spike recoveries from samples (Section 8.3) meet all specified quality control criteria.</P>
                        <P>8.1.6 The laboratory must maintain performance records to document the quality of data that is generated. This procedure is described in Section 8.5.</P>
                        <P>8.2 To establish the ability to generate acceptable accuracy and precision, the analyst must perform the following operations.</P>
                        <P>8.2.1 A quality control (QC) check sample concentrate is required containing each parameter of interest at a concentration of 100 µg/mL in acetone. The QC check sample concentrate must be obtained from the U.S. Environmental Protection Agency, Environmental Monitoring and Support Laboratory in Cincinnati, Ohio, if available. If not available from that source, the QC check sample concentrate must be obtained from another external source. If not available from either source above, the QC check sample concentrate must be prepared by the laboratory using stock standards prepared independently from those used for calibration.</P>
                        <P>8.2.2 Using a pipet, prepare QC check samples at a concentration of 100 µg/L by adding 1.00 mL of QC check sample concentrate to each of four 1-L aliquots of reagent water.</P>
                        <P>8.2.3 Analyze the well-mixed QC check samples according to the method beginning in Section 10.</P>
                        <P>
                            8.2.4 Calculate the average recovery (X
                            <AC T="8"/>
                            ) in µg/L, and the standard deviation of the recovery (s) in µg/L, for each parameter using the four results.
                        </P>
                        <P>
                            8.2.5 For each parameter compare s and X
                            <AC T="8"/>
                             with the corresponding acceptance criteria for precision and accuracy, respectively, found in Table 2. If s and X
                            <AC T="8"/>
                             for all parameters of interest meet the acceptance criteria, the system performance is acceptable and analysis of actual samples can begin. If any individual s exceeds the precision limit or any individual X
                            <AC T="8"/>
                             falls outside the range for accuracy, the system performance is unacceptable for that parameter. Locate and correct the source of the problem and repeat the test for all parameters of interest beginning with Section 8.2.2.
                        </P>
                        <P>8.3 The laboratory must, on an ongoing basis, spike at least 10% of the samples from each sample site being monitored to assess accuracy. For laboratories analyzing one to ten samples per month, at least one spiked sample per month is required.</P>
                        <P>8.3.1. The concentration of the spike in the sample should be determined as follows:</P>
                        <P>8.3.1.1 If, as in compliance monitoring, the concentration of a specific parameter in the sample is being checked against a regulatory concentration limit, the spike should be at that limit or 1 to 5 times higher than the background concentration determined in Section 8.3.2, whichever concentration would be larger.</P>
                        <P>8.3.1.2 If the concentration of a specific parameter in the sample is not being checked against a limit specific to that parameter, the spike should be at 100 µg/L or 1 to 5 times higher than the background concentration determined in Section 8.3.2, whichever concentration would be larger.</P>
                        <P>8.3.1.3 If it is impractical to determine background levels before spiking (e.g., maximum holding times will be exceeded), the spike concentration should be (1) the regulatory concentration limit, if any; or, if none (2) the larger of either 5 times higher than the expected background concentration or 100 µg/L.</P>
                        <P>8.3.2 Analyze one sample aliquot to determine the background concentration (B) of each parameter. If necessary, prepare a new QC check sample concentrate (Section 8.2.1) appropriate for the background concentrations in the sample. Spike a second sample aliquot with 1.0 mL of the QC check sample concentrate and analyze it to determine the concentration after spiking (A) of each parameter. Calculate each percent recovery (P) as 100(A−B)%/T, where T is the known true value of the spike.</P>
                        <P>
                            8.3.3 Compare the percent recovery (P) for each parameter with the corresponding QC acceptance criteria found in Table 2. These acceptance criteria were calculated to include an allowance for error in measurement of both the background and spike concentrations, assuming a spike to background ratio of 5:1. This error will be accounted for to the extent that the analyst's spike to background ratio approaches 5:1. 
                            <SU>8</SU>
                             If spiking was performed at a concentration lower than 100 µg/L, the analyst must use either the QC acceptance criteria in Table 2, or optional QC 
                            <PRTPAGE P="222"/>
                            acceptance criteria calculated for the specific spike concentration. To calculate optional acceptance criteria for the recovery of a parameter: (1) Calculate accuracy (X′) using the equation in Table 3, substituting the spike concentration (T) for C; (2) calculate overall precision (S′) using the equation in Table 3, substituting X′ for X
                            <AC T="8"/>
                            ; (3) calculate the range for recovery at the spike concentration as (100 X′/T)±2.44(100 S′/T)%. 
                            <SU>8</SU>
                        </P>
                        <P>8.3.4 If any individual P falls outside the designated range for recovery, that parameter has failed the acceptance criteria. A check standard containing each parameter that failed the criteria must be analyzed as described in Section 8.4.</P>
                        <P>8.4 If any parameter fails the acceptance criteria for recovery in Section 8.3, a QC check standard containing each parameter that failed must be prepared and analyzed.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>The frequency for the required analysis of a QC check standard will depend upon the number of parameters being simultaneously tested, the complexity of the sample matrix, and the performance of the laboratory.</P>
                        </NOTE>
                        <P>8.4.1 Prepare the QC check standard by adding 1.0 m/L of QC check sample concentrate (Section 8.2.1 or 8.3.2) to 1 L of reagent water. The QC check standard needs only to contain the parameters that failed criteria in the test in Section 8.3.</P>
                        <P>
                            8.4.2 Analyze the QC check standard to determine the concentration measured (A) of each parameter. Calculate each percent recovery (P
                            <E T="52">s</E>
                            ) as 100 (A/T)%, where T is the true value of the standard concentration.
                        </P>
                        <P>
                            8.4.3 Compare the percent recovery (P
                            <E T="52">s</E>
                            ) for each parameter with the corresponding QC acceptance criteria found in Table 2. Only parameters that failed the test in Section 8.3 need to be compared with these criteria. If the recovery of any such parameter falls outside the designated range, the laboratory performance for that parameter is judged to be out of control, and the problem must be immediately identified and corrected. The analytical result for that parameter in the unspiked sample is suspect and may not be reported for regulatory compliance purposes.
                        </P>
                        <P>
                            8.5 As part of the QC program for the laboratory, method accuracy for wastewater samples must be assessed and records must be maintained. After the analysis of five spiked wastewater samples as in Section 8.3, calculate the average percent recovery (P
                            <AC T="8"/>
                            ) and the standard deviation of the percent recovery (s
                            <E T="52">p</E>
                            ). Express the accuracy assessment as a percent recovery interval from P
                            <AC T="8"/>
                            -2s
                            <E T="52">p</E>
                             to P
                            <AC T="8"/>
                             + 2s
                            <E T="52">p</E>
                            . If P
                            <AC T="8"/>
                             = 90% and s
                            <E T="52">p</E>
                             = 10%, for example, the accuracy interval is expressed as 70-110%. Update the accuracy assessment for each parameter on a regular basis (e.g. after each five to ten new accuracy measurements).
                        </P>
                        <P>8.6 It is recommended that the laboratory adopt additional quality assurance practices for use with this method. The specific practices that are most productive depend upon the needs of the laboratory and the nature of the samples. Field duplicates may be analyzed to assess the precision of the environmental measurements. When doubt exists over the identification of a peak on the chromatogram, confirmatory techniques such as gas chromatography with a dissimilar column, specific element detector, or mass spectrometer must be used. Whenever possible, the laboratory should analyze standard reference materials and participate in relevant performance evaluation studies.</P>
                        <HD SOURCE="HD2">9. Sample Collection, Preservation, and Handling</HD>
                        <P>
                            9.1 Grab samples must be collected in glass containers. Conventional sampling practices 
                            <SU>9</SU>
                             should be followed, except that the bottle must not be prerinsed with sample before collection. Composite samples should be collected in refrigerated glass containers in accordance with the requirements of the program. Automatic sampling equipment must be as free as possible of Tygon tubing and other potential sources of contamination.
                        </P>
                        <P>
                            9.2 All samples must be iced or refrigerated at 4 °C from the time of collection until extraction. Fill the sample bottles and, if residual chlorine is present, add 80 mg of sodium thiosulfate per liter of sample and mix well. EPA Methods 330.4 and 330.5 may be used for measurement of residual chlorine. 
                            <SU>10</SU>
                             Field test kits are available for this purpose.
                        </P>
                        <P>
                            9.3 All samples must be extracted within 7 days of collection and completely analyzed within 40 days of extraction. 
                            <SU>2</SU>
                        </P>
                        <HD SOURCE="HD2">10. Sample Extraction</HD>
                        <P>10.1 Mark the water meniscus on the side of the sample bottle for later determination of sample volume. Pour the entire sample into a 2-L separatory funnel.</P>
                        <P>
                            10.2 Add 60 mL methylene chloride to the sample bottle, seal, and shake 30 s to rinse the inner surface. Transfer the solvent to the separatory funnel and extract the sample by shaking the funnel for 2 min with periodic venting to release excess pressure. Allow the organic layer to separate from the water phase for a minimum of 10 min. If the emulsion interface between layers is more than one-third the volume of the solvent layer, the analyst must employ mechanical techniques to complete the phase separation. The optimum technique depends upon the sample, but may include stirring, filtration of the emulsion through glass wool, centrifugation, or other physical methods. Collect the methylene chloride extract in a 250-mL Erlenmeyer flask.
                            <PRTPAGE P="223"/>
                        </P>
                        <P>10.3 Add a second 60-mL volume of methylene chloride to the sample bottle and repeat the extraction procedure a second time, combining the extracts in the Erlenmeyer flask. Perform a third extraction in the same manner.</P>
                        <P>10.4 Assemble a Kuderna-Danish (K-D) concentrator by attaching a 10-mL concentrator tube to a 500-mL evaporative flask. Other concentration devices or techniques may be used in place of the K-D concentrator if the requirements of Section 8.2 are met.</P>
                        <P>10.5 Pour the combined extract through a solvent-rinsed drying column containing about 10 cm of anhydrous sodium sulfate, and collect the extract in the K-D concentrator. Rinse the Erlenmeyer flask and column with 20 to 30 mL of methylene chloride to complete the quantitative transfer.</P>
                        <P>10.6 Add one or two clean boiling chips to the evaporative flask and attach a three-ball Snyder column. Prewet the Snyder column by adding about 1 mL of methylene chloride to the top. Place the K-D apparatus on a hot water bath (60 to 65 °C) so that the concentrator tube is partially immersed in the hot water, and the entire lower rounded surface of the flask is bathed with hot vapor. Adjust the vertical position of the apparatus and the water temperature as required to complete the concentration in 15 to 20 min. At the proper rate of distillation the balls of the column will actively chatter but the chambers will not flood with condensed solvent. When the apparent volume of liquid reaches 1 mL, remove the K-D apparatus and allow it to drain and cool for at least 10 min.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>Some of the haloethers are very volatile and significant losses will occur in concentration steps if care is not exercised. It is important to maintain a constant gentle evaporation rate and not to allow the liquid volume to fall below 1 to 2 mL before removing the K-D apparatus from the hot water bath.</P>
                        </NOTE>
                        <P>10.7 Momentarily remove the Snyder column, add 50 mL of hexane and a new boiling chip, and reattach the Snyder column. Raise the temperature of the water bath to 85 to 90 °C. Concentrate the extract as in Section 10.6, except use hexane to prewet the column. The elapsed time of concentration should be 5 to 10 min.</P>
                        <P>10.8 Remove the Snyder column and rinse the flask and its lower joint into the concentrator tube with 1 to 2 mL of hexane. A 5-mL syringe is recommended for this operation. Stopper the concentrator tube and store refrigerated if further processing will not be performed immediately. If the extract will be stored longer than two days, it should be transferred to a Teflon-sealed screw-cap vial. If the sample extract requires no further cleanup, proceed with gas chromatographic analysis (Section 12). If the sample requires further cleanup, proceed to Section 11.</P>
                        <P>10.9 Determine the original sample volume by refilling the sample bottle to the mark and transferring the liquid to a 1000-mL graduated cylinder. Record the sample volume to the nearest 5 mL.</P>
                        <HD SOURCE="HD2">11. Cleanup and Separation</HD>
                        <P>11.1 Cleanup procedures may not be necessary for a relatively clean sample matrix. If particular circumstances demand the use of a cleanup procedure, the analyst may use the procedure below or any other appropriate procedure. However, the analyst first must demonstrate that the requirements of Section 8.2 can be met using the method as revised to incorporate the cleanup procedure.</P>
                        <P>11.2 Florisil column cleanup for haloethers:</P>
                        <P>11.2.1 Adjust the sample extract volume to 10 mL.</P>
                        <P>11.2.2 Place a weight of Florisil (nominally 20 g) predetermined by calibration (Section 7.5), into a chromatographic column. Tap the column to settle the Florisil and add 1 to 2 cm of anhydrous sodium sulfate to the top.</P>
                        <P>11.2.3 Preelute the column with 50 to 60 mL of petroleum ether. Discard the eluate and just prior to exposure of the sodium sulfate layer to the air, quantitatively transfer the sample extract onto the column by decantation and subsequent petroleum ether washings. Discard the eluate. Just prior to exposure of the sodium sulfate layer to the air, begin eluting the column with 300 mL of ethyl ether/petroleum ether (6 + 94) (V/V). Adjust the elution rate to approximately 5 mL/min and collect the eluate in a 500-mL K-D flask equipped with a 10-mL concentrator tube. This fraction should contain all of the haloethers.</P>
                        <P>11.2.4 Concentrate the fraction as in Section 10.6, except use hexane to prewet the column. When the apparatus is cool, remove the Snyder column and rinse the flask and its lower joint into the concentrator tube with hexane. Adjust the volume of the cleaned up extract to 10 mL with hexane and analyze by gas chromatography (Section 12).</P>
                        <HD SOURCE="HD2">12. Gas Chromatography</HD>
                        <P>12.1 Table 1 summarizes the recommended operating conditions for the gas chromatograph. Included in this table are retention times and MDL that can be achieved under these conditions. Examples of the separations achieved by Columns 1 and 2 are shown in Figures 1 and 2, respectively. Other packed or capillary (open-tubular) columns, chromatographic conditions, or detectors may be used if the requirements of Section 8.2 are met.</P>
                        <P>
                            12.2 Calibrate the system daily as described in Section 7.
                            <PRTPAGE P="224"/>
                        </P>
                        <P>12.3 If the internal standard calibration procedure is being used, the internal standard must be added to the sample extract and mixed thoroughly immediately before injection into the gas chromatrograph.</P>
                        <P>
                            12.4 Inject 2 to 5 µL of the sample extract or standard into the gas chromatograph using the solvent-flush technique. 
                            <SU>11</SU>
                             Smaller (1.0 µL) volumes may be injected if automatic devices are employed. Record the volume injected to the nearest 0.05 µL, the total extract volume, and the resulting peak size in area or peak height units.
                        </P>
                        <P>12.5 Identify the parameters in the sample by comparing the retention times of the peaks in the sample chromatogram with those of the peaks in standard chromatograms. The width of the retention time window used to make identifications should be based upon measurements of actual retention time variations of standards over the course of a day. Three times the standard deviation of a retention time for a compound can be used to calculate a suggested window size; however, the experience of the analyst should weight heavily in the interpretation of chromatograms.</P>
                        <P>12.6 If the response for a peak exceeds the working range of the system, dilute the extract and reanalyze.</P>
                        <P>12.7 If the measurement of the peak response is prevented by the presence of interferences, further cleanup is required.</P>
                        <HD SOURCE="HD2">13. Calculations</HD>
                        <P>13.1 Determine the concentration of individual compounds in the sample.</P>
                        <P>13.1.1 If the external standard calibration procedure is used, calculate the amount of material injected from the peak response using the calibration curve or calibration factor determined in Section 7.2.2. The concentration in the sample can be calculated from Equation 2.</P>
                        <MATH SPAN="1" DEEP="31">
                            <MID>EC15NO91.117</MID>
                        </MATH>
                        <FP SOURCE="FRP0">Equation 2</FP>
                        <FP>where:</FP>
                        <FP SOURCE="FP-2">A = Amount of material injected (ng).</FP>
                        <FP SOURCE="FP-2">
                            V
                            <E T="52">i</E>
                             = Volume of extract injected (µL).
                        </FP>
                        <FP SOURCE="FP-2">
                            V
                            <E T="52">t</E>
                             = Volume of total extract (µL).
                        </FP>
                        <FP SOURCE="FP-2">
                            V
                            <E T="52">s</E>
                             = Volume of water extracted (mL).
                        </FP>
                        <P>13.1.2 If the internal standard calibration procedure is used, calculate the concentration in the sample using the response factor (RF) determined in Section 7.3.2 and Equation 3.</P>
                        <MATH SPAN="1" DEEP="31">
                            <MID>EC15NO91.118</MID>
                        </MATH>
                        <FP SOURCE="FRP0">Equation 3</FP>
                        <FP>where:</FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">s</E>
                             = Response for the parameter to be measured.
                        </FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">is</E>
                             = Response for the internal standard.
                        </FP>
                        <FP SOURCE="FP-2">
                            I
                            <E T="52">s</E>
                             = Amount of internal standard added to each extract (µg).
                        </FP>
                        <FP SOURCE="FP-2">
                            V
                            <E T="52">o</E>
                             = Volume of water extracted (L).
                        </FP>
                        <P>13.2 Report results in µg/L without correction for recovery data. All QC data obtained should be reported with the sample results.</P>
                        <HD SOURCE="HD2">14. Method Performance</HD>
                        <P>
                            14.1 The method detection limit (MDL) is defined as the minimum concentration of a substance that can be measured and reported with 99% confidence that the value is above zero. 
                            <SU>1</SU>
                             The MDL concentrations listed in Table 1 were obtained using reagent water. 
                            <SU>12</SU>
                             Similar results were achieved using representative wastewaters. The MDL actually achieved in a given analysis will vary depending on instrument sensitivity and matrix effects.
                        </P>
                        <P>
                            14.2 This method has been tested for linearity of spike recovery from reagent water and has been demonstrated to be applicable over the concentration range from 4 × MDL to 1000 × MDL. 
                            <SU>12</SU>
                        </P>
                        <P>
                            14.3 This method was tested by 20 laboratories using reagent water, drinking water, surface water, and three industrial wastewaters spiked at six concentrations over the range 1.0 to 626 µ/L. 
                            <SU>12</SU>
                             Single operator precision, overall precision, and method accuracy were found to be directly related to the concentration of the parameter and essentially independent of the sample matrix. Linear equations to describe these relationships are presented in Table 3.
                        </P>
                        <HD SOURCE="HD1">References</HD>
                        <P>1. 40 CFR part 136, appendix B.</P>
                        <P>2. “Determination of Haloethers in Industrial and Municipal Wastewaters,” EPA 600/4-81-062, National Technical Information Service, PB81-232290, Springfield, Virginia 22161, July 1981.</P>
                        <P>3. ASTM Annual Book of Standards, Part 31, D3694-78. “Standard Practices for Preparation of Sample Containers and for Preservation of Organic Constitutents,” American Society for Testing and Materials, Philadelphia.</P>
                        <P>4. “Carcinogens—Working Carcinogens, ” Department of Health, Education, and Welfare, Public Health Services, Center for Disease Control, National Institute for Occupational Safety and Health, Publication No. 77-206, August 1977.</P>
                        <P>
                            5. “OSHA Safety and Health Standards, General Industry,” (29 CFR part 1910), Occupational Safety and Health Administration, OSHA 2206 (Revised, January 1976).
                            <PRTPAGE P="225"/>
                        </P>
                        <P>6. “Safety in Academic Chemistry Laboratories,” American Chemical Society Publication, Committee on Chemical Safety, 3rd Edition, 1979.</P>
                        <P>
                            7. Mills., P.A. “Variation of Florisil Activity: Simple Method for Measuring Absorbent Capacity and Its Use in Standardizing Florisil Columns,” 
                            <E T="03">Journal of the Association of Official Analytical Chemists, 51,</E>
                             29 (1968).
                        </P>
                        <P>
                            8. Provost, L.P., and Elder, R.S. “Interpretation of Percent Recovery Data,” 
                            <E T="03">American Laboratory, 15,</E>
                             58-63 (1983). (The value 2.44 used in the equation in Section 8.3.3 is two times the value 1.22 derived in this report.)
                        </P>
                        <P>9. ASTM Annual Book of Standards, Part 31, D3370-76. “Standard Practices for Sampling Water,” American Society for Testing and Materials, Philadelphia.</P>
                        <P>10. “Methods 330.4 (Titrimetric, DPD-FAS) and 330.5 (Spectrophotometric, DPD) for Chlorine, Total Residual,” Methods for Chemical Analysis of Water and Wastes, EPA-600/4-79-020, U.S. Environmental Protection Agency, Environmental Monitoring and Support Laboratory, Cincinnati, Ohio 45268, March 1979.</P>
                        <P>
                            11. Burke, J.A. “Gas Chromatography for Pesticide Residue Analysis; Some Practical Aspects,” 
                            <E T="03">Journal of the Association of Official Analytical Chemists, 48,</E>
                             1037 (1965).
                        </P>
                        <P>12. “EPA Method Study 21, Method 611, Haloethers,” EPA 600/4-84-052, National Technical Information Service, PB84-205939, Springfield, Virginia 22161, June 1984.</P>
                        <GPOTABLE COLS="4" OPTS="L2" CDEF="s70,6.1,6.1,6.1">
                            <TTITLE>Table 1—Chromatographic Conditions and Methods Detection Limits</TTITLE>
                            <BOXHD>
                                <CHED H="1">Parameters</CHED>
                                <CHED H="1">Retention time (min)</CHED>
                                <CHED H="2">Column 1</CHED>
                                <CHED H="2">Column 2</CHED>
                                <CHED H="1">Method detection limit (µ/L)</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">Bis(2-chloroisopropyl) ether</ENT>
                                <ENT>8.4</ENT>
                                <ENT>9.7</ENT>
                                <ENT>0.8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Bis(2-chloroethyl) ether</ENT>
                                <ENT>9.3</ENT>
                                <ENT>9.1</ENT>
                                <ENT>0.3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Bis(2-chloroethoxy) methane</ENT>
                                <ENT>13.1</ENT>
                                <ENT>10.0</ENT>
                                <ENT>0.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4-Chlorophenyl ether</ENT>
                                <ENT>19.4</ENT>
                                <ENT>15.0</ENT>
                                <ENT>3.9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4-Bromophenyl phenyl ether</ENT>
                                <ENT>21.2</ENT>
                                <ENT>16.2</ENT>
                                <ENT>2.3</ENT>
                            </ROW>
                            <TNOTE>Column 1 conditions: Supelcoport (100/120 mesh) coated with 3% SP-1000 packed in a 1.8 m long × 2 mm ID glass column with helium carrier gas at 40 mL/min. flow rate. Column temperature held at 60 °C for 2 min. after injection then programmed at 8 °C/min. to 230 °C and held for 4 min. Under these conditions the retention time for Aldrin is 22.6 min.</TNOTE>
                            <TNOTE>Column 2 conditions: Tenax-GC (60/80 mesh) packed in a 1.8 m long × 2mm ID glass column with helium carrier gas at 40 mL/min. flow rate. Column temperature held at 150 °C for 4 min. after injection then programmed at 16 °C/min. to 310 °C. Under these conditions the retention time for Aldrin is 18.4 min.</TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="5" OPTS="L2" CDEF="s50,10,9.1,10,10">
                            <TTITLE>Table 2—QC Acceptance Criteria—Method 611</TTITLE>
                            <BOXHD>
                                <CHED H="1">Parameter</CHED>
                                <CHED H="1">Test conc. (µg/L)</CHED>
                                <CHED H="1">Limit for s (µg/L)</CHED>
                                <CHED H="1">
                                    Range for X
                                    <AC T="8"/>
                                     (µg/L)
                                </CHED>
                                <CHED H="1">
                                    Range for P, P
                                    <E T="52">s</E>
                                     percent
                                </CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">Bis (2-chloroethyl)ether</ENT>
                                <ENT>100</ENT>
                                <ENT>26.3</ENT>
                                <ENT>26.3-136.8</ENT>
                                <ENT>11-152</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Bis (2-chloroethoxy)methane</ENT>
                                <ENT>100</ENT>
                                <ENT>25.7</ENT>
                                <ENT>27.3-115.0</ENT>
                                <ENT>12-128</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Bis (2-chloroisopropyl)ether</ENT>
                                <ENT>100</ENT>
                                <ENT>32.7</ENT>
                                <ENT>26.4-147.0</ENT>
                                <ENT>9-165</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4-Bromophenyl phenyl ether</ENT>
                                <ENT>100</ENT>
                                <ENT>39.3</ENT>
                                <ENT>7.6-167.5</ENT>
                                <ENT>D-189</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4-Chlorophenyl phenyl ether</ENT>
                                <ENT>100</ENT>
                                <ENT>30.7</ENT>
                                <ENT>15.4-152.5</ENT>
                                <ENT>D-170</ENT>
                            </ROW>
                            <TNOTE>s = Standard deviation of four recovery measurements, in µg/L (Section 8.2.4).</TNOTE>
                            <TNOTE>
                                X
                                <AC T="8"/>
                                 = Average recovery for four recovery measurements, in µg/L (Section 8.2.4).
                            </TNOTE>
                            <TNOTE>
                                P, P
                                <E T="52">s</E>
                                 = Percent recovery measured (Section 8.3.2, Section 8.4.2).
                            </TNOTE>
                            <TNOTE>D = Detected; result must be greater than zero.</TNOTE>
                            <TNOTE>
                                <E T="04">Note:</E>
                                 These criteria are based directly upon the method performance data in Table 3. Where necessary, the limits for recovery have been broadened to assure applicability of the limits to concentrations below those used to develop Table 3.
                            </TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="4" OPTS="L2" CDEF="s50,12,12,12">
                            <TTITLE>Table 3—Method Accuracy and Precision as Functions of Concentration—Method 611</TTITLE>
                            <BOXHD>
                                <CHED H="1">Parameter</CHED>
                                <CHED H="1">Accuracy, as recovery, X′ (µg/L)</CHED>
                                <CHED H="1">
                                    Single analyst precision, s
                                    <E T="52">r</E>
                                    ′ (µg/L)
                                </CHED>
                                <CHED H="1">Overall precision, S′ (µg/L)</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">Bis(2-chloroethyl) ether</ENT>
                                <ENT>0.81C + 0.54</ENT>
                                <ENT>
                                    0.19X
                                    <AC T="8"/>
                                     + 0.28
                                </ENT>
                                <ENT>
                                    0.35X
                                    <AC T="8"/>
                                     + 0,36
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Bis(2-chloroethoxy) methane</ENT>
                                <ENT>0.71C + 0.13</ENT>
                                <ENT>
                                    0.20X
                                    <AC T="8"/>
                                     + 0.15
                                </ENT>
                                <ENT>
                                    0.33X
                                    <AC T="8"/>
                                     + 0.11
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Bis(2-chloroisopropyl) ether</ENT>
                                <ENT>0.85C + 1.67</ENT>
                                <ENT>
                                    0.20X
                                    <AC T="8"/>
                                     + 1.05
                                </ENT>
                                <ENT>
                                    0.36X
                                    <AC T="8"/>
                                     + 0.79
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4-Bromophenyl phenyl ether</ENT>
                                <ENT>0.85C + 2.55</ENT>
                                <ENT>
                                    0.25X
                                    <AC T="8"/>
                                     + 0.21
                                </ENT>
                                <ENT>
                                    0.47X
                                    <AC T="8"/>
                                     + 0.37
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4-Chlorophenyl phenyl ether</ENT>
                                <ENT>0.82C + 1.97</ENT>
                                <ENT>
                                    0.18X
                                    <AC T="8"/>
                                     + 2.13
                                </ENT>
                                <ENT>
                                    0.41X
                                    <AC T="8"/>
                                     + 0.55
                                </ENT>
                            </ROW>
                            <TNOTE>X′ = Expected recovery for one or more measuremelts of a sample containing a concentration of C, in µg/L.</TNOTE>
                            <TNOTE>
                                s
                                <E T="52">r</E>
                                ′ = Expected single analyst standard deviation of measurements at an average concentration found of X
                                <AC T="8"/>
                                , in µg/L.
                            </TNOTE>
                            <TNOTE>
                                S′ = Expected interlaboratory standard deviation of measurements at an average concentration found of X
                                <AC T="8"/>
                                , in µg/L.
                            </TNOTE>
                            <TNOTE>C = True value for the concentration, in µg/L.</TNOTE>
                            <TNOTE>
                                X
                                <AC T="8"/>
                                 = Average recovery found for measurements of samples containing a concentration of C, in µg/L.
                            </TNOTE>
                        </GPOTABLE>
                        <GPH SPAN="2" DEEP="364">
                            <PRTPAGE P="226"/>
                            <GID>EC02JY92.034</GID>
                        </GPH>
                        <GPH SPAN="2" DEEP="425">
                            <PRTPAGE P="227"/>
                            <GID>EC02JY92.035</GID>
                        </GPH>
                        <HD SOURCE="HD1">Method 612—Chlorinated Hydrocarbons</HD>
                        <EAR>Pt. 136, App. A, Meth. 612</EAR>
                        <HD SOURCE="HD2">1. Scope and Application</HD>
                        <P>1.1 This method covers the determination of certain chlorinated hydrocarbons. The following parameters can be determined by this method:</P>
                        <GPOTABLE COLS="3" OPTS="L2" CDEF="s30,7,10">
                            <BOXHD>
                                <CHED H="1">Parameter</CHED>
                                <CHED H="1">STORET No.</CHED>
                                <CHED H="1">CAS No.</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">2-Chloronaphthalene</ENT>
                                <ENT>34581</ENT>
                                <ENT>91-58-7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2-Dichlorobenzene</ENT>
                                <ENT>34536</ENT>
                                <ENT>95-50-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,3-Dichlorobenzene</ENT>
                                <ENT>34566</ENT>
                                <ENT>541-73-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,4-Dichlorobenzene</ENT>
                                <ENT>34571</ENT>
                                <ENT>106-46-7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Hexachlorobenzene</ENT>
                                <ENT>39700</ENT>
                                <ENT>118-74-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Hexachlorobutadiene</ENT>
                                <ENT>34391</ENT>
                                <ENT>87-68-3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Hexachlorocyclopentadiene</ENT>
                                <ENT>34386</ENT>
                                <ENT>77-47-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Hexachloroethane</ENT>
                                <ENT>34396</ENT>
                                <ENT>67-72-1</ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="228"/>
                                <ENT I="01">1,2,4-Trichlorobenzene</ENT>
                                <ENT>34551</ENT>
                                <ENT>120-82-1</ENT>
                            </ROW>
                        </GPOTABLE>
                        <P>1.2 This is a gas chromatographic (GC) method applicable to the determination of the compounds listed above in municipal and industrial discharges as provided under 40 CFR 136.1. When this method is used to analyze unfamiliar samples for any or all of the compounds above, compound identifications should be supported by at least one additional qualitative technique. This method describes a second gas chromatographic column that can be used to confirm measurements made with the primary column. Method 625 provides gas chromatograph/mass spectrometer (GC/MS) conditions appropriate for the qualitative and quantitative confirmation of results for all of the parameters listed above, using the extract produced by this method.</P>
                        <P>
                            1.3 The method detection limit (MDL, defined in Section 14.1) 
                            <SU>1</SU>
                             for each parameter is listed in Table 1. The MDL for a specific wastewater may differ from those listed, depending upon the nature of interferences in the sample matrix.
                        </P>
                        <P>1.4 The sample extraction and concentration steps in this method are essentially the same as in Methods 606, 608, 609, and 611. Thus, a single sample may be extracted to measure the parameters included in the scope of each of these methods. When cleanup is required, the concentration levels must be high enough to permit selecting aliquots, as necessary, to apply appropriate cleanup procedures. The analyst is allowed the latitude, under Section 12, to select chromatographic conditions appropriate for the simultaneous measurement of combinations of these parameters.</P>
                        <P>1.5 Any modification of this method, beyond those expressly permitted, shall be considered as a major modification subject to application and approval of alternate test procedures under 40 CFR 136.4 and 136.5.</P>
                        <P>1.6 This method is restricted to use by or under the supervision of analysts experienced in the use of a gas chromatograph and in the interpretation of gas chromatograms. Each analyst must demonstrate the ability to generate acceptable results with this method using the procedure described in Section 8.2.</P>
                        <HD SOURCE="HD2">2. Summary of Method</HD>
                        <P>
                            2.1 A measured volume of sample, approximately 1-L, is extracted with methylene chloride using a separatory funnel. The methylene chloride extract is dried and exchanged to hexane during concentration to a volume of 10 mL or less. The extract is separated by gas chromatography and the parameters are then measured with an electron capture detector. 
                            <SU>2</SU>
                        </P>
                        <P>2.2 The method provides a Florisil column cleanup procedure to aid in the elimination of interferences that may be encountered.</P>
                        <HD SOURCE="HD2">3. Interferences</HD>
                        <P>3.1 Method interferences may be caused by contaminants in solvents, reagents, glassware, and other sample processing hardware that lead to discrete artifacts and/or elevated baselines in gas chromatograms. All of these materials must be routinely demonstrated to be free from interferences under the conditions of the analysis by running laboratory reagent blanks as described in Section 8.1.3.</P>
                        <P>
                            3.1.1 Glassware must be scrupulously cleaned. 
                            <SU>3</SU>
                             Clean all glassware as soon as possible after use by rinsing with the last solvent used in it. Solvent rinsing should be followed by detergent washing with hot water, and rinses with tap water and distilled water. The glassware should then be drained dry, and heated in a muffle furnace at 400 °C for 15 to 30 min. Some thermally stable materials, such as PCBs, may not be eliminated by this treatment. Solvent rinses with acetone and pesticide quality hexane may be substituted for the muffle furnace heating. Thorough rinsing with such solvents usually eliminates PCB interference. Volumetric ware should not be heated in a muffle furnace. After drying and cooling, glassware should be sealed and stored in a clean environment to prevent any accumulation of dust or other contaminants. Store inverted or capped with aluminum foil.
                        </P>
                        <P>3.1.2 The use of high purity reagents and solvents helps to minimize interference problems. Purification of solvents by distillation in all-glass systems may be required.</P>
                        <P>3.2 Matrix interferences may be caused by contaminants that are co-extracted from the sample. The extent of matrix interferences will vary considerably from source to source, depending upon the nature and diversity of the industrial complex or municipality being sampled. The cleanup procedure in Section 11 can be used to overcome many of these interferences, but unique samples may require additional cleanup approaches to achieve the MDL listed in Table 1.</P>
                        <HD SOURCE="HD2">4. Safety</HD>
                        <P>
                            4.1 The toxicity or carcinogenicity of each reagent used in this method has not been precisely defined; however, each chemical compound should be treated as a potential health hazard. From this viewpoint, exposure to these chemicals must be reduced to the lowest possible level by whatever means available. The laboratory is responsible for maintaining a current awareness file of OSHA regulations regarding the safe handling of the chemicals specified in this method. A reference file of material data handling sheets should also be made available to all 
                            <PRTPAGE P="229"/>
                            personnel involved in the chemical analysis. Additional references to laboratory safety are available and have been identified 
                            <SU>4-6</SU>
                             for the information of the analyst.
                        </P>
                        <HD SOURCE="HD2">5. Apparatus and Materials</HD>
                        <P>5.1 Sampling equipment, for discrete or composite sampling.</P>
                        <P>5.1.1 Grab sample bottle—1cL or 1-qt, amber glass, fitted with a screw cap lined with Teflon. Foil may be substituted for Teflon if the sample is not corrosive. If amber bottles are not available, protect samples from light. The bottle and cap liner must be washed, rinsed with acetone or methylene chloride, and dried before use to minimize contamination.</P>
                        <P>5.1.2 Automatic sampler (optional)—The sampler must incorporate glass sample containers for the collection of a minimum of 250 mL of sample. Sample containers must be kept refrigerated at 4 °C and protected from light during compositing. If the sampler uses a peristaltic pump, a minimum length of compressible silicone rubber tubing may be used. Before use, however, the compressible tubing should be thoroughly rinsed with methanol, followed by repeated rinsings with distilled water to minimize the potential for contamination of the sample. An integrating flow meter is required to collect flow proportional composites.</P>
                        <P>5.2 Glassware (All specifications are suggested. Catalog numbers are included for illustration only.):</P>
                        <P>5.2.1 Separatory funnel—2-L, with Teflon stopcock.</P>
                        <P>5.2.2 Drying column—Chromatographic column, approximately 400 mm long × 19 mm ID, with coarse frit filter disc.</P>
                        <P>5.2.3 Chromatographic column—300 long × 10 mm ID, with Teflon stopcock and coarse frit filter disc at bottom.</P>
                        <P>5.2.4 Concentrator tube, Kuderna-Danish—10-mL, graduated (Kontes K-570050-1025 or equivalent). Calibration must be checked at the volumes employed in the test. Ground glass stopper is used to prevent evaporation of extracts.</P>
                        <P>5.2.5 Evaporative flask, Kuderna-Danish—500-mL (Kontes K-570001-0500 or equivalent). Attach to concentrator tube with springs.</P>
                        <P>5.2.6 Snyder column, Kuderna-Danish—Three-ball macro (Kontes K-503000-0121 or equivalent).</P>
                        <P>5.2.7 Vials—10 to 15-mL, amber glass, with Teflon-lined screw cap.</P>
                        <P>5.3 Boiling chips—Approximately 10/40 mesh. Heat to 400 °C for 30 min or Soxhlet extract with methylene chloride.</P>
                        <P>5.4 Water bath—Heated, with concentric ring cover, capable of temperature control (±2 °C). The bath should be used in a hood.</P>
                        <P>5.5 Balance—Analytical, capable of accurately weighing 0.0001 g.</P>
                        <P>5.6 Gas chromatograph—An analytical system complete with gas chromatograph suitable for on-column injection and all required accessories including syringes, analytical columns, gases, detector, and strip-chart recorder. A data system is recommended for measuring peak areas.</P>
                        <P>5.6.1 Column 1—1.8 m long × 2 mm ID glass, packed with 1% SP-1000 on Supelcoport (100/120 mesh) or equivalent. Guidelines for the use of alternate column packings are provide in Section 12.1.</P>
                        <P>5.6.2 Column 2—1.8 m long × 2 mm ID glass, packed with 1.5% OV-1/2.4% OV-225 on Supelcoport (80/100 mesh) or equivalent. This column was used to develop the method performance statements in Section 14.</P>
                        <P>5.6.3 Detector—Electron capture detector. This detector has proven effective in the analysis of wastewaters for the parameters listed in the scope (Section 1.1), and was used to develop the method performance statements in Section 14. Guidelines for the use of alternate detectors are provided in Section 12.1.</P>
                        <HD SOURCE="HD2">6. Reagents</HD>
                        <P>6.1 Reagent water—Reagent water is defined as a water in which an interferent is not observed at the MDL of the parameters of interest.</P>
                        <P>6.2 Acetone, hexane, isooctane, methanol, methylene chloride, petroleum ether (boiling range 30 to 60 °C)—Pesticide quality or equivalent.</P>
                        <P>6.3 Sodium sulfate—(ACS) Granular, anhydrous. Purify heating at 400 °C for 4 h in a shallow tray.</P>
                        <P>6.4 Florisil—PR grade (60/100 mesh). Purchase activated at 1250 °F and store in the dark in glass containers with ground glass stoppers or foil-lined screw caps. Before use, activate each batch at least 16 h at 130 °C in a foil-covered glass container and allow to cool.</P>
                        <P>6.5 Stock standard solution (1.00 µg/µL)—Stock standard solutions can be prepared from pure standard materials or purchased as certified solutions.</P>
                        <P>6.5.1 Prepare stock standard solutions by accurately weighing about 0.0100 g of pure material. Dissolve the material in isooctane and dilute to volume in a 120-mL volumetric flask. Larger volumes can be used at the convenience of the analyst. When compound purity is assayed to be 96% or greater, the weight can be used without correction to calculate the concentration of the stock standard. Commercially prepared stock standards can be used at any concentration if they are certified by the manufacturer or by an independent source.</P>
                        <P>
                            6.5.2 Transfer the stock standard solutions into Teflon-sealed screw-cap bottles. Store at 4 °C and protect from light. Stock standard solutions should be checked frequently for signs of degradation or evaporation, especially just prior to preparing calibration standards from them.
                            <PRTPAGE P="230"/>
                        </P>
                        <P>6.5.3 Stock standard solutions must be replaced after six months, or sooner if comparision with check standards indicates a problem.</P>
                        <P>6.6 Quality control check sample concentrate—See Section 8.2.1.</P>
                        <HD SOURCE="HD2">7. Calibration</HD>
                        <P>7.1 Establish gas chromatographic operating conditions equivalent to those given in Table 1. The gas chromatographic system can be calibrated using the external standard technique (Section 7.2) or the internal standard technique (Section 7.3).</P>
                        <P>7.2 External standard calibration procedure:</P>
                        <P>7.2.1 Prepare calibration standards at a minimum of three concentration levels for each parameter of interest by adding volumes of one or more stock standards to a volumetric flask and diluting to volume with isooctane. One of the external standards should be at a concentration near, but above, the MDL (Table 1) and the other concentrations should correspond to the expected range of concentrations found in real samples or should define the working range of the detector.</P>
                        <P>7.2.2 Using injections of 2 to 5 µL, analyze each calibration standard according to Section 12 and tabulate peak height or area responses against the mass injected. The results can be used to prepare a calibration curve for each compound. Alternatively, if the ratio of response to amount injected (calibration factor) is a constant over the working range (&lt;10% relative standard deviation, RSD), linearity through the origin can be assumed and the average ratio or calibration factor can be used in place of a calibration curve.</P>
                        <P>7.3 Internal standard calibration procedure—To use this approach, the analyst must select one or more internal standards that are similar in analytical behavior to the compounds of interest. The analyst must further demonstrate that the measurement of the internal standard is not affected by method or matrix interferences. Because of these limitations, no internal standard can be suggested that is applicable to all samples.</P>
                        <P>7.3.1 Prepare calibration standards at a minimum of three concentration levels for each parameter of interest by adding volumes of one or more stock standards to a volumetric flask. To each calibration standard, add a known constant amount of one or more internal standards, and dilute to volume with isooctane. One of the standards should be at a concentration near, but above, the MDL and the other concentrations should correspond to the expected range of concentrations found in real samples or should define the working range of the detector.</P>
                        <P>7.3.2 Using injections of 2 to 5 µL, analyze each calibration standard according to Section 12 and tabulate peak height or area responses against concentration for each compound and internal standard. Calculate response factors (RF) for each compound using Equation 1.</P>
                        <MATH SPAN="1" DEEP="31">
                            <MID>EC15NO91.119</MID>
                        </MATH>
                        <FP SOURCE="FRP0">Equation 1</FP>
                        <FP>where:</FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">s</E>
                             = Response for the parameter to be measured.
                        </FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">is</E>
                             = Response for the internal standard.
                        </FP>
                        <FP SOURCE="FP-2">
                            C
                            <E T="52">is</E>
                             = Concentration of the internal standard (µg/L).
                        </FP>
                        <FP SOURCE="FP-2">
                            C
                            <E T="52">s</E>
                             = Concentration of the parameter to be measured (µg/L).
                        </FP>
                        <FP>
                            If the RF value over the working range is a constant (&lt;10% RSD), the RF can be assumed to be invariant and the average RF can be used for calculations. Alternatively, the results can be used to plot a calibration curve of response ratios, A
                            <E T="52">s</E>
                            /A
                            <E T="52">is</E>
                            , vs. RF.
                        </FP>
                        <P>7.4 The working calibration curve, calibration factor, or RF must be verified on each working day by the measurement of one or more calibration standards. If the response for any parameter varies from the predicted response by more than ±15%, a new calibration curve must be prepared for that compound.</P>
                        <P>7.5 Before using any cleanup procedure, the analyst must process a series of calibration standards through the procedure to validate elution patterns and the absence of interferences from the reagents.</P>
                        <HD SOURCE="HD2">8. Quality Control</HD>
                        <P>8.1 Each laboratory that uses this method is required to operate a formal quality control program. The minimum requirements of this program consist of an initial demonstration of laboratory capability and an ongoing analysis of spiked samples to evaluate and document data quality. The laboratory must maintain records to document the quality of data that is generated. Ongoing data quality checks are compared with established performance criteria to determine if the results of analyses meet the performance characteristics of the method. When the results of sample spikes indicate atypical method performance, a quality control check standard must be analyzed to confirm that the measurements were performed in an in-control mode of operation.</P>
                        <P>
                            8.1.1 The analyst must make an initial, one-time, demonstration of the ability to generate acceptable accuracy and precision with this method. This ability is established as described in Section 8.2.
                            <PRTPAGE P="231"/>
                        </P>
                        <P>8.1.2 In recognition of advances that are occurring in chromatography, the analyst is permitted certain options (detailed in Sections 10.4, 11.1, and 12.1) to improve the separations or lower the cost of measurements. Each time such modification is made to the method, the analyst is required to repeat the procedure in Section 8.2.</P>
                        <P>8.1.3 Before processing any samples, the analyst must analyze a reagent water blank to demonstrate that interferences from the analytical system and glassware are under control. Each time a set of samples is extracted or reagents are changed, a reagent water blank must be processed as a safeguard against laboratory contamination.</P>
                        <P>8.1.4 The laboratory must, on an ongoing basis, spike and analyze a minimum of 10% of all samples to monitor and evaluate laboratory data quality. This procedure is described in Section 8.3.</P>
                        <P>8.1.5 The laboratory must, on an ongoing basis, demonstrate through the analyses of quality control check standards that the operation of the measurement system is in control. This procedure is described in Section 8.4. The frequency of the check standard analyses is equivalent to 10% of all samples analyzed but may be reduced if spike recoveries from samples (Section 8.3) meet all specified quality control criteria.</P>
                        <P>8.1.6 The laboratory must maintain performance records to document the quality of data that is generated. This procedure is described in Section 8.5.</P>
                        <P>8.2 To establish the ability to generate acceptable accuracy and precision, the analyst must perform the following operations.</P>
                        <P>8.2.1 A quality control (QC) check sample concentrate is required containing each parameter of interest at the following concentrations in acetone: Hexachloro-substituted parameters, 10 µg/mL; any other chlorinated hydrocarbon, 100 µg/mL. The QC check sample concentrate must be obtained from the U.S. Environmental Protection Agency, Environmental Monitoring and Support Laboratory in Cincinnati, Ohio, if available. If not available from that source, the QC check sample concentrate must be obtained from another external source. If not available from either source above, the QC check sample concentrate must be prepared by the laboratory using stock standards prepared independently from those used for calibration.</P>
                        <P>8.2.2 Using a pipet, prepare QC check samples at the test concentrations shown in Table 2 by adding 1.00 mL of QC check sample concentrate to each of four 1-L aliquots of reagent water.</P>
                        <P>8.2.3 Analyze the well-mixed QC check samples according to the method beginning in Section 10.</P>
                        <P>
                            8.2.4 Calculate the average recovery (X
                            <AC T="8"/>
                            ) in µg/L, and the standard deviation of the recovery (s) in µg/L, for each parameter using the four results.
                        </P>
                        <P>
                            8.2.5 For each parameter compare s and X
                            <AC T="8"/>
                             with the corresponding acceptance criteria for precision and accuracy, respectively, found in Table 2. If s and X
                            <AC T="8"/>
                             for all parameters of interest meet the acceptance criteria, the system performance is acceptable and analysis of actual samples can begin. If any individual s exceeds the precision limit or any individual X
                            <AC T="8"/>
                             falls outside the range for accuracy, the system performance is unacceptable for that parameter.
                        </P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>The large number of parameters in Table 2 presents a substantial probability that one or more will fail at least one of the acceptance criteria when all parameters are analyzed.</P>
                        </NOTE>
                        <P>8.2.6 When one or more of the parameters tested fail at least one of the acceptance criteria, the analyst must proceed according to Section 8.2.6.1 or 8.2.6.2.</P>
                        <P>8.2.6.1 Locate and correct the source of the problem and repeat the test for all parameters of interest beginning with Section 8.2.2.</P>
                        <P>8.2.6.2 Beginning with Section 8.2.2, repeat the test only for those parameters that failed to meet criteria. Repeated failure, however, will confirm a general problem with the measurement system. If this occurs, locate and correct the source of the problem and repeat the test for all compounds of interest beginning with Section 8.2.2.</P>
                        <P>8.3 The laboratory must, on an ongoing basis, spike at least 10% of the samples from each sample site being monitored to assess accuracy. For laboratories analyzing one to ten samples per month, at least one spike sample per month is required.</P>
                        <P>8.3.1 The concentration of the spike in the sample should be determined as follows:</P>
                        <P>8.3.1.1 If, as in compliance monitoring, the concentration of a specific parameter in the sample is being checked against a regulatory concentration limit, the spike should be at that limit or 1 to 5 times higher than the background concentration determined in Section 8.3.2, whichever concentration would be larger.</P>
                        <P>8.3.1.2 If the concentration of a specific parameter in the sample is not being checked against a limit specific to that parameter, the spike should be at the test concentration in Section 8.2.2 or 1 to 5 times higher than the background concentration determined in Section 8.3.2, whichever concentration would be larger.</P>
                        <P>
                            8.3.1.3 If it is impractical to determine background levels before spiking (e.g., maximum holding times will be exceeded), the spike concentration should be (1) the regulatory concentration limit, if any; or, if none by (2) the larger of either 5 times higher than the expected background concentration or the test concentration in Section 8.2.2.
                            <PRTPAGE P="232"/>
                        </P>
                        <P>8.3.2 Analyze one sample aliquot to determine the background concentration (B) of each parameter. In necessary, prepare a new QC check sample concentrate (Section 8.2.1) appropriate for the background concentrations in the sample. Spike a second sample aliquot with 1.0 mL of the QC check sample concentrate and analyze it to determine the concentration after spiking (A) of each parameter. Calculate each percent recovery (P) as 100 (A−B)%/T, where T is the known true value of the spike.</P>
                        <P>
                            8.3.3 Compare the percent recovery (P) for each parameter with the corresponding QC acceptance criteria found in Table 2. These acceptance criteria were calculated to include an allowance for error in measurement of both the background and spike concentrations, assuming a spike to background ratio of 5:1. This error will be accounted for to the extent that the analyst's spike to background ratio approaches 5:1. 
                            <SU>7</SU>
                             If spiking was performed at a concentration lower than the test concentration in Section 8.2.2, the analyst must use either the QC acceptance criteria in Table 2, or optional QC acceptance criteria calculated for the specific spike concentration. To calculate optional acceptance criteria for the recovery of a parameter: (1) Calculate accuracy (X′) using the equation in Table 3, substituting the spike concentration (T) for C; (2) calculate overall precision (S′) using the equation in Table 3, substituting X′ for X
                            <AC T="8"/>
                            ; (3) calculate the range for recovery at the spike concentration as (100 X′/T) ±2.44 (100 S′/T)%. 
                            <SU>7</SU>
                        </P>
                        <P>8.3.4 If any individual P falls outside the designated range for recovery, that parameter has failed the acceptance criteria. A check standard containing each parameter that failed the criteria must be analyzed as described in Section 8.4.</P>
                        <P>8.4. If any parameter fails the acceptance criteria for recovery in Section 8.3, a QC check standard containing each parameter that failed must be prepared and analyzed.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>The frequency for the required analysis of a QC check standard will depend upon the number of parameters being simultaneously tested, the complexity of the sample matrix, and the performance of the laboratory.</P>
                        </NOTE>
                        <P>8.4.1 Prepare the QC check standard by adding 1.0 mL of QC check sample concentrate (Sections 8.2.1 or 8.3.2) to 1 L of reagent water. The QC check standard needs only to contain the parameters that failed criteria in the test in Section 8.3.</P>
                        <P>
                            8.4.2 Analyze the QC check standard to determine the concentration measured (A) of each parameter. Calculate each percent recovery (P
                            <E T="52">s</E>
                            ) as 100 (A/T)%, where T is the true value of the standard concentration.
                        </P>
                        <P>
                            8.4.3 Compare the percent recovery (P
                            <E T="52">s</E>
                            ) for each parameter with the corresponding QC acceptance criteria found in Table 2. Only parameters that failed the test in Section 8.3 need to be compared with these criteria. If the recovery of any such parameter falls outside the designated range, the laboratory performance for that parameter is judged to be out of control, and the problem must be immediately identified and corrected. The analytical result for that parameter in the unspiked sample is suspect and may not be reported for regulatory compliance purposes.
                        </P>
                        <P>
                            8.5 As part of the QC program for the laboratory, method accuracy for wastewater samples must be assessed and records must be maintained. After the analysis of five spiked wastewater samples as in Section 8.3, calculate the average percent recovery (P
                            <AC T="8"/>
                            ) and the standard deviation of the percent recovery (s
                            <E T="52">p</E>
                            ). Express the accuracy assessment as a percent recovery interval from P−2s
                            <E T="52">p</E>
                             to P + 2s
                            <E T="52">p</E>
                            . If P = 90% and s
                            <E T="52">p</E>
                             = 10%, for example, the accuracy interval is expressed as 70-110%. Update the accuracy assessment for each parameter on a regular basis (e.g. after each five to ten new accuracy measurements).
                        </P>
                        <P>8.6 It is recommended that the laboratory adopt additional quality assurance practices for use with this method. The specific practices that are most productive depend upon the needs of the laboratory and the nature of the samples. Field duplicates may be analyzed to assess the precision of the environmental measurements. When doubt exists over the identification of a peak on the chromatogram, confirmatory techniques such as gas chromatography with a dissimilar column, specific element detector, or mass spectrometer must be used. Whenever possible, the laboratory should analyze standard reference materials and participate in relevent performance evaluation studies.</P>
                        <HD SOURCE="HD2">9. Sample Collection, Preservation, and Handling</HD>
                        <P>
                            9.1 Grab samples must be collected in glass containers. Conventional sampling practices 
                            <SU>8</SU>
                             should be followed, except that the bottle must not be prerinsed with sample before collection. Composite samples should be collected in refrigerated glass containers in accordance with the requirements of the program. Automatic sampling equipment must be as free as possible of Tygon tubing and other potential sources of contamination.
                        </P>
                        <P>9.2 All samples must be iced or refrigerated at 4 °C from the time of collection until extraction.</P>
                        <P>
                            9.3 All samples must be extracted within 7 days of collection and completely analyzed within 40 days of extraction. 
                            <SU>2</SU>
                        </P>
                        <HD SOURCE="HD2">10. Sample Extraction</HD>
                        <P>
                            10.1 Mark the water meniscus on the side of the sample bottle for later determination of sample volume. Pour the entire sample into a 2-L separatory funnel.
                            <PRTPAGE P="233"/>
                        </P>
                        <P>10.2 Add 60 mL of methylele chloride to the sample bottle, seal, and shake 30 s to rinse the inner surface. Transfer the solvent to the separatory funnel and extract the sample by shaking the funnel for 2 min with periodic venting to release excess pressure. Allow the organic layer to separate from the water phase for a minimum of 10 min. If the emulsion interface between layers is more than one-third the volume of the solvent layer, the analyst must employ mechanical techniques to complete the phase separation. The optimum technique depends upon the sample, but may include stirring, filtration of the emulsion through glass wool, centrifugation, or other physical methods. Collect the methylene chloride extract in a 250-mL Erlenmeyer flask.</P>
                        <P>10.3 Add a second 60-mL volume of methylene chloride to the sample bottle and repeat the extraction procedure a second time, combining the extracts in the Erlenmeyer flask. Perform a third extraction in the same manner.</P>
                        <P>10.4 Assemble a Kuderna-Danish (K-D) concentrator by attaching a 10-mL concentrator tube to a 500-mL evaporative flask. Other concentration devices or techniques may be used in place of the K-D concentrator if the requirements of Section 8.2 are met.</P>
                        <P>10.5 Pour the combined extract through a solvent-rinsed drying column containing about 10 cm of anhydrous sodium sulfate, and collect the extract in the K-D concentrator. Rinse the Erlenmeyer flask and column with 20 to 30 mL of methylene chloride to complete the quantitative transfer.</P>
                        <P>10.6 Add one or two clean boiling chips to the evaporative flask and attach a three-ball Snyder column. Prewet the Snyder column by adding about 1 mL of methylene chloride to the top. Place the K-D apparatus on a hot water bath (60 to 65 °C) so that the concentrator tube is partially immersed in the hot water, and the entire lower rounded surface of the flask is bathed with hot vapor. Adjust the vertical position of the apparatus and the water temperature as required to complete the concentration in 15 to 20 min. At the proper rate of distillation the balls of the column will actively chatter but the chambers will not flood with condensed solvent. When the apparent volume of liquid reaches 1 to 2 mL, remove the K-D apparatus and allow it to drain and cool for at least 10 min.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>The dichloribenzenes have a sufficiently high volatility that significant losses may occur in concentration steps if care is not exercised. It is important to maintain a constant gentle evaporation rate and not to allow the liquid volume to fall below 1 to 2 mL before removing the K-D apparatus from the hot water bath.</P>
                        </NOTE>
                        <P>10.7 Momentarily remove the Snyder column, add 50 mL of hexane and a new boiling chip, and reattach the Snyder column. Raise the tempeature of the water bath to 85 to 90 °C. Concentrate the extract as in Section 10.6, except use hexane to prewet the column. The elapsed time of concentration should be 5 to 10 min.</P>
                        <P>10.8 Romove the Snyder column and rinse the flask and its lower joint into the concentrator tube with 1 to 2 mL of hexane. A 5-mL syringe is recommended for this operation. Stopper the concentrator tube and store refrigerated if further processing will not be performed immediately. If the extract will be stored longer than two days, it should be transferred to a Teflon-sealed screw-cap vial. If the sample extract requires no further cleanup, proceed with gas chromatographic analysis (Section 12). If the sample requires further cleanup, proceed to Section 11.</P>
                        <P>10.9 Determine the original sample volume by refilling the sample bottle to the mark and transferring the liquid to a 1000-mL graduated cylinder. Record the sample volume to the nearest 5 mL.</P>
                        <HD SOURCE="HD2">11. Cleanup and Separation</HD>
                        <P>11.1 Cleanup procedures may not be necessary for a relatively clean sample matrix. If particular circumstances demand the use of a cleanup procedure, the analyst may use the procedure below or any other appropriate procedure. However, the analyst first must demonstrate that the requirements of Section 8.2 can be met using the method as revised to incorporate the cleanup procedure.</P>
                        <P>11.2 Florisil column cleanup for chlorinated hydrocarbons:</P>
                        <P>11.2.1 Adjust the sample extract to 10 mL with hexane.</P>
                        <P>11.2.2 Place 12 g of Florisil into a chromatographic column. Tap the column to settle the Florisil and add 1 to 2 cm of anhydrous sodium sulfate to the top.</P>
                        <P>11.2.3 Preelute the column with 100 mL of petroleum ether. Discard the eluate and just prior to exposure of the sodium sulfate layer to the air, quantitatively transfer the sample extract onto the column by decantation and subsequent petroleum ether washings. Discard the eluate. Just prior to exposure of the sodium sulfate layer to the air, begin eluting the column with 200 mL of petroleum ether and collect the eluate in a 500-mL K-D flask equipped with a 10-mL concentrator tube. This fraction should contain all of the chlorinated hydrocarbons.</P>
                        <P>
                            11.2.4 Concentrate the fraction as in Section 10.6, except use hexane to prewet the column. When the apparatus is cool, remove the Snyder column and rinse the flask and its lower joint into the concentrator tube with hexane. Analyze by gas chromatography (Section 12).
                            <PRTPAGE P="234"/>
                        </P>
                        <HD SOURCE="HD2">12. Gas Chromatography</HD>
                        <P>12.1 Table 1 summarizes the recommended operating conditions for the gas chromatograph. Included in this table are retention times and MDL that can be achieved under these conditions. Examples of the separations achieved by Columl 2 are shown in Figures 1 and 2. Other packed or capillary (open-tubular) columns, chromatographic conditions, or detectors may be used if the requirements of Section 8.2 are met.</P>
                        <P>12.2 Calibrate the system daily as described in Section 7.</P>
                        <P>12.3 If the internal standard calibration procedure is being used, the internal standard must be added to the sample extract and mixed throughly immediately before injection into the gas chromatograph.</P>
                        <P>
                            12.4 Inject 2 to 5 µL of the sample extract or standard into the gas chromatograph using the solvent-flush techlique. 
                            <SU>9</SU>
                             Smaller (1.0 µL) volumes may be injected if automatic devices are employed. Record the volume injected to the nearest 0.05 µL, the total extract volume, and the resulting peak size in area or peak height units.
                        </P>
                        <P>12.5 Identify the parameters in the sample by comparing the retention times of the peaks in the sample chromatogram with those of the peaks in standard chromatograms. The width of the retention time window used to make identifications should be based upon measurements of actual retention time variations of standards over the course of a day. Three times the standard deviation of a retention time for a compound can be used to calculate a suggested window size; however, the experience of the analyst should weigh heavily in the interpretation of chromatograms.</P>
                        <P>12.6 If the response for a peak exceeds the working range of the system, dilute the extract and reanalyze.</P>
                        <P>12.7 If the measurement of the peak response is prevented by the presence of interferences, further cleanup is required.</P>
                        <HD SOURCE="HD2">13. Calculations</HD>
                        <P>13.1 Determine the concentration of individual compounds in the sample.</P>
                        <P>13.1.1 If the external standard calibration procedure is used, calculate the amount of material injected from the peak response using the calibration curve or calibration factor determined in Section 7.2.2. The concentration in the sample can be calculated from Equation 2.</P>
                        <MATH SPAN="1" DEEP="31">
                            <MID>EC15NO91.120</MID>
                        </MATH>
                        <FP SOURCE="FRP0">Equation 2</FP>
                        <FP>where:</FP>
                        <FP SOURCE="FP-2">A = Amount of material injected (ng).</FP>
                        <FP SOURCE="FP-2">
                            V
                            <E T="52">i</E>
                             = Volume of extract injected (µL).
                        </FP>
                        <FP SOURCE="FP-2">
                            V
                            <E T="52">t</E>
                             = Volume of total extract (µL).
                        </FP>
                        <FP SOURCE="FP-2">
                            V
                            <E T="52">s</E>
                             = Volume of water extracted (mL).
                        </FP>
                        <P>13.1.2 If the internal standard calibration procedure is used, calculate the concentration in the sample using the response factor (RF) determined in Section 7.3.2 and Equation 3.</P>
                        <MATH SPAN="1" DEEP="31">
                            <MID>EC15NO91.121</MID>
                        </MATH>
                        <FP SOURCE="FRP0">Equation 3</FP>
                        <FP>where:</FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">s</E>
                             = Response for the parameter to be measured.
                        </FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">is</E>
                             = Response for the internal standard.
                        </FP>
                        <FP SOURCE="FP-2">
                            I
                            <E T="52">s</E>
                             = Amount of internal standard added to each extract (µg).
                        </FP>
                        <FP SOURCE="FP-2">
                            V
                            <E T="52">o</E>
                             = Volume of water extracted (L).
                        </FP>
                        <P>13.2 Report results in µg/L without correction for recovery data. All QC data obtained should be reported with the sample results.</P>
                        <HD SOURCE="HD2">14. Method Performance</HD>
                        <P>
                            14.1 The method detection limit (MDL) is defined as the minimum concentration of a substance that can be measured and reported with 99% confidence that the value is above zero. 
                            <SU>1</SU>
                             The MDL concentrations listed in Table 1 were obtained using reagent water. 
                            <SU>10</SU>
                             Similar results were achieved using representative wastewaters. The MDL actually achieved in a given analysis will vary depending on instrument sensitivity and matrix effects.
                        </P>
                        <P>
                            14.2 This method has been tested for linearity of spike recovery from reagent water and has been demonstrated to be applicable over the concentration range from 4 × MDL to 1000 × MDL. 
                            <SU>10</SU>
                        </P>
                        <P>
                            14.3 This method was tested by 20 laboratories using reagent water, drinking water, surface water, and three industrial wastewaters spiked at six concentrations over the range 1.0 to 356 µg/L. 
                            <SU>11</SU>
                             Single operator precision, overall precision, and method accuracy were found to be directly related to the concentration of the parameter and essentially independent of the sample matrix. Linear equations to describe these relationships are presented in Table 3.
                        </P>
                        <HD SOURCE="HD1">References</HD>
                        <P>1. 40 CFR part 136, appendix B.</P>
                        <P>2. “Determination of Chlorinated Hydrocarbons In Industrial and Municipal Wastewaters, “EPA 6090/4-84-ABC, National Technical Information Service, PBXYZ, Springfield, Virginia, 22161 November 1984.</P>
                        <P>
                            3. ASTM Annual Book of Standards, Part 31, D3694-78. “Standard Practices for Preparation of Sample Containers and for Preservation of Organic Constituents,” American 
                            <PRTPAGE P="235"/>
                            Society for Testing and Materials, Philadelphia.
                        </P>
                        <P>4. “Carcinogens—Working With Carcinogens,” Department of Health, Education, and Welfare, Public Health Service, Center for Disease Control, National Institute for Occupational Safety and Health, Publication No. 77-206, August 1977.</P>
                        <P>5. “OSHA Safety and Health Standards, General Industry,” (29 CFR part 1910), Occupational Safety and Health Administration, OSHA 2206 (Revised, January 1976).</P>
                        <P>6. “Safety in Academic Chemistry Laboratories,” American Chemical Society Publication, Committee on Chemical Safety, 3rd Edition, 1979.</P>
                        <P>
                            7. Provost, L.P., and Elder, R.S. “Interpretation of Percent Recovery Data,”
                            <E T="03">American Laboratory, 15,</E>
                             58-63 (1983). (The value 2.44 used in the equation in Section 8.3.3 is two times the value 1.22 derived in this report.)
                        </P>
                        <P>8. ASTM Annual Book of Standards, Part 31, D3370-76. “Standard Practices for Sampling Water,” American Society for Testing and Materials, Philadelphia.</P>
                        <P>
                            9. Burke, J.A. “Gas Chromatography for Pesticide Residue Analysis; Some Practical Aspects,” 
                            <E T="03">Journal of the Association of Official Analytical Chemists, 48,</E>
                             1037 (1965).
                        </P>
                        <P>10. “Development of Detection Limits, EPA Method 612, Chlorinated Hydrocarbons,” Special letter report for EPA Contract 68-03-2625, U.S. Environmental Protection Agency, Environmental Monitoring and Support Laboratory, Cincinnati, Ohio 45268.</P>
                        <P>11. “EPA Method Study Method 612—Chlorinated Hydrocarbons,” EPA 600/4-84-039, National Technical Information Service, PB84-187772, Springfield, Virginia 22161, May 1984.</P>
                        <P>12. “Method Performance for Hexachlorocyclopentadiene by Method 612,” Memorandum from R. Slater, U.S. Environmental Protection Agency, Environmental Monitoring and Support Laboratory, Cincinnati, Ohio 45268, December 7, 1983.</P>
                        <GPOTABLE COLS="4" OPTS="L2" CDEF="s60,10,10,10">
                            <TTITLE>Table 1—Chromatographic Conditions and Method Detection Limits</TTITLE>
                            <BOXHD>
                                <CHED H="1">Parameter</CHED>
                                <CHED H="1">Retention time (min)</CHED>
                                <CHED H="2">Column 1</CHED>
                                <CHED H="2">Column 2</CHED>
                                <CHED H="1">Method detection limit (µg/L)</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">1,3-Dichlorobenzene</ENT>
                                <ENT>4.5</ENT>
                                <ENT>6.8</ENT>
                                <ENT>1.19</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Hexachloroethane</ENT>
                                <ENT>4.9</ENT>
                                <ENT>8.3</ENT>
                                <ENT>0.03</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,4-Dichlorobenzene</ENT>
                                <ENT>5.2</ENT>
                                <ENT>7.6</ENT>
                                <ENT>1.34</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2-Dichlorobenzene</ENT>
                                <ENT>6.6</ENT>
                                <ENT>9.3</ENT>
                                <ENT>1.14</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Hexachlorobutadiene</ENT>
                                <ENT>7.7</ENT>
                                <ENT>20.0</ENT>
                                <ENT>0.34</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,4-Trichlorobenzene</ENT>
                                <ENT>15.5</ENT>
                                <ENT>22.3</ENT>
                                <ENT>0.05</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Hexachlorocyclopentadiene</ENT>
                                <ENT>nd</ENT>
                                <ENT>
                                    <SU>c</SU>
                                     16.5
                                </ENT>
                                <ENT>0.40</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-Chloronaphthalene</ENT>
                                <ENT>
                                    <SU>a</SU>
                                     2.7
                                </ENT>
                                <ENT>
                                    <SU>b</SU>
                                     3.6
                                </ENT>
                                <ENT>0.94</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Hexachlorobenzene</ENT>
                                <ENT>
                                    <SU>a</SU>
                                     5.6
                                </ENT>
                                <ENT>
                                    <SU>b</SU>
                                     10.1
                                </ENT>
                                <ENT>0.05</ENT>
                            </ROW>
                            <TNOTE>Column 1 conditions: Supelcoport (100/120 mesh) coated with 1% SP-1000 packed in a 1.8 m × 2 mm ID glass column with 5% methane/95% argon carrier gas at 25 mL/min. flow rate. Column temperature held isothermal at 65 °C, except where otherwise indicated.</TNOTE>
                            <TNOTE>Column 2 conditions: Supelcoport (80/100 mesh) coated with 1.5% OV-1/2.4% OV-225 packed in a 1.8 m × 2 mm ID glass column with 5% methane/95% argon carrier gas at 25 mL/min. flow rate. Column temperature held isothermal at 75 °C, except where otherwise indicated.</TNOTE>
                            <TNOTE>nd = Not determined.</TNOTE>
                            <TNOTE>
                                <SU>a</SU>
                                 150 °C column temperature.
                            </TNOTE>
                            <TNOTE>
                                <SU>b</SU>
                                 165 °C column temperature.
                            </TNOTE>
                            <TNOTE>
                                <SU>c</SU>
                                 100 °C column temperature.
                            </TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="5" OPTS="L2" CDEF="s50,8,8,10,8">
                            <TTITLE>Table 2—QC Acceptance Criteria—Method 612</TTITLE>
                            <BOXHD>
                                <CHED H="1">Parameter</CHED>
                                <CHED H="1">Test conc. (µg/L)</CHED>
                                <CHED H="1">Limit for s (µg/L)</CHED>
                                <CHED H="1">
                                    Range for X
                                    <AC T="8"/>
                                     (µg/L)
                                </CHED>
                                <CHED H="1">
                                    Range for P, P
                                    <E T="52">s</E>
                                     (percent)
                                </CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">2-Chloronaphthalene</ENT>
                                <ENT>100</ENT>
                                <ENT>37.3</ENT>
                                <ENT>29.5-126.9</ENT>
                                <ENT>9-148</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2-Dichlorobenzene</ENT>
                                <ENT>100</ENT>
                                <ENT>28.3</ENT>
                                <ENT>23.5-145.1</ENT>
                                <ENT>9-160</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,3-Dichlorobenzene</ENT>
                                <ENT>100</ENT>
                                <ENT>26.4</ENT>
                                <ENT>7.2-138.6</ENT>
                                <ENT>D-150</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,4-Dichlorobenzene</ENT>
                                <ENT>100</ENT>
                                <ENT>20.8</ENT>
                                <ENT>22.7-126.9</ENT>
                                <ENT>13-137</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Hexachlorobenzene</ENT>
                                <ENT>10</ENT>
                                <ENT>2.4</ENT>
                                <ENT>2.6-14.8</ENT>
                                <ENT>15-159</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Hexachlorobutadiene</ENT>
                                <ENT>10</ENT>
                                <ENT>2.2</ENT>
                                <ENT>D-12.7</ENT>
                                <ENT>D-139</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Hexachlorocyclopentadiene</ENT>
                                <ENT>10</ENT>
                                <ENT>2.5</ENT>
                                <ENT>D-10.4</ENT>
                                <ENT>D-111</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Hexachloroethane</ENT>
                                <ENT>10</ENT>
                                <ENT>3.3</ENT>
                                <ENT>2.4-12.3</ENT>
                                <ENT>8-139</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,4-Trichlorobenzene</ENT>
                                <ENT>100</ENT>
                                <ENT>31.6</ENT>
                                <ENT>20.2-133.7</ENT>
                                <ENT>5-149</ENT>
                            </ROW>
                            <TNOTE>s = Standard deviation of four recovery measurements, in µg/L (Section 8.2.4).</TNOTE>
                            <TNOTE>
                                X
                                <AC T="8"/>
                                 = Average recovery for four recovery measurements, in µg/L (Section 8.2.4).
                            </TNOTE>
                            <TNOTE>
                                P, P
                                <E T="52">s</E>
                                 = Percent recovery measured (Section 8.3.2, Section 8.4.2).
                            </TNOTE>
                            <TNOTE>D = Detected; result must be greater than zero.</TNOTE>
                            <TNOTE>
                                <E T="04">Note:</E>
                                 These criteria are based directly upon the method performance data in Table 3. Where necessary, the limits for recovery have been broadened to assure applicability of the limits to concentrations below those used to develop Table 3.
                            </TNOTE>
                        </GPOTABLE>
                        <PRTPAGE P="236"/>
                        <GPOTABLE COLS="4" OPTS="L2" CDEF="s50,xls40,xls40,xls40">
                            <TTITLE>Table 3—Method Accuracy and Precision as Functions of Concentration—Method 612</TTITLE>
                            <BOXHD>
                                <CHED H="1">Parameter</CHED>
                                <CHED H="1">Acccuracy, as recovery, X′ (µg/L)</CHED>
                                <CHED H="1">
                                    Single analyst precision, s
                                    <E T="52">r</E>
                                    ′ (µg/L)
                                </CHED>
                                <CHED H="1">Overall precision, S′ (µg/L)</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">2-Chloronaphthalene</ENT>
                                <ENT>0.75C + 3.21</ENT>
                                <ENT>
                                    0.28X
                                    <AC T="8"/>
                                    −1.17
                                </ENT>
                                <ENT>
                                    0.38X
                                    <AC T="8"/>
                                    −1.39
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2-Dichlorobenzene</ENT>
                                <ENT>0.85C−0.70</ENT>
                                <ENT>
                                    0.22X
                                    <AC T="8"/>
                                    −2.95
                                </ENT>
                                <ENT>
                                    0.41X
                                    <AC T="8"/>
                                    −3.92
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,3-Dichlorobenzene</ENT>
                                <ENT>0.72C + 0.87</ENT>
                                <ENT>
                                    0.21X
                                    <AC T="8"/>
                                    −1.03
                                </ENT>
                                <ENT>
                                    0.49X
                                    <AC T="8"/>
                                    −3.98
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,4-Dichlorobenzene</ENT>
                                <ENT>0.72C + 2.80</ENT>
                                <ENT>
                                    0.16X
                                    <AC T="8"/>
                                    −0.48
                                </ENT>
                                <ENT>
                                    0.35X
                                    <AC T="8"/>
                                    −0.57
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Hexachlorobenzene</ENT>
                                <ENT>0.87C−0.02</ENT>
                                <ENT>
                                    0.14X
                                    <AC T="8"/>
                                     + 0.07
                                </ENT>
                                <ENT>
                                    0.36X
                                    <AC T="8"/>
                                    −0.19
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Hexachlorobutadiene</ENT>
                                <ENT>0.61C + 0.03</ENT>
                                <ENT>
                                    0.18X
                                    <AC T="8"/>
                                     + 0.08
                                </ENT>
                                <ENT>
                                    0.53X
                                    <AC T="8"/>
                                    −0.12
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Hexachlorocyclopentadiene 
                                    <SU>a</SU>
                                </ENT>
                                <ENT>0.47C</ENT>
                                <ENT>
                                    0.24X
                                    <AC T="8"/>
                                </ENT>
                                <ENT>
                                    0.50X
                                    <AC T="8"/>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Hexachloroethane</ENT>
                                <ENT>0.74C−0.02</ENT>
                                <ENT>
                                    0.23X
                                    <AC T="8"/>
                                     + 0.07
                                </ENT>
                                <ENT>
                                    0.36X
                                    <AC T="8"/>
                                    −0.00
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,4-Trichlorobenzene</ENT>
                                <ENT>0.76C + 0.98</ENT>
                                <ENT>
                                    0.23X
                                    <AC T="8"/>
                                    −0.44
                                </ENT>
                                <ENT>
                                    0.40X
                                    <AC T="8"/>
                                    −1.37
                                </ENT>
                            </ROW>
                            <TNOTE>X′ = Expected recovery for one or more measurements of a sample containing a concentration of C, in µg/L.</TNOTE>
                            <TNOTE>
                                s
                                <E T="52">r</E>
                                ′ = Expected single analyst standard deviation of measurements at an average concentration found of X
                                <AC T="8"/>
                                , in µg/L.
                            </TNOTE>
                            <TNOTE>
                                S′ = Expected interlaboratory standard deviation of measurements at an average concentration found of X
                                <AC T="8"/>
                                , in µg/L.
                            </TNOTE>
                            <TNOTE>C = True value for the concentration, in µg/L.</TNOTE>
                            <TNOTE>
                                X
                                <AC T="8"/>
                                 = Average recovery found for measurements of samples containing a concentration of C, in µg/L.
                            </TNOTE>
                            <TNOTE>
                                <SU>a</SU>
                                 Estimates based upon the performance in a single laboratory. 
                                <SU>12</SU>
                            </TNOTE>
                        </GPOTABLE>
                        <GPH SPAN="2" DEEP="470">
                            <PRTPAGE P="237"/>
                            <GID>EC02JY92.036</GID>
                        </GPH>
                        <GPH SPAN="2" DEEP="470">
                            <PRTPAGE P="238"/>
                            <GID>EC02JY92.037</GID>
                        </GPH>
                        <PRTPAGE P="239"/>
                        <HD SOURCE="HD1">Method 613—2,3,7,8-Tetrachlorodibenzo-p-Dioxin</HD>
                        <EAR>Pt. 136, App. A, Meth. 613</EAR>
                        <HD SOURCE="HD2">1. Scope and Application</HD>
                        <P>1.1 This method covers the determination of 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD). The following parameter may be determined by this method:</P>
                        <GPOTABLE COLS="3" OPTS="L2" CDEF="s25,6,11">
                            <BOXHD>
                                <CHED H="1">Parameter</CHED>
                                <CHED H="1">STORET No.</CHED>
                                <CHED H="1">GAS No.</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">2,3,7,8-TCDD</ENT>
                                <ENT>34675</ENT>
                                <ENT>1746-01-6</ENT>
                            </ROW>
                        </GPOTABLE>
                        <P>1.2 This is a gas chromatographic/mass spectrometer (GC/MS) method applicable to the determination of 2,3,7,8-TCDD in municipal and industrial discharges as provided under 40 CFR 136.1. Method 625 may be used to screen samples for 2,3,7,8-TCDD. When the screening test is positive, the final qualitative confirmation and quantification must be made using Method 613.</P>
                        <P>
                            1.3 The method detection limit (MDL, defined in Section 14.1) 
                            <SU>1</SU>
                             for 2,3,7,8-TCDD is listed in Table 1. The MDL for a specific wastewater may be different from that listed, depending upon the nature of interferences in the sample matrix.
                        </P>
                        <P>1.4 Because of the extreme toxicity of this compound, the analyst must prevent exposure to himself, of to others, by materials knows or believed to contain 2,3,7,8-TCDD. Section 4 of this method contains guidelines and protocols that serve as minimum safe-handling standards in a limited-access laboratory.</P>
                        <P>1.5 Any modification of this method, beyond those expressly permitted, shall be considered as a major modification subject to application and approval of alternate test procedures under 40 CFR 136.4 and 136.5.</P>
                        <P>1.6 This method is restricted to use by or under the supervision of analysts experienced in the use of a gas chromatograph/mass spectrometer and in the interpretation of mass spectra. Each analyst must demonstrate the ability to generate acceptable results with this method using the procedure described in Section 8.2.</P>
                        <HD SOURCE="HD2">2. Summary of Method</HD>
                        <P>
                            2.1 A measured volume of sample, approximately 1-L, is spiked with an internal standard of labeled 2,3,7,8-TCDD and extracted with methylene chloride using a separatory funnel. The methylene chloride extract is exchanged to hexane during concentration to a volume of 1.0 mL or less. The extract is then analyzed by capillary column GC/MS to separate and measure 2,3,7,8-TCDD. 
                            <SU>2 3</SU>
                        </P>
                        <P>2.2 The method provides selected column chromatographic cleanup proceudres to aid in the elimination of interferences that may be encountered.</P>
                        <HD SOURCE="HD2">3. Interferences</HD>
                        <P>3.1 Method interferences may be caused by contaminants in solvents, reagents, glassware, and other sample processing hardware that lead to discrete artifacts and/or elevated backgrounds at the masses (m/z) monitored. All of these materials must be routinely demonstrated to be free from interferences under the conditions of the analysis by running laboratory reagent blanks as described in Section 8.1.3.</P>
                        <P>
                            3.1.1 Glassware must be scrupulously cleaned. 
                            <SU>4</SU>
                             Clean all glassware as soon as possible after use by rinsing with the last solvent used in it. Solvent rinsing should be followed by detergent washing with hot water, and rinses with tap water and distilled water. The glassware should then be drained dry, and heated in a muffle furnace at 400 °C for 15 to 30 min. Some thermally stable materials, such as PCBs, may not be eliminated by the treatment. Solvent rinses with acetone and pesticide quality hexane may be substituted for the muffle furnace heating. Thorough rinsing with such solvents usually eliminates PCB interference. Volumetric ware should not be heated in a muffle furnace. After drying and cooling, glassware should be sealed and stored in a clean environment to prevent any accumulation of dust or other contaminants. Store inverted or capped with aluminum foil.
                        </P>
                        <P>3.1.2 The use of high purity reagents and solvents helps to mininmize interference problems. Purification of solvents by distillation in all-glass systems may be required.</P>
                        <P>
                            3.2 Matrix interferences may be caused by contaminants that are coextracted from the sample. The extent of matrix interferences will vary considerably from source to source, depending upon the nature and diversity of the industrial complex or municipality being sampled. 2,3,7,8-TCDD is often associated with other interfering chlorinated compounds which are at concentrations several magnitudes higher than that of 2,3,7,8-TCDD. The cleanup producers in Section 11 can be used to overcome many of these interferences, but unique samples may require additional cleanup approaches 
                            <SU>1 5-7</SU>
                             to eliminate false positives and achieve the MDL listed in Table 1.
                        </P>
                        <P>3.3 The primary column, SP-2330 or equivalent, resolves 2,3,7,8-TCDD from the other 21 TCDD insomers. Positive results using any other gas chromatographic column must be confirmed using the primary column.</P>
                        <HD SOURCE="HD2">4. Safety</HD>
                        <P>
                            4.1 The toxicity or carcinogenicity of each reagent used in this method has not been precisely defined; however, each chemical compound should be treated as a potential health hazard. From this viewpoint, exposure to these chemicals must be reduced to 
                            <PRTPAGE P="240"/>
                            the lowest possible level by whatever means available. The laboratory is responsible for maintaining a current awareness file of OSHA regulations regarding the safe handling of the chemicals specified in this method. A reference file of material data handling sheets should also be made available to all personnel involved in the chemical analysis. Additional references to laboratory safety are available and have been identified 
                            <SU>8-10</SU>
                             for the information of the analyst. Benzene and 2,3,7,8-TCDD have been identified as suspected human or mammalian carcinogens.
                        </P>
                        <P>4.2 Each laboratory must develop a strict safety program for handling 2,3,7,8-TCDD. The following laboratory practices are recommended:</P>
                        <P>4.2.1 Contamination of the laboratory will be minimized by conducting all manipulations in a hood.</P>
                        <P>4.2.2 The effluents of sample splitters for the gas chromatograph and roughing pumps on the GC/MS should pass through either a column of activated charcoal or be bubbled through a trap containing oil or high-boiling alcohols.</P>
                        <P>4.2.3 Liquid waste should be dissolved in methanol or ethanol and irradiated with ultraviolet light with a wavelength greater than 290 nm for several days. (Use F 40 BL lamps or equivalent). Analyze liquid wastes and dispose of the solutions when 2,3,7,8-TCDD can no longer be detected.</P>
                        <P>4.3 Dow Chemical U.S.A. has issued the following precautimns (revised November 1978) for safe handling of 2,3,7,8-TCDD in the laboratory:</P>
                        <P>4.3.1 The following statements on safe handling are as complete as possible on the basis of available toxicological information. The precautions for safe handling and use are necessarily general in nature since detailed, specific recommendations can be made only for the particular exposure and circumstances of each individual use. Inquiries about specific operations or uses may be addressed to the Dow Chemical Company. Assistance in evaluating the health hazards of particular plant conditions may be obtained from certain consulting laboratories and from State Departments of Health or of Labor, many of which have an industrial health service. 2,3,7,8-TCDD is extremely toxic to laboratory animals. However, it has been handled for years without injury in analytical and biological laboratories. Techniques used in handling radioactive and infectious materials are applicable to 2,3,7,8,-TCDD.</P>
                        <P>4.3.1.1 Protective equipment—Throw-away plastic gloves, apron or lab coat, safety glasses, and a lab hood adequate for radioactive work.</P>
                        <P>4.3.1.2 Training—Workers must be trained in the proper method of removing contaminated gloves and clothing without contacting the exterior surfaces.</P>
                        <P>4.3.1.3 Personal hygiene—Thorough washing of hands and forearms after each manipulation and before breaks (coffee, lunch, and shift).</P>
                        <P>4.3.1.4 Confinement—Isolated work area, posted with signs, segregated glassware and tools, plastic-backed absorbent paper on benchtops.</P>
                        <P>4.3.1.5 Waste—Good technique includes minimizing contaminated waste. Plastic bag liners should be used in waste cans. Janitors must be trained in the safe handling of waste.</P>
                        <P>4.3.1.6 Disposal of wastes—2,3,7,8-TCDD decomposes above 800 °C. Low-level waste such as absorbent paper, tissues, animal remains, and plastic gloves may be burned in a good incinerator. Gross quantities (milligrams) should be packaged securely and disposed through commercial or governmental channels which are capable of handling high-level radioactive wastes or extremely toxic wastes. Liquids should be allowed to evaporate in a good hood and in a disposable container. Residues may then be handled as above.</P>
                        <P>4.3.1.7 Decontamination—For personal decontamination, use any mild soap with plenty of scrubbing action. For decontamination of glassware, tools, and surfaces, Chlorothene NU Solvent (Trademark of the Dow Chemical Company) is the least toxic solvent shown to be effective. Satisfactory cleaning may be accomplished by rinsing with Chlorothene, then washing with any detergent and water. Dishwater may be disposed to the sewer. It is prudent to minimize solvent wastes because they may require special disposal through commercial sources which are expensive.</P>
                        <P>4.3.1.8 Laundry—Clothing known to be contaminated should be disposed with the precautions described under Section 4.3.1.6. Lab coats or other clothing worn in 2,3,7,8-TCDD work areas may be laundered.</P>
                        <P>Clothing should be collected in plastic bags. Persons who convey the bags and launder the clothing should be advised of the hazard and trained in proper handling. The clothing may be put into a washer without contact if the launderer knows the problem. The washer should be run through a cycle before being used again for other clothing.</P>
                        <P>
                            4.3.1.9 Wipe tests—A useful method of determining cleanliness of work surfaces and tools is to wipe the surface with a piece of filter paper. Extraction and analysis by gas chromatography can achieve a limit of sensitivity of 0.1 µg per wipe. Less than 1 µg of 2,3,7,8-TCDD per sample indicates acceptable cleanliness; anything higher warrants further cleaning. More than 10 µg on a wipe sample constitutes an acute hazard and requires prompt cleaning before further use of the equipment or work space. A high (&gt;10 µg) 
                            <PRTPAGE P="241"/>
                            2,3,7,8-TCDD level indicates that unacceptable work practices have been employed in the past.
                        </P>
                        <P>4.3.1.10 Inhalation—Any procedure that may produce airborne contamination must be done with good ventilation. Gross losses to a ventilation system must not be allowed. Handling of the dilute solutions normally used in analytical and animal work presents no inhalation hazards except in the case of an accident.</P>
                        <P>4.3.1.11 Accidents—Remove contaminated clothing immediately, taking precautions not to contaminate skin or other articles. Wash exposed skin vigorously and repeatedly until medical attention is obtained.</P>
                        <HD SOURCE="HD2">5. Apparatus and Materials</HD>
                        <P>5.1 Sampling equipment, for discrete or composite sampling.</P>
                        <P>5.1.1 Grab sample bottle—1-L or 1-qt, amber glass, fitted with a screw cap lined with Teflon. Foil may be substituted for Teflon if the sample is not corrosive. If amber bottles are not available, protect samples from light. The bottle and cap liner must be washed, rinsed with acetone or methylene chloride, and dried before use to minimize contamination.</P>
                        <P>5.1.2 Automatic sampler (optional)—The sampler must incorporate glass sample containers for the collection of a minimum of 250 mL of sample. Sample containers must be kept refrigerated at 4 °C and protected from light during compositing. If the sampler uses a peristaltic pump, a minimum length of compressible silicone rubber tubing may be used. Before use, however, the compressible tubing should be thoroughly rinsed with methanol, followed by repeated rinsings with distilled water to minimize the potential for contamination of the sample. An integrating flow meter is required to collect flow proportional composites.</P>
                        <P>5.1.3 Clearly label all samples as “POISON” and ship according to U.S. Department of Transportation regulations.</P>
                        <P>5.2 Glassware (All specifications are suggested. Catalog numbers are included for illustration only.):</P>
                        <P>5.2.1 Separatory funnels—2-L and 125-mL, with Teflon stopcock.</P>
                        <P>5.2.2 Concentrator tube, Kuderna-Danish—10-mL, graduated (Kontes K-570050-1025 or equivalent). Calibration must be checked at the volumes employed in the test. Ground glass stopper is used to prevent evaporation of extracts.</P>
                        <P>5.2.3 Evaporative flask, Kuderna-Danish—500-mL (Kontes K-570001-0500 or equivalent). Attach to concentrator tube with springs.</P>
                        <P>5.2.4 Snyder column, Kuderna-Danish—Three-ball macro (Kontes K-503000-0121 or equivalent).</P>
                        <P>5.2.5 Snyder column, Kuderna-Danish—Two-ball micro (Kontes K-569001-0219 or equivalent).</P>
                        <P>5.2.6 Vials—10 to 15-mL, amber glass, with Teflon-lined screw cap.</P>
                        <P>5.2.7 Chromatographic column—300 mm long × 10 mm ID, with Teflon stopcock and coarse frit filter disc at bottom.</P>
                        <P>5.2.8 Chromatographic column—400 mm long × 11 mm ID, with Teflon stopcock and coarse frit filter disc at bottom.</P>
                        <P>5.3 Boiling chips—Approximately 10/40 mesh. Heat to 400 °C for 30 min or Soxhlet extract with methylene chloride.</P>
                        <P>5.4 Water bath—Heated, with concentric ring cover, capable of temperature control (±2 °C). The bath should be used in a hood.</P>
                        <P>5.5 GC/MS system:</P>
                        <P>5.5.1 Gas chromatograph—An analytical system complete with a temperature programmable gas chromatograph and all required accessories including syringes, analytical columns, and gases. The injection port must be designed for capillary columns. Either split, splitless, or on-column injection techniques may be employed, as long as the requirements of Section 7.1.1 are achieved.</P>
                        <P>
                            5.5.2 Column—60 m long × 0.25 mm ID glass or fused silica, coated with SP-2330 (or equivalent) with a film thickness of 0.2 µm. Any equivalent column must resolve 2, 3, 7, 8-TCDD from the other 21 TCDD isomers. 
                            <SU>16</SU>
                        </P>
                        <P>5.5.3 Mass spectrometer—Either a low resolution mass spectrometer (LRMS) or a high resolution mass spectrometer (HRMS) may be used. The mass spectrometer must be equipped with a 70 V (nominal) ion source and be capable of aquiring m/z abundance data in real time selected ion monitoring (SIM) for groups of four or more masses.</P>
                        <P>5.5.4 GC/MS interface—Any GC to MS interface can be used that achieves the requirements of Section 7.1.1. GC to MS interfaces constructed of all glass or glass-lined materials are recommended. Glass surfaces can be deactivated by silanizing with dichlorodimethylsilane. To achieve maximum sensitivity, the exit end of the capillary column should be placed in the ion source. A short piece of fused silica capillary can be used as the interface to overcome problems associated with straightening the exit end of glass capillary columns.</P>
                        <P>5.5.5 The SIM data acquired during the chromatographic program is defined as the Selected Ion Current Profile (SICP). The SICP can be acquired under computer control or as a real time analog output. If computer control is used, there must be software available to plot the SICP and report peak height or area data for any m/z in the SICP between specified time or scan number limits.</P>
                        <P>5.6 Balance—Analytical, capable of accurately weighing 0.0001 g.</P>
                        <HD SOURCE="HD2">6. Reagents</HD>
                        <P>
                            6.1 Reagent water—Reagent water is defined as a water in which an interferent is not observed at the MDL of 2, 3, 7, 8-TCDD.
                            <PRTPAGE P="242"/>
                        </P>
                        <P>6.2 Sodium hydroxide solution (10 N)—Dissolve 40 g of NaOH (ACS) in reagent water and dilute to 100 mL. Wash the solution with methylene chloride and hexane before use.</P>
                        <P>6.3 Sodium thiosulfate—(ACS) Granular.</P>
                        <P>6.4 Sulfuric acid—Concentrated (ACS, sp. gr. 1.84).</P>
                        <P>6.5 Acetone, methylene chloride, hexane, benzene, ortho-xylene, tetradecane—Pesticide quality or equivalent.</P>
                        <P>6.6 Sodium sulfate—(ACS) Granular, anhydrous. Purify by heating at 400 °C for 4 h in a shallow tray.</P>
                        <P>6.7 Alumina—Neutral, 80/200 mesh (Fisher Scientific Co., No. A-540 or equivalent). Before use, activate for 24 h at 130 °C in a foil-covered glass container.</P>
                        <P>6.8 Silica gel—High purity grade, 100/120 mesh (Fisher Scientific Co., No. S-679 or equivalent).</P>
                        <P>6.9 Stock standard solutions (1.00 µg/µL)—Stock standard solutimns can be prepared from pure standard materials or purchased as certified solutions. Acetone should be used as the solvent for spiking solutions; ortho-xylene is recommended for calibration standards for split injectors; and tetradecane is recommended for splitless or on-colum injectors. Analyze stock internal standards to verify the absence of native 2,3,7,8-TCDD.</P>
                        <P>
                            6.9.1 Prepare stock standard solutions of 2,3,7,8-TCDD (mol wt 320) and either 
                            <SU>37</SU>
                            C1
                            <E T="52">4</E>
                             2,3,7,8-TCDD (mol wt 328) or 
                            <SU>13</SU>
                            C1
                            <E T="52">12</E>
                             2,3,7,8-TCDD (mol wt 332) in an isolated area by accurately weighing about 0.0100 g of pure material. Dissolve the material in pesticide quality solvent and dilute to volume in a 10-mL volumetric flask. When compound purity is assayed to be 96% or greater, the weight can be used without correction to calculate the concentration of the stock standard. Commercially prepared stock standards can be used at any concentration if they are certified by the manufacturer or by an independent source.
                        </P>
                        <P>6.9.2 Transfer the stock standard solutions into Teflon-sealed screw-cap bottles. Store in an isolated refrigerator protected from light. Stock standard solutions should be checked frequently for signs of degradation or evaporation, especially just prior to preparing calibration standards or spiking solutions from them.</P>
                        <P>6.9.3 Stock standard solutions must be replaced after six months, or sooner if comparison with check standards indicates a problem.</P>
                        <P>
                            6.10 Internal standard spiking solution (25 ng/mL)—Using stock standard solution, prepare a spiking solution in acetone of either 
                            <SU>13</SU>
                             Cl
                            <E T="52">12</E>
                             or 
                            <SU>37</SU>
                             Cl
                            <E T="52">4</E>
                             2,3,7,8-TCDD at a concentration of 25 ng/mL. (See Section 10.2)
                        </P>
                        <P>6.11 Quality control check sample concentrate—See Section 8.2.1.</P>
                        <HD SOURCE="HD2">7. Calibration</HD>
                        <P>7.1 Establish gas chromatograhic operating conditions equivalent to those given in Table 1 and SIM conditions for the mass spectrometer as described in Section 12.2 The GC/MS system must be calibrated using the internal standard technique.</P>
                        <P>7.1.1 Using stock standards, prepare calibration standards that will allow measurement of relative response factors of at least three concentration ratios of 2,3,7,8-TCDD to internal standard. Each calibration standard must be prepared to contain the internal standard at a concentration of 25 ng/mL. If any interferences are contributed by the internal standard at m/z 320 and 322, its concentration may be reduced in the calibration standards and in the internal standard spiking solution (Section 6.10). One of the calibration standards should contain 2,3,7,8-TCDD at a concentration near, but above, the MDL and the other 2,3,7,8-TCDD concentrations should correspond to the expected range of concentrations found in real samples or should define the working range of the GC/MS system.</P>
                        <P>7.1.2 Using injections of 2 to 5 µL, analyze each calibration standardaccording to Section 12 and tabulate peak height or area response against the concentration of 2,3,7,8-TCDD and internal standard. Calculate response factors (RF) for 2,3,7,8-TCDD using Equation 1.</P>
                        <MATH SPAN="1" DEEP="31">
                            <MID>EC15NO91.122</MID>
                        </MATH>
                        <FP SOURCE="FRP0">Equation 1</FP>
                        <FP>where:</FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">s</E>
                             = SIM response for 2,3,7,8-TCDD m/z 320.
                        </FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">is</E>
                             = SIM response for the internal standard, m/z 332 for 
                            <SU>13</SU>
                             C
                            <E T="52">12</E>
                             2,3,7,8-TCDD m/z 328 for 
                            <SU>37</SU>
                             Cl
                            <E T="52">4</E>
                             2,3,7,8-TCDD.
                        </FP>
                        <FP SOURCE="FP-2">
                            C
                            <E T="52">is</E>
                             = Concentration of the internal standard (µg/L).
                        </FP>
                        <FP SOURCE="FP-2">
                            C
                            <E T="52">s</E>
                             = Concentration of 2,3,7,8-TCDD (µg/L).
                        </FP>
                        <FP>
                            If the RF value over the working range is a constant (&lt;10% relative standard deviation, RSD), the RF can be assumed to be invariant and the average RF can be used for calculations. Alternatively, the results can be used to plot a calibration curve of response ratios, A
                            <E T="52">s</E>
                            /A
                            <E T="52">is</E>
                            , vs. RF.
                        </FP>
                        <P>
                            7.1.3 The working calibration curve or RF must be verified on each working day by the measurement of one or more 2,3,7,8-TCDD calibration standards. If the response for 2,3,7,8-TCDD varies from the predicted response by more than ±15%, the test must be repeated using a fresh calibration standard. Alternatively, a new calibration curve must be prepared.
                            <PRTPAGE P="243"/>
                        </P>
                        <P>7.2 Before using any cleanup procedure, the analyst must process a series of calibration standards through the procedure to validate elution patterns and the absence of interferences from the reagents.</P>
                        <HD SOURCE="HD2">8. Quality Control</HD>
                        <P>8.1 Each laboratory that uses this method is required to operate a formal quality control program. The minimum requirements of this program consist of an initial demonstration of laboratory capability and an ongoing analysis of spiked samples to evaluate and document data quality. The laboratory must maintain records to document the quality of data that is generated. Ongoing data quality checks are compared with established performance criteria to determine if the results of analyses meet the performance characteristics of the method. When results of sample spikes indicate atypical method performance, a quality control check standard must be analyzed to confirm that the measurements were performed in an in-control mode of operation.</P>
                        <P>8.1.1 The analyst must make an initial, one-time, demonstration of the ability to generate acceptable accuracy and precision with this method. This ability is established as described in Section 8.2.</P>
                        <P>8.1.2 In recognition of advances that are occurring in chromatography, the analyst is permitted certain options (detailed in Sections 10.5, 11.1, and 12.1) to improve the separations or lower the cost of measurements. Each time such a modification is made to the method, the analyst is required to repeat the procedure in Section 8.2</P>
                        <P>8.1.3 Before processing any samples, the analyst must analyze a reagent water blank to demonstrate that interferences from the analytical system and glassware are under control. Each time a set of samples is extracted or reagents are changed, a reagent water blank must be processed as a safeguard against laboratory contamination.</P>
                        <P>8.1.4 The laboratory must, on an ongoing basis, spike and analyze a minimum of 10% of all samples with native 2,3,7,8-TCDD to monitor and evaluate laboratory data quality. This procedure is described in Section 8.3.</P>
                        <P>8.1.5 The laboratory must, on an ongoing basis, demonstrate through the analyses of quality control check standards that the operation of the measurement system is in control. This procedure is described in Section 8.4. The frequency of the check standard analyses is equivalent to 10% of all samples analyzed but may be reduced if spike recoveries from samples (Section 8.3) meet all specified quality control criteria.</P>
                        <P>8.1.6 The laboratory must maintain performance records to document the quality of data that is generated. This procedure is described in Section 8.5.</P>
                        <P>8.2 To establish the ability to generate acceptable accuracy and precision, the analyst must perform the following operations.</P>
                        <P>8.2.1 A quality control (QC) check sample concentrate is required containing 2,3,7,8-TCDD at a concentration of 0.100 µg/mL in acetone. The QC check sample concentrate must be obtained from the U.S. Environmental Protection Agency, Environmental Monitoring and Support Laboratory in Cincinnati, Ohio, if available. If not available from that source, the QC check sample concentrate must be obtained from another external source. If not available from either source above, the QC check sample concentrate must be prepared by the laboratory using stock standards prepared independently from those used for calibration.</P>
                        <P>8.2.2 Using a pipet, prepare QC check samples at a concentration of 0.100 µg/L (100 ng/L) by adding 1.00 mL of QC check sample concentrate to each of four 1-L aliquots of reagent water.</P>
                        <P>8.2.3 Analyze the well-mixed QC check samples according to the method beginning in Section 10.</P>
                        <P>
                            8.2.4 Calculate the average recovery (X
                            <AC T="8"/>
                            ) in µg/L, and the standard deviation of the recovery (s) in µg/L, for 2,3,7,8-TCDD using the four results.
                        </P>
                        <P>
                            8.2.5 Compare s and (X
                            <AC T="8"/>
                            ) with the corresponding acceptance criteria for precision and accuracy, respectively, found in Table 2. If s and X
                            <AC T="8"/>
                             meet the acceptance criteria, the system performance is acceptable and analysis of actual samples can begin. If s exceeds the precision limit or X
                            <AC T="8"/>
                             falls outside the range for accuracy, the system performance is unacceptable for 2,3,7,8-TCDD. Locate and correct the source of the problem and repeat the test beginning with Section 8.2.2.
                        </P>
                        <P>8.3 The laboratory must, on an ongoing basis, spike at least 10% of the samples from each sample site being monitored to assess accuracy. For laboratories analyzing one to ten samples per month, at least one spiked sample per month is required.</P>
                        <P>8.3.1 The concentration of the spike in the sample should be determined as follows:</P>
                        <P>8.3.1.1 If, as in compliance monitoring, the concentration of 2,3,7,8-TCDD in the sample is being checked against a regulatory concentration limit, the spike should be at that limit or 1 to 5 times higher than the background concentration determined in Section 8.3.2, whichever concentration would be larger.</P>
                        <P>8.3.1.2 If the concentration of 2,3,7,8-TCDD in the sample is not being checked against a limit specific to that parameter, the spike should be at 0.100 µg/L or 1 to 5 times higher than the background concentration determined in Section 8.3.2, whichever concentration would be larger.</P>
                        <P>
                            8.3.1.3 If it is impractical to determine background levels before spiking (e.g., maximum holding times will be exceeded), the 
                            <PRTPAGE P="244"/>
                            spike concentration should be (1) the regulatory concentration limit, if any; or, if none (2) the larger of either 5 times higher than the expected background concentration or 0.100 µg/L.
                        </P>
                        <P>8.3.2 Analyze one sample aliquot to determine the background concentration (B) of 2,3,7,8-TCDD. If necessary, prepare a new QC check sample concentrate (Section 8.2.1) appropriate for the background concentration in the sample. Spike a second sample aliquot with 1.0 mL of the QC check sample concentrate and analyze it to determine the concentration after spiking (A) of 2,3,7,8-TCDD. Calculate percent recovery (P) as 100(A−B)%T, where T is the known true value of the spike.</P>
                        <P>
                            8.3.3 Compare the percent recovery (P) for 2,3,7,8-TCDD with the corresponding QC acceptance criteria found in Table 2. These acceptance criteria were calculated to include an allowance for error in measurement of both the background and spike concentrations, assuming a spike to background ratio of 5:1. This error will be accounted for to the extent that the analyst's spike to background ratio approaches 5:1. 
                            <SU>11</SU>
                             If spiking was performed at a concentration lower than 0.100 µg/L, the analyst must use either the QC acceptance criteria in Table 2, or optional QC acceptance criteria calculated for the specific spike concentration. To calculate optional acceptance criteria for the recovery of 2,3,7,8-TCDD: (1) Calculate accuracy (X′) using the equation in Table 3, substituting the spike concentration (T) for C; (2) calculate overall precision (S′) using the equation in Table 3, substituting X′ for X; (3) calculate the range for recovery at the spike concentration as (100 X′/T)±2.44(100 S′/T)%. 
                            <SU>11</SU>
                        </P>
                        <P>8.3.4 If the recovery of 2,3,7,8-TCDD falls outside the designated range for recovery, a check standard must be analyzed as described in Section 8.4.</P>
                        <P>8.4 If the recovery of 2,3,7,8-TCDD fails the acceptance criteria for recovery in Section 8.3, a QC check standard must be prepared and analyzed.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>The frequency for the required analysis of a QC check standard will depend upon the complexity of the sample matrix and the performance of the laboratory.</P>
                        </NOTE>
                        <P>8.4.1 Prepare the QC check standard by adding 1.0 mL of QC check sample concentrate (Section 8.2.1 or 8.3.2) to 1 L of reagent water.</P>
                        <P>
                            8.4.2 Analyze the QC check standard to determine the concentration measured (A) of 2,3,7,8-TCDD. Calculate the percent recovery (P
                            <E T="52">s</E>
                            ) as 100 (A/T)%, where T is the true value of the standard concentration.
                        </P>
                        <P>
                            8.4.3 Compare the percent recovery (P
                            <E T="52">s</E>
                            ) with the corresponding QC acceptance criteria found in Table 2. If the recovery of 2,3,7,8-TCDD falls outside the designated range, the laboratory performance is judged to be out of control, and the problem must be immediately identified and corrected. The analytical result for 2,3,7,8-TCDD in the unspiked sample is suspect and may not be reported for regulatory compliance purposes.
                        </P>
                        <P>
                            8.5 As part of the QC program for the laboratory, method accuracy for wastewater samples must be assessed and records must be maintained. After the analysis of five spiked wastewater samples as in Section 8.3, calculate the average percent recovery (P
                            <AC T="8"/>
                            ) and the spandard deviation of the percent recovery (s
                            <E T="52">p</E>
                            ). Express the accuracy assessment as a percent recovery interval from P
                            <AC T="8"/>
                            −2s
                            <E T="52">p</E>
                             to P
                            <AC T="8"/>
                             + 2s
                            <E T="52">p</E>
                            . If P
                            <AC T="8"/>
                             = 90% and s
                            <E T="52">p</E>
                             = 10%, for example, the accuracy interval is expressed as 70-110%. Update the accuracy assessment on a regular basis (e.g. after each five to ten new accuracy measurements).
                        </P>
                        <P>8.6 It is recommended that the laboratory adopt additional quality assurance practices for use with this method. The specific practices that are most productive depend upon the needs of the laboratory and the nature of the samples. Field duplicates may be analyzed to assess the precision of the environmental measurements. Whenever possible, the laboratory should analyze standard reference materials and participate in relevant performance evaluation studies.</P>
                        <HD SOURCE="HD2">9. Sample Collection, Preservation, and Handling</HD>
                        <P>
                            9.1 Grab samples must be collected in glass containers. Conventional sampling practices 
                            <SU>12</SU>
                             should be followed, except that the bottle must not be prerinsed with sample before collection. Composite samples should be collected in refrigerated glass containers in accordance with the requirements of the program. Automatic sampling equipment must be as free as possible of Tygon tubing and other potential sources of contamination.
                        </P>
                        <P>
                            9.2 All samples must be iced or refrigerated at 4 °C and protected from light from the time of collection until extraction. Fill the sample bottles and, if residual chlorine is present, add 80 mg of sodium thiosulfate per liter of sample and mix well. EPA Methods 330.4 and 330.5 may be used for measurement of residual chlorine. 
                            <SU>13</SU>
                             Field test kits are available for this purpose.
                        </P>
                        <P>9.3 Label all samples and containers “POISON” and ship according to applicable U.S. Department of Transportation regulations.</P>
                        <P>
                            9.4 All samples must be extracted within 7 days of collection and completely analyzed within 40 days of extraction. 
                            <SU>2</SU>
                        </P>
                        <HD SOURCE="HD2">10. Sample Extraction</HD>
                        <P>
                            <E T="04">Caution:</E>
                             When using this method to analyze for 2,3,7,8-TCDD, all of the following operations must be performed in a limited-access laboratory with the analyst wearing full 
                            <PRTPAGE P="245"/>
                            protective covering for all exposed skin surfaces. See Section 4.2.
                        </P>
                        <P>10.1 Mark the water meniscus on the side of the sample bottle for later determination of sample volume. Pour the entire sample into a 2-L separatory funnel.</P>
                        <P>10.2 Add 1.00 mL of internal standard spiking solution to the sample in the separatory funnel. If the final extract will be concentrated to a fixed volume below 1.00 mL (Section 12.3), only that volume of spiking solution should be added to the sample so that the final extract will contain 25 ng/mL of internal standard at the time of analysis.</P>
                        <P>10.3 Add 60 mL of methylene chloride to the sample bottle, seal, and shake 30 s to rinse the inner surface. Transfer the solvent to the separatory funnel and extract the sample by shaking the funnel for 2 min. with periodic venting to release excess pressure. Allow the organic layer to separate from the water phase for a minimum of 10 min. If the emulsion interface between layers is more than one-third the vmlume of the solvent layer, the analyst must employ mechanical techniques to complete the phase separation. The optimum technique depends upon the sample, but may include stirring, filtration of the emulsion through glass wool, centrifugation, or other physical methods. Collect the methylene chloride extract in a 250-mL Erlenmeyer flask.</P>
                        <P>10.4 Add a second 60-mL volume of methylene chloride to the sample bottle and repeat the extraction procedure a second time, combining the extracts in the Erlenmeyer flask. Perform a third extraction in the same manner.</P>
                        <P>10.5 Assemble a Kuderna-Danish (K-D) concentrator by attaching a 10-mL concentrator tube to a 500-mL evaporative flask. Other concentration devices or techniques may be used in place of the K-D concentrator if the requirements of Section 8.2 are met.</P>
                        <P>10.6 Pour the combined extract into the K-D concentrator. Rinse the Erlenmeyer flask with 20 to 30 mL of methylele chloride to complete the quantitative transfer.</P>
                        <P>10.7 Add one or two clean boiling chips to the evaporative flask and attach a three-ball Snyder column. Prewet the Snyder column by adding about 1 mL of methylene chloride to the top. Place the K-D apparatus on a hot water bath (60 to 65 °C) so that the concentrator tube is partially immersed in the hot water, and the entire lower rounded surface of the flask is bathed with hot vapor. Adjust the vertical position of the apparatus and the water temperature as required to complete the concentration in 15 to 20 min. At the proper rate of distillation the balls of the column will actively chatter but the chambers will not flood with condensed solvent. When the apparent volume of liquid reaches 1 mL, remove the K-D apparatus and allow it to drain and cool for at least 10 min.</P>
                        <P>10.8 Momentarily remove the Snyder column, add 50 mL of hexane and a new boiling chip, and reattach the Snyder column. Raise the temperature of the water bath to 85 to 90 °C. Concentrate the extract as in Section 10.7, except use hexane to prewet the column. Remove the Snyder column and rinse the flask and its lower joint into the concentrator tube with 1 to 2 mL of hexane. A 5-mL syringe is recommended for this operation. Set aside the K-D glassware for reuse in Section 10.14.</P>
                        <P>10.9 Pour the hexane extract from the concentrator tube into a 125-mL separatory funnel. Rinse the concentrator tube four times with 10-mL aliquots of hexane. Combine all rinses in the 125-mL separatory funnel.</P>
                        <P>10.10 Add 50 mL of sodium hydroxide solution to the funnel and shake for 30 to 60 s. Discard the aqueous phase.</P>
                        <P>10.11 Perform a second wash of the organic layer with 50 mL of reagent water. Discard the aqueous phase.</P>
                        <P>10.12 Wash the hexane layer with a least two 50-mL aliquots of concentrated sulfuric acid. Continue washing the hexane layer with 50-mL aliquots of concentrated sulfuric acid until the acid layer remains colorless. Discard all acid fractions.</P>
                        <P>10.13 Wash the hexane layer with two 50-mL aliquots of reagent water. Discard the aqueous phases.</P>
                        <P>10.14 Transfer the hexane extract into a 125-mL Erlenmeyer flask containing 1 to 2 g of anhydrous sodium sulfate. Swirl the flask for 30 s and decant the hexane extract into the reassembled K-D apparatus. Complete the quantitative transfer with two 10-mL hexane rinses of the Erlenmeyer flask.</P>
                        <P>10.15 Replace the one or two clean boiling chips and concentrate the extract to 6 to 10 mL as in Section 10.8.</P>
                        <P>10.16 Add a clean boiling chip to the concentrator tube and attach a two-ball micro-Snyder column. Prewet the column by adding about 1 mL of hexane to the top. Place the micro-K-D apparatus on the water bath so that the concentrator tube is partially immersed in the hot water. Adjust the vertical position of the apparatus and the water temperature as required to complete the concentration in 5 to 10 min. At the proper rate of distillation the balls of the column will actively chatter but the chambers will not flood. When the apparent volume of liquid reaches about 0.5 mL, remove the K-D apparatus and allow it to drain and cool for at least 10 min. Remove the micro-Snyder column and rinse its lower joint into the concentrator tube with 0.2 mL of hexane.</P>
                        <P>
                            Adjust the extract volume to 1.0 mL with hexane. Stopper the concentrator tube and store refrigerated and protected from light if further processing will not be performed immediately. If the extract will be stored 
                            <PRTPAGE P="246"/>
                            longer than two days, it should be transferred to a Teflon-sealed screw-cap vial. If the sample extract requires no further cleanup, proceed with GC/MS analysis (Section 12). If the sample requires further cleanup, proceed to Section 11.
                        </P>
                        <P>10.17 Determine the original sample volume by refilling the sample bottle to the mark and transferring the liquid to a 1000-mL graduated cylinder. Record the sample volume to the nearest 5 mL.</P>
                        <HD SOURCE="HD2">11. Cleanup and Separation</HD>
                        <P>
                            11.1 Cleanup procedures may not be necessary for a relatively clean sample matrix. If particular circumstances demand the use of a cleanup procedure, the analyst may use either procedure below or any other appropriate procedure. 
                            <SU>1 5-7</SU>
                             However, the analyst first must demonstrate that the requirements of Section 8.2 can be met using the method as revised to incorporate the cleanup procedure. Two cleanup column options are offered to the analyst in this section. The alumina column should be used first to overcome interferences. If background problems are still encountered, the silica gel column may be helpful.
                        </P>
                        <P>11.2 Alumina column cleanup for 2,3,7,8-TCDD:</P>
                        <P>11.2.1 Fill a 300 mm long × 10 mm ID chromatographic column with activated alumina to the 150 mm level. Tap the column gently to settle the alumina and add 10 mm of anhydrous sodium sulfate to the top.</P>
                        <P>11.2.2 Preelute the column with 50 mL of hexane. Adjust the elution rate to 1 mL/min. Discard the eluate and just prior to exposure of the sodium sulfate layer to the air, quantitatively transfer the 1.0-mL sample extract onto the column using two 2-mL portions of hexane to complete the transfer.</P>
                        <P>11.2.3 Just prior to exposure of the sodium sulfate layer to the air, add 50 mL of 3% methylene chloride/95% hexane (V/V) and continue the elution of the column. Discard the eluate.</P>
                        <P>11.2.4 Next, elute the column with 50 mL of 20% methylene chloride/80% hexane (V/V) into a 500-mL K-D flask equipped with a 10-mL concentrator tube. Concentrate the collected fraction to 1.0 mL as in Section 10.16 and analyze by GC/MS (Section 12).</P>
                        <P>11.3 Silica gel column cleanup for 2,3,7,8-TCDD:</P>
                        <P>11.3.1 Fill a 400 mm long × 11 mm ID chromatmgraphic column with silica gel to the 300 mm level. Tap the column gently to settle the silica gel and add 10 mm of anhydrous sodium sulfate to the top.</P>
                        <P>11.3.2 Preelute the column with 50 mL of 20% benzene/80% hexane (V/V). Adjust the elution rate to 1 mL/min. Discard the eluate and just prior to exposure of the sodium sulfate layer to the air, quantitatively transfer the 1.0-mL sample extract onto the column using two 2-mL portions of 20% benzene/80% hexane to complete the transfer.</P>
                        <P>11.3.3 Just prior to exposure of the sodium sulfate layer to the air, add 40 mL of 20% benzene/80% hexane to the column. Collect the eluate in a clean 500-mL K-D flask equipped with a 10-mL concentrator tube. Concentrate the collected fraction to 1.0 mL as in Section 10.16 and analyze by GC/MS.</P>
                        <HD SOURCE="HD2">12. GC/MS Analysis</HD>
                        <P>12.1 Table 1 summarizes the recommended operating conditions for the gas chromatograph. Included in this table are retention times and MDL that can be achieved under these conditions. Other capillary columns or chromatographic conditions may be used if the requirements of Sections 5.5.2 and 8.2 are met.</P>
                        <P>
                            12.2 Analyze standards and samples with the mass spectrometer operating in the selected ion monitoring (SIM) mode using a dwell time to give at least seven points per peak. For LRMS, use masses at m/z 320, 322, and 257 for 2,3,7,8-TCDD and either m/z 328 for 
                            <SU>37</SU>
                            Cl
                            <E T="52">4</E>
                             2,3,7,8-TCDD or m/z 332 for 
                            <SU>13</SU>
                            C
                            <E T="52">12</E>
                             2,3,7,8-TCDD. For HRMS, use masses at m/z 319.8965 and 321.8936 for 2,3,7,8-TCDD and either m/z 327.8847 for 
                            <SU>37</SU>
                            Cl
                            <E T="52">4</E>
                             2,3,7,8-TCDD or m/z 331.9367 for 
                            <SU>13</SU>
                            C
                            <E T="52">12</E>
                             2,3,7,8-TCDD.
                        </P>
                        <P>12.3 If lower detection limits are required, the extract may be carefully evaporated to dryness under a gentle stream of nitrogen with the concentrator tube in a water bath at about 40 °C. Conduct this operation immediately before GC/MS analysis. Redissolve the extract in the desired final volume of ortho-xylene or tetradecane.</P>
                        <P>12.4 Calibrate the system daily as described in Section 7.</P>
                        <P>12.5 Inject 2 to 5 µL of the sample extract into the gas chromatograph. The volume of calibration standard injected must be measured, or be the same as all sample injection volumes.</P>
                        <P>12.6 The presence of 2,3,7,8-TCDD is qualitatively confirmed if all of the following criteria are achieved:</P>
                        <P>12.6.1 The gas chromatographic column must resolve 2,3,7,8-TCDD from the other 21 TCDD isomers.</P>
                        <P>12.6.2 The masses for native 2,3,7,8-TCDD (LRMS-m/z 320, 322, and 257 and HRMS-m/z 320 and 322) and labeled 2,3,7,8-TCDD (m/z 328 or 332) must exhibit a simultaneous maximum at a retention time that matches that of native 2,3,7,8-TCDD in the calibration standard, with the performance specifications of the analytical system.</P>
                        <P>12.6.3 The chlorine isotope ratio at m/z 320 and m/z 322 must agree to within±10% of that in the calibration standard.</P>
                        <P>12.6.4 The signal of all peaks must be greater than 2.5 times the noise level.</P>
                        <P>
                            12.7 For quantitation, measure the response of the m/z 320 peak for 2,3,7,8-TCDD 
                            <PRTPAGE P="247"/>
                            and the m/z 332 peak for 
                            <SU>13</SU>
                            C
                            <E T="52">12</E>
                             2,3,7,8-TCDD or the m/z 328 peak for 
                            <SU>37</SU>
                            Cl
                            <E T="52">4</E>
                             2,3,7,8-TCDD.
                        </P>
                        <P>
                            12.8 Co-eluting impurities are suspected if all criteria are achieved except those in Section 12.6.3. In this case, another SIM analysis using masses at m/z 257, 259, 320 and either m/a 328 or m/z 322 can be performed. The masses at m/z 257 and m/z 259 are indicative of the loss of one chlorine and one carbonyl group from 2,3,7,8-TCDD. If masses m/z 257 and m/z 259 give a chlorine isotope ratio that agrees to within ±10% of the same cluster in the calibration standards, then the presence of TCDD can be confirmed. Co-eluting DDD, DDE, and PCB residues can be confirmed, but will require another injection using the appropriate SIM masses or full repetitive mass scans. If the response for 
                            <SU>37</SU>
                            Cl
                            <E T="52">4</E>
                             2,3,7,8-TCDD at m/z 328 is too large, PCB contamination is suspected and can be confirmed by examining the response at both m/z 326 and m/z 328. The 
                            <SU>37</SU>
                            Cl
                            <E T="52">4</E>
                             2,3,7,8-TCDD internal standard gives negligible response at m/z 326. These pesticide residues can be removed using the alumina column cleanup procedure.
                        </P>
                        <P>12.9 If broad background interference restricts the sensitivity of the GC/MS analysis, the analyst should employ additional cleanup procedures and reanalyze by GC/MS.</P>
                        <P>
                            12.10 In those circumstances where these procedures do not yield a definitive conclusion, the use of high resolution mass spectrometry is suggested. 
                            <SU>5</SU>
                        </P>
                        <HD SOURCE="HD2">13. Calculations</HD>
                        <P>13.1 Calculate the concentration of 2,3,7,8-TCDD in the sample using the response factor (RF) determined in Section 7.1.2 and Equation 2.</P>
                        <MATH SPAN="1" DEEP="31">
                            <MID>EC15NO91.123</MID>
                        </MATH>
                        <FP SOURCE="FRP0">Equation 2</FP>
                        <FP>where:</FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">s</E>
                             = SIM response for 2,3,7,8-TCDD at m/z 320.
                        </FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">is</E>
                             = SIM response for the internal standard at m/z 328 or 332.
                        </FP>
                        <FP SOURCE="FP-2">
                            I
                            <E T="52">s</E>
                             = Amount of internal standard added to each extract (µg).
                        </FP>
                        <FP SOURCE="FP-2">
                            V
                            <E T="52">o</E>
                             = Volume of water extracted (L).
                        </FP>
                        <P>13.2 For each sample, calculate the percent recovery of the internal standard by comparing the area of the m/z peak measured in the sample to the area of the same peak in the calibration standard. If the recovery is below 50%, the analyst should review all aspects of his analytical technique.</P>
                        <P>13.3 Report results in µg/L without correction for recovery data. All QC data obtained should be reported with the sample results.</P>
                        <HD SOURCE="HD2">14. Method Performance</HD>
                        <P>
                            14.1 The method detection limit (MDL) is defined as the minimum concentration of a substance that can be measured and reported with 99% confidence that the value is above zero. 
                            <SU>1</SU>
                             The MDL concentration listed in Table 1 was obtained using reagent water. 
                            <SU>14</SU>
                             The MDL actually achieved in a given analysis will vary depending on instrument sensitivity and matrix effects.
                        </P>
                        <P>
                            14.2 This method was tested by 11 laboratories using reagent water, drinking water, surface water, and three industrial wastewaters spiked at six concentrations over the range 0.02 to 0.20 µg/L. 
                            <SU>15</SU>
                             Single operator precision, overall precision, and method accuracy were found to be directly related to the concentration of the parameter and essentially independent of the sample matrix. Linear equations to describe these relationships are presented in Table 3.
                        </P>
                        <HD SOURCE="HD1">References</HD>
                        <P>1. 40 CFR part 136, appendix B.</P>
                        <P>2. “Determination of TCDD in Industrial and Municipal Wastewaters,” EPA 600/4-82-028, National Technical Information Service, PB82-196882, Springfield, Virginia 22161, April 1982.</P>
                        <P>
                            3. Buser, H.R., and Rappe, C. “High Resolution Gas Chromatography of the 22 Tetrachlorodibenzo-p-dioxin Isomers,” 
                            <E T="03">Analytical Chemistry, 52,</E>
                             2257 (1980).
                        </P>
                        <P>4. ASTM Annual Book of Standards, Part 31, D3694-78. “Standard Practices for Preparation of Sample Containers and for Preservation of Organic Constituents,” American Society for Testing and Materials, Philadelphia.</P>
                        <P>
                            5. Harless, R. L., Oswald, E. O., and Wilkinson, M. K. “Sample Preparation and Gas Chromatography/Mass Spectrometry Determination of 2,3,7,8-Tetrachlorodibenzo-p-dioxin,” 
                            <E T="03">Analytical Chemistry, 52,</E>
                             1239 (1980).
                        </P>
                        <P>
                            6. Lamparski, L. L., and Nestrick, T. J. “Determination of Tetra-, Hepta-, and Octachlorodibenzo-p-dioxin Isomers in Particulate Samples at Parts per Trillion Levels,” 
                            <E T="03">Analytical Chemistry, 52,</E>
                             2045 (1980).
                        </P>
                        <P>
                            7. Longhorst, M. L., and Shadoff, L. A. “Determination of Parts-per-Trillion Concentrations of Tetra-, Hexa-, and Octachlorodibenzo-p-dioxins in Human Milk,” 
                            <E T="03">Analytical Chemistry, 52,</E>
                             2037 (1980).
                        </P>
                        <P>8. “Carcinogens—Working with Carcinogens,” Department of Health, Education, and Welfare, Public Health Service, Center for Disease Control, National Institute for Occupational Safety and Health, Publication No. 77-206, August 1977.</P>
                        <P>
                            9. “OSHA Safety and Health Standards, General Industry,” (29 CFR part 1910), Occuptional Safety and Health Administration, OSHA 2206 (Revised, January 1976).
                            <PRTPAGE P="248"/>
                        </P>
                        <P>10. “Safety in Academic Chemistry Laboratories,” American Chemical Society Publication, Committee on Chemical Safety, 3rd Edition, 1979.</P>
                        <P>
                            11. Provost, L. P., and Elder, R. S., “Interpretation of Percent Recovery Data,” 
                            <E T="03">American Laboratory, 15,</E>
                             58-63 (1983). (The value 2.44 used in the equation in Section 8.3.3 is two times the value 1.22 derived in this report.)
                        </P>
                        <P>12. ASTM Annual Book of Standards, Part 31, D3370-76, “Standard Practices for Sampling Water,” American Society for Testing and Materials, Philadelphia.</P>
                        <P>13. “Methods, 330.4 (Titrimetric, DPD-FAS) and 330.5 (Spectrophotometric DPD) for Chlorine, Total Residual,” Methods for Chemical Analysis of Water and Wastes, EPA-600/4-79-020, U.S. Environmental Protection Agency, Environmental Monitoring and Support Laboratory, Cincinnati, Ohio 45268, March 1979.</P>
                        <P>14. Wong, A.S. et al. “The Determination of 2,3,7,8-TCDD in Industrial and Municipal Wastewaters, Method 613, Part 1—Development and Detection Limits,” G. Choudhay, L. Keith, and C. Ruppe, ed., Butterworth Inc., (1983).</P>
                        <P>15. “EPA Method Study 26, Method 613: 2,3,7,8-Tetrachlorodibenzo-p-dioxin,” EPA 600/4-84-037, National Technical Information Service, PB84-188879, Springfield, Virginia 22161, May 1984.</P>
                        <GPOTABLE COLS="3" OPTS="L2" CDEF="s10,8,8">
                            <TTITLE>Table 1—Chromatographic Conditions and Method Detection Limit</TTITLE>
                            <BOXHD>
                                <CHED H="1">Parameter</CHED>
                                <CHED H="1">Retention time (min)</CHED>
                                <CHED H="1">Method detection limit (µg/L)</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">2,3,7,8-TCDD</ENT>
                                <ENT>13.1</ENT>
                                <ENT>0.002</ENT>
                            </ROW>
                            <TNOTE>Column conditions: SP-2330 coated on a 60 m long × 0.25 mm ID glass column with hydrogen carrier gas at 40 cm/sec linear velocity, splitless injection using tetradecane. Column temperature held isothermal at 200 °C for 1 min, then programmed at 8 °C/min to 250 °C and held. Use of helium carrier gas will approximately double the retention time.</TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="5" OPTS="L2" CDEF="s25,6,6,12,6">
                            <TTITLE>Table 2—QC Acceptance Criteria—Method 613</TTITLE>
                            <BOXHD>
                                <CHED H="1">Parameter</CHED>
                                <CHED H="1">Test conc. (µg/L)</CHED>
                                <CHED H="1">Limit for s (µg/L)</CHED>
                                <CHED H="1">Range for X (µg/L)</CHED>
                                <CHED H="1">
                                    Range for P, P
                                    <E T="52">s</E>
                                     (%)
                                </CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">2,3,7,8-TCDD</ENT>
                                <ENT>0.100</ENT>
                                <ENT>0.0276</ENT>
                                <ENT>0.0523-0.1226</ENT>
                                <ENT>45-129</ENT>
                            </ROW>
                            <TNOTE>s = Standard deviation of four recovery measurements, in µg/L (Section 8.2.4).</TNOTE>
                            <TNOTE>
                                X
                                <AC T="8"/>
                                 = Average recovery for four recovery measurements, in µg/L (Section 8.2.4).
                            </TNOTE>
                            <TNOTE>
                                P, P
                                <E T="52">s</E>
                                 = Percent recovery measured (Section 8.3.2, Section 8.4.2).
                            </TNOTE>
                            <TNOTE>
                                <E T="04">Note:</E>
                                 These criteria are based directly upon the method performance data in Table 3. Where necessary, the limits for recovery have been broadened to assure applicability of the limits to concentrations below those used to develop Table 3.
                            </TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="4" OPTS="L2" CDEF="s50,16,16,16">
                            <TTITLE>Table 3—Method Accuracy and Precision as Functions of Concentration—Method 613</TTITLE>
                            <BOXHD>
                                <CHED H="1">Parameter</CHED>
                                <CHED H="1">Accuracy, as recovery, X″ (µg/L)</CHED>
                                <CHED H="1">
                                    Single analyst, precision, s
                                    <E T="52">r</E>
                                    ″ (µ/L)
                                </CHED>
                                <CHED H="1">Overall precision, S″ (µ/g/L)</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">2,3,7,8-TCDD</ENT>
                                <ENT>0.86C + 0.00145</ENT>
                                <ENT>
                                    0.13X
                                    <AC T="8"/>
                                     + 0.00129
                                </ENT>
                                <ENT>
                                    0.19X
                                    <AC T="8"/>
                                     + 0.00028
                                </ENT>
                            </ROW>
                            <TNOTE>X′ = Expected recovery for one or more measurements. of a sample containing a concentration of C, in µg/L.</TNOTE>
                            <TNOTE>
                                s
                                <E T="52">r</E>
                                ′ = Expected single analyst standard deviation of measurements at an average concentration found of X
                                <AC T="8"/>
                                , in µg/L.
                            </TNOTE>
                            <TNOTE>
                                S′ = Expected interlaboratory standard deviation of measurements at an average concentration found of X
                                <AC T="8"/>
                                , in µg/L.
                            </TNOTE>
                            <TNOTE>C = True value for the concentration, in µg/L.</TNOTE>
                            <TNOTE>
                                X
                                <AC T="8"/>
                                 = Average recovery found for measurements of samples containing a concentration of C, in µg/L.
                            </TNOTE>
                        </GPOTABLE>
                        <EAR>Pt. 136, App. A, Meth. 624.1</EAR>
                        <HD SOURCE="HD1">Method 624.1—Purgeables by GC/MS</HD>
                        <HD SOURCE="HD2">1. Scope and Application</HD>
                        <P>1.1 This method is for determination of purgeable organic pollutants in industrial discharges and other environmental samples by gas chromatography combined with mass spectrometry (GC/MS), as provided under 40 CFR 136.1. This revision is based on previous protocols (References 1—3), on the revision promulgated October 26, 1984, and on an interlaboratory method validation study (Reference 4). Although this method was validated through an interlaboratory study conducted in the early 1980s, the fundamental chemistry principles used in this method remain sound and continue to apply.</P>
                        <P>1.2 The analytes that may be qualitatively and quantitatively determined using this method and their CAS Registry numbers are listed in Table 1. The method may be extended to determine the analytes listed in Table 2; however, poor purging efficiency or gas chromatography of some of these analytes may make quantitative determination difficult. For example, an elevated temperature may be required to purge some analytes from water. If an elevated temperature is used, calibration and all quality control (QC) tests must be performed at the elevated temperature. EPA encourages the use of this method to determine additional compounds amenable to purge-and-trap GC/MS.</P>
                        <P>
                            1.3 The large number of analytes in Tables 1 and 2 of this method makes testing difficult if all analytes are determined simultaneously. Therefore, it is necessary to determine and perform QC tests for “analytes of interest” only. Analytes of interest are those required to be determined by a regulatory/control authority or in a permit, or by a client. If a list of analytes is not specified, the 
                            <PRTPAGE P="249"/>
                            analytes in Table 1 must be determined, at a minimum, and QC testing must be performed for these analytes. The analytes in Table 1 and some of the analytes in Table 2 have been identified as Toxic Pollutants (40 CFR 401.15), expanded to a list of Priority Pollutants (40 CFR part 423, appendix A).
                        </P>
                        <P>1.4 Method detection limits (MDLs; Reference 5) for the analytes in Table 1 are listed in that table. These MDLs were determined in reagent water (Reference 6). Advances in analytical technology, particularly the use of capillary (open-tubular) columns, allowed laboratories to routinely achieve MDLs for the analytes in this method that are 2-10 times lower than those in the version promulgated in 1984. The MDL for a specific wastewater may differ from those listed, depending on the nature of interferences in the sample matrix.</P>
                        <P>1.4.1 EPA has promulgated this method at 40 CFR part 136 for use in wastewater compliance monitoring under the National Pollutant Discharge Elimination System (NPDES). The data reporting practices described in section 13.2 are focused on such monitoring needs and may not be relevant to other uses of the method.</P>
                        <P>1.4.2 This method includes “reporting limits” based on EPA's “minimum level” (ML) concept (see the glossary in section 20). Table 1 contains MDL values and ML values for many of the analytes. The MDL for an analyte in a specific wastewater may differ from that listed in Table 1, depending upon the nature of interferences in the sample matrix.</P>
                        <P>1.5 This method is performance-based. It may be modified to improve performance (e.g., to overcome interferences or improve the accuracy of results) provided all performance requirements are met.</P>
                        <P>1.5.1 Examples of allowed method modifications are described at 40 CFR 136.6. Other examples of allowed modifications specific to this method are described in section 8.1.2.</P>
                        <P>1.5.2 Any modification beyond those expressly allowed at 40 CFR 136.6 or in section 8.1.2 of this method shall be considered a major modification that is subject to application and approval of an alternate test procedure under 40 CFR 136.4 and 136.5.</P>
                        <P>1.5.3 For regulatory compliance, any modification must be demonstrated to produce results equivalent or superior to results produced by this method when applied to relevant wastewaters (section 8.3).</P>
                        <P>1.6 This method is restricted to use by or under the supervision of analysts experienced in the operation of a purge-and-trap system and a gas chromatograph/mass spectrometer and in the interpretation of mass spectra. Each analyst must demonstrate the ability to generate acceptable results with this method using the procedure in section 8.2.</P>
                        <P>1.7 Terms and units of measure used in this method are given in the glossary at the end of the method.</P>
                        <HD SOURCE="HD3">2. Summary of Method</HD>
                        <P>2.1 A gas is bubbled through a measured volume of water in a specially-designed purging chamber. The purgeables are efficiently transferred from the aqueous phase to the vapor phase. The vapor is swept through a sorbent trap where the purgeables are trapped. After purging is completed, the trap is heated and backflushed with the gas to desorb the purgeables onto a gas chromatographic column. The column is temperature programmed to separate the purgeables which are then detected with a mass spectrometer.</P>
                        <P>2.2 Different sample sizes in the range of 5-25 mL are allowed in order to meet differing sensitivity requirements. Calibration and QC samples must have the same volume as field samples.</P>
                        <HD SOURCE="HD3">3. Interferences</HD>
                        <P>3.1 Impurities in the purge gas, organic compounds outgassing from the plumbing ahead of the trap, and solvent vapors in the laboratory account for the majority of contamination problems. The analytical system must be demonstrated to be free from contamination under the conditions of the analysis by analyzing blanks initially and with each analytical batch (samples analyzed on a given 12-hour shift, to a maximum of 20 samples), as described in Section 8.5. Fluoropolymer tubing, fittings, and thread sealant should be used to avoid contamination.</P>
                        <P>3.2 Samples can be contaminated by diffusion of volatile organics (particularly fluorocarbons and methylene chloride) through the septum seal into the sample during shipment and storage. Protect samples from sources of volatiles during collection, shipment, and storage. A reagent water field blank carried through sampling and analysis can serve as a check on such contamination.</P>
                        <P>
                            3.3 Contamination by carry-over can occur whenever high level and low level samples are analyzed sequentially. To reduce the potential for carry-over, the purging device and sample syringe must be rinsed with reagent water between sample analyses. Whenever an unusually concentrated sample is encountered, it should be followed by an analysis of a blank to check for cross contamination. For samples containing large amounts of water-soluble materials, suspended solids, high boiling compounds or high purgeable levels, it may be necessary to wash the purging device with a detergent solution, rinse it with distilled water, and then dry it in a 105 °C oven between analyses. The trap and other parts of the system are also subject to contamination; therefore, frequent bakeout 
                            <PRTPAGE P="250"/>
                            and purging of the entire system may be required. Screening samples at high dilution may prevent introduction of contaminants into the system.
                        </P>
                        <HD SOURCE="HD3">4. Safety</HD>
                        <P>4.1 The toxicity or carcinogenicity of each reagent used in this method has not been precisely defined; however, each chemical compound should be treated as a potential health hazard. From this viewpoint, exposure to these chemicals must be reduced to the lowest possible level. The laboratory is responsible for maintaining a current awareness file of OSHA regulations regarding the safe handling of the chemicals specified in this method. A reference file of safety data sheets (SDSs, OSHA, 29 CFR 1910.1200(g)) should also be made available to all personnel involved in sample handling and chemical analysis. Additional references to laboratory safety are available and have been identified (References 7-9) for the information of the analyst.</P>
                        <P>4.2. The following analytes covered by this method have been tentatively classified as known or suspected human or mammalian carcinogens: Benzene; carbon tetrachloride; chloroform; 1,4-dichlorobenzene; 1,2-dichloroethane; 1,2-dichloropropane; methylene chloride; tetrachloroethylene; trichloroethylene; and vinyl chloride. Primary standards of these toxic compounds should be prepared in a chemical fume hood, and a NIOSH/MESA approved toxic gas respirator should be worn when handling high concentrations of these compounds.</P>
                        <P>4.3 This method allows the use of hydrogen as a carrier gas in place of helium (Section 5.3.1.2). The laboratory should take the necessary precautions in dealing with hydrogen, and should limit hydrogen flow at the source to prevent buildup of an explosive mixture of hydrogen in air.</P>
                        <HD SOURCE="HD3">5. Apparatus and Materials</HD>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>Brand names, suppliers, and part numbers are cited for illustration purposes only. No endorsement is implied. Equivalent performance may be achieved using equipment and materials other than those specified here. Demonstration of equivalent performance that meets the requirements of this method is the responsibility of the laboratory. Suppliers for equipment and materials in this method may be found through an on-line search.</P>
                        </NOTE>
                        <P>5.1 Sampling equipment for discrete sampling.</P>
                        <P>5.1.1 Vial—25- or 40-mL capacity, or larger, with screw cap with a hole in the center (Fisher #13075 or equivalent). Unless pre-cleaned, detergent wash, rinse with tap and reagent water, and dry at 105 ± 5 °C before use.</P>
                        <P>5.1.2 Septum—Fluoropolymer-faced silicone (Fisher #12722 or equivalent). Unless pre-cleaned, detergent wash, rinse with tap and reagent water, and dry at 105 ± 5 °C for one hour before use.</P>
                        <P>5.2 Purge-and-trap system—The purge-and-trap system consists of three separate pieces of equipment: A purging device, trap, and desorber. Several complete systems are commercially available with autosamplers. Any system that meets the performance requirements in this method may be used.</P>
                        <P>5.2.1 The purging device should accept 5- to 25-mL samples with a water column at least 3 cm deep. The purge gas must pass though the water column as finely divided bubbles. The purge gas must be introduced no more than 5 mm from the base of the water column. Purge devices of a different volume may be used so long as the performance requirements in this method are met.</P>
                        <P>5.2.2 The trap should be at least 25 cm long and have an inside diameter of at least 0.105 in. The trap should be packed to contain the following minimum lengths of adsorbents: 1.0 cm of methyl silicone coated packing (section 6.3.2), 15 cm of 2,6-diphenylene oxide polymer (section 6.3.1), and 8 cm of silica gel (section 6.3.3). A trap with different dimensions and packing materials is acceptable so long as the performance requirements in this method are met.</P>
                        <P>5.2.3 The desorber should be capable of rapidly heating the trap to the temperature necessary to desorb the analytes of interest, and of maintaining this temperature during desorption. The trap should not be heated higher than the maximum temperature recommended by the manufacturer.</P>
                        <P>5.2.4 The purge-and-trap system may be assembled as a separate unit or coupled to a gas chromatograph.</P>
                        <P>5.3 GC/MS system.</P>
                        <P>5.3.1 Gas chromatograph (GC)—An analytical system complete with a temperature programmable gas chromatograph and all required accessories, including syringes and analytical columns. Autosamplers designed for purge-and-trap analysis of volatiles also may be used.</P>
                        <P>5.3.1.1 Injection port—Volatiles interface, split, splitless, temperature programmable split/splitless (PTV), large volume, on-column, backflushed, or other.</P>
                        <P>5.3.1.2 Carrier gas—Data in the tables in this method were obtained using helium carrier gas. If another carrier gas is used, analytical conditions may need to be adjusted for optimum performance, and calibration and all QC tests must be performed with the alternative carrier gas. See Section 4.3 for precautions regarding the use of hydrogen as a carrier gas.</P>
                        <P>
                            5.3.2 GC column—See the footnote to Table 3. Other columns or column systems may be used provided all requirements in this method are met.
                            <PRTPAGE P="251"/>
                        </P>
                        <P>5.3.3 Mass spectrometer—Capable of repetitively scanning from 35-260 Daltons (amu) every 2 seconds or less, utilizing a 70 eV (nominal) electron energy in the electron impact ionization mode, and producing a mass spectrum which meets all criteria in Table 4 when 50 ng or less of 4-bromofluorobenzene (BFB) is injected through the GC inlet. If acrolein, acrylonitrile, chloromethane, and vinyl chloride are to be determined, it may be necessary to scan from below 25 Daltons to measure the peaks in the 26-35 Dalton range for reliable identification.</P>
                        <P>5.3.4 GC/MS interface—Any GC to MS interface that meets all performance requirements in this method may be used.</P>
                        <P>5.3.5 Data system—A computer system must be interfaced to the mass spectrometer that allows continuous acquisition and storage of mass spectra throughout the chromatographic program. The computer must have software that allows searching any GC/MS data file for specific m/z's (masses) and plotting m/z abundances versus time or scan number. This type of plot is defined as an extracted ion current profile (EICP). Software must also be available that allows integrating the abundance at any EICP between specified time or scan number limits.</P>
                        <P>5.4 Syringes—Graduated, 5-25 mL, glass hypodermic with Luerlok tip, compatible with the purging device.</P>
                        <P>5.5 Micro syringes—Graduated, 25-1000 µL, with 0.006 in. ID needle.</P>
                        <P>5.6 Syringe valve—Two-way, with Luer ends.</P>
                        <P>5.7 Syringe—5 mL, gas-tight with shut-off valve.</P>
                        <P>5.8 Bottle—15 mL, screw-cap, with Teflon cap liner.</P>
                        <P>5.9 Balance—Analytical, capable of accurately weighing 0.0001 g.</P>
                        <HD SOURCE="HD3">6. Reagents</HD>
                        <P>6.1 Reagent water—Reagent water is defined as water in which the analytes of interest and interfering compounds are not detected at the MDLs of the analytes of interest. It may be generated by passing deionized water, distilled water, or tap water through a carbon bed, passing the water through a water purifier, or heating the water to between 90 and 100 °C while bubbling contaminant-free gas through it for approximately 1 hour. While still hot, transfer the water to screw-cap bottles and seal with a fluoropolymer-lined cap.</P>
                        <P>6.2 Sodium thiosulfate—(ACS) Granular.</P>
                        <P>6.3 Trap materials.</P>
                        <P>6.3.1 2,6-Diphenylene oxide polymer—Tenax, 60/80 mesh, chromatographic grade, or equivalent.</P>
                        <P>6.3.2 Methyl silicone packing—3% OV-1 on Chromosorb-W, 60/80 mesh, or equivalent.</P>
                        <P>6.3.3 Silica gel—35/60 mesh, Davison, Grade-15 or equivalent.</P>
                        <P>6.3.4 Other trap materials are acceptable if performance requirements in this method are met.</P>
                        <P>6.4 Methanol—Demonstrated to be free from the target analytes and potentially interfering compounds.</P>
                        <P>6.5 Stock standard solutions—Stock standard solutions may be prepared from pure materials, or purchased as certified solutions. Traceability must be to the National Institute of Standards and Technology (NIST) or other national or international standard, when available. Stock solution concentrations alternative to those below may be used. Prepare stock standard solutions in methanol using assayed liquids or gases as appropriate. Because some of the compounds in this method are known to be toxic, primary dilutions should be prepared in a hood, and a NIOSH/MESA approved toxic gas respirator should be worn when high concentrations of neat materials are handled. The following procedure may be used to prepare standards from neat materials:</P>
                        <P>6.5.1 Place about 9.8 mL of methanol in a 10-mL ground-glass-stoppered volumetric flask. Allow the flask to stand, unstoppered, for about 10 minutes or until all alcohol wetted surfaces have dried. Weigh the flask to the nearest 0.1 mg.</P>
                        <P>6.5.2 Add the assayed reference material.</P>
                        <P>6.5.2.1 Liquids—Using a 100 µL syringe, immediately add two or more drops of assayed reference material to the flask. Be sure that the drops fall directly into the alcohol without contacting the neck of the flask. Reweigh, dilute to volume, stopper, then mix by inverting the flask several times. Calculate the concentration in µg/µL from the net gain in weight.</P>
                        <P>6.5.2.2 Gases—To prepare standards for any of compounds that boil below 30 °C, fill a 5-mL valved gas-tight syringe with reference standard vapor to the 5.0 mL mark. Lower the needle to 5 mm above the methanol meniscus. Slowly introduce the vapor above the surface of the liquid (the vapor will rapidly dissolve in the methanol). Reweigh, dilute to volume, stopper, then mix by inverting the flask several times. Calculate the concentration in µg/µL from the net gain in weight.</P>
                        <P>6.5.3 When compound purity is assayed to be 96% or greater, the weight may be used without correction to calculate the concentration of the stock standard. Commercially prepared stock standards may be used at any concentration if they are certified by the manufacturer or by an independent source.</P>
                        <P>
                            6.5.4 Prepare fresh standards weekly for the gases and 2-chloroethylvinyl ether. Unless stated otherwise in this method, store non-aqueous standards in fluoropolymer-
                            <PRTPAGE P="252"/>
                            lined screw-cap, or heat-sealed, glass containers, in the dark at −20 to −10 °C. Store aqueous standards; e.g., the aqueous LCS (section 8.4.1) in the dark at ≤6 °C (but do not freeze) with zero headspace; e.g., in VOA vials (section 5.1.1). Standards prepared by the laboratory may be stored for up to one month, except when comparison with QC check standards indicates that a standard has degraded or become more concentrated due to evaporation, or unless the laboratory has data on file to prove stability for a longer period. Commercially prepared standards may be stored until the expiration date provided by the vendor, except when comparison with QC check standards indicates that a standard has degraded or become more concentrated due to evaporation, or unless the laboratory has data from the vendor on file to prove stability for a longer period.
                        </P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>2-Chloroethylvinyl ether has been shown to be stable for as long as one month if prepared as a separate standard, and the other analytes have been shown to be stable for as long as 2 months if stored at less than −10 °C with minimal headspace in sealed, miniature inert-valved vials.</P>
                        </NOTE>
                        <P>6.6 Secondary dilution standards—Using stock solutions, prepare secondary dilution standards in methanol that contain the compounds of interest, either singly or mixed. Secondary dilution standards should be prepared at concentrations such that the aqueous calibration standards prepared in section 7.3.2 will bracket the working range of the analytical system.</P>
                        <P>6.7 Surrogate standard spiking solution—Select a minimum of three surrogate compounds from Table 5. The surrogates selected should match the purging characteristics of the analytes of interest as closely as possible. Prepare a stock standard solution for each surrogate in methanol as described in section 6.5, and prepare a solution for spiking the surrogates into all blanks, LCSs, and MS/MSDs. Prepare the spiking solution such that spiking a small volume will result in a constant concentration of the surrogates. For example, add 10 µL of a spiking solution containing the surrogates at a concentration of 15 µg/mL in methanol to a 5-mL aliquot of water to produce a concentration of 30 µg/L for each surrogate. Other surrogate concentrations may be used. Store per section 6.5.4.</P>
                        <P>6.8 BFB standard—Prepare a solution of BFB in methanol as described in Sections 6.5 and 6.6. The solution should be prepared such that an injection or purging from water will result in introduction of ≤ 50 ng into the GC. BFB may be included in a mixture with the internal standards and/or surrogates.</P>
                        <P>6.9 Quality control check sample concentrate—See Section 8.2.1.</P>
                        <HD SOURCE="HD3">7. Calibration</HD>
                        <P>7.1 Assemble a purge-and-trap system that meets the specifications in Section 5.2. Prior to first use, condition the trap overnight at 180 °C by backflushing with gas at a flow rate of at least 20 mL/min. Condition the trap after each analysis at a temperature and time sufficient to prevent detectable concentrations of the analytes or contaminants in successive analyses.</P>
                        <P>7.2 Connect the purge-and-trap system to the gas chromatograph. The gas chromatograph should be operated using temperature and flow rate conditions equivalent to those given in the footnotes to Table 3. Alternative temperature and flow rate conditions may be used provided that performance requirements in this method are met.</P>
                        <P>7.3 Internal standard calibration.</P>
                        <P>7.3.1 Internal standards.</P>
                        <P>7.3.1.1 Select three or more internal standards similar in chromatographic behavior to the compounds of interest. Suggested internal standards are listed in Table 5. Use the base peak m/z as the primary m/z for quantification of the standards. If interferences are found at the base peak, use one of the next two most intense m/z's for quantitation. Demonstrate that measurements of the internal standards are not affected by method or matrix interferences.</P>
                        <P>7.3.1.2 To assure accurate analyte identification, particularly when selected ion monitoring (SIM) is used, it may be advantageous to include more internal standards than those suggested in Section 7.3.1.1. An analyte will be located most accurately if its retention time relative to an internal standard is in the range of 0.8 to 1.2.</P>
                        <P>7.3.1.3 Prepare a stock standard solution for each internal standard in methanol as described in Section 6.5, and prepare a solution for spiking the internal standards into all blanks, LCSs, and MS/MSDs. Prepare the spiking solution such that spiking a small volume will result in a constant concentration of the internal standards. For example, add 10 µL of a spiking solution containing the internal standards at a concentration of 15 µg/mL in methanol to a 5-mL aliquot of water to produce a concentration of 30 µg/L for each internal standard. Other concentrations may be used. The internal standard solution and the surrogate standard spiking solution (Section 6.7) may be combined, if desired. Store per section 6.5.4.</P>
                        <P>7.3.2 Calibration.</P>
                        <P>7.3.2.1 Calibration standards.</P>
                        <P>
                            7.3.2.1.1 Prepare calibration standards at a minimum of five concentration levels for each analyte of interest by adding appropriate volumes of one or more stock standards to a fixed volume (e.g., 40 mL) of reagent water in volumetric glassware. Fewer levels may be necessary for some analytes based on the sensitivity of the MS, but no 
                            <PRTPAGE P="253"/>
                            fewer than 3 levels may be used, and only the highest or lowest point(s) may be dropped from the calibration. One of the calibration standards should be at a concentration at or below the ML or as specified by a regulatory/control authority or in a permit. The ML value may be rounded to a whole number that is more convenient for preparing the standard, but must not exceed the ML values listed in Table 1 for those analytes which list ML values. Alternatively, the laboratory may establish the ML for each analyte based on the concentration of the lowest calibration standard in a series of standards produced in the laboratory or obtained from a commercial vendor, again, provided that the ML value does not exceed the MLs in Table 1, and provided that the resulting calibration meets the acceptance criteria in Section 7.3.4, based on the RSD, RSE, or R
                            <SU>2</SU>
                            . The concentrations of the higher standards should correspond to the expected range of concentrations found in real samples, or should define the working range of the GC/MS system for full-scan and/or SIM operation, as appropriate. A minimum of six concentration levels is required for a second order, non-linear (e.g., quadratic; ax
                            <SU>2</SU>
                             + bx + c = 0) calibration. Calibrations higher than second order are not allowed.
                        </P>
                        <P>7.3.2.1.2 To each calibration standard or standard mixture, add a known constant volume of the internal standard spiking solution (section 7.3.1.3) and surrogate standard spiking solution (section 6.7) or the combined internal standard solution and surrogate spiking solution (section 7.3.1.3). Aqueous standards may be stored up to 24 hours, if held in sealed vials with zero headspace. If not so stored, they must be discarded after one hour.</P>
                        <P>7.3.2.2 Prior to analysis of the calibration standards, analyze the BFB standard (section 6.8) and adjust the scan rate of the MS to produce a minimum of 5 mass spectra across the BFB GC peak, but do not exceed 2 seconds per scan. Adjust instrument conditions until the BFB criteria in Table 4 are met. Once the scan conditions are established, they must be used for analyses of all standards, blanks, and samples.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>The BFB spectrum may be evaluated by summing the intensities of the m/z's across the GC peak, subtracting the background at each m/z in a region of the chromatogram within 20 scans of but not including any part of the BFB peak. The BFB spectrum may also be evaluated by fitting a Gaussian to each m/z and using the intensity at the maximum for each Gaussian, or by integrating the area at each m/z and using the integrated areas. Other means may be used for evaluation of the BFB spectrum so long as the spectrum is not distorted to meet the criteria in Table 4.</P>
                        </NOTE>
                        <P>7.3.2.3 Analyze the mid-point standard and enter or review the retention time, relative retention time, mass spectrum, and quantitation m/z in the data system for each analyte of interest, surrogate, and internal standard. If additional analytes (Table 2) are to be quantified, include these analytes in the standard. The mass spectrum for each analyte must be comprised of a minimum of 2 m/z's; 3 to 5 m/z's assure more reliable analyte identification. Suggested quantitation m/z's are shown in Table 6 as the primary m/z. For analytes in Table 6 that do not have a secondary m/z, acquire a mass spectrum and enter one or more secondary m/z's for more reliable identification. If an interference occurs at the primary m/z, use one of the secondary m/z's or an alternative m/z. A single m/z only is required for quantitation.</P>
                        <P>7.3.2.4 For SIM operation, determine the analytes in each descriptor, the quantitation m/z for each analyte (the quantitation m/z can be the same as for full-scan operation; Section 7.3.2.3), the dwell time on each m/z for each analyte, and the beginning and ending retention time for each descriptor. Analyze the verification standard in scan mode to verify m/z's and establish retention times for the analytes. There must be a minimum of two m/z's for each analyte to assure analyte identification. To maintain sensitivity, the number of m/z's in a descriptor should be limited. For example, for a descriptor with 10 m/z's and a chromatographic peak width of 5 sec, a dwell time of 100 ms at each m/z would result in a scan time of 1 second and provide 5 scans across the GC peak. The quantitation m/z will usually be the most intense peak in the mass spectrum. The quantitation m/z and dwell time may be optimized for each analyte. The acquisition table used for SIM must take into account the mass defect (usually less than 0.2 Dalton) that can occur at each m/z monitored. Refer to the footnotes to Table 3 for establishing operating conditions and to section 7.3.2.2 for establishing scan conditions.</P>
                        <P>7.3.2.5 For combined scan and SIM operation, set up the scan segments and descriptors to meet requirements in sections 7.3.2.2-7.3.2.4. Analyze unfamiliar samples in the scan mode to assure that the analytes of interest are determined.</P>
                        <P>7.3.3 Analyze each calibration standard according to Section 10 and tabulate the area at the quantitation m/z against concentration for each analyte of interest, surrogate, and internal standard. Calculate the response factor (RF) for each compound at each concentration using Equation 1.</P>
                        <GPH SPAN="2" DEEP="29">
                            <PRTPAGE P="254"/>
                            <GID>ER28AU17.012</GID>
                        </GPH>
                        <FP SOURCE="FP-2">Where:</FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">s</E>
                             = Area of the characteristic m/z for the analyte to be measured.
                        </FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">is</E>
                             = Area of the characteristic m/z for the internal standard.
                        </FP>
                        <FP SOURCE="FP-2">
                            C
                            <E T="52">is</E>
                             = Concentration of the internal standard (µg/L).
                        </FP>
                        <FP SOURCE="FP-2">
                            C
                            <E T="52">s</E>
                             = Concentration of the analyte to be measured (µg/L).
                        </FP>
                        <P>
                            7.3.4 Calculate the mean (average) and relative standard deviation (RSD) of the response factors. If the RSD is less than 35%, the RF can be assumed to be invariant and the average RF can be used for calculations. Alternatively, the results can be used to fit a linear or quadratic regression of response ratios, A
                            <E T="52">s</E>
                            /A
                            <E T="52">is</E>
                            , vs. concentration ratios Cs/Cis. If used, the regression must be weighted inversely proportional to concentration (1/C). The coefficient of determination (R
                            <SU>2</SU>
                            ) of the weighted regression must be greater than 0.920 (this value roughly corresponds to the RSD limit of 35%). Alternatively, the relative standard error (Reference 10) may be used as an acceptance criterion. As with the RSD, the RSE must be less than 35%. If an RSE less than 35% cannot be achieved for a quadratic regression, system performance is unacceptable, and the system must be adjusted and re-calibrated.
                        </P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>Using capillary columns and current instrumentation, it is quite likely that a laboratory can calibrate the target analytes in this method and achieve a linearity metric (either RSD or RSE) well below 35%. Therefore, laboratories are permitted to use more stringent acceptance criteria for calibration than described here, for example, to harmonize their application of this method with those from other sources.</P>
                        </NOTE>
                        <P>7.4 Calibration verification—Because the analytical system is calibrated by purge of the analytes from water, calibration verification is performed using the laboratory control sample (LCS). See section 8.4 for requirements for calibration verification using the LCS, and the Glossary for further definition.</P>
                        <HD SOURCE="HD3">8. Quality Control</HD>
                        <P>8.1 Each laboratory that uses this method is required to operate a formal quality assurance program. The minimum requirements of this program consist of an initial demonstration of laboratory capability and ongoing analysis of spiked samples and blanks to evaluate and document data quality (40 CFR 136.7). The laboratory must maintain records to document the quality of data generated. Results of ongoing performance tests are compared with established QC acceptance criteria to determine if the results of analyses meet performance requirements of this method. When results of spiked samples do not meet the QC acceptance criteria in this method, a quality control check sample (laboratory control sample; LCS) must be analyzed to confirm that the measurements were performed in an in-control mode of operation. A laboratory may develop its own performance criteria (as QC acceptance criteria), provided such criteria are as or more restrictive than the criteria in this method.</P>
                        <P>8.1.1 The laboratory must make an initial demonstration of capability (DOC) to generate acceptable precision and recovery with this method. This demonstration is detailed in Section 8.2. On a continuing basis, the laboratory must repeat demonstration of capability (DOC) at least annually.</P>
                        <P>8.1.2 In recognition of advances that are occurring in analytical technology, and to overcome matrix interferences, the laboratory is permitted certain options (section 1.5 and 40 CFR 136.6(b)) to improve separations or lower the costs of measurements. These options may include an alternative purge-and-trap device, and changes in both column and type of mass spectrometer (see 40 CFR 136.6(b)(4)(xvi)). Alternative determinative techniques, such as substitution of spectroscopic or immunoassay techniques, and changes that degrade method performance, are not allowed. If an analytical technique other than GC/MS is used, that technique must have a specificity equal to or greater than the specificity of GC/MS for the analytes of interest. The laboratory is also encouraged to participate in inter-comparison and performance evaluation studies (see section 8.8).</P>
                        <P>
                            8.1.2.1 Each time a modification is made to this method, the laboratory is required to repeat the procedure in section 8.2. If the detection limit of the method will be affected by the change, the laboratory must demonstrate that the MDLs (40 CFR part 136, appendix B) are lower than one-third the regulatory compliance limit or the MDLs in this method, whichever are greater. If calibration will be affected by the change, the instrument must be recalibrated per section 7. Once the modification is demonstrated to produce results equivalent or superior to results produced by this method, that modification may be used routinely thereafter, so long as the other requirements in this method are met (e.g., matrix spike/matrix spike 
                            <PRTPAGE P="255"/>
                            duplicate recovery and relative percent difference).
                        </P>
                        <P>8.1.2.1.1 If a modification is to be applied to a specific discharge, the laboratory must prepare and analyze matrix spike/matrix spike duplicate (MS/MSD) samples (Section 8.3) and LCS samples (section 8.4). The laboratory must include internal standards and surrogates (section 8.7) in each of the samples. The MS/MSD and LCS samples must be fortified with the analytes of interest (section 1.3.). If the modification is for nationwide use, MS/MSD samples must be prepared from a minimum of nine different discharges (See section 8.1.2.1.2), and all QC acceptance criteria in this method must be met. This evaluation only needs to be performed once, other than for the routine QC required by this method (for example it could be performed by the vendor of the alternative materials) but any laboratory using that specific material must have the results of the study available. This includes a full data package with the raw data that will allow an independent reviewer to verify each determination and calculation performed by the laboratory (see section 8.1.2.2.5, items (a)-(l)).</P>
                        <P>8.1.2.1.2 Sample matrices on which MS/MSD tests must be performed for nationwide use of an allowed modification:</P>
                        <P>(a) Effluent from a publicly owned treatment works (POTW).</P>
                        <P>(b) ASTM D5905 Standard Specification for Substitute Wastewater.</P>
                        <P>(c) Sewage sludge, if sewage sludge will be in the permit.</P>
                        <P>(d) ASTM D1141 Standard Specification for Substitute Ocean Water, if ocean water will be in the permit.</P>
                        <P>
                            (e) Untreated and treated wastewaters up to a total of nine matrix types (see 
                            <E T="03">https://www.epa.gov/eg/industrial-effluent-guidelines</E>
                             for a list of industrial categories with existing effluent guidelines).
                        </P>
                        <P>(i) At least one of the above wastewater matrix types must have at least one of the following characteristics:</P>
                        <P>(A) Total suspended solids greater than 40 mg/L.</P>
                        <P>(B) Total dissolved solids greater than 100 mg/L.</P>
                        <P>(C) Oil and grease greater than 20 mg/L.</P>
                        <P>(D) NaCl greater than 120 mg/L.</P>
                        <P>(E) CaCO3 greater than 140 mg/L.</P>
                        <P>(ii) Results of MS/MSD tests must meet QC acceptance criteria in section 8.3.</P>
                        <P>(f) A proficiency testing (PT) sample from a recognized provider, in addition to tests of the nine matrices (section 8.1.2.1.1).</P>
                        <P>8.1.2.2 The laboratory is required to maintain records of modifications made to this method. These records include the following, at a minimum:</P>
                        <P>8.1.2.2.1 The names, titles, and business street addresses, telephone numbers, and email addresses of the analyst(s) that performed the analyses and modification, and of the quality control officer that witnessed and will verify the analyses and modifications.</P>
                        <P>8.1.2.2.2 A list of analytes, by name and CAS Registry Number.</P>
                        <P>8.1.2.2.3 A narrative stating reason(s) for the modifications.</P>
                        <P>8.1.2.2.4 Results from all quality control (QC) tests comparing the modified method to this method, including:</P>
                        <P>(a) Calibration (section 7).</P>
                        <P>(b) Calibration verification/LCS (section 8.4).</P>
                        <P>(c) Initial demonstration of capability (section 8.2).</P>
                        <P>(d) Analysis of blanks (section 8.5).</P>
                        <P>(e) Matrix spike/matrix spike duplicate analysis (section 8.3).</P>
                        <P>(f) Laboratory control sample analysis (section 8.4).</P>
                        <P>8.1.2.2.5 Data that will allow an independent reviewer to validate each determination by tracing the instrument output (peak height, area, or other signal) to the final result. These data are to include:</P>
                        <P>(a) Sample numbers and other identifiers.</P>
                        <P>(b) Analysis dates and times.</P>
                        <P>(c) Analysis sequence/run chronology.</P>
                        <P>(d) Sample volume (Section 10).</P>
                        <P>(e) Sample dilution (Section 13.2).</P>
                        <P>(f) Instrument and operating conditions.</P>
                        <P>(g) Column (dimensions, material, etc).</P>
                        <P>(h) Operating conditions (temperature program, flow rate, etc).</P>
                        <P>(i) Detector (type, operating conditions, etc).</P>
                        <P>(j) Chromatograms, mass spectra, and other recordings of raw data.</P>
                        <P>(k) Quantitation reports, data system outputs, and other data to link the raw data to the results reported.</P>
                        <P>(l) A written Standard Operating Procedure (SOP).</P>
                        <P>8.1.2.2.6 Each individual laboratory wishing to use a given modification must perform the start-up tests in section 8.1.2 (e.g., DOC, MDL), with the modification as an integral part of this method prior to applying the modification to specific discharges. Results of the DOC must meet the QC acceptance criteria in Table 7 for the analytes of interest (section 1.3), and the MDLs must be equal to or lower than the MDLs in Table3 for the analytes of interest</P>
                        <P>8.1.3 Before analyzing samples, the laboratory must analyze a blank to demonstrate that interferences from the analytical system, labware, and reagents are under control. Each time a batch of samples is analyzed or reagents are changed, a blank must be analyzed as a safeguard against laboratory contamination. Requirements for the blank are given in section 8.5.</P>
                        <P>
                            8.1.4 The laboratory must, on an ongoing basis, spike and analyze samples to monitor 
                            <PRTPAGE P="256"/>
                            and evaluate method and laboratory performance on the sample matrix. The procedure for spiking and analysis is given in section 8.3.
                        </P>
                        <P>8.1.5 The laboratory must, on an ongoing basis, demonstrate through analysis of a quality control check sample (laboratory control sample, LCS; on-going precision and recovery sample, OPR) that the measurement system is in control. This procedure is given in section 8.4.</P>
                        <P>8.1.6 The laboratory must maintain performance records to document the quality of data that is generated. This procedure is given in section 8.8.</P>
                        <P>8.1.7 The large number of analytes tested in performance tests in this method present a substantial probability that one or more will fail acceptance criteria when many analytes are tested simultaneously, and a re-test is allowed if this situation should occur. If, however, continued re-testing results in further repeated failures, the laboratory must document and report the failures (e.g., as qualifiers on results), unless the failures are not required to be reported as determined by the regulatory/control authority. Results associated with a QC failure for an analyte regulated in a discharge cannot be used to demonstrate regulatory compliance. QC failures do not relieve a discharger or permittee of reporting timely results.</P>
                        <P>8.2 Initial demonstration of capability (DOC)—To establish the ability to generate acceptable recovery and precision, the laboratory must perform the DOC in sections 8.2.1 through 8.2.6 for the analytes of interest. The laboratory must also establish MDLs for the analytes of interest using the MDL procedure at 40 CFR part 136, appendix B. The laboratory's MDLs must be equal to or lower than those listed in Table 1 for those analytes which list MDL values, or lower than one-third the regulatory compliance limit, whichever is greater. For MDLs not listed in Table 1, the laboratory must determine the MDLs using the MDL procedure at 40 CFR part 136, appendix B under the same conditions used to determine the MDLs for the analytes listed in Table 1. All procedures used in the analysis must be included in the DOC.</P>
                        <P>8.2.1 For the DOC, a QC check sample concentrate (LCS concentrate) containing each analyte of interest (section 1.3) is prepared in methanol. The QC check sample concentrate must be prepared independently from those used for calibration, but may be from the same source as the second-source standard used for calibration verification/LCS (sections 7.4 and 8.4). The concentrate should produce concentrations of the analytes of interest in water at the mid-point of the calibration range, and may be at the same concentration as the LCS (section 8.4).</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>QC check sample concentrates are no longer available from EPA.</P>
                        </NOTE>
                        <P>8.2.2 Using a pipet or micro-syringe, prepare four LCSs by adding an appropriate volume of the concentrate to each of four aliquots of reagent water. The volume of reagent water must be the same as the volume that will be used for the sample, blank (section 8.5), and MS/MSD (section 8.3). A volume of 5 mL and a concentration of 20 µg/L were used to develop the QC acceptance criteria in Table 7. An alternative volume and sample concentration may be used, provided that all QC tests are performed and all QC acceptance criteria in this method are met. Also add an aliquot of the surrogate spiking solution (section 6.7) and internal standard spiking solution (section 7.3.1.3) to the reagent-water aliquots.</P>
                        <P>8.2.3 Analyze the four LCSs according to the method beginning in section 10.</P>
                        <P>
                            8.2.4 Calculate the average percent recovery (
                            <E T="7501">X</E>
                            ) and the standard deviation of the percent recovery (s) for each analyte using the four results.
                        </P>
                        <P>
                            8.2.5 For each analyte, compare s and 
                            <E T="7501">X</E>
                             with the corresponding acceptance criteria for precision and recovery in Table 7. For analytes in Tables 1 and 2 not listed in Table 7, DOC QC acceptance criteria must be developed by the laboratory. EPA has provided guidance for development of QC acceptance criteria (References 11 and 12). Alternatively, acceptance criteria for analytes not listed in Table 7 may be based on laboratory control charts. If s and 
                            <E T="7501">X</E>
                             for all analytes of interest meet the acceptance criteria, system performance is acceptable and analysis of blanks and samples may begin. If any individual s exceeds the precision limit or any individual 
                            <E T="7501">X</E>
                             falls outside the range for recovery, system performance is unacceptable for that analyte.
                        </P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>The large number of analytes in Tables 1 and 2 present a substantial probability that one or more will fail at least one of the acceptance criteria when many or all analytes are determined simultaneously. Therefore, the analyst is permitted to conduct a “re-test” as described in section 8.2.6.</P>
                        </NOTE>
                        <P>8.2.6 When one or more of the analytes tested fail at least one of the acceptance criteria, repeat the test for only the analytes that failed. If results for these analytes pass, system performance is acceptable and analysis of samples and blanks may proceed. If one or more of the analytes again fail, system performance is unacceptable for the analytes that failed the acceptance criteria. Correct the problem and repeat the test (section 8.2). See section 8.1.7 for disposition of repeated failures.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>To maintain the validity of the test and re-test, system maintenance and/or adjustment is not permitted between this pair of tests.</P>
                        </NOTE>
                        <P>
                            8.3 Matrix spike and matrix spike duplicate (MS/MSD)—The purpose of the MS/MSD 
                            <PRTPAGE P="257"/>
                            requirement is to provide data that demonstrate the effectiveness of the method as applied to the samples in question by a given laboratory, and both the data user (discharger, permittee, regulated entity, regulatory/control authority, customer, other) and the laboratory share responsibility for provision of such data. The data user should identify the sample and the analytes of interest (section 1.3) to be spiked and provide sufficient sample volume to perform MS/MSD analyses. The laboratory must, on an ongoing basis, spike at least 5% of the samples in duplicate from each discharge being monitored to assess accuracy (recovery and precision). If direction cannot be obtained from the data user, the laboratory must spike at least one sample in duplicate per extraction batch of up to 20 samples with the analytes in Table 1. Spiked sample results should be reported only to the data user whose sample was spiked, or as requested or required by a regulatory/control authority, or in a permit.
                        </P>
                        <P>8.3.1 If, as in compliance monitoring, the concentration of a specific analyte will be checked against a regulatory concentration limit, the concentration of the spike should be at that limit; otherwise, the concentration of the spike should be one to five times higher than the background concentration determined in section 8.3.2, at or near the mid-point of the calibration range, or at the concentration in the LCS (section 8.4) whichever concentration would be larger.</P>
                        <P>
                            8.3.2 Analyze one sample aliquot to determine the background concentration (B) of the each analyte of interest. If necessary, prepare a new check sample concentrate (section 8.2.1) appropriate for the background concentration. Spike and analyze two additional sample aliquots, and determine the concentration after spiking (A
                            <E T="52">1</E>
                             and A
                            <E T="52">2</E>
                            ) of each analyte. Calculate the percent recoveries (P
                            <E T="52">1</E>
                             and P
                            <E T="52">2</E>
                            ) as 100 (A
                            <E T="52">1</E>
                            −B)/T and 100 (A
                            <E T="52">2</E>
                            −B)/T, where T is the known true value of the spike. Also calculate the relative percent difference (RPD) between the concentrations (A
                            <E T="52">1</E>
                             and A
                            <E T="52">2</E>
                            ) as 200 |A
                            <E T="52">1</E>
                            −A
                            <E T="52">2</E>
                            |/(A
                            <E T="52">1</E>
                             + A
                            <E T="52">2</E>
                            ). If necessary, adjust the concentrations used to calculate the RPD to account for differences in the volumes of the spiked aliquots.
                        </P>
                        <P>
                            8.3.3 Compare the percent recoveries (P
                            <E T="52">1</E>
                             and P
                            <E T="52">2</E>
                            ) and the RPD for each analyte in the MS/MSD aliquots with the corresponding QC acceptance criteria in Table 7. A laboratory may develop and apply QC acceptance criteria more restrictive than the criteria in Table 7, if desired.
                        </P>
                        <P>8.3.3.1 If any individual P falls outside the designated range for recovery in either aliquot, or the RPD limit is exceeded, the result for the analyte in the unspiked sample is suspect. See Section 8.1.7 for disposition of failures.</P>
                        <P>
                            8.3.3.2 The acceptance criteria in Table 7 were calculated to include an allowance for error in measurement of both the background and spike concentrations, assuming a spike to background ratio of 5:1. This error will be accounted for to the extent that the spike to background ratio approaches 5:1 (Reference 13) and is applied to spike concentrations of 20 µg/L and higher. If spiking is performed at a concentration lower than 20 µg/L, the laboratory must use the QC acceptance criteria in Table 7, the optional QC acceptance criteria calculated for the specific spike concentration in Table 8, or optional in-house criteria (Section 8.3.4). To use the acceptance criteria in Table 8: (1) Calculate recovery (X') using the equation in Table 8, substituting the spike concentration (T) for C; (2) Calculate overall precision (S') using the equation in Table 8, substituting X' for 
                            <E T="7501">X</E>
                            ; (3) Calculate the range for recovery at the spike concentration as (100 X'/T) ± 2.44(100 S'/T)% (Reference 4). For analytes of interest in Tables 1 and 2 not listed in Table 7, QC acceptance criteria must be developed by the laboratory. EPA has provided guidance for development of QC acceptance criteria (References 11 and 12). Alternatively, acceptance criteria may be based on laboratory control charts. In-house LCS QC acceptance criteria must be updated at least every two years.
                        </P>
                        <P>8.3.4 After analysis of a minimum of 20 MS/MSD samples for each target analyte and surrogate, and if the laboratory chooses to develop and apply in-house QC limits, the laboratory should calculate and apply in-house QC limits for recovery and RPD of future MS/MSD samples (section 8.3). The QC limits for recovery are calculated as the mean observed recovery ± 3 standard deviations, and the upper QC limit for RPD is calculated as the mean RPD plus 3 standard deviations of the RPDs. The in-house QC limits must be updated at least every two years and re-established after any major change in the analytical instrumentation or process. If in-house QC limits are developed, at least 80% of the analytes tested in the MS/MSD must have in-house QC acceptance criteria that are tighter than those in Table 7 and the remaining analytes (those other than the analytes included in the 80%) must meet the acceptance criteria in Table 7. If an in-house QC limit for the RPD is greater than the limit in Table 7, then the limit in Table 7 must be used. Similarly, if an in-house lower limit for recovery is below the lower limit in Table 7, then the lower limit in Table 7 must be used, and if an in-house upper limit for recovery is above the upper limit in Table 7, then the upper limit in Table 7 must be used.</P>
                        <P>
                            8.4 Calibration verification/laboratory control sample (LCS)—The working calibration curve or RF must be verified immediately after calibration and at the beginning of each 12-hour shift by the measurement of an LCS. The LCS must be from a source different from the source used for 
                            <PRTPAGE P="258"/>
                            calibration (section 7.3.2.1), but may be the same as the sample prepared for the DOC (section 8.2.1).
                        </P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>The 12-hour shift begins after analysis of BFB, the LCS, and the blank, and ends 12 hours later. BFB, the LCS, and blank are outside of the 12-hour shift (Section 11.4). The MS and MSD are treated as samples and are analyzed within the 12-hour shift.</P>
                        </NOTE>
                        <P>8.4.1 Prepare the LCS by adding QC check sample concentrate (section 8.2.1) to reagent water. Include all analytes of interest (Section 1.3) in the LCS. The volume of reagent water must be the same as the volume used for the sample, blank (Section 8.5), and MS/MSD (section 8.3). Also add an aliquot of the surrogate solution (Section 6.7) and internal standard solution (section 7.3.1.3). The concentration of the analytes in reagent water should be the same as the concentration in the DOC (section 8.2.2).</P>
                        <P>
                            8.4.2 Analyze the LCS prior to analysis of field samples in the batch of samples analyzed during the 12-hour shift (see the 
                            <E T="04">Note</E>
                             at section 8.4). Determine the concentration (A) of each analyte. Calculate the percent recovery (Q) as 100 (A/T) %, where T is the true value of the concentration in the LCS.
                        </P>
                        <P>8.4.3 Compare the percent recovery (Q) for each analyte with its corresponding QC acceptance criterion in Table 7. For analytes of interest in Tables 1 and 2 not listed in Table 7, use the QC acceptance criteria developed for the LCS (section 8.4.5). If the recoveries for all analytes of interest fall within their respective QC acceptance criteria, analysis of blanks and field samples may proceed. If any individual Q falls outside the range, proceed according to section 8.4.4.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>The large number of analytes in Tables 1—2 present a substantial probability that one or more will fail the acceptance criteria when all analytes are tested simultaneously. Because a re-test is allowed in event of failure (sections 8.1.7 and 8.4.3), it may be prudent to analyze two LCSs together and evaluate results of the second analysis against the QC acceptance criteria only if an analyte fails the first test.</P>
                        </NOTE>
                        <P>8.4.4 Repeat the test only for those analytes that failed to meet the acceptance criteria (Q). If these analytes now pass, system performance is acceptable and analysis of blanks and samples may proceed. Repeated failure, however, will confirm a general problem with the measurement system. If this occurs, repeat the test (section 8.4.2). using a fresh LCS (section 8.2.2) or an LCS prepared with a fresh QC check sample concentrate (section 8.2.1), or perform and document system repair. Subsequent to repair, repeat the calibration verification/LCS test (section 8.4). If the acceptance criteria for Q cannot be met, re-calibrate the instrument (section 7). See section 8.1.7 for disposition of repeated failures.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>To maintain the validity of the test and re-test, system maintenance and/or adjustment is not permitted between the pair of tests.</P>
                        </NOTE>
                        <P>8.4.5 After analysis of 20 LCS samples, and if the laboratory chooses to develop and apply in-house QC limits, the laboratory should calculate and apply in-house QC limits for recovery to future LCS samples (section 8.4). Limits for recovery in the LCS calculated as the mean recovery ±3 standard deviations. A minimum of 80% of the analytes tested for in the LCS must have QC acceptance criteria tighter than those in Table 7, and the remaining analytes (those other than the analytes included in the 80%) must meet the acceptance criteria in Table 7. If an in-house lower limit for recovery is lower than the lower limit in Table 7, the lower limit in Table 7 must be used, and if an in-house upper limit for recovery is higher than the upper limit in Table 7, the upper limit in Table 7 must be used. Many of the analytes and surrogates do not have acceptance criteria. The laboratory should use 60-140% as interim acceptance criteria for recoveries of spiked analytes that do not have recovery limits specified in Table 7, and least 80% of the analytes should meet the 60-140% interim criteria until in-house LCS limits are developed. Alternatively, acceptance criteria for analytes that do not have recovery limits in Table 7 may be based on laboratory control charts. In-house QC acceptance criteria must be updated at least every two years.</P>
                        <P>8.5 Blank—A blank must be analyzed prior to each 12-hour shift to demonstrate freedom from contamination. A blank must also be analyzed after a sample containing a high concentration of an analyte or potentially interfering compound to demonstrate freedom from carry-over.</P>
                        <P>8.5.1 Spike the internal standards and surrogates into the blank. Analyze the blank immediately after analysis of the LCS (Section 8.4) and prior to analysis of the MS/MSD and samples to demonstrate freedom from contamination.</P>
                        <P>
                            8.5.2 If any analyte of interest is found in the blank: At a concentration greater than the MDL for the analyte, at a concentration greater than one-third the regulatory compliance limit, or at a concentration greater than one-tenth the concentration in a sample analyzed during the 12-hour shift (section 8.4), 
                            <E T="03">whichever is greater;</E>
                             analysis of samples must be halted and samples affected by the blank must be re-analyzed. If, however, continued re-testing results in repeated blank contamination, the laboratory must document and report the failures (e.g., as qualifiers on results), unless the failures are not required to be reported as determined by the regulatory/control authority. Results associated with blank contamination for an analyte regulated in a discharge cannot be used to demonstrate regulatory compliance. 
                            <PRTPAGE P="259"/>
                            QC failures do not relieve a discharger or permittee of reporting timely results.
                        </P>
                        <P>8.6 Surrogate recoveries—The laboratory must evaluate surrogate recovery data in each sample against its in-house surrogate recovery limits for surrogates that do not have acceptance criteria in Table 7. The laboratory may use 60-140% as interim acceptance criteria for recoveries for surrogates not listed in Table 5. At least 80% of the surrogates must meet the 60-140% interim criteria until in-house limits are developed. Alternatively, surrogate recovery limits may be developed from laboratory control charts.</P>
                        <P>8.6.1 Spike the surrogates into all samples, blanks, LCSs, and MS/MSDs. Compare surrogate recoveries against the QC acceptance criteria in Table 7. For surrogates in Table 5 without QC acceptance criteria in Table 7, and for other surrogates that may be used by the laboratory, limits must be developed by the laboratory. EPA has provided guidance for development of QC acceptance criteria (References 11 and 12). Alternatively, surrogate recovery limits may be developed from laboratory control charts. In-house QC acceptance criteria must be updated at least every two years.</P>
                        <P>8.6.2 If any recovery fails its criteria, attempt to find and correct the cause of the failure. See section 8.1.7 for disposition of failures.</P>
                        <P>8.7 Internal standard responses.</P>
                        <P>8.7.1 Calibration verification/LCS—The responses (GC peak heights or areas) of the internal standards in the calibration verification/LCS must be within 50% to 200% (1/2 to 2×) of their respective responses in the mid-point calibration standard. If they are not, repeat the LCS test using a fresh QC check sample (section 8.4.1) or perform and document system repair. Subsequent to repair, repeat the calibration verification/LCS test (section 8.4). If the responses are still not within 50% to 200%, re-calibrate the instrument (section 7) and repeat the calibration verification/LCS test.</P>
                        <P>8.7.2 Samples, blanks, and MS/MSDs—The responses (GC peak heights or areas) of each internal standard in each sample, blank, and MS/MSD must be within 50% to 200% (1/2 to 2×) of its respective response in the mid-point calibration standard. If, as a group, all internal standards are not within this range, perform and document system repair, repeat the calibration verification/LCS test (section 8.4), and re-analyze the affected samples. If a single internal standard is not within the 50% to 200% range, use an alternative internal standard for quantitation of the analyte referenced to the affected internal standard. It may be necessary to use the data system to calculate a new response factor from calibration data for the alternative internal standard/analyte pair. If an internal standard fails the 50-200% criteria and no analytes are detected in the sample, ignore the failure or report it if required by the regulatory/control authority.</P>
                        <P>
                            8.8 As part of the QC program for the laboratory, control charts or statements of accuracy for wastewater samples must be assessed and records maintained periodically (see 40 CFR 136.7(c)(1)(viii)). After analysis of five or more spiked wastewater samples as in section 8.3, calculate the average percent recovery (P
                            <E T="52">X</E>
                            ) and the standard deviation of the percent recovery (sp). Express the accuracy assessment as a percent interval from P
                            <E T="52">X</E>
                            −2
                            <E T="52">sp</E>
                             to P
                            <E T="52">X</E>
                             + 2
                            <E T="52">sp</E>
                            . For example, if P
                            <E T="52">X</E>
                             = 90% and sp = 10%, the accuracy interval is expressed as 70-110%. Update the accuracy assessment for each analyte on a regular basis (e.g., after each 5-10 new accuracy measurements). If desired, statements of accuracy for laboratory performance, independent of performance on samples, may be developed using LCSs.
                        </P>
                        <P>8.9 It is recommended that the laboratory adopt additional quality assurance practices for use with this method. The specific practices that are most productive depend upon the needs of the laboratory and the nature of the samples. Field duplicates may be analyzed to assess the precision of environmental measurements. Whenever possible, the laboratory should analyze standard reference materials and participate in relevant performance evaluation studies.</P>
                        <HD SOURCE="HD3">9. Sample Collection, Preservation, and Handling</HD>
                        <P>9.1 Collect the sample as a grab sample in a glass container having a total volume of at least 25 mL. Fill the sample bottle just to overflowing in such a manner that no air bubbles pass through the sample as the bottle is being filled. Seal the bottle so that no air bubbles are entrapped in it. If needed, collect additional sample(s) for the MS/MSD (section 8.3).</P>
                        <P>
                            9.2 Ice or refrigerate samples at ≤6 °C from the time of collection until analysis, but do not freeze. If residual chlorine is present, add sodium thiosulfate preservative (10 mg/40 mL is sufficient for up to 5 ppm Cl
                            <E T="52">2</E>
                            ) to the empty sample bottle just prior to shipping to the sampling site. Any method suitable for field use may be employed to test for residual chlorine (Reference 14). Field test kits are also available for this purpose. If sodium thiosulfate interferes in the determination of the analytes, an alternative preservative (e.g., ascorbic acid or sodium sulfite) may be used. If preservative has been added, shake the sample vigorously for one minute. Maintain the hermetic seal on the sample bottle until time of analysis.
                        </P>
                        <P>9.3 If acrolein is to be determined, analyze the sample within 3 days. To extend the holding time to 14 days, acidify a separate sample to pH 4-5 with HCl using the procedure in section 9.7.</P>
                        <P>
                            9.4 Experimental evidence indicates that some aromatic compounds, notably benzene, 
                            <PRTPAGE P="260"/>
                            toluene, and ethyl benzene are susceptible to rapid biological degradation under certain environmental conditions (Reference 3). Refrigeration alone may not be adequate to preserve these compounds in wastewaters for more than seven days. To extend the holding time for aromatic compounds to 14 days, acidify the sample to approximately pH 2 using the procedure in section 9.7.
                        </P>
                        <P>9.5 If halocarbons are to be determined, either use the acidified aromatics sample in section 9.4 or acidify a separate sample to a pH of about 2 using the procedure in section 9.7.</P>
                        <P>9.6 The ethers listed in Table 2 are prone to hydrolysis at pH 2 when a heated purge is used. Aqueous samples should not be acid preserved if these ethers are of interest, or if the alcohols they would form upon hydrolysis are of interest and the ethers are anticipated to present.</P>
                        <P>9.7 Sample acidification—Collect about 500 mL of sample in a clean container and adjust the pH of the sample to 4-5 for acrolein (section 9.3), or to about 2 for the aromatic compounds (section 9.4) by adding 1+1 HCl while swirling or stirring. Check the pH with narrow range pH paper. Fill a sample container as described in section 9.1. Alternatively, fill a precleaned vial (section 5.1.1) that contains approximately 0.25 mL of 1+1 HCl with sample as in section 9.1. If preserved using this alternative procedure, the pH of the sample can be verified to be &lt;2 after some of the sample is removed for analysis. Acidification will destroy 2-chloroethylvinyl ether; therefore, determine 2-chloroethylvinyl ether from the unacidified sample.</P>
                        <P>9.8 All samples must be analyzed within 14 days of collection (Reference 3), unless specified otherwise in sections 9.3-9.7.</P>
                        <HD SOURCE="HD3">10. Sample Purging and Gas Chromatography</HD>
                        <P>10.1 The footnote to Table 3 gives the suggested GC column and operating conditions MDLs and MLs for many of the analytes are given in Table 1. Retention times for many of the analytes are given in Table 3. Sections 10.2 through 10.7 suggest procedures that may be used with a manual purge-and-trap system. Auto-samplers and other columns or chromatographic conditions may be used if requirements in this method are met. Prior to performing analyses, and between analyses, it may be necessary to bake the purge-and-trap and GC systems (section 3.3).</P>
                        <P>10.2 Attach the trap inlet to the purging device, and set the purge-and-trap system to purge. Open the syringe valve located on the purging device sample introduction needle.</P>
                        <P>10.3 Allow the sample to come to ambient temperature prior to pouring an aliquot into the syringe. Remove the plunger from a syringe and attach a closed syringe valve. Open the sample bottle (or standard) and carefully pour the sample into the syringe barrel to just short of overflowing. Replace the syringe plunger and compress the sample. Open the syringe valve and vent any residual air while adjusting the sample volume. Since this process of taking an aliquot destroys the validity of the sample for future analysis, the analyst should fill a second syringe at this time to protect against possible loss of data. Add the surrogate spiking solution (section 6.7) and internal standard spiking solution (section 7.3.1.3) through the valve bore, then close the valve. The surrogate and internal standards may be mixed and added as a single spiking solution. Autosamplers designed for purge-and-trap analysis of volatiles also may be used.</P>
                        <P>10.4 Attach the syringe valve assembly to the syringe valve on the purging device. Open the syringe valve and inject the sample into the purging chamber.</P>
                        <P>10.5 Close both valves and purge the sample at a temperature, flow rate, and duration sufficient to purge the less-volatile analytes onto the trap, yet short enough to prevent blowing the more-volatile analytes through the trap. The temperature, flow rate, and time should be determined by test. The same purge temperature, flow rate, and purge time must be used for all calibration, QC, and field samples.</P>
                        <P>10.6 After the purge, set the purge-and-trap system to the desorb mode, and begin the temperature program of the gas chromatograph. Introduce the trapped materials to the GC column by rapidly heating the trap to the desorb temperature while backflushing the trap with carrier gas at the flow rate and for the time necessary to desorb the analytes of interest. The optimum temperature, flow rate, and time should be determined by test. The same temperature, desorb time, and flow rate must be used for all calibration, QC, and field samples. If heating of the trap does not result in sharp peaks for the early eluting analytes, the GC column may be used as a secondary trap by cooling to an ambient or subambient temperature. To avoid carry-over and interferences, maintain the trap at the desorb temperature and flow rate until the analytes, interfering compounds, and excess water are desorbed. The optimum conditions should be determined by test.</P>
                        <P>10.7 Start MS data acquisition at the start of the desorb cycle and stop data collection when the analytes of interest, potentially interfering compounds, and water have eluted (see the footnote to Table 3 for conditions).</P>
                        <P>10.8 Cool the trap to the purge temperature and return the trap to the purge mode. When the trap is cool, the next sample can be analyzed.</P>
                        <HD SOURCE="HD3">11. Performance Tests</HD>
                        <P>
                            11.1 At the beginning of each 12-hour shift during which standards or samples will be 
                            <PRTPAGE P="261"/>
                            analyzed, perform the tests in sections 11.2-11.3 to verify system performance. Use the instrument operating conditions in the footnotes to Table 3 for these performance tests. Alternative conditions may be used so as long as all QC requirements are met.
                        </P>
                        <P>11.2 BFB—Inject 50 ng of BFB solution directly on the column. Alternatively, add BFB to reagent water or an aqueous standard such that 50 ng or less of BFB will be introduced into the GC. Analyze according to section 10. Confirm that all criteria in section 7.3.2.2 and Table 4 are met. If all criteria are not met, perform system repair, retune the mass spectrometer, and repeat the test until all criteria are met.</P>
                        <P>11.3 Verify calibration with the LCS (section 8.4) after the criteria for BFB are met (Reference 15) and prior to analysis of a blank or sample. After verification, analyze a blank (section 8.5) to demonstrate freedom from contamination and carry-over at the MDL. Tests for BFB, the LCS, and the blank are outside of the 12-hour shift, and the 12-hour shift includes samples and matrix spikes and matrix spike duplicates (section 8.4). The total time for analysis of BFB, the LCS, the blank, and the 12-hour shift must not exceed 14 hours.</P>
                        <HD SOURCE="HD3">12. Qualitative Identification</HD>
                        <P>12.1 Identification is accomplished by comparison of results from analysis of a sample or blank with data stored in the GC/MS data system (section 7.3.2.3). Identification of an analyte is confirmed per sections 12.1.1 through 12.1.4.</P>
                        <P>12.1.1 The signals for the quantitation and secondary m/z's stored in the data system (section 7.3.2.3) for each analyte of interest must be present and must maximize within the same two consecutive scans.</P>
                        <P>12.1.2 The retention time for the analyte should be within ± 10 seconds of the analyte in the LCS run at the beginning of the shift (section 8.4).</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>Retention time windows other than ± 10 seconds may be appropriate depending on the performance of the gas chromatograph or observed retention time drifts due to certain types of matrix effects. Relative retention time (RRT) may be used as an alternative to absolute retention times if retention time drift is a concern. RRT is a unitless quantity (see section 20.2), although some procedures refer to “RRT units” in providing the specification for the agreement between the RRT values in the sample and the LCS or other standard. When significant retention time drifts are observed, dilutions or spiked samples may help the analyst determine the effects of the matrix on elution of the target analytes and to assist in qualitative identification.</P>
                        </NOTE>
                        <P>
                            12.1.3 Either the background corrected EICP areas, or the corrected relative intensities of the mass spectral peaks at the GC peak maximum, must agree within 50% to 200% (
                            <FR>1/2</FR>
                             to 2 times) for the quantitation and secondary m/z's in the reference mass spectrum stored in the data system (section 7.3.2.3), or from a reference library. For example, if a peak has an intensity of 20% relative to the base peak, the analyte is identified if the intensity of the peak in the sample is in the range of 10% to 40% of the base peak.
                        </P>
                        <P>12.1.4 If the acquired mass spectrum is contaminated, or if identification is ambiguous, an experienced spectrometrist (section 1.6) must determine the presence or absence of the compound.</P>
                        <P>12.2 Structural isomers that produce very similar mass spectra should be identified as individual isomers if they have sufficiently different gas chromatographic retention times. Sufficient gas chromatographic resolution is achieved if the height of the valley between two isomer peaks is less than 50% of the average of the two peak heights. Otherwise, structural isomers are identified as isomeric pairs. The resolution should be verified on the mid-point concentration of the initial calibration as well as the laboratory designated continuing calibration verification level if closely eluting isomers are to be reported.</P>
                        <HD SOURCE="HD3">13. Calculations</HD>
                        <P>13.1 When an analyte has been identified, quantitation of that analyte is based on the integrated abundance from the EICP of the primary characteristic m/z in Table 5 or 6. Calculate the concentration using the response factor (RF) determined in section 7.3.3 and Equation 2. If a calibration curve was used, calculate the concentration using the regression equation for the curve. If the concentration of an analyte exceeds the calibration range, dilute the sample by the minimum amount to bring the concentration into the calibration range, and re-analyze. Determine a dilution factor (DF) from the amount of the dilution. For example, if the extract is diluted by a factor of 2, DF = 2.</P>
                        <GPH SPAN="2" DEEP="28">
                            <GID>ER28AU17.013</GID>
                        </GPH>
                        <PRTPAGE P="262"/>
                        <FP SOURCE="FP-2">Where:</FP>
                        <FP SOURCE="FP-2">
                            C
                            <E T="52">s</E>
                             = Concentration of the analyte in the sample, and the other terms are as defined in Section 7.3.3.
                        </FP>
                        <P>13.2 Reporting of results</P>
                        <P>As noted in section 1.4.1, EPA has promulgated this method at 40 CFR part 136 for use in wastewater compliance monitoring under the National Pollutant Discharge Elimination System (NPDES). The data reporting practices described here are focused on such monitoring needs and may not be relevant to other uses of this method.</P>
                        <P>13.2.1 Report results for wastewater samples in µg/L without correction for recovery. (Other units may be used if required by a permit.) Report all QC data with the sample results.</P>
                        <P>13.2.2 Reporting level. Unless otherwise specified in by a regulatory authority or in a discharge permit, results for analytes that meet the identification criteria are reported down to the concentration of the ML established by the laboratory through calibration of the instrument (see section 7.3.2 and the glossary for the derivation of the ML). EPA considers the terms “reporting limit,” “limit of quantitation,” “quantitation limit,” and “minimum level” to be synonymous.</P>
                        <P>13.2.2.1 Report a result for each analyte in each field sample or QC standard at or above the ML to 3 significant figures. Report a result for each analyte found in each field sample or QC standard below the ML as “&lt;ML,” where ML is the concentration of the analyte at the ML, or as required by the regulatory/control authority or permit. Report a result for each analyte in a blank at or above the MDL to 2 significant figures. Report a result for each analyte found in a blank below the MDL as “&lt;MDL,” where MDL is the concentration of the analyte at the MDL, or as required by the regulatory/control authority or permit.</P>
                        <P>13.2.2.2 In addition to reporting results for samples and blanks separately, the concentration of each analyte in a blank associated with the sample may be subtracted from the result for that sample, but only if requested or required by a regulatory authority or in a permit. In this case, both the sample result and the blank result must be reported together.</P>
                        <P>
                            13.2.2.3 Report a result for an analyte found in a sample that has been diluted at the least dilute level at which the area at the quantitation m/z is within the calibration range (
                            <E T="03">i.e.,</E>
                             above the ML for the analyte) and the MS/MSD recovery and RPD are within their respective QC acceptance criteria (Table 7). This may require reporting results for some analytes from different analyses.
                        </P>
                        <P>
                            13.2.3 Results from tests performed with an analytical system that is not in control (
                            <E T="03">i.e.,</E>
                             that does not meet acceptance criteria for any of the QC test in this method) must be documented and reported (e.g., as a qualifier on results), unless the failure is not required to be reported as determined by the regulatory/control authority. Results associated with a QC failure cannot be used to demonstrate regulatory compliance. QC failures do not relieve a discharger or permittee of reporting timely results. If the holding time would be exceeded for a re-analysis of the sample, the regulatory/control authority should be consulted for disposition.
                        </P>
                        <HD SOURCE="HD3">14. Method Performance</HD>
                        <P>14.1 This method was tested by 15 laboratories using reagent water, drinking water, surface water, and industrial wastewaters spiked at six concentrations over the range 5-600 µg/L (References 4 and 16). Single-operator precision, overall precision, and method accuracy were found to be directly related to the concentration of the analyte and essentially independent of the sample matrix. Linear equations to describe these relationships are presented in Table 8.</P>
                        <P>14.2 As noted in section 1.1, this method was validated through an interlaboratory study conducted in the early 1980s. However, the fundamental chemistry principles used in this method remain sound and continue to apply.</P>
                        <HD SOURCE="HD3">15. Pollution Prevention</HD>
                        <P>15.1 Pollution prevention encompasses any technique that reduces or eliminates the quantity or toxicity of waste at the point of generation. Many opportunities for pollution prevention exist in laboratory operations. EPA has established a preferred hierarchy of environmental management techniques that places pollution prevention as the management option of first choice. Whenever feasible, the laboratory should use pollution prevention techniques to address waste generation. When wastes cannot be reduced at the source, the Agency recommends recycling as the next best option.</P>
                        <P>15.2 The analytes in this method are used in extremely small amounts and pose little threat to the environment when managed properly. Standards should be prepared in volumes consistent with laboratory use to minimize the disposal of excess volumes of expired standards.</P>
                        <P>
                            15.3 For information about pollution prevention that may be applied to laboratories and research institutions, consult “Less is Better: Laboratory Chemical Management for Waste Reduction,” available from the American Chemical Society's Department of Governmental Relations and Science Policy, 1155 16th Street NW., Washington, DC 20036, 202-872-4477.
                            <PRTPAGE P="263"/>
                        </P>
                        <HD SOURCE="HD3">16. Waste Management</HD>
                        <P>16.1 The laboratory is responsible for complying with all Federal, State, and local regulations governing waste management, particularly the hazardous waste identification rules and land disposal restrictions, and to protect the air, water, and land by minimizing and controlling all releases from fume hoods and bench operations. Compliance is also required with any sewage discharge permits and regulations. An overview of requirements can be found in Environmental Management Guide for Small Laboratories (EPA 233-B-98-001).</P>
                        <P>16.2 Samples at pH &lt;2, or pH &gt;12, are hazardous and must be handled and disposed of as hazardous waste, or neutralized and disposed of in accordance with all federal, state, and local regulations. It is the laboratory's responsibility to comply with all federal, state, and local regulations governing waste management, particularly the hazardous waste identification rules and land disposal restrictions. The laboratory using this method has the responsibility to protect the air, water, and land by minimizing and controlling all releases from fume hoods and bench operations. Compliance is also required with any sewage discharge permits and regulations. For further information on waste management, see “The Waste Management Manual for Laboratory Personnel,” also available from the American Chemical Society at the address in Section 15.3.</P>
                        <P>16.3 Many analytes in this method decompose above 500 °C. Low-level waste such as absorbent paper, tissues, and plastic gloves may be burned in an appropriate incinerator. Gross quantities of neat or highly concentrated solutions of toxic or hazardous chemicals should be packaged securely and disposed of through commercial or governmental channels that are capable of handling these types of wastes.</P>
                        <P>16.4 For further information on waste management, consult “Waste Management Manual for Laboratory Personnel and Less is Better-Laboratory Chemical Management for Waste Reduction,” available from the American Chemical Society's Department of Government Relations and Science Policy, 1155 16th Street NW., Washington, DC 20036, 202-872-4477.</P>
                        <HD SOURCE="HD3">17. References</HD>
                        <P>1. Bellar, T.A. and Lichtenberg, J.J. “Determining Volatile Organics at Microgram-per-Litre Levels by Gas Chromatography,” Journal American Water Works Association, 66: 739 (1974).</P>
                        <P>2. “Sampling and Analysis Procedures for Screening of Industrial Effluents for Priority Pollutants,” U.S. Environmental Protection Agency, Environmental Monitoring and Support Laboratory, Cincinnati, Ohio 45268, March 1977, Revised April 1977.</P>
                        <P>3. Bellar, T.A. and Lichtenberg, J.J. “Semi-Automated Headspace Analysis of Drinking Waters and Industrial Waters for Purgeable Volatile Organic Compounds,” Measurement of Organic Pollutants in Water and Wastewater, C.E. Van Hall, editor, American Society for Testing and Materials, Philadelphia, PA. Special Technical Publication 686, 1978.</P>
                        <P>4. “EPA Method Study 29 EPA Method 624-Purgeables,” EPA 600/4-84-054, National Technical Information Service, PB84-209915, Springfield, Virginia 22161, June 1984.</P>
                        <P>5. 40 CFR part 136, appendix B.</P>
                        <P>6. “Method Detection Limit for Methods 624 and 625,” Olynyk, P., Budde, W.L., and Eichelberger, J.W. Unpublished report, May 14, 1980.</P>
                        <P>7. “Carcinogens-Working With Carcinogens,” Department of Health, Education, and Welfare, Public Health Service, Center for Disease Control, National Institute for Occupational Safety and Health, Publication No. 77-206, August 1977.</P>
                        <P>8. “OSHA Safety and Health Standards, General Industry,” (29 CFR part 1910), Occupational Safety and Health Administration, OSHA 2206 (Revised, January 1976).</P>
                        <P>9. “Safety in Academic Chemistry Laboratories,” American Chemical Society Publication, Committee on Chemical Safety, 7th Edition, 2003.</P>
                        <P>10. 40 CFR 136.6(b)(5)(x).</P>
                        <P>11. 40 CFR 136.6(b)(2)(i).</P>
                        <P>12. Protocol for EPA Approval of New Methods for Organic and Inorganic Analytes in Wastewater and Drinking Water (EPA-821-B-98-003) March 1999.</P>
                        <P>13. Provost, L.P. and Elder, R.S. “Interpretation of Percent Recovery Data,” American Laboratory, 15, 58-63 (1983).</P>
                        <P>14. 40 CFR 136.3(a), Table IB, Chlorine—Total residual.</P>
                        <P>15. Budde, W.L. and Eichelberger, J.W. “Performance Tests for the Evaluation of Computerized Gas Chromatography/Mass Spectrometry Equipment and Laboratories,” EPA-600/4-80-025, U.S. Environmental Protection Agency, Environmental Monitoring and Support Laboratory, Cincinnati, Ohio 45268, April 1980.</P>
                        <P>16. “Method Performance Data for Method 624,” Memorandum from R. Slater and T. Pressley, U.S. Environmental Protection Agency, Environmental Monitoring and Support Laboratory, Cincinnati, Ohio 45268, January 17, 1984.</P>
                        <HD SOURCE="HD3">18. Tables</HD>
                        <PRTPAGE P="264"/>
                        <GPOTABLE COLS="4" OPTS="L2" CDEF="s100,12,12,12">
                            <TTITLE>
                                Table 1—Purgeables 
                                <SU>1</SU>
                            </TTITLE>
                            <BOXHD>
                                <CHED H="1">Analyte</CHED>
                                <CHED H="1">CAS Registry No.</CHED>
                                <CHED H="1">
                                    MDL (µg/L) 
                                    <SU>2</SU>
                                </CHED>
                                <CHED H="1">
                                    ML (µg/L) 
                                    <SU>3</SU>
                                </CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">Acrolein</ENT>
                                <ENT>107-02-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Acrylonitrile</ENT>
                                <ENT>107-13-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzene</ENT>
                                <ENT>71-43-2</ENT>
                                <ENT>4.4</ENT>
                                <ENT>13.2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Bromodichloromethane</ENT>
                                <ENT>75-27-4</ENT>
                                <ENT>2.2</ENT>
                                <ENT>6.6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Bromoform</ENT>
                                <ENT>75-25-2</ENT>
                                <ENT>4.7</ENT>
                                <ENT>14.1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Bromomethane</ENT>
                                <ENT>74-83-9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Carbon tetrachloride</ENT>
                                <ENT>56-23-5</ENT>
                                <ENT>2.8</ENT>
                                <ENT>8.4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chlorobenzene</ENT>
                                <ENT>108-90-7</ENT>
                                <ENT>6.0</ENT>
                                <ENT>18.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chloroethane</ENT>
                                <ENT>75-00-3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-Chloroethylvinyl ether</ENT>
                                <ENT>110-75-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chloroform</ENT>
                                <ENT>67-66-3</ENT>
                                <ENT>1.6</ENT>
                                <ENT>4.8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chloromethane</ENT>
                                <ENT>74-87-3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dibromochloromethane</ENT>
                                <ENT>124-48-1</ENT>
                                <ENT>3.1</ENT>
                                <ENT>9.3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2-Dichlorobenzene</ENT>
                                <ENT>95-50-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,3-Dichlorobenzene</ENT>
                                <ENT>541-73-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,4-Dichlorobenzene</ENT>
                                <ENT>106-46-7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1-Dichloroethane</ENT>
                                <ENT>75-34-3</ENT>
                                <ENT>4.7</ENT>
                                <ENT>14.1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2-Dichloroethane</ENT>
                                <ENT>107-06-2</ENT>
                                <ENT>2.8</ENT>
                                <ENT>8.4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1-Dichloroethene</ENT>
                                <ENT>75-35-4</ENT>
                                <ENT>2.8</ENT>
                                <ENT>8.4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">trans-1,2-Dichloroethene</ENT>
                                <ENT>156-60-5</ENT>
                                <ENT>1.6</ENT>
                                <ENT>4.8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2-Dichloropropane</ENT>
                                <ENT>78-87-5</ENT>
                                <ENT>6.0</ENT>
                                <ENT>18.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">cis</E>
                                    -1,3-Dichloropropene
                                </ENT>
                                <ENT>10061-01-5</ENT>
                                <ENT>5.0</ENT>
                                <ENT>15.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">trans</E>
                                    -1,3-Dichloropropene
                                </ENT>
                                <ENT>10061-02-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ethyl benzene</ENT>
                                <ENT>100-41-4</ENT>
                                <ENT>7.2</ENT>
                                <ENT>21.6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Methylene chloride</ENT>
                                <ENT>75-09-2</ENT>
                                <ENT>2.8</ENT>
                                <ENT>8.4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1,2,2-Tetrachloroethane</ENT>
                                <ENT>79-34-5</ENT>
                                <ENT>6.9</ENT>
                                <ENT>20.7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Tetrachloroethene</ENT>
                                <ENT>127-18-4</ENT>
                                <ENT>4.1</ENT>
                                <ENT>12.3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Toluene</ENT>
                                <ENT>108-88-3</ENT>
                                <ENT>6.0</ENT>
                                <ENT>18.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1,1-Trichloroethane</ENT>
                                <ENT>71-55-6</ENT>
                                <ENT>3.8</ENT>
                                <ENT>11.4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1,2-Trichloroethane</ENT>
                                <ENT>79-00-5</ENT>
                                <ENT>5.0</ENT>
                                <ENT>15.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Trichloroethene</ENT>
                                <ENT>79-01-6</ENT>
                                <ENT>1.9</ENT>
                                <ENT>5.7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Vinyl chloride</ENT>
                                <ENT>75-01-4</ENT>
                            </ROW>
                            <TNOTE>
                                <SU>1</SU>
                                 All the analytes in this table are Priority Pollutants (40 CFR part 423, appendix A).
                            </TNOTE>
                            <TNOTE>
                                <SU>2</SU>
                                 MDL values from the 1984 promulgated version of Method 624.
                            </TNOTE>
                            <TNOTE>
                                <SU>3</SU>
                                 ML = Minimum Level—see Glossary for definition and derivation.
                            </TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="2" OPTS="L2" CDEF="s100,12">
                            <TTITLE>Table 2—Additional Purgeables</TTITLE>
                            <BOXHD>
                                <CHED H="1">Analyte</CHED>
                                <CHED H="1">CAS Registry</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">
                                    Acetone 
                                    <SU>1</SU>
                                </ENT>
                                <ENT>67-64-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Acetonitrile 
                                    <SU>2</SU>
                                </ENT>
                                <ENT>75-05-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Acrolein</ENT>
                                <ENT>107-02-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Acrylonitrile</ENT>
                                <ENT>107-13-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Allyl alcohol 
                                    <SU>1</SU>
                                </ENT>
                                <ENT>107-18-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Allyl chloride</ENT>
                                <ENT>107-05-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">t</E>
                                    -Amyl ethyl ether (TAEE)
                                </ENT>
                                <ENT>919-94-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">t</E>
                                    -Amyl methyl ether (TAME)
                                </ENT>
                                <ENT>994-058</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzyl chloride</ENT>
                                <ENT>100-44-7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Bromoacetone 
                                    <SU>2</SU>
                                </ENT>
                                <ENT>598-31-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Bromobenzene</ENT>
                                <ENT>108-86-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Bromochloromethane</ENT>
                                <ENT>74-97-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,3-Butadiene</ENT>
                                <ENT>106-99-0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">n</E>
                                    -Butanol 
                                    <SU>1</SU>
                                </ENT>
                                <ENT>71-36-3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    2-Butanone (MEK) 
                                    <SU>1 2</SU>
                                </ENT>
                                <ENT>78-93-3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">t</E>
                                    -Butyl alcohol (TBA)
                                </ENT>
                                <ENT>75-65-0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">n</E>
                                    -Butylbenzene
                                </ENT>
                                <ENT>104-51-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">sec</E>
                                    -Butylbenzene
                                </ENT>
                                <ENT>135-98-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">t</E>
                                    -Butylbenzene
                                </ENT>
                                <ENT>98-06-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">t</E>
                                    -Butyl ethyl ether (ETBE)
                                </ENT>
                                <ENT>637-92-3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Carbon disulfide</ENT>
                                <ENT>75-15-0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Chloral hydrate 
                                    <SU>2</SU>
                                </ENT>
                                <ENT>302-17-0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Chloroacetonitrile 
                                    <SU>1</SU>
                                </ENT>
                                <ENT>107-14-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1-Chlorobutane</ENT>
                                <ENT>109-69-3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chlorodifluoromethane</ENT>
                                <ENT>75-45-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    2-Chloroethanol 
                                    <SU>2</SU>
                                </ENT>
                                <ENT>107-07-3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    bis (2-Chloroethyl) sulfide 
                                    <SU>2</SU>
                                </ENT>
                                <ENT>505-60-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1-Chlorohexanone</ENT>
                                <ENT>20261-68-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chloroprene (2-chloro-1,3-butadiene)</ENT>
                                <ENT>126-99-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">3-Chloropropene</ENT>
                                <ENT>107-05-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">3-Chloropropionitrile</ENT>
                                <ENT>542-76-7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-Chlorotoluene</ENT>
                                <ENT>95-49-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4-Chlorotoluene</ENT>
                                <ENT>106-43-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Crotonaldehyde 
                                    <SU>1 2</SU>
                                </ENT>
                                <ENT>123-73-9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Cyclohexanone</ENT>
                                <ENT>108-94-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2-Dibromo-3-chloropropane</ENT>
                                <ENT>96-12-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2-Dibromoethane</ENT>
                                <ENT>106-93-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dibromomethane</ENT>
                                <ENT>74-95-3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">cis</E>
                                    -1,4-Dichloro-2-butene
                                </ENT>
                                <ENT>1476-11-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">trans</E>
                                    -1,4-Dichloro-2-butene
                                </ENT>
                                <ENT>110-57-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">cis</E>
                                    -1,2-Dichloroethene
                                </ENT>
                                <ENT>156-59-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dichlorodifluoromethane</ENT>
                                <ENT>75-71-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,3-Dichloropropane</ENT>
                                <ENT>142-28-9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,2-Dichloropropane</ENT>
                                <ENT>590-20-7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    1,3-Dichloro-2-propanol 
                                    <SU>2</SU>
                                </ENT>
                                <ENT>96-23-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1-Dichloropropene</ENT>
                                <ENT>563-58-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">cis</E>
                                    -1,3-Dichloropropene
                                </ENT>
                                <ENT>10061-01-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1:2,3:4-Diepoxybutane</ENT>
                                <ENT>1464-53-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Diethyl ether</ENT>
                                <ENT>60-29-7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Diisopropyl ether (DIPE)</ENT>
                                <ENT>108-20-3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    1,4-Dioxane 
                                    <SU>2</SU>
                                </ENT>
                                <ENT>123-91-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Epichlorohydrin 
                                    <SU>2</SU>
                                </ENT>
                                <ENT>106-89-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Ethanol 
                                    <SU>2</SU>
                                </ENT>
                                <ENT>64-17-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Ethyl acetate 
                                    <SU>2</SU>
                                </ENT>
                                <ENT>141-78-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ethyl methacrylate</ENT>
                                <ENT>97-63-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Ethylene oxide 
                                    <SU>2</SU>
                                </ENT>
                                <ENT>75-21-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Hexachlorobutadiene</ENT>
                                <ENT>87-63-3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Hexachloroethane</ENT>
                                <ENT>67-72-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    2-Hexanone 
                                    <SU>2</SU>
                                </ENT>
                                <ENT>591-78-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Iodomethane</ENT>
                                <ENT>74-88-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Isobutyl alcohol 
                                    <SU>1</SU>
                                </ENT>
                                <ENT>78-83-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Isopropylbenzene</ENT>
                                <ENT>98-82-8</ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="265"/>
                                <ENT I="01">
                                    <E T="03">p</E>
                                    -Isopropyltoluene
                                </ENT>
                                <ENT>99-87-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Methacrylonitrile 
                                    <SU>2</SU>
                                </ENT>
                                <ENT>126-98-7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Methanol 
                                    <SU>2</SU>
                                </ENT>
                                <ENT>67-56-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Malonitrile 
                                    <SU>2</SU>
                                </ENT>
                                <ENT>109-77-3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Methyl acetate</ENT>
                                <ENT>79-20-9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Methyl acrylate</ENT>
                                <ENT>96-33-3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Methyl cyclohexane</ENT>
                                <ENT>108-87-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Methyl iodide</ENT>
                                <ENT>74-88-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Methyl methacrylate</ENT>
                                <ENT>78-83-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    4-Methyl-2-pentanone (MIBK) 
                                    <SU>2</SU>
                                </ENT>
                                <ENT>108-10-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Methyl-
                                    <E T="03">t</E>
                                    -butyl ether (MTBE)
                                </ENT>
                                <ENT>1634-04-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Naphthalene</ENT>
                                <ENT>91-20-3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Nitrobenzene</ENT>
                                <ENT>98-95-3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    N-Nitroso-di-
                                    <E T="03">n</E>
                                    -butylamine 
                                    <SU>2</SU>
                                </ENT>
                                <ENT>924-16-3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-Nitropropane</ENT>
                                <ENT>79-46-9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Paraldehyde 
                                    <SU>2</SU>
                                </ENT>
                                <ENT>123-63-7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Pentachloroethane 
                                    <SU>2</SU>
                                </ENT>
                                <ENT>76-01-7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Pentafluorobenzene</ENT>
                                <ENT>363-72-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    2-Pentanone 
                                    <SU>2</SU>
                                </ENT>
                                <ENT>107-19-7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    2-Picoline 
                                    <SU>2</SU>
                                </ENT>
                                <ENT>109-06-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    1-Propanol 
                                    <SU>1</SU>
                                </ENT>
                                <ENT>71-23-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    2-Propanol 
                                    <SU>1</SU>
                                </ENT>
                                <ENT>67-63-0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Propargyl alcohol 
                                    <SU>2</SU>
                                </ENT>
                                <ENT>107-19-7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">beta</E>
                                    -Propiolactone 
                                    <SU>2</SU>
                                </ENT>
                                <ENT>57-58-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Propionitrile (ethyl cyanide) 
                                    <SU>1</SU>
                                </ENT>
                                <ENT>107-12-0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">n</E>
                                    -Propylamine
                                </ENT>
                                <ENT>107-10-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">n</E>
                                    -Propylbenzene
                                </ENT>
                                <ENT>103-65-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Pyridine 
                                    <SU>2</SU>
                                </ENT>
                                <ENT>110-86-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Styrene</ENT>
                                <ENT>100-42-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1,1,2-Tetrachloroethane</ENT>
                                <ENT>630-20-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Tetrahydrofuran</ENT>
                                <ENT>109-99-9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">o</E>
                                    -Toluidine 
                                    <SU>2</SU>
                                </ENT>
                                <ENT>95-53-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3-Trichlorobenzene</ENT>
                                <ENT>87-61-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Trichlorofluoromethane</ENT>
                                <ENT>75-69-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3-Trichloropropane</ENT>
                                <ENT>96-18-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3-Trimethylbenzene</ENT>
                                <ENT>526-73-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,4-Trimethylbenzene</ENT>
                                <ENT>95-63-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,3,5-Trimethylbenzene</ENT>
                                <ENT>108-67-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Vinyl acetate</ENT>
                                <ENT>108-05-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">m</E>
                                    -Xylene 
                                    <SU>3</SU>
                                </ENT>
                                <ENT>108-38-3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">o</E>
                                    -Xylene 
                                    <SU>3</SU>
                                </ENT>
                                <ENT>95-47-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">p</E>
                                    -Xylene 
                                    <SU>3</SU>
                                </ENT>
                                <ENT>106-42-3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">m</E>
                                    +
                                    <E T="03">o</E>
                                    -Xylene 
                                    <SU>3</SU>
                                </ENT>
                                <ENT>179601-22-0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">m</E>
                                    +
                                    <E T="03">p</E>
                                    -Xylene 
                                    <SU>3</SU>
                                </ENT>
                                <ENT>179601-23-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">o</E>
                                    +
                                    <E T="03">p</E>
                                    -Xylene 
                                    <SU>3</SU>
                                </ENT>
                                <ENT>136777-61-2</ENT>
                            </ROW>
                            <TNOTE>
                                <SU>1</SU>
                                 Determined at a purge temperature of 80 °C.
                            </TNOTE>
                            <TNOTE>
                                <SU>2</SU>
                                 May be detectable at a purge temperature of 80 °C.
                            </TNOTE>
                            <TNOTE>
                                <SU>3</SU>
                                 Determined in combination separated by GC column. Most GC columns will resolve 
                                <E T="03">o</E>
                                -xylene from 
                                <E T="03">m</E>
                                +
                                <E T="03">p</E>
                                -xylene. Report using the CAS number for the individual xylene or the combination, as determined.
                            </TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="2" OPTS="L2" CDEF="s50,12">
                            <TTITLE>Table 3—Example Retention Times</TTITLE>
                            <BOXHD>
                                <CHED H="1">Analyte</CHED>
                                <CHED H="1">
                                    Retention time
                                    <LI>(min)</LI>
                                </CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">Chloromethane</ENT>
                                <ENT>3.68</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Vinyl chloride</ENT>
                                <ENT>3.92</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Bromomethane</ENT>
                                <ENT>4.50</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chloroethane</ENT>
                                <ENT>4.65</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Trichlorofluoromethane</ENT>
                                <ENT>5.25</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Diethyl ether</ENT>
                                <ENT>5.88</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Acrolein</ENT>
                                <ENT>6.12</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1-Dichloroethene</ENT>
                                <ENT>6.30</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Acetone</ENT>
                                <ENT>6.40</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Iodomethane</ENT>
                                <ENT>6.58</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Carbon disulfide</ENT>
                                <ENT>6.72</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">3-Chloropropene</ENT>
                                <ENT>6.98</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Methylene chloride</ENT>
                                <ENT>7.22</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Acrylonitrile</ENT>
                                <ENT>7.63</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">trans</E>
                                    -1,2-Dichloroethene
                                </ENT>
                                <ENT>7.73</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1-Dichloroethane</ENT>
                                <ENT>8.45</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Vinyl acetate</ENT>
                                <ENT>8.55</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Allyl alcohol</ENT>
                                <ENT>8.58</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-Chloro-1,3-butadiene</ENT>
                                <ENT>8.65</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Methyl ethyl ketone</ENT>
                                <ENT>9.50</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">cis</E>
                                    -1,2-Dichloroethene
                                </ENT>
                                <ENT>9.50</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ethyl cyanide</ENT>
                                <ENT>9.57</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Methacrylonitrile</ENT>
                                <ENT>9.83</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chloroform</ENT>
                                <ENT>10.05</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1,1-Trichloroethane</ENT>
                                <ENT>10.37</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Carbon tetrachloride</ENT>
                                <ENT>10.70</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Isobutanol</ENT>
                                <ENT>10.77</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzene</ENT>
                                <ENT>10.98</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2-Dichloroethane</ENT>
                                <ENT>11.00</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Crotonaldehyde</ENT>
                                <ENT>11.45</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Trichloroethene</ENT>
                                <ENT>12.08</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2-Dichloropropane</ENT>
                                <ENT>12.37</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Methyl methacrylate</ENT>
                                <ENT>12.55</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">p</E>
                                    -Dioxane
                                </ENT>
                                <ENT>12.63</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dibromomethane</ENT>
                                <ENT>12.65</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Bromodichloromethane</ENT>
                                <ENT>12.95</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chloroacetonitrile</ENT>
                                <ENT>13.27</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-Chloroethylvinyl ether</ENT>
                                <ENT>13.45</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">cis</E>
                                    -1,3-Dichloropropene
                                </ENT>
                                <ENT>13.65</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4-Methyl-2-pentanone</ENT>
                                <ENT>13.83</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Toluene</ENT>
                                <ENT>14.18</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">trans</E>
                                    -1,3-Dichloropropene
                                </ENT>
                                <ENT>14.57</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ethyl methacrylate</ENT>
                                <ENT>14.70</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1,2-Trichloroethane</ENT>
                                <ENT>14.93</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,3-Dichloropropane</ENT>
                                <ENT>15.18</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Tetrachloroethene</ENT>
                                <ENT>15.22</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-Hexanone</ENT>
                                <ENT>15.30</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dibromochloromethane</ENT>
                                <ENT>15.68</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2-Dibromoethane</ENT>
                                <ENT>15.90</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chlorobenzene</ENT>
                                <ENT>16.78</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ethylbenzene</ENT>
                                <ENT>16.82</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1,1,2-Tetrachloroethane</ENT>
                                <ENT>16.87</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">m</E>
                                    +
                                    <E T="03">p</E>
                                    -Xylene
                                </ENT>
                                <ENT>17.08</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">o</E>
                                    -Xylene
                                </ENT>
                                <ENT>17.82</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Bromoform</ENT>
                                <ENT>18.27</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Bromofluorobenzene</ENT>
                                <ENT>18.80</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1,2,2-Tetrachloroethane</ENT>
                                <ENT>18.98</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3-Trichloropropane</ENT>
                                <ENT>19.08</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">trans</E>
                                    -1,4-Dichloro-2-butene
                                </ENT>
                                <ENT>19.12</ENT>
                            </ROW>
                            <TNOTE>
                                <E T="03">Column:</E>
                                 75 m x 0.53 mm ID x 3.0 µm wide-bore DB-624
                            </TNOTE>
                            <TNOTE>
                                <E T="03">Conditions:</E>
                                 40 °C for 4 min, 9 °C/min to 200 °C, 20 °C/min (or higher) to 250 °C, hold for 20 min at 250 °C to remove water.
                            </TNOTE>
                            <TNOTE>
                                <E T="03">Carrier gas flow rate:</E>
                                 6-7 mL/min at 40 °C.
                            </TNOTE>
                            <TNOTE>
                                <E T="03">Inlet split ratio:</E>
                                 3:1.
                            </TNOTE>
                            <TNOTE>
                                <E T="03">Interface split ratio:</E>
                                 7:2.
                            </TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="2" OPTS="L2" CDEF="s50,r50">
                            <TTITLE>
                                Table 4—BFB Key 
                                <E T="01">m/z</E>
                                 Abundance Criteria 
                                <SU>1</SU>
                            </TTITLE>
                            <BOXHD>
                                <CHED H="1">m/z</CHED>
                                <CHED H="1">Abundance criteria</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">50</ENT>
                                <ENT>15-40% of m/z 95.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">75</ENT>
                                <ENT>30-60% of m/z 95.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">95</ENT>
                                <ENT>Base Peak, 100% Relative Abundance.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">96</ENT>
                                <ENT>5-9% of m/z 95.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">173</ENT>
                                <ENT>&lt;2% of m/z 174.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">174</ENT>
                                <ENT>&gt;50% of m/z 95.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">175</ENT>
                                <ENT>5-9% of m/z 174.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">176</ENT>
                                <ENT>&gt;95% but &lt;101% of m/z 174.</ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="266"/>
                                <ENT I="01">177</ENT>
                                <ENT>5-9% of m/z 176.</ENT>
                            </ROW>
                            <TNOTE>
                                <SU>1</SU>
                                 Abundance criteria are for a quadrupole mass spectrometer. Alternative tuning criteria from other published EPA reference methods may be used, provided method performance is not adversely affected. Alternative tuning criteria specified by an instrument manufacturer may also be used for another type of mass spectrometer, or for an alternative carrier gas, provided method performance is not adversely affected.
                            </TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="4" OPTS="L2" CDEF="s50,12,12,12">
                            <TTITLE>Table 5—Suggested Surrogate and Internal Standards</TTITLE>
                            <BOXHD>
                                <CHED H="1">Analyte</CHED>
                                <CHED H="1">
                                    Retention time (min) 
                                    <SU>1</SU>
                                </CHED>
                                <CHED H="1">Primary m/z</CHED>
                                <CHED H="1">
                                    Secondary
                                    <LI>m/z's</LI>
                                </CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">
                                    Benzene-d
                                    <E T="52">6</E>
                                </ENT>
                                <ENT>10.95</ENT>
                                <ENT>84</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4-Bromofluorobenzene</ENT>
                                <ENT>18.80</ENT>
                                <ENT>95</ENT>
                                <ENT>174, 176</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Bromochloromethane</ENT>
                                <ENT>9.88</ENT>
                                <ENT>128</ENT>
                                <ENT>49, 130, 51</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-Bromo-1-chloropropane</ENT>
                                <ENT>14.80</ENT>
                                <ENT>77</ENT>
                                <ENT>79, 156</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    2-Butanone-d
                                    <E T="52">5</E>
                                </ENT>
                                <ENT>9.33</ENT>
                                <ENT>77</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Chloroethane-d
                                    <E T="52">5</E>
                                </ENT>
                                <ENT>4.63</ENT>
                                <ENT>71</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Chloroform-
                                    <SU>13</SU>
                                    C
                                </ENT>
                                <ENT>10.00</ENT>
                                <ENT>86</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    1,2-Dichlorobenzene-d
                                    <E T="52">4</E>
                                </ENT>
                                <ENT/>
                                <ENT>152</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,4-Dichlorobutane</ENT>
                                <ENT>18.57</ENT>
                                <ENT>55</ENT>
                                <ENT>90, 92</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    1,2-Dichloroethane-d
                                    <E T="52">4</E>
                                </ENT>
                                <ENT>10.88</ENT>
                                <ENT>102</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    1,1-Dichloroethene-d
                                    <E T="52">2</E>
                                </ENT>
                                <ENT>6.30</ENT>
                                <ENT>65</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    1,2-Dichloropropane-d
                                    <E T="52">6</E>
                                </ENT>
                                <ENT>12.27</ENT>
                                <ENT>67</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">trans</E>
                                    -1,3-Dichloropropene-d
                                    <E T="52">4</E>
                                </ENT>
                                <ENT>14.50</ENT>
                                <ENT>79</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,4-Difluorobenzene</ENT>
                                <ENT/>
                                <ENT>114</ENT>
                                <ENT>63, 88</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Ethylbenzene-d
                                    <E T="52">10</E>
                                </ENT>
                                <ENT>16.77</ENT>
                                <ENT>98</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Fluorobenzene</ENT>
                                <ENT/>
                                <ENT>96</ENT>
                                <ENT>70</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    2-Hexanone-d
                                    <E T="52">5</E>
                                </ENT>
                                <ENT>15.30</ENT>
                                <ENT>63</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Pentafluorobenzene</ENT>
                                <ENT/>
                                <ENT>168</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    1,1,2,2-Tetrachloroethane-d
                                    <E T="52">2</E>
                                </ENT>
                                <ENT>18.93</ENT>
                                <ENT>84</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Toluene-d
                                    <E T="52">8</E>
                                </ENT>
                                <ENT>14.13</ENT>
                                <ENT>100</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Vinyl chloride-d
                                    <E T="52">3</E>
                                </ENT>
                                <ENT>3.87</ENT>
                                <ENT>65</ENT>
                            </ROW>
                            <TNOTE>
                                <SU>1</SU>
                                 For chromatographic conditions, see the footnote to Table 3.
                            </TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="3" OPTS="L2" CDEF="s100,12,r50">
                            <TTITLE>
                                Table 6—Characteristic 
                                <E T="01">m/z's</E>
                                 for Purgeable Organics
                            </TTITLE>
                            <BOXHD>
                                <CHED H="1">Analyte</CHED>
                                <CHED H="1">Primary m/z</CHED>
                                <CHED H="1">Secondary m/z's</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">Acrolein</ENT>
                                <ENT>56</ENT>
                                <ENT>55 and 58.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Acrylonitrile</ENT>
                                <ENT>53</ENT>
                                <ENT>52 and 51.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chloromethane</ENT>
                                <ENT>50</ENT>
                                <ENT>52.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Bromomethane</ENT>
                                <ENT>94</ENT>
                                <ENT>96.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Vinyl chloride</ENT>
                                <ENT>62</ENT>
                                <ENT>64.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chloroethane</ENT>
                                <ENT>64</ENT>
                                <ENT>66.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Methylene chloride</ENT>
                                <ENT>84</ENT>
                                <ENT>49, 51, and 86.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Trichlorofluoromethane</ENT>
                                <ENT>101</ENT>
                                <ENT>103.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1-Dichloroethene</ENT>
                                <ENT>96</ENT>
                                <ENT>61 and 98.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1-Dichloroethane</ENT>
                                <ENT>63</ENT>
                                <ENT>65, 83, 85, 98, and 100.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">trans</E>
                                    -1,2-Dichloroethene
                                </ENT>
                                <ENT>96</ENT>
                                <ENT>61 and 98.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chloroform</ENT>
                                <ENT>83</ENT>
                                <ENT>85.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2-Dichloroethane</ENT>
                                <ENT>98</ENT>
                                <ENT>62, 64, and 100.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1,1-Trichloroethane</ENT>
                                <ENT>97</ENT>
                                <ENT>99, 117, and 119.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Carbon tetrachloride</ENT>
                                <ENT>117</ENT>
                                <ENT>119 and 121.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Bromodichloromethane</ENT>
                                <ENT>83</ENT>
                                <ENT>127, 85, and 129.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2-Dichloropropane</ENT>
                                <ENT>63</ENT>
                                <ENT>112, 65, and 114.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">trans</E>
                                    -1,3-Dichloropropene
                                </ENT>
                                <ENT>75</ENT>
                                <ENT>77.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Trichloroethene</ENT>
                                <ENT>130</ENT>
                                <ENT>95, 97, and 132.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzene</ENT>
                                <ENT>78</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dibromochloromethane</ENT>
                                <ENT>127</ENT>
                                <ENT>129, 208, and 206.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1,2-Trichloroethane</ENT>
                                <ENT>97</ENT>
                                <ENT>83, 85, 99, 132, and 134.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">cis</E>
                                    -1,3-Dichloropropene
                                </ENT>
                                <ENT>75</ENT>
                                <ENT>77.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-Chloroethylvinyl ether</ENT>
                                <ENT>106</ENT>
                                <ENT>63 and 65.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Bromoform</ENT>
                                <ENT>173</ENT>
                                <ENT>171, 175, 250, 252, 254, and 256.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1,2,2-Tetrachloroethane</ENT>
                                <ENT>168</ENT>
                                <ENT>83, 85, 131, 133, and 166.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Tetrachloroethene</ENT>
                                <ENT>164</ENT>
                                <ENT>129, 131, and 166.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Toluene</ENT>
                                <ENT>92</ENT>
                                <ENT>91.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chlorobenzene</ENT>
                                <ENT>112</ENT>
                                <ENT>114.</ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="267"/>
                                <ENT I="01">Ethyl benzene</ENT>
                                <ENT>106</ENT>
                                <ENT>91.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,3-Dichlorobenzene</ENT>
                                <ENT>146</ENT>
                                <ENT>148 and 111.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2-Dichlorobenzene</ENT>
                                <ENT>146</ENT>
                                <ENT>148 and 111.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,4-Dichlorobenzene</ENT>
                                <ENT>146</ENT>
                                <ENT>148 and 111.</ENT>
                            </ROW>
                        </GPOTABLE>
                        <GPOTABLE COLS="6" OPTS="L2" CDEF="s50,12,12,12,12,12">
                            <TTITLE>
                                Table 7—LCS (Q), DOC (s and 
                                <E T="7501">X</E>
                                ), and MS/MSD (P and RPD) Acceptance Criteria 
                                <SU>1</SU>
                            </TTITLE>
                            <BOXHD>
                                <CHED H="1">Analyte</CHED>
                                <CHED H="1">
                                    Range for Q
                                    <LI>(%)</LI>
                                </CHED>
                                <CHED H="1">
                                    Limit for s
                                    <LI>(%)</LI>
                                </CHED>
                                <CHED H="1">
                                    Range for 
                                    <E T="7501">X</E>
                                    <LI>(%)</LI>
                                </CHED>
                                <CHED H="1">
                                    Range for P
                                    <E T="52">1</E>
                                    , P
                                    <E T="52">2</E>
                                    <LI>(%)</LI>
                                </CHED>
                                <CHED H="1">Limit for RPD</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">Acrolein</ENT>
                                <ENT>60-140</ENT>
                                <ENT>30</ENT>
                                <ENT>50-150</ENT>
                                <ENT>40-160</ENT>
                                <ENT>60</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Acrylonitrile</ENT>
                                <ENT>60-140</ENT>
                                <ENT>30</ENT>
                                <ENT>50-150</ENT>
                                <ENT>40-160</ENT>
                                <ENT>60</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzene</ENT>
                                <ENT>65-135</ENT>
                                <ENT>33</ENT>
                                <ENT>75-125</ENT>
                                <ENT>37-151</ENT>
                                <ENT>61</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Benzene-d
                                    <E T="52">6</E>
                                </ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                            </ROW>
                            <ROW>
                                <ENT I="01">Bromodichloromethane</ENT>
                                <ENT>65-135</ENT>
                                <ENT>34</ENT>
                                <ENT>50-140</ENT>
                                <ENT>35-155</ENT>
                                <ENT>56</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Bromoform</ENT>
                                <ENT>70-130</ENT>
                                <ENT>25</ENT>
                                <ENT>57-156</ENT>
                                <ENT>45-169</ENT>
                                <ENT>42</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Bromomethane</ENT>
                                <ENT>15-185</ENT>
                                <ENT>90</ENT>
                                <ENT>D-206</ENT>
                                <ENT>D-242</ENT>
                                <ENT>61</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    2-Butanone-d
                                    <E T="52">5</E>
                                </ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                            </ROW>
                            <ROW>
                                <ENT I="01">Carbon tetrachloride</ENT>
                                <ENT>70-130</ENT>
                                <ENT>26</ENT>
                                <ENT>65-125</ENT>
                                <ENT>70-140</ENT>
                                <ENT>41</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chlorobenzene</ENT>
                                <ENT>65-135</ENT>
                                <ENT>29</ENT>
                                <ENT>82-137</ENT>
                                <ENT>37-160</ENT>
                                <ENT>53</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chloroethane</ENT>
                                <ENT>40-160</ENT>
                                <ENT>47</ENT>
                                <ENT>42-202</ENT>
                                <ENT>14-230</ENT>
                                <ENT>78</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Chloroethane-d
                                    <E T="52">5</E>
                                </ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-Chloroethylvinyl ether</ENT>
                                <ENT>D-225</ENT>
                                <ENT>130</ENT>
                                <ENT>D-252</ENT>
                                <ENT>D-305</ENT>
                                <ENT>71</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chloroform</ENT>
                                <ENT>70-135</ENT>
                                <ENT>32</ENT>
                                <ENT>68-121</ENT>
                                <ENT>51-138</ENT>
                                <ENT>54</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Chloroform-
                                    <SU>13</SU>
                                    C
                                </ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chloromethane</ENT>
                                <ENT>D-205</ENT>
                                <ENT>472</ENT>
                                <ENT>D-230</ENT>
                                <ENT>D-273</ENT>
                                <ENT>60</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dibromochloromethane</ENT>
                                <ENT>70-135</ENT>
                                <ENT>30</ENT>
                                <ENT>69-133</ENT>
                                <ENT>53-149</ENT>
                                <ENT>50</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2-Dichlorobenzene</ENT>
                                <ENT>65-135</ENT>
                                <ENT>31</ENT>
                                <ENT>59-174</ENT>
                                <ENT>18-190</ENT>
                                <ENT>57</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    1,2-Dichlorobenzene-d
                                    <E T="52">4</E>
                                </ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,3-Dichlorobenzene</ENT>
                                <ENT>70-130</ENT>
                                <ENT>24</ENT>
                                <ENT>75-144</ENT>
                                <ENT>59-156</ENT>
                                <ENT>43</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,4-Dichlorobenzene</ENT>
                                <ENT>65-135</ENT>
                                <ENT>31</ENT>
                                <ENT>59-174</ENT>
                                <ENT>18-190</ENT>
                                <ENT>57</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1-Dichloroethane</ENT>
                                <ENT>70-130</ENT>
                                <ENT>24</ENT>
                                <ENT>71-143</ENT>
                                <ENT>59-155</ENT>
                                <ENT>40</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2-Dichloroethane</ENT>
                                <ENT>70-130</ENT>
                                <ENT>29</ENT>
                                <ENT>72-137</ENT>
                                <ENT>49-155</ENT>
                                <ENT>49</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    1,2-Dichloroethane-d
                                    <E T="52">4</E>
                                </ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1-Dichloroethene</ENT>
                                <ENT>50-150</ENT>
                                <ENT>40</ENT>
                                <ENT>19-212</ENT>
                                <ENT>D-234</ENT>
                                <ENT>32</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    1,1-Dichloroethene-d
                                    <E T="52">2</E>
                                </ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">trans</E>
                                    -1,2-Dichloroethene
                                </ENT>
                                <ENT>70-130</ENT>
                                <ENT>27</ENT>
                                <ENT>68-143</ENT>
                                <ENT>54-156</ENT>
                                <ENT>45</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2-Dichloropropane</ENT>
                                <ENT>35-165</ENT>
                                <ENT>69</ENT>
                                <ENT>19-181</ENT>
                                <ENT>D-210</ENT>
                                <ENT>55</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    1,2-Dichloropropane-d
                                    <E T="52">6</E>
                                </ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">cis</E>
                                    -1,3-Dichloropropene
                                </ENT>
                                <ENT>25-175</ENT>
                                <ENT>79</ENT>
                                <ENT>5-195</ENT>
                                <ENT>D-227</ENT>
                                <ENT>58</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">trans</E>
                                    -1,3-Dichloropropene
                                </ENT>
                                <ENT>50-150</ENT>
                                <ENT>52</ENT>
                                <ENT>38-162</ENT>
                                <ENT>17-183</ENT>
                                <ENT>86</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">trans</E>
                                    -1,3-Dichloropropene-d
                                    <E T="52">4</E>
                                </ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ethyl benzene</ENT>
                                <ENT>60-140</ENT>
                                <ENT>34</ENT>
                                <ENT>75-134</ENT>
                                <ENT>37-162</ENT>
                                <ENT>63</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    2-Hexanone-d
                                    <E T="52">5</E>
                                </ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                            </ROW>
                            <ROW>
                                <ENT I="01">Methylene chloride</ENT>
                                <ENT>60-140</ENT>
                                <ENT>192</ENT>
                                <ENT>D-205</ENT>
                                <ENT>D-221</ENT>
                                <ENT>28</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1,2,2-Tetrachloroethane</ENT>
                                <ENT>60-140</ENT>
                                <ENT>36</ENT>
                                <ENT>68-136</ENT>
                                <ENT>46-157</ENT>
                                <ENT>61</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    1,1,2,2-Tetrachloroethane-d
                                    <E T="52">2</E>
                                </ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                            </ROW>
                            <ROW>
                                <ENT I="01">Tetrachloroethene</ENT>
                                <ENT>70-130</ENT>
                                <ENT>23</ENT>
                                <ENT>65-133</ENT>
                                <ENT>64-148</ENT>
                                <ENT>39</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Toluene</ENT>
                                <ENT>70-130</ENT>
                                <ENT>22</ENT>
                                <ENT>75-134</ENT>
                                <ENT>47-150</ENT>
                                <ENT>41</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Toluene-d
                                    <E T="52">8</E>
                                </ENT>
                                <ENT/>
                                <ENT/>
                                <ENT/>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1,1-Trichloroethane</ENT>
                                <ENT>70-130</ENT>
                                <ENT>21</ENT>
                                <ENT>69-151</ENT>
                                <ENT>52-162</ENT>
                                <ENT>36</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1,2-Trichloroethane</ENT>
                                <ENT>70-130</ENT>
                                <ENT>27</ENT>
                                <ENT>75-136</ENT>
                                <ENT>52-150</ENT>
                                <ENT>45</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Trichloroethene</ENT>
                                <ENT>65-135</ENT>
                                <ENT>29</ENT>
                                <ENT>75-138</ENT>
                                <ENT>70-157</ENT>
                                <ENT>48</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Trichlorofluoromethane</ENT>
                                <ENT>50-150</ENT>
                                <ENT>50</ENT>
                                <ENT>45-158</ENT>
                                <ENT>17-181</ENT>
                                <ENT>84</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Vinyl chloride</ENT>
                                <ENT>5-195</ENT>
                                <ENT>100</ENT>
                                <ENT>D-218</ENT>
                                <ENT>D-251</ENT>
                                <ENT>66</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Vinyl chloride-d
                                    <E T="52">3</E>
                                </ENT>
                            </ROW>
                            <TNOTE>
                                <SU>1</SU>
                                 Criteria were calculated using an LCS concentration of 20 µg/L.
                            </TNOTE>
                            <TNOTE>Q = Percent recovery in calibration verification/LCS (section 8.4).</TNOTE>
                            <TNOTE>s = Standard deviation of percent recovery for four recovery measurements (section 8.2.4).</TNOTE>
                            <TNOTE>
                                <E T="7501">X</E>
                                 = Average percent recovery for four recovery measurements (section 8.2.4).
                            </TNOTE>
                            <TNOTE>P = Percent recovery for the MS or MSD (section 8.3.3).</TNOTE>
                            <TNOTE>D = Detected; result must be greater than zero.</TNOTE>
                            <TNOTE>
                                <E T="02">Notes:</E>
                            </TNOTE>
                            <TNOTE>1. Criteria for pollutants are based upon the method performance data in Reference 4. Where necessary, limits have been broadened to assure applicability to concentrations below those used to develop Table 7.</TNOTE>
                            <TNOTE>2. Criteria for surrogates are from EPA CLP SOM01.2D.</TNOTE>
                        </GPOTABLE>
                        <PRTPAGE P="268"/>
                        <GPOTABLE COLS="4" OPTS="L2" CDEF="s50,12,12,12">
                            <TTITLE>Table 8—Recovery and Precision as Functions of Concentration</TTITLE>
                            <BOXHD>
                                <CHED H="1">Analyte</CHED>
                                <CHED H="1">
                                    Recovery, X′
                                    <LI>(µg/L)</LI>
                                </CHED>
                                <CHED H="1">
                                    Single analyst precision, s
                                    <E T="52">r</E>
                                    ′
                                    <LI>(µg/L)</LI>
                                </CHED>
                                <CHED H="1">
                                    Overall
                                    <LI>precision, S′</LI>
                                    <LI>(µg/L)</LI>
                                </CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">Benzene</ENT>
                                <ENT>0.93C+2.00</ENT>
                                <ENT>
                                    20.26 
                                    <E T="7501">X</E>
                                    −1.74
                                </ENT>
                                <ENT>
                                    0.25 
                                    <E T="7501">X</E>
                                    −1.33
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Bromodichloromethane</ENT>
                                <ENT>1.03C−1.58</ENT>
                                <ENT>
                                    0.15 
                                    <E T="7501">X</E>
                                    +0.59
                                </ENT>
                                <ENT>
                                    0.20 
                                    <E T="7501">X</E>
                                    +1.13
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Bromoform</ENT>
                                <ENT>1.18C−2.35</ENT>
                                <ENT>
                                    0.12 
                                    <E T="7501">X</E>
                                    +0.36
                                </ENT>
                                <ENT>
                                    0.17 
                                    <E T="7501">X</E>
                                    +1.38
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Bromomethane 
                                    <SU>a</SU>
                                </ENT>
                                <ENT>1.00C</ENT>
                                <ENT>
                                    0.43 
                                    <E T="7501">X</E>
                                </ENT>
                                <ENT>
                                    0.58 
                                    <E T="7501">X</E>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Carbon tetrachloride</ENT>
                                <ENT>1.10C−1.68</ENT>
                                <ENT>
                                    0.12 
                                    <E T="7501">X</E>
                                    +0.25
                                </ENT>
                                <ENT>
                                    0.11 
                                    <E T="7501">X</E>
                                    +0.37
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chlorobenzene</ENT>
                                <ENT>0.98C+2.28</ENT>
                                <ENT>
                                    0.16 
                                    <E T="7501">X</E>
                                    −0.09
                                </ENT>
                                <ENT>
                                    0.26 
                                    <E T="7501">X</E>
                                    −1.92
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chloroethane</ENT>
                                <ENT>1.18C+0.81</ENT>
                                <ENT>
                                    0.14 
                                    <E T="7501">X</E>
                                    +2.78
                                </ENT>
                                <ENT>
                                    0.29 
                                    <E T="7501">X</E>
                                    +1.75
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    2-Chloroethylvinyl ether 
                                    <SU>a</SU>
                                </ENT>
                                <ENT>1.00C</ENT>
                                <ENT>
                                    0.62 
                                    <E T="7501">X</E>
                                </ENT>
                                <ENT>
                                    0.84 
                                    <E T="7501">X</E>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chloroform</ENT>
                                <ENT>0.93C+0.33</ENT>
                                <ENT>
                                    0.16 
                                    <E T="7501">X</E>
                                    +0.22
                                </ENT>
                                <ENT>
                                    0.18 
                                    <E T="7501">X</E>
                                    +0.16
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chloromethane</ENT>
                                <ENT>1.03C+0.81</ENT>
                                <ENT>
                                    0.37 
                                    <E T="7501">X</E>
                                    +2.14
                                </ENT>
                                <ENT>
                                    0.58 
                                    <E T="7501">X</E>
                                    +0.43
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dibromochloromethane</ENT>
                                <ENT>1.01C−0.03</ENT>
                                <ENT>
                                    0.17 
                                    <E T="7501">X</E>
                                    −0.18
                                </ENT>
                                <ENT>
                                    0.17 
                                    <E T="7501">X</E>
                                    +0.49
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    1,2-Dichlorobenzene 
                                    <SU>b</SU>
                                </ENT>
                                <ENT>0.94C+4.47</ENT>
                                <ENT>
                                    0.22 
                                    <E T="7501">X</E>
                                    −1.45
                                </ENT>
                                <ENT>
                                    0.30 
                                    <E T="7501">X</E>
                                    −1.20
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,3-Dichlorobenzene</ENT>
                                <ENT>1.06C+1.68</ENT>
                                <ENT>
                                    0.14 
                                    <E T="7501">X</E>
                                    −0.48
                                </ENT>
                                <ENT>
                                    0.18 
                                    <E T="7501">X</E>
                                    −0.82
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    1,4-Dichlorobenzene 
                                    <SU>b</SU>
                                </ENT>
                                <ENT>0.94C+4.47</ENT>
                                <ENT>
                                    0.22 
                                    <E T="7501">X</E>
                                    −1.45
                                </ENT>
                                <ENT>
                                    0.30 
                                    <E T="7501">X</E>
                                    −1.20
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1-Dichloroethane</ENT>
                                <ENT>1.05C+0.36</ENT>
                                <ENT>
                                    0.13 
                                    <E T="7501">X</E>
                                    −0.05
                                </ENT>
                                <ENT>
                                    0.16 
                                    <E T="7501">X</E>
                                    +0.47
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2-Dichloroethane</ENT>
                                <ENT>1.02C+0.45</ENT>
                                <ENT>
                                    0.17 
                                    <E T="7501">X</E>
                                    −0.32
                                </ENT>
                                <ENT>
                                    0.21 
                                    <E T="7501">X</E>
                                    −0.38
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1-Dichloroethene</ENT>
                                <ENT>1.12C+0.61</ENT>
                                <ENT>
                                    0.17 
                                    <E T="7501">X</E>
                                    +1.06
                                </ENT>
                                <ENT>
                                    0.43 
                                    <E T="7501">X</E>
                                    −0.22
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">trans</E>
                                    -1,2,-Dichloroethene
                                </ENT>
                                <ENT>1.05C+0.03</ENT>
                                <ENT>
                                    0.14 
                                    <E T="7501">X</E>
                                    −+0.09
                                </ENT>
                                <ENT>
                                    0.19 
                                    <E T="7501">X</E>
                                    −+0.17
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    1,2-Dichloropropane 
                                    <SU>a</SU>
                                </ENT>
                                <ENT>1.00C</ENT>
                                <ENT>
                                    0.33 
                                    <E T="7501">X</E>
                                </ENT>
                                <ENT>
                                    0.45 
                                    <E T="7501">X</E>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">cis</E>
                                    -1,3-Dichloropropene 
                                    <SU>a</SU>
                                </ENT>
                                <ENT>1.00C</ENT>
                                <ENT>
                                    0.38 
                                    <E T="7501">X</E>
                                </ENT>
                                <ENT>
                                    0.52 
                                    <E T="7501">X</E>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">trans</E>
                                    -1,3-Dichloropropene 
                                    <SU>a</SU>
                                </ENT>
                                <ENT>1.00C</ENT>
                                <ENT>
                                    0.25 
                                    <E T="7501">X</E>
                                </ENT>
                                <ENT>
                                    0.34 
                                    <E T="7501">X</E>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ethyl benzene</ENT>
                                <ENT>0.98C+2.48</ENT>
                                <ENT>
                                    0.14 
                                    <E T="7501">X</E>
                                    +1.00
                                </ENT>
                                <ENT>
                                    0.26 
                                    <E T="7501">X</E>
                                    −1.72
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Methylene chloride</ENT>
                                <ENT>0.87C+1.88</ENT>
                                <ENT>
                                    0.15 
                                    <E T="7501">X</E>
                                    +1.07
                                </ENT>
                                <ENT>
                                    0.32 
                                    <E T="7501">X</E>
                                    +4.00
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1,2,2-Tetrachloroethane</ENT>
                                <ENT>0.93C+1.76</ENT>
                                <ENT>
                                    0.16 
                                    <E T="7501">X</E>
                                    +0.69
                                </ENT>
                                <ENT>
                                    0.20 
                                    <E T="7501">X</E>
                                    +0.41
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Tetrachloroethene</ENT>
                                <ENT>1.06C+0.60</ENT>
                                <ENT>
                                    0.13 
                                    <E T="7501">X</E>
                                    −0.18
                                </ENT>
                                <ENT>
                                    0.16 
                                    <E T="7501">X</E>
                                    −0.45
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Toluene</ENT>
                                <ENT>0.98C+2.03</ENT>
                                <ENT>
                                    0.15 
                                    <E T="7501">X</E>
                                    −0.71
                                </ENT>
                                <ENT>
                                    0.22 
                                    <E T="7501">X</E>
                                    −1.71
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1,1-Trichloroethane</ENT>
                                <ENT>1.06C+0.73</ENT>
                                <ENT>
                                    0.12 
                                    <E T="7501">X</E>
                                    −0.15
                                </ENT>
                                <ENT>
                                    0.21 
                                    <E T="7501">X</E>
                                    −0.39
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1,2-Trichloroethane</ENT>
                                <ENT>0.95C+1.71</ENT>
                                <ENT>
                                    0.14 
                                    <E T="7501">X</E>
                                    +0.02
                                </ENT>
                                <ENT>
                                    0.18 
                                    <E T="7501">X</E>
                                    +0.00
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Trichloroethene</ENT>
                                <ENT>1.04C+2.27</ENT>
                                <ENT>
                                    0.13 
                                    <E T="7501">X</E>
                                    +0.36
                                </ENT>
                                <ENT>
                                    0.12 
                                    <E T="7501">X</E>
                                    +0.59
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Trichlorofluoromethane</ENT>
                                <ENT>0.99C+0.39</ENT>
                                <ENT>
                                    0.33 
                                    <E T="7501">X</E>
                                    −1.48
                                </ENT>
                                <ENT>
                                    0.34 
                                    <E T="7501">X</E>
                                    −0.39
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Vinyl chloride</ENT>
                                <ENT>1.00C</ENT>
                                <ENT>
                                    0.48 
                                    <E T="7501">X</E>
                                </ENT>
                                <ENT>
                                    0.65 
                                    <E T="7501">X</E>
                                </ENT>
                            </ROW>
                            <TNOTE>
                                <E T="7501">X</E>
                                ′ = Expected recovery for one or more measurements of a sample containing a concentration of C, in µg/L.
                            </TNOTE>
                            <TNOTE>
                                S
                                <E T="52">r</E>
                                ′ = Expected single analyst standard deviation of measurements at an average concentration found of 
                                <E T="7501">X</E>
                                , in µg/L.
                            </TNOTE>
                            <TNOTE>
                                S′ = Expected interlaboratory standard deviation of measurements at an average concentration found of 
                                <E T="7501">X</E>
                                , in µg/L.
                            </TNOTE>
                            <TNOTE>C = True value for the concentration, in µg/L.</TNOTE>
                            <TNOTE>
                                <E T="7501">X</E>
                                 = Average recovery found for measurements of samples containing a concentration of C, in µg/L.
                            </TNOTE>
                            <TNOTE>
                                <SU>a</SU>
                                 Estimates based upon the performance in a single laboratory (References 4 and 16).
                            </TNOTE>
                            <TNOTE>
                                <SU>b</SU>
                                 Due to coelutions, performance statements for these isomers are based upon the sums of their concentrations.
                            </TNOTE>
                        </GPOTABLE>
                        <HD SOURCE="HD3">19. Glossary</HD>
                        <P>These definitions and purposes are specific to this method, but have been conformed to common usage to the extent possible.</P>
                        <P>19.1 Units of weight and measure and their abbreviations.</P>
                        <P>19.1.1 Symbols.</P>
                        <FP SOURCE="FP-2"> °C degrees Celsius</FP>
                        <FP SOURCE="FP-2">µg microgram</FP>
                        <FP SOURCE="FP-2">µL microliter</FP>
                        <FP SOURCE="FP-2">&lt; less than</FP>
                        <FP SOURCE="FP-2">&gt; greater than</FP>
                        <FP SOURCE="FP-2">% percent</FP>
                        <P>19.1.2 Abbreviations (in alphabetical order).</P>
                        <FP SOURCE="FP-2">cm centimeter</FP>
                        <FP SOURCE="FP-2">g gram</FP>
                        <FP SOURCE="FP-2">h hour</FP>
                        <FP SOURCE="FP-2">ID inside diameter</FP>
                        <FP SOURCE="FP-2">in. inch</FP>
                        <FP SOURCE="FP-2">L liter</FP>
                        <FP SOURCE="FP-2">m mass</FP>
                        <FP SOURCE="FP-2">mg milligram</FP>
                        <FP SOURCE="FP-2">min minute</FP>
                        <FP SOURCE="FP-2">mL milliliter</FP>
                        <FP SOURCE="FP-2">mm millimeter</FP>
                        <FP SOURCE="FP-2">ms millisecond</FP>
                        <FP SOURCE="FP-2">m/z mass-to-charge ratio</FP>
                        <FP SOURCE="FP-1">N normal; gram molecular weight of solute divided by hydrogen equivalent of solute, per liter of solution</FP>
                        <FP SOURCE="FP-2">ng nanogram</FP>
                        <FP SOURCE="FP-2">pg picogram</FP>
                        <FP SOURCE="FP-2">ppb part-per-billion</FP>
                        <FP SOURCE="FP-2">ppm part-per-million</FP>
                        <FP SOURCE="FP-2">ppt part-per-trillion</FP>
                        <FP SOURCE="FP-2">psig pounds-per-square inch gauge</FP>
                        <FP SOURCE="FP-2">v/v volume per unit volume</FP>
                        <FP SOURCE="FP-2">w/v weight per unit volume</FP>
                        <P>19.2 Definitions and acronyms (in alphabetical order).</P>
                        <P>Analyte—A compound tested for by this method. The analytes are listed in Tables 1 and 2.</P>
                        <P>Analyte of interest—An analyte of interest is an analyte required to be determined by a regulatory/control authority or in a permit, or by a client.</P>
                        <P>
                            Analytical batch—The set of samples analyzed on a given instrument during a 12-hour period that begins with analysis of a calibration verification/LCS. See section 8.4.
                            <PRTPAGE P="269"/>
                        </P>
                        <P>Blank—An aliquot of reagent water that is treated exactly as a sample including exposure to all glassware, equipment, solvents, reagents, internal standards, and surrogates that are used with samples. The blank is used to determine if analytes or interferences are present in the laboratory environment, the reagents, or the apparatus. See section 8.5.</P>
                        <P>Calibration—The process of determining the relationship between the output or response of a measuring instrument and the value of an input standard. Historically, EPA has referred to a multi-point calibration as the “initial calibration,” to differentiate it from a single-point calibration verification.</P>
                        <P>Calibration standard—A solution prepared from stock solutions and/or a secondary standards and containing the analytes of interest, surrogates, and internal standards. The calibration standard is used to calibrate the response of the GC/MS instrument against analyte concentration.</P>
                        <P>Calibration verification standard—The laboratory control sample (LCS) used to verify calibration. See Section 8.4.</P>
                        <P>Descriptor—In SIM, the beginning and ending retention times for the RT window, the m/z's sampled in the RT window, and the dwell time at each m/z.</P>
                        <P>Extracted ion current profile (EICP)—The line described by the signal at a given m/z.</P>
                        <P>Field duplicates—Two samples collected at the same time and place under identical conditions, and treated identically throughout field and laboratory procedures. Results of analyses of field duplicates provide an estimate of the precision associated with sample collection, preservation, and storage, as well as with laboratory procedures.</P>
                        <P>Field blank—An aliquot of reagent water or other reference matrix that is placed in a sample container in the field, and treated as a sample in all respects, including exposure to sampling site conditions, storage, preservation, and all analytical procedures. The purpose of the field blank is to determine if the field or sample transporting procedures and environments have contaminated the sample.</P>
                        <P>GC—Gas chromatograph or gas chromatography.</P>
                        <P>Internal standard—A compound added to a sample in a known amount and used as a reference for quantitation of the analytes of interest and surrogates. Internal standards are listed in Table 5. Also see Internal standard quantitation.</P>
                        <P>Internal standard quantitation—A means of determining the concentration of an analyte of interest (Tables 1 and 2) by reference to a compound added to a sample and not expected to be found in the sample.</P>
                        <P>DOC—Initial demonstration of capability (DOC; section 8.2); four aliquots of reagent water spiked with the analytes of interest and analyzed to establish the ability of the laboratory to generate acceptable precision and recovery. A DOC is performed prior to the first time this method is used and any time the method or instrumentation is modified.</P>
                        <P>Laboratory control sample (LCS; laboratory fortified blank (LFB); on-going precision and recovery sample; OPR)—An aliquot of reagent water spiked with known quantities of the analytes of interest and surrogates. The LCS is analyzed exactly like a sample. Its purpose is to assure that the results produced by the laboratory remain within the limits specified in this method for precision and recovery. In this method, the LCS is synonymous with a calibration verification sample (See sections 7.4 and 8.4).</P>
                        <P>Laboratory fortified sample matrix—See Matrix spike.</P>
                        <P>Laboratory reagent blank—See Blank.</P>
                        <P>Matrix spike (MS) and matrix spike duplicate (MSD) (laboratory fortified sample matrix and duplicate)—Two aliquots of an environmental sample to which known quantities of the analytes of interest and surrogates are added in the laboratory. The MS/MSD are prepared and analyzed exactly like a field sample. Their purpose is to quantify any additional bias and imprecision caused by the sample matrix. The background concentrations of the analytes in the sample matrix must be determined in a separate aliquot and the measured values in the MS/MSD corrected for background concentrations.</P>
                        <P>May—This action, activity, or procedural step is neither required nor prohibited.</P>
                        <P>May not—This action, activity, or procedural step is prohibited.</P>
                        <P>Method blank (laboratory reagent blank)—See Blank.</P>
                        <P>Method detection limit (MDL)—A detection limit determined by the procedure at 40 CFR part 136, appendix B. The MDLs determined by EPA in the original version of the method are listed in Table 1. As noted in Sec. 1.4, use the MDLs in Table 1 in conjunction with current MDL data from the laboratory actually analyzing samples to assess the sensitivity of this procedure relative to project objectives and regulatory requirements (where applicable).</P>
                        <P>
                            Minimum level (ML)—The term “minimum level” refers to either the sample concentration equivalent to the lowest calibration point in a method or a multiple of the method detection limit (MDL), whichever is higher. Minimum levels may be obtained in several ways: They may be published in a method; they may be based on the lowest acceptable calibration point used by a laboratory; or they may be calculated by multiplying the MDL in a method, or the MDL determined by a laboratory, by a factor of 3. For the purposes of NPDES compliance monitoring, EPA considers the following terms to 
                            <PRTPAGE P="270"/>
                            be synonymous: “quantitation limit,” “reporting limit,” and “minimum level.”
                        </P>
                        <P>MS—Mass spectrometer or mass spectrometry.</P>
                        <P>Must—This action, activity, or procedural step is required.</P>
                        <P>m/z—The ratio of the mass of an ion (m) detected in the mass spectrometer to the charge (z) of that ion.</P>
                        <P>Quality control sample (QCS)—A sample containing analytes of interest at known concentrations. The QCS is obtained from a source external to the laboratory or is prepared from standards obtained from a different source than the calibration standards.</P>
                        <P>The purpose is to check laboratory performance using test materials that have been prepared independent of the normal preparation process.</P>
                        <P>Reagent water—Water demonstrated to be free from the analytes of interest and potentially interfering substances at the MDLs for the analytes in this method.</P>
                        <P>Regulatory compliance limit (or regulatory concentration limit)—A limit on the concentration or amount of a pollutant or contaminant specified in a nationwide standard, in a permit, or otherwise established by a regulatory/control authority.</P>
                        <P>Relative retention time (RRT)—The ratio of the retention time of an analyte to the retention time of its associated internal standard. RRT compensates for small changes in the GC temperature program that can affect the absolute retention times of the analyte and internal standard. RRT is a unitless quantity.</P>
                        <P>Relative standard deviation (RSD)—The standard deviation times 100 divided by the mean. Also termed “coefficient of variation.”</P>
                        <P>RF—Response factor. See section 7.3.3.</P>
                        <P>RSD—See relative standard deviation.</P>
                        <P>Safety Data Sheet (SDS)—Written information on a chemical's toxicity, health hazards, physical properties, fire, and reactivity, including storage, spill, and handling precautions that meet the requirements of OSHA, 29 CFR 1910.1200(g) and appendix D to § 1910.1200. United Nations Globally Harmonized System of Classification and Labelling of Chemicals (GHS), third revised edition, United Nations, 2009.</P>
                        <P>Selected Ion Monitoring (SIM)—An MS technique in which a few m/z's are monitored. When used with gas chromatography, the m/z's monitored are usually changed periodically throughout the chromatographic run to correlate with the characteristic m/z's for the analytes, surrogates, and internal standards as they elute from the chromatographic column. The technique is often used to increase sensitivity and minimize interferences.</P>
                        <P>Signal-to-noise ratio (S/N)—The height of the signal as measured from the mean (average) of the noise to the peak maximum divided by the width of the noise.</P>
                        <P>SIM—See Selection Ion Monitoring.</P>
                        <P>Should—This action, activity, or procedural step is suggested but not required.</P>
                        <P>Stock solution—A solution containing an analyte that is prepared using a reference material traceable to EPA, the National Institute of Science and Technology (NIST), or a source that will attest to the purity and authenticity of the reference material.</P>
                        <P>Surrogate—A compound unlikely to be found in a sample, and which is spiked into sample in a known amount before purge-and-trap. The surrogate is quantitated with the same procedures used to quantitate the analytes of interest. The purpose of the surrogate is to monitor method performance with each sample.</P>
                        <P>VOA—Volatile organic analysis: e.g., the analysis performed by this method.</P>
                        <HD SOURCE="HD1">Method 625.1—Base/Neutrals and Acids by GC/MS</HD>
                        <EAR>Pt. 136, App. A, Meth. 625.1</EAR>
                        <HD SOURCE="HD2">1. Scope and Application</HD>
                        <P>1.1 This method is for determination of semivolatile organic pollutants in industrial discharges and other environmental samples by gas chromatography combined with mass spectrometry (GC/MS), as provided under 40 CFR 136.1. This revision is based on a previous protocol (Reference 1), on the basic revision promulgated October 26, 1984, and on an interlaboratory method validation study (Reference 2). Although this method was validated through an interlaboratory study conducted in the early 1980s, the fundamental chemistry principles used in this method remain sound and continue to apply.</P>
                        <P>
                            1.2 The analytes that may be qualitatively and quantitatively determined using this method and their CAS Registry numbers are listed in Tables 1 and 2. The method may be extended to determine the analytes listed in Table 3; however, extraction or gas chromatography of some of these analytes may make quantitative determination difficult. For example, benzidine is subject to oxidative losses during extraction and/or solvent concentration. Under the alkaline conditions of the extraction, 
                            <E T="03">alpha</E>
                            -BHC, 
                            <E T="03">gamma</E>
                            -BHC, endosulfan I and II, and endrin are subject to decomposition. Hexachlorocyclopentadiene is subject to thermal decomposition in the inlet of the gas chromatograph, chemical reaction in acetone solution, and photochemical decomposition. N-nitrosodiphenylamine and other nitrosoamines may decompose in the gas chromatographic inlet. The sample may be extracted at neutral pH if necessary to overcome these or other decomposition problems that could occur at alkaline or acidic pH. EPA also has provided other methods (e.g., Method 607—Nitrosamines) that may be used for determination of some of these analytes. 
                            <PRTPAGE P="271"/>
                            EPA encourages use of Method 625.1 to determine additional compounds amenable to extraction and GC/MS.
                        </P>
                        <P>1.3 The large number of analytes in Tables 1-3 of this method makes testing difficult if all analytes are determined simultaneously. Therefore, it is necessary to determine and perform quality control (QC) tests for the “analytes of interest” only. Analytes of interest are those required to be determined by a regulatory/control authority or in a permit, or by a client. If a list of analytes is not specified, the analytes in Tables 1 and 2 must be determined, at a minimum, and QC testing must be performed for these analytes. The analytes in Tables 1 and 2, and some of the analytes in Table 3 have been identified as Toxic Pollutants (40 CFR 401.15), expanded to a list of Priority Pollutants (40 CFR part 423, appendix A).</P>
                        <P>
                            1.4 In this revision to Method 625, the pesticides and polychlorinated biphenyls (PCBs) have been moved from Table 1 to Table 3 (Additional Analytes) to distinguish these analytes from the analytes required in quality control tests (Tables 1 and 2). QC acceptance criteria for pesticides and PCBs have been retained in Table 6 and may continue to be applied if desired, or if requested or required by a regulatory/control authority or in a permit. Method 608.3 should be used for determination of pesticides and PCBs. However, if pesticides and/or PCBs are to be determined, an additional sample must be collected and extracted using the pH adjustment and extraction procedures specified in Method 608.3. Method 1668C may be useful for determination of PCBs as individual chlorinated biphenyl congeners, and Method 1699 may be useful for determination of pesticides. At the time of writing of this revision, Methods 1668C and 1699 had not been approved for use at 40 CFR part 136. The screening procedure for 2,3,7,8-tetrachlorodibenzo-
                            <E T="03">p</E>
                            -dioxin (2,3,7,8-TCDD) contained in the version of Method 625 promulgated October 26, 1984 has been replaced with procedures for selected ion monitoring (SIM), and 2,3,7,8-TCDD may be determined using the SIM procedures. However, EPA Method 613 or 1613B should be used for analyte-specific determination of 2,3,7,8-TCDD because of the focus of these methods on this compound. Methods 613 and 1613B are approved for use at 40 CFR part 136.
                        </P>
                        <P>1.5 Method detection limits (MDLs; Reference 3) for the analytes in Tables 1, 2, and 3 are listed in those tables. These MDLs were determined in reagent water (Reference 4). Advances in analytical technology, particularly the use of capillary (open-tubular) columns, allowed laboratories to routinely achieve MDLs for the analytes in this method that are 2-10 times lower than those in the version promulgated in 1984. The MDL for an analyte in a specific wastewater may differ from those listed, depending upon the nature of interferences in the sample matrix.</P>
                        <P>1.5.1 EPA has promulgated this method at 40 CFR part 136 for use in wastewater compliance monitoring under the National Pollutant Discharge Elimination System (NPDES). The data reporting practices described in section 15.2 are focused on such monitoring needs and may not be relevant to other uses of the method.</P>
                        <P>1.5.2 This method includes “reporting limits” based on EPA's “minimum level” (ML) concept (see the glossary in section 22). Tables 1, 2, and 3 contain MDL values and ML values for many of the analytes.</P>
                        <P>1.6 This method is performance-based. It may be modified to improve performance (e.g., to overcome interferences or improve the accuracy of results) provided all performance requirements are met.</P>
                        <P>1.6.1 Examples of allowed method modifications are described at 40 CFR 136.6. Other examples of allowed modifications specific to this method, including solid-phase extraction (SPE) are described in section 8.1.2.</P>
                        <P>1.6.2 Any modification beyond those expressly permitted at 40 CFR 136.6 or in section 8.1.2 of this method shall be considered a major modification subject to application and approval of an alternate test procedure under 40 CFR 136.4 and 136.5.</P>
                        <P>1.6.3 For regulatory compliance, any modification must be demonstrated to produce results equivalent or superior to results produced by this method when applied to relevant wastewaters (section 8.3).</P>
                        <P>1.7 This method is restricted to use by or under the supervision of analysts experienced in the use of a gas chromatograph/mass spectrometer and in the interpretation of mass spectra. Each laboratory that uses this method must demonstrate the ability to generate acceptable results using the procedure in Section 8.2.</P>
                        <P>1.8 Terms and units of measure used in this method are given in the glossary at the end of the method.</P>
                        <HD SOURCE="HD3">2. Summary of Method</HD>
                        <P>2.1 A measured volume of sample, sufficient to meet an MDL or reporting limit, is serially extracted with methylene chloride at pH 11-13 and again at a pH less than 2 using a separatory funnel or continuous liquid/liquid extractor.</P>
                        <P>
                            2.2 The extract is concentrated to a volume necessary to meet the required compliance or detection limit, and analyzed by GC/MS. Qualitative identification of an analyte in the extract is performed using the retention time and the relative abundance of two or more characteristic masses (m/z's). Quantitative analysis is performed using the internal standard technique with a single characteristic m/z.
                            <PRTPAGE P="272"/>
                        </P>
                        <HD SOURCE="HD3">3. Contamination and Interferences</HD>
                        <P>3.1 Solvents, reagents, glassware, and other sample processing labware may yield artifacts, elevated baselines, or matrix interferences causing misinterpretation of chromatograms and mass spectra. All materials used in the analysis must be demonstrated to be free from contamination and interferences by analyzing blanks initially and with each extraction batch (samples started through the extraction process in a given 24-hour period, to a maximum of 20 samples—see Glossary for detailed definition), as described in Section 8.5. Specific selection of reagents and purification of solvents by distillation in all-glass systems may be required. Where possible, labware is cleaned by extraction or solvent rinse, or baking in a kiln or oven.</P>
                        <P>3.2 Glassware must be scrupulously cleaned (Reference 5). Clean all glassware as soon as possible after use by rinsing with the last solvent used in it. Solvent rinsing should be followed by detergent washing with hot water, and rinses with tap water and reagent water. The glassware should then be drained dry, and heated at 400 °C for 15-30 minutes. Some thermally stable materials, such as PCBs, may require higher temperatures and longer baking times for removal. Solvent rinses with pesticide quality acetone, hexane, or other solvents may be substituted for heating. Do not heat volumetric labware above 90 °C. After drying and cooling, store inverted or capped with solvent-rinsed or baked aluminum foil in a clean environment to prevent accumulation of dust or other contaminants.</P>
                        <P>3.3 Matrix interferences may be caused by contaminants co-extracted from the sample. The extent of matrix interferences will vary considerably from source to source, depending upon the nature and diversity of the industrial complex or municipality being sampled. Interferences extracted from samples high in total organic carbon (TOC) may result in elevated baselines, or by enhancing or suppressing a signal at or near the retention time of an analyte of interest. Analyses of the matrix spike and duplicate (section 8.3) may be useful in identifying matrix interferences, and gel permeation chromatography (GPC; Section 11.1) and sulfur removal (section 11.2) may aid in eliminating these interferences. EPA has provided guidance that may aid in overcoming matrix interferences (Reference 6).</P>
                        <P>3.4 In samples that contain an inordinate number of interferences, the use of chemical ionization (CI) or triple quadrupole (MRM) mass spectrometry may make identification easier. Tables 4 and 5 give characteristic CI and MRM m/z's for many of the analytes covered by this method. The use of CI or MRM mass spectrometry may be utilized to support electron ionization (EI) mass spectrometry or as a primary method for identification and quantification. While the use of these enhanced techniques is encouraged, it is not required.</P>
                        <HD SOURCE="HD3">4. Safety</HD>
                        <P>4.1 Hazards associated with each reagent used in this method have not been precisely defined; however, each chemical compound should be treated as a potential health hazard. From this viewpoint, exposure to these chemicals must be reduced to the lowest possible level by whatever means available. The laboratory is responsible for maintaining a current awareness file of OSHA regulations regarding the safe handling of the chemicals specified in this method. A reference file of safety data sheets (SDSs, OSHA, 29 CFR 1910.1200(g)) should also be made available to all personnel involved in sample handling and chemical analysis. Additional references to laboratory safety are available and have been identified (References 7-9) for the information of the analyst.</P>
                        <P>
                            4.2 The following analytes covered by this method have been tentatively classified as known or suspected human or mammalian carcinogens: Benzo(a)anthracene, benzidine, 3,3′-dichlorobenzidine, benzo(a)pyrene, 
                            <E T="03">alpha</E>
                            -BHC, 
                            <E T="03">beta</E>
                            -BHC, 
                            <E T="03">delta</E>
                            -BHC, 
                            <E T="03">gamma</E>
                            -BHC, Dibenz(a,h)-anthracene, N-nitrosodimethylamine, 4,4′-DDT, and PCBs. Other compounds in Table 3 may also be toxic. Primary standards of toxic compounds should be prepared in a chemical fume hood, and a NIOSH/MESA approved toxic gas respirator should be worn when handling high concentrations of these compounds.
                        </P>
                        <P>4.3 This method allows the use of hydrogen as a carrier gas in place of helium (section 5.6.1.2). The laboratory should take the necessary precautions in dealing with hydrogen, and should limit hydrogen flow at the source to prevent buildup of an explosive mixture of hydrogen in air.</P>
                        <HD SOURCE="HD3">5. Apparatus and Materials</HD>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>Brand names, suppliers, and part numbers are for illustration purposes only. No endorsement is implied. Equivalent performance may be achieved using equipment and materials other than those specified here. Demonstrating that the equipment and supplies used in the laboratory achieves the required performance is the responsibility of the laboratory. Suppliers for equipment and materials in this method may be found through an on-line search. Please do not contact EPA for supplier information.</P>
                        </NOTE>
                        <P>5.1 Sampling equipment, for discrete or composite sampling.</P>
                        <P>
                            5.1.1 Grab sample bottle—amber glass bottle large enough to contain the necessary sample volume, fitted with a fluoropolymer-lined screw cap. Foil may be substituted for fluoropolymer if the sample is not corrosive. 
                            <PRTPAGE P="273"/>
                            If amber bottles are not available, protect samples from light. Unless pre-cleaned, the bottle and cap liner must be washed, rinsed with acetone or methylene chloride, and dried before use to minimize contamination.
                        </P>
                        <P>5.1.2 Automatic sampler (optional)—the sampler must incorporate a pre-cleaned glass sample container. Samples must be kept refrigerated at ≤6 °C and protected from light during compositing. If the sampler uses a peristaltic pump, a minimum length of compressible silicone rubber tubing may be used. Before use, however, rinse the compressible tubing with methanol, followed by repeated rinsing with reagent water, to minimize the potential for sample contamination. An integrating flow meter is required to collect flow-proportioned composites.</P>
                        <P>5.2 Glassware.</P>
                        <P>5.2.1 Separatory funnel—Size appropriate to hold sample volume and extraction solvent volume, and equipped with fluoropolymer stopcock.</P>
                        <P>5.2.2 Drying column—Chromatographic column, approximately 400 mm long by 19 mm ID, with coarse frit, or equivalent, sufficient to hold 15 g of anhydrous sodium sulfate.</P>
                        <P>5.2.3 Concentrator tube, Kuderna-Danish—10 mL, graduated (Kontes 570050-1025 or equivalent). Calibration must be checked at the volumes employed in the test. A ground glass stopper is used to prevent evaporation of extracts.</P>
                        <P>5.2.4 Evaporative flask, Kuderna-Danish—500 mL (Kontes 57001-0500 or equivalent). Attach to concentrator tube with springs.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>Use of a solvent recovery system with the K-D or other solvent evaporation apparatus is strongly recommended.</P>
                        </NOTE>
                        <P>5.2.5 Snyder column, Kuderna-Danish—Three-ball macro (Kontes 503000-0121 or equivalent).</P>
                        <P>5.2.6 Snyder column, Kuderna-Danish—Two-ball micro (Kontes 569001-0219 or equivalent).</P>
                        <P>5.2.7 Vials—10-15 mL, amber glass, with Teflon-lined screw cap.</P>
                        <P>5.2.8 Continuous liquid-liquid extractor—Equipped with fluoropolymer or glass connecting joints and stopcocks requiring no lubrication. (Hershberg-Wolf Extractor, Ace Glass Company, Vineland, NJ, P/N 6848-20, or equivalent.)</P>
                        <P>5.2.9 In addition to the glassware listed above, the laboratory should be equipped with all necessary pipets, volumetric flasks, beakers, and other glassware listed in this method and necessary to perform analyses successfully.</P>
                        <P>5.3 Boiling chips—Approximately 10/40 mesh, glass, silicon carbide, or equivalent. Heat to 400 °C for 30 minutes, or solvent rinse or Soxhlet extract with methylene chloride.</P>
                        <P>5.4 Water bath—Heated, with concentric ring cover, capable of temperature control (±2 °C). The bath should be used in a hood.</P>
                        <P>5.5 Balances.</P>
                        <P>5.5.1 Analytical, capable of accurately weighing 0.1 mg.</P>
                        <P>5.5.2 Top loading, capable of accurately weighing 10 mg.</P>
                        <P>5.6 GC/MS system.</P>
                        <P>5.6.1 Gas chromatograph (GC)—An analytical system complete with a temperature programmable gas chromatograph and all required accessories, including syringes and analytical columns.</P>
                        <P>5.6.1.1 Injection port—Can be split, splitless, temperature programmable vaporization split/splitless (PTV), solvent-purge, large-volume, on-column, backflushed, or other. An autosampler is highly recommended because it injects volumes more precisely than volumes injected manually.</P>
                        <P>5.6.1.2 Carrier gas—Helium or hydrogen. Data in the tables in this method were obtained using helium carrier gas. If hydrogen is used, analytical conditions may need to be adjusted for optimum performance, and calibration and all QC tests must be performed with hydrogen carrier gas. See Section 4.3 for precautions regarding the use of hydrogen as a carrier gas.</P>
                        <P>5.6.2 GC column—See the footnotes to Tables 4 and 5. Other columns or column systems may be used provided all requirements in this method are met.</P>
                        <P>5.6.3 Mass spectrometer—Capable of repetitively scanning from 35-450 Daltons (amu) every two seconds or less, utilizing a 70 eV (nominal) electron energy in the electron impact ionization mode, and producing a mass spectrum which meets all the criteria in Table 9A or 9B when 50 ng or less of decafluorotriphenyl phosphine (DFTPP; CAS 5074-71-5; bis(pentafluorophenyl) phenyl phosphine) is injected into the GC.</P>
                        <P>5.6.4 GC/MS interface—Any GC to MS interface that meets all performance requirements in this method may be used.</P>
                        <P>5.6.5 Data system—A computer system must be interfaced to the mass spectrometer that allows the continuous acquisition and storage of mass spectra acquired throughout the chromatographic program. The computer must have software that allows searching any GC/MS data file for specific m/z's (masses) and plotting m/z abundances versus time or scan number. This type of plot is defined as an extracted ion current profile (EICP). Software must also be available that allows integrating the abundance at any EICP between specified time or scan number limits.</P>
                        <P>5.7 Automated gel permeation chromatograph (GPC).</P>
                        <P>5.7.1 GPC column—150-700 mm long × 21-25 mm ID, packed with 70 g of SX-3 Biobeads; Bio-Rad Labs, or equivalent.</P>
                        <P>
                            5.7.2 Pump, injection valve, UV detector, and other apparatus necessary to meet the requirements in this method.
                            <PRTPAGE P="274"/>
                        </P>
                        <P>5.8 Nitrogen evaporation device—Equipped with a water bath than can be maintained at 30-45 °C; N-Evap, Organomation Associates, or equivalent.</P>
                        <P>5.9 Muffle furnace or kiln—Capable of baking glassware or sodium sulfate in the range of 400-450 °C.</P>
                        <HD SOURCE="HD3">6. Reagents</HD>
                        <P>6.1 Reagent water—Reagent water is defined as water in which the analytes of interest and interfering compounds are not detected at the MDLs of the analytes of interest.</P>
                        <P>6.2 Sodium hydroxide solution (10 N)—Dissolve 40 g of NaOH (ACS) in reagent water and dilute to 100 mL.</P>
                        <P>6.3 Sodium thiosulfate—(ACS) granular.</P>
                        <P>
                            6.4 Sulfuric acid (1+1)—Slowly add 50 mL of H
                            <E T="52">2</E>
                            SO
                            <E T="52">4</E>
                             (ACS, sp. gr. 1.84) to 50 mL of reagent water.
                        </P>
                        <P>6.5 Acetone, methanol, methylene chloride, 2-propanol—High purity pesticide quality, or equivalent, demonstrated to be free of the analytes of interest and interferences (Section 3). Purification of solvents by distillation in all-glass systems may be required.</P>
                        <P>6.6 Sodium sulfate—(ACS) granular, anhydrous, rinsed or Soxhlet extracted with methylene chloride (20 mL/g), baked in a shallow tray at 450 °C for one hour minimum, cooled in a desiccator, and stored in a pre-cleaned glass bottle with screw cap that prevents moisture from entering.</P>
                        <P>6.7 Stock standard solutions (1.00 µg/µL)—Stock standard solutions may be prepared from pure materials, or purchased as certified solutions. Traceability must be to the National Institute of Standards and Technology (NIST) or other national or international standard, when available. Stock solution concentrations alternate to those below may be used. Because of the toxicity of some of the compounds, primary dilutions should be prepared in a hood, and a NIOSH/MESA approved toxic gas respirator should be worn when high concentrations of neat materials are handled. The following procedure may be used to prepare standards from neat materials.</P>
                        <P>6.7.1 Prepare stock standard solutions by accurately weighing about 0.0100 g of pure material. Dissolve the material in pesticide quality methanol or other suitable solvent and dilute to volume in a 10-mL volumetric flask. Larger volumes may be used at the convenience of the laboratory. When compound purity is assayed to be 96% or greater, the weight may be used without correction to calculate the concentration of the stock standard. Commercially prepared stock standards may be used at any concentration if they are certified by the manufacturer or by an independent source.</P>
                        <P>6.7.2 Unless stated otherwise in this method, store non-aqueous standards in fluoropolymer-lined screw-cap, or heat-sealed, glass containers, in the dark at −20 to −10 °C. Store aqueous standards; e.g., the aqueous LCS (section 8.4.1), in the dark at ≤ 6 °C, but do not freeze. Standards prepared by the laboratory may be stored for up to one year, except when comparison with QC check standards indicates that a standard has degraded or become more concentrated due to evaporation, or unless the laboratory has data on file to prove stability for a longer period. Commercially prepared standards may be stored until the expiration date provided by the vendor, except when comparison with QC check standards indicates that a standard has degraded or become more concentrated due to evaporation, or unless the laboratory has data from the vendor on file to prove stability for a longer period.</P>
                        <P>6.8 Surrogate standard spiking solution.</P>
                        <P>6.8.1 Select a minimum of three surrogate compounds from Table 8 that most closely match the recovery of the analytes of interest. For example, if all analytes tested are considered acids, use surrogates that have similar chemical attributes. Other compounds may be used as surrogates so long as they do not interfere in the analysis. If only one or two analytes are determined, one or two surrogates may be used.</P>
                        <P>6.8.2 Prepare a solution containing each selected surrogate such that the concentration in the sample would match the concentration in the mid-point calibration standard. For example, if the midpoint of the calibration is 100 µg/L, prepare the spiking solution at a concentration of 100 µg/mL in methanol. Addition of 1.00 mL of this solution to 1000 mL of sample will produce a concentration of 100 µg/L of the surrogate. Alternate volumes and concentrations appropriate to the response of the GC/MS instrument or for selective ion monitoring (SIM) may be used, if desired. Store per section 6.7.2.</P>
                        <P>6.9 Internal standard spiking solution.</P>
                        <P>
                            6.9.1 Select three or more internal standards similar in chromatographic behavior to the analytes of interest. Internal standards are listed in Table 8. Suggested internal standards are: 1,4-dichlorobenzene-d
                            <E T="52">4</E>
                            ; naphthalene-d
                            <E T="52">8</E>
                            ; acenaphthene-d
                            <E T="52">10</E>
                            ; phenanthrene-d
                            <E T="52">10</E>
                            ; chrysene-d
                            <E T="52">12</E>
                            ; and perylene-d
                            <E T="52">12</E>
                            . The laboratory must demonstrate that measurement of the internal standards is not affected by method or matrix interferences (see also section 7.3.4).
                        </P>
                        <P>
                            6.9.2 Prepare the internal standards at a concentration of 10 mg/mL in methylene chloride or other suitable solvent. When 10 µL of this solution is spiked into a 1-mL extract, the concentration of the internal standards will be 100 µg/mL. A lower concentration appropriate to the response of the GC/MS instrument or for SIM may be used, if desired. Store per section 6.7.3.
                            <PRTPAGE P="275"/>
                        </P>
                        <P>6.9.3 To assure accurate analyte identification, particularly when SIM is used, it may be advantageous to include more internal standards than those suggested in section 6.9.1. An analyte will be located most accurately if its retention time relative to an internal standard is in the range of 0.8 to 1.2.</P>
                        <P>6.10 DFTPP standard—Prepare a solution of DFTPP in methanol or other suitable solvent such that 50 ng or less will be injected (see section 13.2). An alternative concentration may be used to compensate for specific injection volumes or to assure that the operating range of the instrument is not exceeded, so long as the total injected is 50 ng or less. Include benzidine and pentachlorophenol in this solution such that ≤100 ng of benzidine and ≤50 ng of pentachlorophenol will be injected.</P>
                        <P>6.11 Quality control check sample concentrate—See section 8.2.1.</P>
                        <P>6.12 GPC calibration solution.</P>
                        <P>6.12.1 Prepare a methylene chloride solution to contain corn oil, bis(2-ethylhexyl) phthalate (BEHP), perylene, and sulfur at the concentrations in section 6.12.2, or at concentrations appropriate to the response of the detector.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>Sulfur does not readily dissolve in methylene chloride, but is soluble in warm corn oil. The following procedure is suggested for preparation of the solution.</P>
                        </NOTE>
                        <P>6.12.2 Weigh 8 mg sulfur and 2.5 g corn oil into a 100-mL volumetric flask and warm to dissolve the sulfur. Separately weigh 100 mg BEHP, 20 mg pentachlorophenol, and 2 mg perylene and add to flask. Bring to volume with methylene chloride and mix thoroughly.</P>
                        <P>6.12.3 Store the solution in an amber glass bottle with a fluoropolymer-lined screw cap at 0-6 °C. Protect from light. Refrigeration may cause the corn oil to precipitate. Before use, allow the solution to stand at room temperature until the corn oil dissolves, or warm slightly to aid in dissolution. Replace the solution every year, or more frequently if the response of a component changes.</P>
                        <P>6.13 Sulfur removal—Copper foil or powder (bright, non-oxidized), or tetrabutylammonium sulfite (TBA sulfite).</P>
                        <P>6.13.1 Copper foil, or powder—Fisher, Alfa Aesar 42455-18, 625 mesh, or equivalent. Cut copper foil into approximately 1-cm squares. Copper must be activated before it may be used, as described below:</P>
                        <P>6.13.1.1 Place the quantity of copper needed for sulfur removal (section 11.2.1.3) in a ground-glass-stoppered Erlenmeyer flask or bottle. Cover the foil or powder with methanol.</P>
                        <P>6.13.1.2 Add HCl dropwise (0.5-1.0 mL) while swirling, until the copper brightens.</P>
                        <P>6.13.1.3 Pour off the methanol/HCl and rinse 3 times with reagent water to remove all traces of acid, then 3 times with acetone, then 3 times with hexane.</P>
                        <P>6.13.1.4 For copper foil, cover with hexane after the final rinse. Store in a stoppered flask under nitrogen until used. For the powder, dry on a rotary evaporator or under a stream of nitrogen. Store in a stoppered flask under nitrogen until used. Inspect the copper foil or powder before each use. It must have a bright, non-oxidized appearance to be effective. Copper foil or powder that has oxidized may be reactivated using the procedure described above.</P>
                        <P>6.13.2 Tetrabutylammonium sodium sulfite (TBA sodium sulfite).</P>
                        <P>
                            6.13.2.1 Tetrabutylammonium hydrogen sulfate, [CH
                            <E T="52">3</E>
                            (CH
                            <E T="52">2</E>
                            )
                            <E T="52">3</E>
                            ]
                            <E T="52">4</E>
                            NHSO
                            <E T="52">4</E>
                            .
                        </P>
                        <P>
                            6.13.2.2 Sodium sulfite, Na
                            <E T="52">2</E>
                            SO
                            <E T="52">3</E>
                            .
                        </P>
                        <P>6.13.2.3 Dissolve approximately 3 g tetrabutylammonium hydrogen sulfate in 100 mL of reagent water in an amber bottle with fluoropolymer-lined screw cap. Extract with three 20-mL portions of hexane and discard the hexane extracts.</P>
                        <P>6.13.2.4 Add 25 g sodium sulfite to produce a saturated solution. Store at room temperature. Replace after 1 month.</P>
                        <P>6.14 DDT and endrin decomposition (breakdown) solution—Prepare a solution containing endrin at a concentration of 1 µg/mL and 4,4′-DDT at a concentration of 2 µg/mL, in isooctane or hexane. A 1-µL injection of this standard will contain 1 nanogram (ng) of endrin and 2 ng of DDT. The concentration of the solution may be adjusted by the laboratory to accommodate other injection volumes such that the same masses of the two analytes are introduced into the instrument.</P>
                        <HD SOURCE="HD3">7. Calibration</HD>
                        <P>7.1 Establish operating conditions equivalent to those in the footnote to Table 4 or 5 for the base/neutral or acid fraction, respectively. If a combined base/neutral/acid fraction will be analyzed, use the conditions in the footnote to Table 4. Alternative temperature program and flow rate conditions may be used. It is necessary to calibrate the GC/MS for the analytes of interest (Section 1.3) only.</P>
                        <P>7.2 Internal standard calibration.</P>
                        <P>
                            7.2.1 Prepare calibration standards for the analytes of interest and surrogates at a minimum of five concentration levels by adding appropriate volumes of one or more stock standards to volumetric flasks. One of the calibration standards should be at a concentration at or below the ML specified in Table 1, 2, or 3, or as specified by a regulatory/control authority or in a permit. The ML value may be rounded to a whole number that is more convenient for preparing the standard, but must not exceed the ML in Table 1, 2, or 3 for those analytes which list ML values. Alternatively, the laboratory may establish a laboratory ML for each analyte based on the concentration in a 
                            <PRTPAGE P="276"/>
                            nominal whole-volume sample that is equivalent to the concentration of the lowest calibration standard in a series of standards produced in the laboratory or obtained from a commercial vendor. The laboratory's ML must not exceed the ML in Table 1, 2, or 3, and the resulting calibration must meet the acceptance criteria in Section 7.2.3, based on the RSD, RSE, or R
                            <SU>2</SU>
                            . The concentrations of the other calibration standards should correspond to the expected range of concentrations found in real samples or should define the working range of the GC/MS system for full-scan and/or SIM operation, as appropriate. A minimum of six concentration levels is required for a second order, non-linear (e.g., quadratic; ax
                            <SU>2</SU>
                             + bx + c = 0) calibration (section 7.2.3). Calibrations higher than second order are not allowed. To each calibration standard or standard mixture, add a known constant volume of the internal standard solution (section 6.9), and dilute to volume with methylene chloride.
                        </P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>The large number of analytes in Tables 1 through 3 may not be soluble or stable in a single solution; multiple solutions may be required if a large number of analytes are to be determined simultaneously.</P>
                        </NOTE>
                        <P>7.2.1.1 Prior to analysis of the calibration standards, inject the DFTPP standard (Section 6.10) and adjust the scan rate of the mass spectrometer to produce a minimum of 5 mass spectra across the DFTPP GC peak. Adjust instrument conditions until the DFTPP criteria in Table 9A or 9B are met. Calculate peak tailing factors for benzidine and pentachlorophenol. Calculation of the tailing factor is illustrated in Figure 1. The tailing factor for benzidine and pentachlorophenol must be &lt;2; otherwise, adjust instrument conditions and either replace the column or break off a short section of the front end of the column, and repeat the test. Once the scan conditions are established, they must be used for analyses of all standards, blanks, and samples.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>The DFTPP spectrum may be evaluated by summing the intensities of the m/z's across the GC peak, subtracting the background at each m/z in a region of the chromatogram within 20 scans of but not including any part of, the DFTPP peak. The DFTPP spectrum may also be evaluated by fitting a Gaussian to each m/z and using the intensity at the maximum for each Gaussian or by integrating the area at each m/z and using the integrated areas. Other means may be used for evaluation of the DFTPP spectrum so long as the spectrum is not distorted to meet the criteria in Table 9A or 9B.</P>
                        </NOTE>
                        <P>7.2.1.2 Analyze the mid-point combined base/neutral and acid calibration standard and enter or review the retention time, relative retention time, mass spectrum, and quantitation m/z in the data system for each analyte of interest, surrogate, and internal standard. If additional analytes (Table 3) are to be quantified, include these analytes in the standard. The mass spectrum for each analyte must be comprised of a minimum of 2 m/z's (Tables 4 and 5); 3 to 5 m/z's assure more reliable analyte identification. Suggested quantitation m/z's are shown in Tables 4 and 5 as the primary m/z. If an interference occurs at the primary m/z, use one of the secondary m/z's or an alternate m/z. A single m/z only is required for quantitation.</P>
                        <P>7.2.1.3 For SIM operation, determine the analytes in each descriptor, the quantitation m/z for each analyte (the quantitation m/z can be the same as for full-scan operation; section 7.2.1.2), the dwell time on each m/z for each analyte, and the beginning and ending retention time for each descriptor. Analyze the verification standard in scan mode to verify m/z's and establish retention times for the analytes. There must be a minimum of two m/z's for each analyte to assure analyte identification. To maintain sensitivity, the number of m/z's in a descriptor should be limited. For example, for a descriptor with 10 m/z's and a chromatographic peak width of 5 sec, a dwell time of 100 ms at each m/z would result in a scan time of 1 second and provide 5 scans across the GC peak. The quantitation m/z will usually be the most intense peak in the mass spectrum. The quantitation m/z and dwell time may be optimized for each analyte. The acquisition table used for SIM must take into account the mass defect (usually less than 0.2 Dalton) that can occur at each m/z monitored. Refer to the footnotes to Table 4 or 5 for establishing operating conditions and to section 7.2.1.1 for establishing scan conditions.</P>
                        <P>7.2.1.4 For combined scan and SIM operation, set up the scan segments and descriptors to meet requirements in sections 7.2.1.1-7.2.1.3. Analyze unfamiliar samples in the scan mode to assure that the analytes of interest are determined.</P>
                        <P>7.2.2 Analyze each calibration standard according to section 12 and tabulate the area at the quantitation m/z against concentration for each analyte of interest, surrogate, and internal standard. If an interference is encountered, use a secondary m/z (Table 4 or 5) for quantitation. Calculate a response factor (RF) for each analyte of interest at each concentration using Equation 1.</P>
                        <GPH SPAN="2" DEEP="29">
                            <PRTPAGE P="277"/>
                            <GID>ER28AU17.014</GID>
                        </GPH>
                        <FP SOURCE="FP-2">where:</FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">s</E>
                             = Area of the characteristic m/z for the analyte of interest or surrogate.
                        </FP>
                        <FP SOURCE="FP-2">
                            A
                            <E T="52">is</E>
                             = Area of the characteristic m/z for the internal standard.
                        </FP>
                        <FP SOURCE="FP-2">
                            C
                            <E T="52">is</E>
                             = Concentration of the internal standard (µg/mL).
                        </FP>
                        <FP SOURCE="FP-2">
                            C
                            <E T="52">s</E>
                             = Concentration of the analyte of interest or surrogate (µg/mL).
                        </FP>
                        <P>
                            7.2. Calculate the mean (average) and relative standard deviation (RSD) of the responses factors. If the RSD is less than 35%, the RF can be assumed to be invariant and the average RF can be used for calculations. Alternatively, the results can be used to fit a linear or quadratic regression of response ratios, As/Ais, vs. concentration ratios Cs/Cis. If used, the regression must be weighted inversely proportional to concentration. The coefficient of determination (R
                            <SU>2</SU>
                            ; Reference 10) of the weighted regression must be greater than 0.920 (this value roughly corresponds to the RSD limit of 35%). Alternatively, the relative standard error (Reference 11) may be used as an acceptance criterion. As with the RSD, the RSE must be less than 35%. If an RSE less than 35% cannot be achieved for a quadratic regression, system performance is unacceptable and the system must be adjusted and re-calibrated.
                        </P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>Using capillary columns and current instrumentation, it is quite likely that a laboratory can calibrate the target analytes in this method and achieve a linearity metric (either RSD or RSE) well below 35%. Therefore, laboratories are permitted to use more stringent acceptance criteria for calibration than described here, for example, to harmonize their application of this method with those from other sources.</P>
                        </NOTE>
                        <P>7.3 Calibration verification—The RF or calibration curve must be verified immediately after calibration and at the beginning of each 12-hour shift, by analysis of a standard at or near the concentration of the mid-point calibration standard (section 7.2.1). The standard(s) must be obtained from a second manufacturer or a manufacturer's batch prepared independently from the batch used for calibration. Traceability must be to a national standard, when available. Include the surrogates (section 6.8) in this solution. It is necessary to verify calibration for the analytes of interest (section 1.3) only.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>The 12-hour shift begins after the DFTPP (section 13.1) and DDT/endrin tests (if DDT and endrin are to be determined), and after analysis of the calibration verification standard. The 12-hour shift ends 12 hours later. The DFTPP, DDT/endrin, and calibration verification tests are outside of the 12-hour shift.</P>
                        </NOTE>
                        <P>7.3.1 Analyze the calibration verification standard(s) beginning in section 12. Calculate the percent recovery of each analyte. Compare the recoveries for the analytes of interest against the acceptance criteria for recovery (Q) in Table 6, and the recoveries for the surrogates against the acceptance criteria in Table 8. If recovery of the analytes of interest and surrogates meet acceptance criteria, system performance is acceptable and analysis of samples may continue. If any individual recovery is outside its limit, system performance is unacceptable for that analyte.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>The large number of analytes in Tables 6 and 8 present a substantial probability that one or more will fail acceptance criteria when all analytes are tested simultaneously.</P>
                        </NOTE>
                        <P>7.3.2 When one or more analytes fail acceptance criteria, analyze a second aliquot of the calibration verification standard and compare ONLY those analytes that failed the first test (section 7.3.1) with their respective acceptance criteria. If these analytes now pass, system performance is acceptable and analysis of samples may continue. A repeat failure of any analyte that failed the first test, however, will confirm a general problem with the measurement system. If this occurs, repair the system (section 7.2.1.1) and repeat the test (section 7.3.1), or prepare a fresh calibration standard and repeat the test. If calibration cannot be verified after maintenance or injection of the fresh calibration standard, re-calibrate the instrument.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>
                                If it is necessary to perform a repeat verification test frequently; 
                                <E T="03">i.e.,</E>
                                 perform two tests in order to pass, it may be prudent to perform two injections in succession and review the results, rather than perform one injection, review the results, then perform the second injection if results from the first injection fail. To maintain the validity of the test and re-test, system maintenance and/or adjustment is not permitted between the injections.
                            </P>
                        </NOTE>
                        <P>
                            7.3.3 Many of the analytes in Table 3 do not have QC acceptance criteria in Table 6, and some of the surrogates in Table 8 do not have acceptance criteria. If calibration is to be verified and other QC tests are to be performed for these analytes, acceptance criteria must be developed and applied. EPA has provided guidance for development of QC acceptance criteria (References 12 and 13). Alternatively, analytes that do not have acceptance criteria in Table 6 or Table 8 may 
                            <PRTPAGE P="278"/>
                            be based on laboratory control charts, or 60 to 140% may be used.
                        </P>
                        <P>7.3.4 Internal standard responses—Verify that detector sensitivity has not changed by comparing the response of each internal standard in the calibration verification standard (section 7.3) to the response of the respective internal standard in the midpoint calibration standard (section 7.2.1). The peak areas or heights of the internal standards in the calibration verification standard must be within 50% to 200% (1/2 to 2x) of their respective peak areas or heights in the mid-point calibration standard. If not, repeat the calibration verification test using a fresh calibration verification standard (7.3), or perform and document system repair. Subsequent to repair, repeat the calibration verification test (section 7.3.1). If the responses are still not within 50% to 200%, re-calibrate the instrument (section 7.2.2) and repeat the calibration verification test.</P>
                        <HD SOURCE="HD3">8. Quality Control</HD>
                        <P>8.1 Each laboratory that uses this method is required to operate a formal quality assurance program. The minimum requirements of this program consist of an initial demonstration of laboratory capability and ongoing analysis of spiked samples and blanks to evaluate and document data quality (40 CFR 136.7). The laboratory must maintain records to document the quality of data generated. Results of ongoing performance tests are compared with established QC acceptance criteria to determine if the results of analyses meet performance requirements of this method. When results of spiked samples do not meet the QC acceptance criteria in this method, a quality control check sample (laboratory control sample; LCS) must be analyzed to confirm that the measurements were performed in an in-control mode of operation. A laboratory may develop its own performance criteria (as QC acceptance criteria), provided such criteria are as or more restrictive than the criteria in this method.</P>
                        <P>8.1.1 The laboratory must make an initial demonstration of capability (DOC) to generate acceptable precision and recovery with this method. This demonstration is detailed in Section 8.2.</P>
                        <P>8.1.2 In recognition of advances that are occurring in analytical technology, and to overcome matrix interferences, the laboratory is permitted certain options (section 1.6 and 40 CFR 136.6(b)) to improve separations or lower the costs of measurements. These options may include alternate extraction, concentration, and cleanup procedures (e.g., solid-phase extraction; rotary-evaporator concentration; column chromatography cleanup), changes in column and type of mass spectrometer (40 CFR 136.6(b)(4)(xvi)). Alternate determinative techniques, such as substitution of spectroscopic or immunoassay techniques, and changes that degrade method performance, are not allowed. If an analytical technique other than GC/MS is used, that technique must have a specificity equal to or greater than the specificity of GC/MS for the analytes of interest. The laboratory is also encouraged to participate in inter-comparison and performance evaluation studies (see section 8.10).</P>
                        <P>8.1.2.1 Each time a modification is made to this method, the laboratory is required to repeat the procedure in section 8.2. If the detection limit of the method will be affected by the change, the laboratory must demonstrate that the MDLs (40 CFR part 136, appendix B) are lower than one-third the regulatory compliance limit or the MDLs in this method, whichever are greater. If calibration will be affected by the change, the instrument must be recalibrated per section 7. Once the modification is demonstrated to produce results equivalent or superior to results produced by this method, that modification may be used routinely thereafter, so long as the other requirements in this method are met (e.g., matrix spike/matrix spike duplicate recovery and relative percent difference).</P>
                        <P>8.1.2.1.1 If SPE, or another allowed method modification, is to be applied to a specific discharge, the laboratory must prepare and analyze matrix spike/matrix spike duplicate (MS/MSD) samples (section 8.3) and LCS samples (section 8.4). The laboratory must include surrogates (section 8.7) in each of the samples. The MS/MSD and LCS samples must be fortified with the analytes of interest (Section 1.3). If the modification is for nationwide use, MS/MSD samples must be prepared from a minimum of nine different discharges (See section 8.1.2.1.2), and all QC acceptance criteria in this method must be met. This evaluation only needs to be performed once other than for the routine QC required by this method (for example it could be performed by the vendor of the SPE materials) but any laboratory using that specific material must have the results of the study available. This includes a full data package with the raw data that will allow an independent reviewer to verify each determination and calculation performed by the laboratory (see section 8.1.2.2.5, items (a)-(q)).</P>
                        <P>8.1.2.1.2 Sample matrices on which MS/MSD tests must be performed for nationwide use of an allowed modification:</P>
                        <P>(a) Effluent from a POTW.</P>
                        <P>(b) ASTM D5905 Standard Specification for Substitute Wastewater.</P>
                        <P>(c) Sewage sludge, if sewage sludge will be in the permit.</P>
                        <P>(d) ASTM D1141 Standard Specification for Substitute Ocean Water, if ocean water will be in the permit.</P>
                        <P>
                            (e) Untreated and treated wastewaters up to a total of nine matrix types (see 
                            <E T="03">https://www.epa.gov/eg/industrial-effluent-guidelines</E>
                             
                            <PRTPAGE P="279"/>
                            for a list of industrial categories with existing effluent guidelines).
                        </P>
                        <P>(i) At least one of the above wastewater matrix types must have at least one of the following characteristics:</P>
                        <P>(A) Total suspended solids greater than 40 mg/L.</P>
                        <P>(B) Total dissolved solids greater than 100 mg/L.</P>
                        <P>(C) Oil and grease greater than 20 mg/L.</P>
                        <P>(D) NaCl greater than 120 mg/L.</P>
                        <P>
                            (E) CaCO
                            <E T="52">3</E>
                             greater than 140 mg/L.
                        </P>
                        <P>(ii) Results of MS/MSD tests must meet QC acceptance criteria in Section 8.3.</P>
                        <P>(f) A proficiency testing (PT) sample from a recognized provider, in addition to tests of the nine matrices (section 8.1.2.1.1).</P>
                        <P>8.1.2.2 The laboratory is required to maintain records of modifications made to this method. These records include the following, at a minimum:</P>
                        <P>8.1.2.2.1 The names, titles, and business street addresses, telephone numbers, and email addresses, of the analyst(s) that performed the analyses and modification, and of the quality control officer that witnessed and will verify the analyses and modifications.</P>
                        <P>8.1.2.2.2 A list of analytes, by name and CAS Registry Number.</P>
                        <P>8.1.2.2.3 A narrative stating reason(s) for the modifications.</P>
                        <P>8.1.2.2.4 Results from all quality control (QC) tests comparing the modified method to this method, including:</P>
                        <P>(a) Calibration (section 7).</P>
                        <P>(b) Calibration verification (section 7).</P>
                        <P>(c) Initial demonstration of capability (section 8.2).</P>
                        <P>(d) Analysis of blanks (section 8.5).</P>
                        <P>(e) Matrix spike/matrix spike duplicate analysis (section 8.3).</P>
                        <P>(f) Laboratory control sample analysis (section 8.4).</P>
                        <P>8.1.2.2.5 Data that will allow an independent reviewer to validate each determination by tracing the instrument output (peak height, area, or other signal) to the final result. These data are to include:</P>
                        <P>(a) Sample numbers and other identifiers.</P>
                        <P>(b) Extraction dates.</P>
                        <P>(c) Analysis dates and times.</P>
                        <P>(d) Analysis sequence/run chronology.</P>
                        <P>(e) Sample weight or volume (ssection 10).</P>
                        <P>(f) Extract volume prior to each cleanup step (sections 10 and 11).</P>
                        <P>(g) Extract volume after each cleanup step (section 11).</P>
                        <P>(h) Final extract volume prior to injection (sections 10 and 12).</P>
                        <P>(i) Injection volume (section 12.2.3).</P>
                        <P>(j) Sample or extract dilution (section 12.2.3.2).</P>
                        <P>(k) Instrument and operating conditions.</P>
                        <P>(l) Column (dimensions, material, etc).</P>
                        <P>(m) Operating conditions (temperature program, flow rate, etc).</P>
                        <P>(n) Detector (type, operating conditions, etc).</P>
                        <P>(o) Chromatograms, mass spectra, and other recordings of raw data.</P>
                        <P>(p) Quantitation reports, data system outputs, and other data to link the raw data to the results reported.</P>
                        <P>(q) A written Standard Operating Procedure (SOP).</P>
                        <P>8.1.2.2.6 Each individual laboratory wishing to use a given modification must perform the start-up tests in section 8.1.2 (e.g., DOC, MDL), with the modification as an integral part of this method prior to applying the modification to specific discharges. Results of the DOC must meet the QC acceptance criteria in Table 6 for the analytes of interest (section 1.3), and the MDLs must be equal to or lower than the MDLs in Tables 1, 2, or 3 for the analytes of interest.</P>
                        <P>8.1.3 Before analyzing samples, the laboratory must analyze a blank to demonstrate that interferences from the analytical system, labware, and reagents, are under control. Each time a batch of samples is extracted or reagents are changed, a blank must be extracted and analyzed as a safeguard against laboratory contamination. Requirements for the blank are given in section 8.5.</P>
                        <P>8.1.4 The laboratory must, on an ongoing basis, spike and analyze to monitor and evaluate method and laboratory performance on the sample matrix. The procedure for spiking and analysis is given in section 8.3.</P>
                        <P>8.1.5 The laboratory must, on an ongoing basis, demonstrate through analysis of a quality control check sample (laboratory control sample, LCS; on-going precision and recovery sample, OPR) that the measurement system is in control. This procedure is given in section 8.4.</P>
                        <P>8.1.6 The laboratory must maintain performance records to document the quality of data that is generated. This procedure is given in section 8.9.</P>
                        <P>8.1.7 The large number of analytes tested in performance tests in this method present a substantial probability that one or more will fail acceptance criteria when many analytes are tested simultaneously, and a re-test is allowed if this situation should occur. If, however, continued re-testing results in further repeated failures, the laboratory must document and report the failures (e.g., as qualifiers on results), unless the failures are not required to be reported as determined by the regulatory/control authority. Results associated with a QC failure for an analyte regulated in a discharge cannot be used to demonstrate regulatory compliance. QC failures do not relieve a discharger or permittee of reporting timely results.</P>
                        <P>
                            8.2 Initial demonstration of capability (DOC)—To establish the ability to generate acceptable recovery and precision, the laboratory must perform the DOC in sections 
                            <PRTPAGE P="280"/>
                            8.2.1 through 8.2.6 for the analytes of interest. The laboratory must also establish MDLs for the analytes of interest using the MDL procedure at 40 CFR part 136, appendix B. The laboratory's MDLs must be equal to or lower than those listed in Tables 1, 2, or 3 or lower than one third the regulatory compliance limit, whichever is greater. For MDLs not listed in Tables 4 and 5, the laboratory must determine the MDLs using the MDL procedure at 40 CFR part 136, appendix B under the same conditions used to determine the MDLs for the analytes listed in Tables 1, 2, and 3. All procedures used in the analysis, including cleanup procedures, must be included in the DOC.
                        </P>
                        <P>8.2.1 For the DOC, a QC check sample concentrate (LCS concentrate) containing each analyte of interest (section 1.3) is prepared in a water-miscible solvent. The QC check sample concentrate must be prepared independently from those used for calibration, but may be from the same source as the second-source standard used for calibration verification (Section 7.3). The concentrate should produce concentrations of the analytes of interest in water at the mid-point of the calibration range, and may be at the same concentration as the LCS (section 8.4). Multiple solutions may be required.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>QC check sample concentrates are no longer available from EPA.</P>
                        </NOTE>
                        <P>8.2.2 Using a pipet or micro-syringe, prepare four LCSs by adding an appropriate volume of the concentrate to each of four aliquots of reagent water, and mix well. The volume of reagent water must be the same as the volume that will be used for the sample, blank (section 8.5), and MS/MSD (section 8.3). A volume of 1-L and a concentration of 100 µg/L were used to develop the QC acceptance criteria in Table 6. Also add an aliquot of the surrogate spiking solution (section 6.8) to the reagent-water aliquots.</P>
                        <P>8.2.3 Extract and analyze the four LCSs according to the method beginning in Section 10.</P>
                        <P>
                            8.2.4 Calculate the average percent recovery (
                            <E T="7501">X</E>
                            ) and the standard deviation of the percent recovery (s) for each analyte using the four results.
                        </P>
                        <P>
                            8.2.5 For each analyte, compare s and (
                            <E T="7501">X</E>
                            ) with the corresponding acceptance criteria for precision and recovery in Table 6. For analytes in Table 3 not listed in Table 6, DOC QC acceptance criteria must be developed by the laboratory. EPA has provided guidance for development of QC acceptance criteria (References 12 and 13). Alternatively, acceptance criteria for analytes not listed in Table 6 may be based on laboratory control charts. If s and (
                            <E T="7501">X</E>
                            ) for all analytes of interest meet the acceptance criteria, system performance is acceptable and analysis of blanks and samples may begin. If any individual s exceeds the precision limit or any individual (
                            <E T="7501">X</E>
                            ) falls outside the range for recovery, system performance is unacceptable for that analyte.
                        </P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>The large number of analytes in Tables 1-3 present a substantial probability that one or more will fail at least one of the acceptance criteria when many or all analytes are determined simultaneously. Therefore, the analyst is permitted to conduct a “re-test” as described in section 8.2.6.</P>
                        </NOTE>
                        <P>8.2.6 When one or more of the analytes tested fail at least one of the acceptance criteria, repeat the test for only the analytes that failed. If results for these analytes pass, system performance is acceptable and analysis of samples and blanks may proceed. If one or more of the analytes again fail, system performance is unacceptable for the analytes that failed the acceptance criteria. Correct the problem and repeat the test (section 8.2). See section 8.1.7 for disposition of repeated failures.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>To maintain the validity of the test and re-test, system maintenance and/or adjustment is not permitted between this pair of tests.</P>
                        </NOTE>
                        <P>8.3 Matrix spike and matrix spike duplicate (MS/MSD)—The purpose of the MS/MSD requirement is to provide data that demonstrate the effectiveness of the method as applied to the samples in question by a given laboratory, and both the data user (discharger, permittee, regulated entity, regulatory/control authority, customer, other) and the laboratory share responsibility for provision of such data. The data user should identify the sample and the analytes of interest (section 1.3) to be spiked and provide sufficient sample volume to perform MS/MSD analyses. The laboratory must, on an ongoing basis, spike at least 5% of the samples in duplicate from each discharge being monitored to assess accuracy (recovery and precision). If direction cannot be obtained from the data user, the laboratory must spike at least one sample in duplicate per extraction batch of up to 20 samples with the analytes in Table 1. Spiked sample results should be reported only to the data user whose sample was spiked, or as requested or required by a regulatory/control authority, or in a permit.</P>
                        <P>8.3.1 If, as in compliance monitoring, the concentration of a specific analyte will be checked against a regulatory concentration limit, the concentration of the spike should be at that limit; otherwise, the concentration of the spike should be one to five times higher than the background concentration determined in section 8.3.2, at or near the midpoint of the calibration range, or at the concentration in the LCS (section 8.4) whichever concentration would be larger.</P>
                        <P>
                            8.3.2 Analyze one sample aliquot to determine the background concentration (B) of the each analyte of interest. If necessary, prepare a new check sample concentrate (section 8.2.1) appropriate for the background 
                            <PRTPAGE P="281"/>
                            concentration. Spike and analyze two additional sample aliquots, and determine the concentration after spiking (A
                            <E T="52">1</E>
                             and A
                            <E T="52">2</E>
                            ) of each analyte. Calculate the percent recoveries (P
                            <E T="52">1</E>
                             and P
                            <E T="52">2</E>
                            ) as 100 (A
                            <E T="52">1</E>
                             − B)/T and 100 (A
                            <E T="52">2</E>
                             − B)/T, where T is the known true value of the spike. Also calculate the relative percent difference (RPD) between the concentrations (A
                            <E T="52">1</E>
                             and A
                            <E T="52">2</E>
                            ) as 200 |A
                            <E T="52">1</E>
                             − A
                            <E T="52">2</E>
                            |/(A
                            <E T="52">1</E>
                             + A
                            <E T="52">2</E>
                            ). If necessary, adjust the concentrations used to calculate the RPD to account for differences in the volumes of the spiked aliquots.
                        </P>
                        <P>
                            8.3.3 Compare the percent recoveries (P
                            <E T="52">1</E>
                             and P
                            <E T="52">2</E>
                            ) and the RPD for each analyte in the MS/MSD aliquots with the corresponding QC acceptance criteria in Table 6. A laboratory may develop and apply QC acceptance criteria more restrictive than the criteria in Table 6, if desired.
                        </P>
                        <P>8.3.3.1 If any individual P falls outside the designated range for recovery in either aliquot, or the RPD limit is exceeded, the result for the analyte in the unspiked sample is suspect. See Section 8.1.7 for disposition of failures.</P>
                        <P>
                            8.3.3.2 The acceptance criteria in Table 6 were calculated to include an allowance for error in measurement of both the background and spike concentrations, assuming a spike to background ratio of 5:1. This error will be accounted for to the extent that the spike to background ratio approaches 5:1 (Reference 14) and is applied to spike concentrations of 100 µg/L and higher. If spiking is performed at a concentration lower than 100 µg/L, the laboratory must use the QC acceptance criteria in Table 6, the optional QC acceptance criteria calculated for the specific spike concentration in Table 7, or optional in-house criteria (section 8.3.4). To use the acceptance criteria in Table 7: (1) Calculate recovery (X′) using the equation in Table 7, substituting the spike concentration (T) for C; (2) Calculate overall precision (S′) using the equation in Table 7, substituting X′ for 
                            <E T="7501">X</E>
                            ; (3) Calculate the range for recovery at the spike concentration as (100 X′/T) ± 2.44(100 S′/T)% (Reference 14). For analytes in Table 3 not listed in Table 6, QC acceptance criteria must be developed by the laboratory. EPA has provided guidance for development of QC acceptance criteria (References 12 and 13). Alternatively, acceptance criteria may be based on laboratory control charts.
                        </P>
                        <P>8.3.4 After analysis of a minimum of 20 MS/MSD samples for each target analyte and surrogate, and if the laboratory chooses to develop and apply the optional in-house QC limits (Section 8.3.3), the laboratory should calculate and apply the optional in-house QC limits for recovery and RPD of future MS/MSD samples (Section 8.3). The QC limits for recovery are calculated as the mean observed recovery ±3 standard deviations, and the upper QC limit for RPD is calculated as the mean RPD plus 3 standard deviations of the RPDs. The in-house QC limits must be updated at least every two years and re-established after any major change in the analytical instrumentation or process. If in-house QC limits are developed, at least 80% of the analytes tested in the MS/MSD must have in-house QC acceptance criteria that are tighter than those in Table 6, and the remaining analytes (those other than the analytes included in the 80%) must meet the acceptance criteria in Table 6. If an in-house QC limit for the RPD is greater than the limit in Table 6, then the limit in Table 6 must be used. Similarly, if an in-house lower limit for recovery is below the lower limit in Table 6, then the lower limit in Table 6 must be used, and if an in-house upper limit for recovery is above the upper limit in Table 6, then the upper limit in Table 6 must be used.</P>
                        <P>8.4 Laboratory control sample (LCS)—A QC check sample (laboratory control sample, LCS; on-going precision and recovery sample, OPR) containing each analyte of interest (Section 1.3) and surrogate must be prepared and analyzed with each extraction batch of up to 20 samples to demonstrate acceptable recovery of the analytes of interest from a clean sample matrix.</P>
                        <P>8.4.1 Prepare the LCS by adding QC check sample concentrate (section 8.2.1) to reagent water. Include all analytes of interest (section 1.3) in the LCS. The LCS may be the same sample prepared for the DOC (section 8.2.1). The volume of reagent water must be the same as the volume used for the sample, blank (section 8.5), and MS/MSD (Section 8.3). Also add an aliquot of the surrogate spiking solution (section 6.8). The concentration of the analytes in reagent water should be the same as the concentration in the DOC (section 8.2.2).</P>
                        <P>8.4.2 Analyze the LCS prior to analysis of field samples in the extraction batch. Determine the concentration (A) of each analyte. Calculate the percent recovery (PS) as 100 (A/T)%, where T is the true value of the concentration in the LCS.</P>
                        <P>8.4.3 Compare the percent recovery (PS) for each analyte with its corresponding QC acceptance criterion in Table 6. For analytes of interest in Table 3 not listed in Table 6, use the QC acceptance criteria developed for the LCS (section 8.4.5), or limits based on laboratory control charts. If the recoveries for all analytes of interest fall within their respective QC acceptance criteria, analysis of blanks and field samples may proceed. If any individual PS falls outside the range, proceed according to section 8.4.4.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>
                                The large number of analytes in Tables 1-3 present a substantial probability that one or more will fail the acceptance criteria when all analytes are tested simultaneously. Because a re-test is allowed in event of failure (sections 8.1.7 and 8.4.3), it may be prudent to extract and analyze two LCSs together and evaluate results of the second 
                                <PRTPAGE P="282"/>
                                analysis against the QC acceptance criteria only if an analyte fails the first test.
                            </P>
                        </NOTE>
                        <P>8.4.4 Repeat the test only for those analytes that failed to meet the acceptance criteria (PS). If these analytes now pass, system performance is acceptable and analysis of blanks and samples may proceed. Repeated failure, however, will confirm a general problem with the measurement system. If this occurs, repeat the test using a fresh LCS (section 8.2.2) or an LCS prepared with a fresh QC check sample concentrate (section 8.2.1), or perform and document system repair. Subsequent to analysis of the LCS prepared with a fresh sample concentrate, or to system repair, repeat the LCS test (section 8.4). If failure of the LCS indicates a systemic problem with samples in the batch, re-extract and re-analyze the samples in the batch. See section 8.1.7 for disposition of repeated failures.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>To maintain the validity of the test and re-test, system maintenance and/or adjustment is not permitted between the pair of tests.</P>
                        </NOTE>
                        <P>8.4.5 After analysis of 20 LCS samples, and if the laboratory chooses to develop and apply in-house QC limits, the laboratory should calculate and apply in-house QC limits for recovery to future LCS samples (section 8.4). Limits for recovery in the LCS should be calculated as the mean recovery ±3 standard deviations. A minimum of 80% of the analytes tested for in the LCS must have QC acceptance criteria tighter than those in Table 6, and the remaining analytes (those other than the analytes included in the 80%) must meet the acceptance criteria in Table 6. If an in-house lower limit for recovery is lower than the lower limit in Table 6, the lower limit in Table 6 must be used, and if an in-house upper limit for recovery is higher than the upper limit in Table 6, the upper limit in Table 6 must be used. Many of the analytes and surrogates do not contain acceptance criteria. The laboratory should use 60-140% as interim acceptance criteria for recoveries of spiked analytes and surrogates that do not have recovery limits specified in Table 8, and at least 80% of the surrogates must meet the 60-140% interim criteria until in-house LCS and surrogate limits are developed. Alternatively, acceptance criteria for analytes that do not have recovery limits in Table 6 may be based on laboratory control charts. In-house QC acceptance criteria must be updated at least every two years.</P>
                        <P>8.5 Blank—A blank must be extracted and analyzed with each extraction batch to demonstrate that the reagents and equipment used for preparation and analysis are free from contamination.</P>
                        <P>8.5.1 Spike the surrogates into the blank. Extract and concentrate the blank using the same procedures and reagents used for the samples, LCS, and MS/MSD in the batch. Analyze the blank immediately after analysis of the LCS (section 8.4) and prior to analysis of the MS/MSD and samples to demonstrate freedom from contamination.</P>
                        <P>
                            8.5.2 If an analyte of interest is found in the blank: At a concentration greater than the MDL for the analyte, at a concentration greater than one-third the regulatory compliance limit, or at a concentration greater than one-tenth the concentration in a sample in the extraction batch, 
                            <E T="03">whichever is greater,</E>
                             analysis of samples must be halted, and the problem corrected. If the contamination is traceable to the extraction batch, samples affected by the blank must be re-extracted and the extracts re-analyzed. If, however, continued re-testing results in repeated blank contamination, the laboratory must document and report the failures (e.g., as qualifiers on results), unless the failures are not required to be reported as determined by the regulatory/control authority. Results associated with blank contamination for an analyte regulated in a discharge cannot be used to demonstrate regulatory compliance. QC failures do not relieve a discharger or permittee of reporting timely results.
                        </P>
                        <P>8.6 Internal standards responses.</P>
                        <P>8.6.1 Calibration verification—The responses (GC peak heights or areas) of the internal standards in the calibration verification must be within 50% to 200% (1/2 to 2x) of their respective responses in the mid-point calibration standard. If they are not, repeat the calibration verification (Section 7.4) test or perform and document system repair. Subsequent to repair, repeat the calibration verification. If the responses are still not within 50% to 200%, re-calibrate the instrument (Section 7) and repeat the calibration verification test.</P>
                        <P>8.6.2 Samples, blanks, LCSs, and MS/MSDs—The responses (GC peak heights or areas) of each internal standard in each sample, blank, and MS/MSD must be within 50% to 200% (1/2 to 2x) of its respective response in the LCS for the extraction batch. If, as a group, all internal standards are not within this range, perform and document system repair, repeat the calibration verification (section 8.4), and re-analyze the affected samples. If a single internal standard is not within the 50% to 200% range, use an alternate internal standard for quantitation of the analyte referenced to the affected internal standard. It may be necessary to use the data system to calculate a new response factor from calibration data for the alternate internal standard/analyte pair. If an internal standard fails the 50-200% criteria and no analytes are detected in the sample, ignore the failure or report it if required by the regulatory/control authority.</P>
                        <P>
                            8.7 Surrogate recoveries—The laboratory must evaluate surrogate recovery data in each sample against its in-house surrogate recovery limits. The laboratory may use 60-
                            <PRTPAGE P="283"/>
                            140% as interim acceptance criteria for recoveries for surrogates not listed in Table 8. At least 80% of the surrogates must meet the 60-140% interim criteria until in-house limits are developed. Alternatively, surrogate recovery limits may be developed from laboratory control charts, but such limits must be at least as restrictive as those in Table 8. Spike the surrogates into all samples, blanks, LCSs, and MS/MSDs. Compare surrogate recoveries against the QC acceptance criteria in Table 8 and/or those developed in section 7.3.3 or 8.4.5. If any recovery fails its criteria, attempt to find and correct the cause of the failure. See section 8.1.7 for disposition of failures.
                        </P>
                        <P>8.8 DDT and endrin decomposition (breakdown)—If DDT and/or endrin are to be analyzed using this method, the DDT/endrin decomposition test in section 13.8 must be performed to reliably quantify these two pesticides.</P>
                        <P>
                            8.9 As part of the QC program for the laboratory, control charts or statements of accuracy for wastewater samples must be assessed and records maintained (40 CFR 136.7(c)(1)(viii)). After analysis of five or more spiked wastewater samples as in section 8.3, calculate the average percent recovery (P
                            <E T="52">X</E>
                            ) and the standard deviation of the percent recovery (sp). Express the accuracy assessment as a percent interval from P
                            <E T="52">X</E>
                             −2sp to P
                            <E T="52">X</E>
                             +2sp. For example, if P
                            <E T="52">X</E>
                             = 90% and sp = 10%, the accuracy interval is expressed as 70-110%. Update the accuracy assessment for each analyte on a regular basis (e.g., after each 5-10 new accuracy measurements). If desired, statements of accuracy for laboratory performance, independent of performance on samples, may be developed using LCSs.
                        </P>
                        <P>8.10 It is recommended that the laboratory adopt additional quality assurance practices for use with this method. The specific practices that are most productive depend upon the needs of the laboratory and the nature of the samples. Field duplicates may be analyzed to assess the precision of environmental measurements. Whenever possible, the laboratory should analyze standard reference materials and participate in relevant performance evaluation studies.</P>
                        <HD SOURCE="HD3">9. Sample Collection, Preservation, and Handling</HD>
                        <P>9.1 Collect samples as grab samples in amber or clear glass bottles, or in refrigerated bottles using automatic sampling equipment. If clear glass is used, protect samples from light. Collect 1-L of ambient waters, effluents, and other aqueous samples. If the sensitivity of the analytical system is sufficient, a smaller volume (e.g., 250 mL), but no less than 100 mL, may be used. Conventional sampling practices (Reference 15) should be followed, except that the bottle must not be pre-rinsed with sample before collection. Automatic sampling equipment must be as free as possible of polyvinyl chloride or other tubing or other potential sources of contamination. If needed, collect additional sample(s) for the MS/MSD (section 8.3).</P>
                        <P>9.2 Ice or refrigerate samples at ≤6 °C from the time of collection until extraction, but do not freeze. If residual chlorine is present, add 80 mg of sodium thiosulfate per liter of sample and mix well. Any method suitable for field use may be employed to test for residual chlorine (Reference 16). Add more sodium sulfate if 80 mg/L is insufficient but do not add excess sodium thiosulfate. If sodium thiosulfate interferes in the determination of the analytes, an alternate preservative (e.g., ascorbic acid or sodium sulfite) may be used. If preservative has been added, shake the sample vigorously for one minute. Maintain the hermetic seal on the sample bottle until time of analysis.</P>
                        <P>9.3 All samples must be extracted within 7 days of collection and sample extracts must be analyzed within 40 days of extraction.</P>
                        <HD SOURCE="HD3">10. Extraction</HD>
                        <P>10.1 This section contains procedures for separatory funnel liquid-liquid extraction (SFLLE) and continuous liquid-liquid extraction (CLLE). SFLLE is faster, but may not be as effective as CLLE for recovery of polar analytes such as phenol. SFLLE is labor intensive and may result in formation of emulsions that are difficult to break. CLLE is less labor intensive, avoids emulsion formation, but requires more time (18-24 hours) and more hood space, and may require more solvent. The procedures assume base-neutral extraction followed by acid extraction. For some matrices and analytes of interest, improved results may be obtained by acid-neutral extraction followed by base extraction. A single acid or base extraction may also be performed. If an extraction scheme alternate to base-neutral followed by acid extraction is used, all QC tests must be performed and all QC acceptance criteria must be met with that extraction scheme as an integral part of this method. Solid-phase extraction (SPE) may be used provided requirements in section 8.1.2 are met.</P>
                        <P>10.2 Separatory funnel liquid-liquid extraction (SFLLE) and extract concentration.</P>
                        <P>10.2.1 The SFLLE procedure below assumes a sample volume of 1 L. When a different sample volume is extracted, adjust the volume of methylene chloride accordingly.</P>
                        <P>
                            10.2.2 Mark the water meniscus on the side of the sample bottle for later determination of sample volume. Pour the entire sample into the separatory funnel. Pipet the surrogate standard spiking solution (section 6.8) into the separatory funnel. If the sample will be used for the LCS or MS or MSD, pipet the 
                            <PRTPAGE P="284"/>
                            appropriate check sample concentrate (section 8.2.1 or 8.3.2) into the separatory funnel. Mix well. Check the pH of the sample with wide-range pH paper and adjust to pH 11-13 with sodium hydroxide solution.
                        </P>
                        <P>10.2.3 Add 60 mL of methylene chloride to the sample bottle, seal, and shake for approximately 30 seconds to rinse the inner surface. Transfer the solvent to the separatory funnel and extract the sample by shaking the funnel for two minutes with periodic venting to release excess pressure. Allow the organic layer to separate from the water phase for a minimum of 10 minutes. If the emulsion interface between layers is more than one-third the volume of the solvent layer, the analyst must employ mechanical techniques to complete the phase separation. The optimum technique depends upon the sample, but may include stirring, filtration of the emulsion through glass wool or phase-separation paper, salting, centrifugation, or other physical methods. Collect the methylene chloride extract in a flask. If the emulsion cannot be broken (recovery of &lt;80% of the methylene chloride), transfer the sample, solvent, and emulsion into a continuous extractor and proceed as described in section 10.3.</P>
                        <P>10.2.4 Add a second 60-mL volume of methylene chloride to the sample bottle and repeat the extraction procedure a second time, combining the extracts in the Erlenmeyer flask. Perform a third extraction in the same manner.</P>
                        <P>10.2.5 Adjust the pH of the aqueous phase to less than 2 using sulfuric acid. Serially extract the acidified aqueous phase three times with 60 mL aliquots of methylene chloride. Collect and combine the extracts in a flask in the same manner as the base/neutral extracts.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>Base/neutral and acid extracts may be combined for concentration and analysis provided all QC tests are performed and all QC acceptance criteria met for the analytes of interest with the combined extract as an integral part of this method, and provided that the analytes of interest are as reliably identified and quantified as when the extracts are analyzed separately. If doubt exists as to whether identification and quantitation will be affected by use of a combined extract, the fractions must be analyzed separately.</P>
                        </NOTE>
                        <P>10.2.6 For each fraction or the combined fractions, assemble a Kuderna-Danish (K-D) concentrator by attaching a 10-mL concentrator tube to a 500-mL evaporative flask. Other concentration devices or techniques may be used in place of the K-D concentrator so long as the requirements in section 8.2 are met.</P>
                        <P>10.2.7 For each fraction or the combined fractions, pour the extract through a solvent-rinsed drying column containing about 10 cm of anhydrous sodium sulfate, and collect the extract in the K-D concentrator. Rinse the Erlenmeyer flask and column with 20-30 mL of methylene chloride to complete the quantitative transfer.</P>
                        <P>10.2.8 Add one or two clean boiling chips and attach a three-ball Snyder column to the evaporative flask for each fraction (section 10.2.7). Pre-wet the Snyder column by adding about 1 mL of methylene chloride to the top. Place the K-D apparatus on a hot water bath (60-65 °C) so that the concentrator tube is partially immersed in the hot water, and the entire lower rounded surface of the flask is bathed with hot vapor. Adjust the vertical position of the apparatus and the water temperature as required to complete the concentration in 15-20 minutes. At the proper rate of distillation, the balls of the column will actively chatter but the chambers will not flood with condensed solvent. When the apparent volume of liquid reaches 1 mL or other determined amount, remove the K-D apparatus from the water bath and allow to drain and cool for at least 10 minutes. Remove the Snyder column and rinse the flask and its lower joint into the concentrator tube with 1-2 mL of methylene chloride. A 5-mL syringe is recommended for this operation. If the sample will be cleaned up, reserve the K-D apparatus for concentration of the cleaned up extract. Adjust the volume to 5 mL with methylene chloride and proceed to section 11 for cleanup; otherwise, further concentrate the extract for GC/MS analysis per section 10.2.9 or 10.2.10.</P>
                        <P>
                            10.2.9 Micro Kuderna-Danish concentration—Add another one or two clean boiling chips to the concentrator tube for each fraction and attach a two-ball micro-Snyder column. Pre-wet the Snyder column by adding about 0.5 mL of methylene chloride to the top. Place the K-D apparatus on a hot water bath (60-65 °C) so that the concentrator tube is partially immersed in hot water. Adjust the vertical position of the apparatus and the water temperature as required to complete the concentration in 5-10 minutes. At the proper rate of distillation the balls of the column will actively chatter but the chambers will not flood with condensed solvent. When the apparent volume of liquid reaches about 1 mL or other determined amount, remove the K-D apparatus from the water bath and allow it to drain and cool for at least 10 minutes. Remove the Snyder column and rinse the flask and its lower joint into the concentrator tube with approximately 0.2 mL of or methylene chloride. Adjust the final volume to 1.0 mL or a volume appropriate to the sensitivity desired (e.g., to meet lower MDLs or for selected ion monitoring). Record the volume, stopper the concentrator tube and store refrigerated if further processing will not be performed immediately. If the extracts will be stored longer than two days, they should be transferred to 
                            <PRTPAGE P="285"/>
                            fluoropolymer-lined screw-cap vials and labeled base/neutral or acid fraction as appropriate. Mark the level of the extract on the vial so that solvent loss can be detected.
                        </P>
                        <P>10.2.10 Nitrogen evaporation and solvent exchange—Extracts may be concentrated for analysis using nitrogen evaporation in place of micro K-D concentration (section 10.2.9). Extracts that have been cleaned up using sulfur removal (section 11.2) and are ready for analysis are exchanged into methylene chloride.</P>
                        <P>10.2.10.1 Transfer the vial containing the sample extract to the nitrogen evaporation (blowdown) device (section 5.8). Lower the vial into the water bath and begin concentrating. If the more volatile analytes (section 1.2) are to be concentrated, use room temperature for concentration; otherwise, a slightly elevated (e.g., 30-45 °C) may be used. During the solvent evaporation process, keep the solvent level below the water level of the bath and do not allow the extract to become dry. Adjust the flow of nitrogen so that the surface of the solvent is just visibly disturbed. A large vortex in the solvent may cause analyte loss.</P>
                        <P>10.2.10.2 Extracts to be solvent exchanged—When the volume of the liquid is approximately 200 µL, add 2 to 3 mL of methylene chloride and continue concentrating to approximately 100 µL. Repeat the addition of solvent and concentrate once more. Adjust the final extract volume to be consistent with the volume extracted and the sensitivity desired.</P>
                        <P>10.2.10.3 For extracts that have been cleaned up by GPC and that are to be concentrated to a nominal volume of 1 mL, adjust the final volume to compensate the GPC loss. For a 50% GPC loss, concentrate the extract to 1/2000 of the volume extracted. For example, if the volume extracted is 950 mL, adjust the final volume to 0.48 mL. For extracts that have not been cleaned up by GPC and are to be concentrated to a nominal volume of 1.0 mL, adjust the final extract volume to 1/1000 of the volume extracted. For example, if the volume extracted is 950 mL, adjust the final extract volume to 0.95 mL. Alternative means of compensating the loss during GPC are acceptable so long as they produce results as accurate as results produced using the procedure detailed in this Section. An alternative final volume may be used, if desired, and the calculations adjusted accordingly.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>The difference in the volume fraction for an extract cleaned up by GPC accounts for the loss in GPC cleanup. Also, by preserving the ratio between the volume extracted and the final extract volume, the concentrations and detection limits do not need to be adjusted for differences in the volume extracted and the extract volume.</P>
                        </NOTE>
                        <P>10.2.11 Transfer the concentrated extract to a vial with fluoropolymer-lined cap. Seal the vial and label with the sample number. Store in the dark at room temperature until ready for GC analysis. If GC analysis will not be performed on the same day, store the vial in the dark at ≤6 °C. Analyze the extract by GC/MS per the procedure in section 12.</P>
                        <P>10.2.12 Determine the original sample volume by refilling the sample bottle to the mark and transferring the liquid to an appropriately sized graduated cylinder. For sample volumes on the order of 1000 mL, record the sample volume to the nearest 10 mL; for sample volumes on the order of 100 mL, record the volume to the nearest 1 mL. Sample volumes may also be determined by weighing the container before and after filling to the mark with water.</P>
                        <P>10.3 Continuous liquid/liquid extraction (CLLE).</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>With CLLE, phenol, 2,4-dimethyl phenol, and some other analytes may be preferentially extracted into the base-neutral fraction. Determine an analyte in the fraction in which it is identified and quantified most reliably. Also, the short-chain phthalate esters (e.g., dimethyl phthalate, diethyl phthalate) and some other compounds may hydrolyze during prolonged exposure to basic conditions required for continuous extraction, resulting in low recovery of these analytes. When these analytes are of interest, their recovery may be improved by performing the acid extraction first.</P>
                        </NOTE>
                        <P>10.3.1 Use CLLE when experience with a sample from a given source indicates an emulsion problem, or when an emulsion is encountered during SFLLE. CLLE may be used for all samples, if desired.</P>
                        <P>10.3.2 Mark the water meniscus on the side of the sample bottle for later determination of sample volume. Check the pH of the sample with wide-range pH paper and adjust to pH 11-13 with sodium hydroxide solution. Transfer the sample to the continuous extractor. Pipet surrogate standard spiking solution (section 6.8) into the sample. If the sample will be used for the LCS or MS or MSD, pipet the appropriate check sample concentrate (section 8.2.1 or 8.3.2) into the extractor. Mix well. Add 60 mL of methylene chloride to the sample bottle, seal, and shake for 30 seconds to rinse the inner surface. Transfer the solvent to the extractor.</P>
                        <P>10.3.3 Repeat the sample bottle rinse with an additional 50-100 mL portion of methylene chloride and add the rinse to the extractor.</P>
                        <P>
                            10.3.4 Add a suitable volume of methylene chloride to the distilling flask (generally 200-500 mL), add sufficient reagent water to ensure proper operation, and extract for 18-24 hours. A shorter or longer extraction time may be used if all QC acceptance criteria are met. Test and, if necessary, adjust the pH of the water during the second or third hour of the extraction. After extraction, allow the apparatus to cool, then detach the distilling flask. Dry, concentrate, and seal the extract 
                            <PRTPAGE P="286"/>
                            per sections 10.2.6 through 10.2.11. See the note at section 10.2.5 regarding combining extracts of the base/neutral and acid fractions.
                        </P>
                        <P>10.3.5 Charge the distilling flask with methylene chloride and attach it to the continuous extractor. Carefully, while stirring, adjust the pH of the aqueous phase to less than 2 using sulfuric acid. Extract for 18-24 hours. A shorter or longer extraction time may be used if all QC acceptance criteria are met. Test and, if necessary, adjust the pH of the water during the second or third hour of the extraction. After extraction, allow the apparatus to cool, then detach the distilling flask. Dry, concentrate, and seal the extract per sections 10.2.6 through 10.2.11. Determine the sample volume per section 10.2.12.</P>
                        <HD SOURCE="HD3">11. Extract Cleanup</HD>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>Cleanup may not be necessary for relatively clean samples (e.g., treated effluents, groundwater, drinking water). If particular circumstances require the use of a cleanup procedure, the laboratory may use any or all of the procedures below or any other appropriate procedure. Before using a cleanup procedure, the laboratory must demonstrate that the requirements of section 8.1.2 can be met using the cleanup procedure as an integral part of this method.</P>
                        </NOTE>
                        <P>11.1 Gel permeation chromatography (GPC).</P>
                        <P>11.1.1 Calibration.</P>
                        <P>11.1.1.1 Load the calibration solution (section 6.12) into the sample loop.</P>
                        <P>11.1.1.2 Inject the calibration solution and record the signal from the detector. The elution pattern will be corn oil, bis(2-ethylhexyl) phthalate, pentachlorophenol, perylene, and sulfur.</P>
                        <P>11.1.1.3 Set the “dump time” to allow &gt;85% removal of the corn oil and &gt;85% collection of the phthalate.</P>
                        <P>11.1.1.4 Set the “collect time” to the peak minimum between perylene and sulfur.</P>
                        <P>11.1.1.5 Verify calibration with the calibration solution after every 20 or fewer extracts. Calibration is verified if the recovery of the pentachlorophenol is greater than 85%. If calibration is not verified, recalibrate using the calibration solution, and re-extract and clean up the preceding extracts using the calibrated GPC system.</P>
                        <P>11.1.2 Extract cleanup—GPC requires that the column not be overloaded. The column specified in this method is designed to handle a maximum of 0.5 g of high molecular weight material in a 5-mL extract. If the extract is known or expected to contain more than 0.5 g, the extract is split into fractions for GPC and the fractions are combined after elution from the column. The solids content of the extract may be obtained gravimetrically by evaporating the solvent from a 50-µL aliquot.</P>
                        <P>11.1.2.1 Filter the extract or load through the filter holder to remove particulates. Load the extract into the sample loop. The maximum capacity of the column is 0.5-1.0 g. If necessary, split the extract into multiple aliquots to prevent column overload.</P>
                        <P>11.1.2.2 Elute the extract using the calibration data determined in Section 11.1.1. Collect the eluate in the K-D apparatus reserved in section 10.2.8.</P>
                        <P>11.1.3 Concentrate the cleaned up extract per sections 10.2.8 and 10.2.9 or 10.2.10.</P>
                        <P>11.1.4 Rinse the sample loading tube thoroughly with methylene chloride between extracts to prepare for the next sample.</P>
                        <P>11.1.5 If a particularly dirty extract is encountered, run a methylene chloride blank through the system to check for carry-over.</P>
                        <P>11.2 Sulfur removal.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>Separate procedures using copper or TBA sulfite are provided in this section for sulfur removal. They may be used separately or in combination, if desired.</P>
                        </NOTE>
                        <P>11.2.1 Removal with copper (Reference 17).</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>If an additional compound (Table 3) is to be determined; sulfur is to be removed; copper will be used for sulfur removal; and a sulfur matrix is known or suspected to be present, the laboratory must demonstrate that the additional compound can be successfully extracted and treated with copper in the sulfur matrix. Some of the additional compounds (Table 3) are known not to be amenable to sulfur removal with copper (e.g., Atrazine and Diazinon).</P>
                        </NOTE>
                        <P>11.2.1.1 Quantitatively transfer the extract from section 10.2.8 to a 40- to 50-mL flask or bottle. If there is evidence of water in the concentrator tube after the transfer, rinse the tube with small portions of hexane:acetone (40:60) and add to the flask or bottle. Mark and set aside the concentrator tube for use in re-concentrating the extract.</P>
                        <P>11.2.1.2 Add 10-20 g of granular anhydrous sodium sulfate to the flask. Swirl to dry the extract.</P>
                        <P>11.2.1.3 Add activated copper (section 6.13.1.4) and allow to stand for 30—60 minutes, swirling occasionally. If the copper does not remain bright, add more and swirl occasionally for another 30-60 minutes.</P>
                        <P>11.2.1.4 After drying and sulfur removal, quantitatively transfer the extract to a nitrogen-evaporation vial or tube and proceed to section 10.2.10 for nitrogen evaporation and solvent exchange, taking care to leave the sodium sulfate and copper in the flask.</P>
                        <P>11.2.2 Removal with TBA sulfite.</P>
                        <P>11.2.2.1 Using small volumes of hexane, quantitatively transfer the extract to a 40- to 50-mL centrifuge tube with fluoropolymer-lined screw cap.</P>
                        <P>
                            11.2.2.2 Add 1-2 mL of TBA sulfite reagent (section 6.13.2.4), 2-3 mL of 2-propanol, and approximately 0.7 g of sodium sulfite (section 6.13.2.2) crystals to the tube. Cap and 
                            <PRTPAGE P="287"/>
                            shake for 1-2 minutes. If the sample is colorless or if the initial color is unchanged, and if clear crystals (precipitated sodium sulfite) are observed, sufficient sodium sulfite is present. If the precipitated sodium sulfite disappears, add more crystalline sodium sulfite in approximately 0.5 g portions until a solid residue remains after repeated shaking.
                        </P>
                        <P>11.2.2.3 Add 5-10 mL of reagent water and shake for 1-2 minutes. Centrifuge to settle the solids.</P>
                        <P>11.2.2.4 Quantitatively transfer the hexane (top) layer through a small funnel containing a few grams of granular anhydrous sodium sulfate to a nitrogen-evaporation vial or tube and proceed to section 10.2.10 for nitrogen evaporation and solvent exchange.</P>
                        <HD SOURCE="HD3">12. Gas Chromatography/Mass Spectrometry</HD>
                        <P>12.1 Establish the operating conditions in Table 4 or 5 for analysis of a base/neutral or acid extract, respectively. For analysis of a combined extract (section 10.2.5, note), use the operating conditions in Table 4 MDLs and MLs for the analytes are given in Tables 1, 2, and 3. Retention times for many of the analytes are given in Tables 4 and 5. Examples of the separations achieved are shown in Figure 2 for the combined extract. Alternative columns or chromatographic conditions may be used if the requirements of section 8.2 are met. Verify system performance per section 13.</P>
                        <P>12.2 Analysis of a standard or extract.</P>
                        <P>12.2.1 Bring the standard or concentrated extract (section 10.2.9 or 10.2.11) to room temperature and verify that any precipitate has redissolved. Verify the level on the extract and bring to the mark with solvent if required.</P>
                        <P>12.2.2 Add the internal standard solution (section 6.9) to the extract. Mix thoroughly.</P>
                        <P>12.2.3 Inject an appropriate volume of the sample extract or standard solution using split, splitless, solvent purge, large-volume, or on-column injection. If the sample is injected manually the solvent-flush technique should be used. The injection volume depends upon the technique used and the ability to meet MDLs or reporting limits for regulatory compliance. Injected volumes must be the same for standards and sample extracts. Record the volume injected to two significant figures.</P>
                        <P>12.2.3.1 Start the GC column oven program upon injection. Start MS data collection after the solvent peak elutes. Stop data collection after benzo(ghi)perylene elutes for the base/neutral or combined fractions, or after pentachlorophenol elutes for the acid fraction. Return the column to the initial temperature for analysis of the next standard solution or extract.</P>
                        <P>12.2.3.2 If the concentration of any analyte of interest exceeds the calibration range, either extract and analyze a smaller sample volume, or dilute and analyze the diluted extract after bringing the concentrations of the internal standards to the levels in the undiluted extract.</P>
                        <P>12.2.4 Perform all qualitative and quantitative measurements as described in Sections 14 and 15. When standards and extracts are not being used for analyses, store them refrigerated at ≤6 °C protected from light in screw-cap vials equipped with un-pierced fluoropolymer-lined septa.</P>
                        <HD SOURCE="HD3">13. Performance Tests</HD>
                        <P>13.1 At the beginning of each 12-hour shift during which standards or extracts will be analyzed, perform the tests in sections 13.2-13.4 to verify system performance. If an extract is concentrated for greater sensitivity (e.g., by SIM), all tests must be performed at levels consistent with the reduced extract volume.</P>
                        <P>13.2 DFTPP—Inject the DFTPP standard (section 6.10) and verify that the criteria for DFTPP in section 7.2.1.1 and Table 9A (Reference 18) for a quadrupole MS, or Table 9B (Reference 19) for a time-of-flight MS, are met.</P>
                        <P>13.3 GC resolution—The resolution should be verified on the mid-point concentration of the initial calibration as well as the laboratory designated continuing calibration verification level if closely eluting isomers are to be reported (e.g., benzo(b)fluoranthene and benzo(k)fluoranthene). Sufficient gas chromatographic resolution is achieved if the height of the valley between two isomer peaks is less than 50% of the average of the two peak heights.</P>
                        <P>13.4 Calibration verification—Verify calibration per sections 7.3 and Table 6.</P>
                        <P>13.5 Peak tailing—Verify the tailing factor specifications are met per Section 7.2.1.1.</P>
                        <P>13.6 Laboratory control sample and blank—Analyze the extracts of the LCS and blank at the beginning of analyses of samples in the extraction batch (section 3.1). The LCS must meet the requirements in section 8.4, and the blank must meet the requirements in section 8.5 before sample extracts may be analyzed.</P>
                        <P>13.7 Analysis of DFTPP, the DDT/Endrin decomposition test (if used), the LCS, and the blank are outside of the 12-hour analysis shift (section 3.1). The total time for DFTPP, DDT/Endrin, the LCS, the blank, and the 12-hour shift must not exceed 15 hours.</P>
                        <P>13.8 Decomposition of DDT and endrin—If DDT and/or endrin are to be determined, this test must be performed prior to calibration verification (section 13.4). The QC acceptance criteria (section 13.8.3) must be met before analyzing samples for DDE and/or Endrin. DDT decomposes to DDE and DDD. Endrin decomposes to endrin aldehyde and endrin ketone.</P>
                        <P>
                            13.8.1 Inject 1 µL of the DDT and endrin decomposition solution (section 6.14). As 
                            <PRTPAGE P="288"/>
                            noted in section 6.14, other injection volumes may be used as long as the concentrations of DDT and endrin in the solution are adjusted to introduce the masses of the two analytes into the instrument that are listed in section 6.14.
                        </P>
                        <P>13.8.2 Measure the areas of the peaks for DDT, DDE, DDD, Endrin, Endrin aldehyde, and Endrin ketone. Calculate the percent breakdown as shown in the equations below:</P>
                        <GPH SPAN="2" DEEP="96">
                            <GID>ER28AU17.015</GID>
                        </GPH>
                        <P>13.8.3 Both the % breakdown of DDT and of Endrin must be less than 20%, otherwise the system is not performing acceptably for DDT and endrin. In this case, repair the GC column system that failed and repeat the performance tests (sections 13.2 to 13.6) until the specification is met.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>DDT and endrin decomposition are usually caused by accumulation of particulates in the injector and in the front end of the column. Cleaning and silanizing the injection port liner, and breaking off a short section of the front end of the column will usually eliminate the decomposition problem. Either of these corrective actions may affect retention times, GC resolution, and calibration linearity.</P>
                        </NOTE>
                        <HD SOURCE="HD3">14. Qualitative Identification</HD>
                        <P>14.1 Identification is accomplished by comparison of data from analysis of a sample or blank with data stored in the GC/MS data system (sections 5.6.5 and 7.2.1.2). Identification of an analyte is confirmed per sections 14.1.1 through 14.1.4.</P>
                        <P>14.1.1 The signals for the quantitation and secondary m/z's stored in the data system for each analyte of interest must be present and must maximize within the same two consecutive scans.</P>
                        <P>14.1.2 The retention time for the analyte should be within ± 10 seconds of the analyte in the calibration verification run at the beginning of the shift (section 7.3 or 13.4).</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>Retention time windows other than ± 10 seconds may be appropriate depending on the performance of the gas chromatograph or observed retention time drifts due to certain types of matrix effects. Relative retention time (RRT) may be used as an alternative to absolute retention times if retention time drift is a concern. RRT is a unitless quantity (see Sec. 22.2), although some procedures refer to “RRT units” in providing the specification for the agreement between the RRT values in the sample and the calibration verification or other standard. When significant retention time drifts are observed, dilutions or spiked samples may help the analyst determine the effects of the matrix on elution of the target analytes and to assist in qualitative identification.</P>
                        </NOTE>
                        <P>14.1.3 Either the background corrected EICP areas, or the corrected relative intensities of the mass spectral peaks at the GC peak maximum, must agree within 50% to 200% (1/2 to 2 times) for the quantitation and secondary m/z's in the reference mass spectrum stored in the data system (section 7.2.1.2), or from a reference library. For example, if a peak has an intensity of 20% relative to the base peak, the analyte is identified if the intensity of the peak in the sample is in the range of 10% to 40% of the base peak. If identification is ambiguous, an experienced spectrometrist (section 1.7) must determine the presence or absence of the compound.</P>
                        <P>14.2 Structural isomers that produce very similar mass spectra should be identified as individual isomers if they have sufficiently different gas chromatographic retention times. Sufficient gas chromatographic resolution is achieved if the height of the valley between two isomer peaks is less than 50% of the average of the two peak heights. Otherwise, structural isomers are identified as isomeric pairs.</P>
                        <HD SOURCE="HD3">15. Calculations</HD>
                        <P>
                            15.1 When an analyte has been identified, quantitation of that analyte is based on the integrated abundance from the EICP of the primary characteristic m/z in Table 4 or 5. Calculate the concentration in the extract 
                            <PRTPAGE P="289"/>
                            using the response factor (RF) determined in Section 7.2.2 and Equation 2. If the concentration of an analyte exceeds the calibration range, dilute the extract by the minimum amount to bring the concentration into the calibration range, and re-analyze the extract. Determine a dilution factor (DF) from the amount of the dilution. For example, if the extract is diluted by a factor of 2, DF = 2.
                        </P>
                        <GPH SPAN="2" DEEP="28">
                            <GID>ER28AU17.016</GID>
                        </GPH>
                        <FP SOURCE="FP-2">where:</FP>
                        <FP SOURCE="FP-2">
                            C
                            <E T="52">ex</E>
                             = Concentration of the analyte in the extract, in µg/mL, and the other terms are as defined in section 7.2.2.
                        </FP>
                        <P>Calculate the concentration of the analyte in the sample using the concentration in the extract, the extract volume, the sample volume, and the dilution factor, per Equation 3:</P>
                        <GPH SPAN="2" DEEP="28">
                            <GID>ER28AU17.017</GID>
                        </GPH>
                        <FP SOURCE="FP-2">where:</FP>
                        <FP SOURCE="FP-2">
                            C
                            <E T="52">samp</E>
                             = Concentration of the analyte in the sample
                        </FP>
                        <FP SOURCE="FP-2">
                            C
                            <E T="52">ex</E>
                             = Concentration of the analyte in the extract, in µg/mL
                        </FP>
                        <FP SOURCE="FP-2">
                            V
                            <E T="52">ex</E>
                             = Volume of extract (mL)
                        </FP>
                        <FP SOURCE="FP-2">
                            V
                            <E T="52">s</E>
                             = Volume of sample (L)
                        </FP>
                        <FP SOURCE="FP-2">DF = Dilution factor</FP>
                        <P>15.2 Reporting of results. As noted in section 1.4.1, EPA has promulgated this method at 40 CFR part 136 for use in wastewater compliance monitoring under the National Pollutant Discharge Elimination System (NPDES). The data reporting practices described here are focused on such monitoring needs and may not be relevant to other uses of the method.</P>
                        <P>15.2.1 Report results for wastewater samples in µg/L without correction for recovery. (Other units may be used if required by in a permit.) Report all QC data with the sample results.</P>
                        <P>15.2.2 Reporting level. Unless specified otherwise by a regulatory authority or in a discharge permit, results for analytes that meet the identification criteria are reported down to the concentration of the ML established by the laboratory through calibration of the instrument (see section 7.3.2 and the glossary for the derivation of the ML). EPA considers the terms “reporting limit,” “quantitation limit,” “limit of quantitation,” and “minimum level” to be synonymous.</P>
                        <P>15.2.2.1 Report a result for each analyte in each field sample or QC standard at or above the ML to 3 significant figures. Report a result for each analyte found in each field sample or QC standard below the ML as “ML” where ML is the concentration of the analyte at the ML, or as required by the regulatory/control authority or permit. Report a result for each analyte in a blank at or above the MDL to 2 significant figures. Report a result for each analyte found in a blank below the MDL as “MDL,” where MDL is the concentration of the analyte at the MDL, or as required by the regulatory/control authority or permit.</P>
                        <P>15.2.2.2 In addition to reporting results for samples and blanks separately, the concentration of each analyte in a blank associated with the sample may be subtracted from the result for that sample, but only if requested or required by a regulatory authority or in a permit. In this case, both the sample result and the blank results must be reported together.</P>
                        <P>
                            15.2.2.3 Report a result for an analyte found in a sample or extract that has been diluted at the least dilute level at which the area at the quantitation m/z is within the calibration range (
                            <E T="03">i.e.,</E>
                             above the ML for the analyte) and the MS/MSD recovery and RPD are within their respective QC acceptance criteria (Table 6). This may require reporting results for some analytes from different analyses.
                        </P>
                        <P>
                            15.2.3 Results from tests performed with an analytical system that is not in control (
                            <E T="03">i.e.,</E>
                             that does not meet acceptance criteria for any QC test in this method) must be documented and reported (e.g., as a qualifier on results), unless the failure is not required to be reported as determined by the regulatory/control authority. Results associated with a QC failure cannot be used to demonstrate regulatory compliance. QC failures do not relieve a discharger or permittee of reporting 
                            <PRTPAGE P="290"/>
                            timely results. If the holding time would be exceeded for a re-analysis of the sample, the regulatory/control authority should be consulted for disposition.
                        </P>
                        <HD SOURCE="HD3">16. Method Performance</HD>
                        <P>16.1 The basic version of this method was tested by 15 laboratories using reagent water, drinking water, surface water, and industrial wastewaters spiked at six concentrations over the range 5-1300 µg/L (Reference 2). Single operator precision, overall precision, and method accuracy were found to be directly related to the concentration of the analyte and essentially independent of the sample matrix. Linear equations to describe these relationships are presented in Table 7.</P>
                        <P>16.2 As noted in section 1.1, this method was validated through an interlaboratory study in the early 1980s. However, the fundamental chemistry principles used in this method remain sound and continue to apply.</P>
                        <P>16.3 A chromatogram of the combined acid/base/neutral calibration standard is shown in Figure 2.</P>
                        <HD SOURCE="HD3">17. Pollution Prevention</HD>
                        <P>17.1 Pollution prevention encompasses any technique that reduces or eliminates the quantity or toxicity of waste at the point of generation. Many opportunities for pollution prevention exist in laboratory operations. EPA has established a preferred hierarchy of environmental management techniques that places pollution prevention as the management option of first choice. Whenever feasible, the laboratory should use pollution prevention techniques to address waste generation. When wastes cannot be reduced at the source, the Agency recommends recycling as the next best option.</P>
                        <P>17.2 The analytes in this method are used in extremely small amounts and pose little threat to the environment when managed properly. Standards should be prepared in volumes consistent with laboratory use to minimize the disposal of excess volumes of expired standards. This method utilizes significant quantities of methylene chloride. Laboratories are encouraged to recover and recycle this and other solvents during extract concentration.</P>
                        <P>17.3 For information about pollution prevention that may be applied to laboratories and research institutions, consult Less is Better: Laboratory Chemical Management for Waste Reduction, available from the American Chemical Society's Department of Governmental Relations and Science Policy, 1155 16th Street NW., Washington DC 20036, 202-872-4477.</P>
                        <HD SOURCE="HD3">18. Waste Management</HD>
                        <P>18.1 The laboratory is responsible for complying with all Federal, State, and local regulations governing waste management, particularly the hazardous waste identification rules and land disposal restrictions, and to protect the air, water, and land by minimizing and controlling all releases from fume hoods and bench operations. Compliance is also required with any sewage discharge permits and regulations. An overview of requirements can be found in Environmental Management Guide for Small Laboratories (EPA 233-B-98-001).</P>
                        <P>18.2 Samples at pH &lt;2, or pH &gt;12, are hazardous and must be handled and disposed of as hazardous waste, or neutralized and disposed of in accordance with all federal, state, and local regulations. It is the laboratory's responsibility to comply with all federal, state, and local regulations governing waste management, particularly the hazardous waste identification rules and land disposal restrictions. The laboratory using this method has the responsibility to protect the air, water, and land by minimizing and controlling all releases from fume hoods and bench operations. Compliance is also required with any sewage discharge permits and regulations. For further information on waste management, see “The Waste Management Manual for Laboratory Personnel,” also available from the American Chemical Society at the address in section 17.3.</P>
                        <P>18.3 Many analytes in this method decompose above 500 ºC. Low-level waste such as absorbent paper, tissues, and plastic gloves may be burned in an appropriate incinerator. Gross quantities of neat or highly concentrated solutions of toxic or hazardous chemicals should be packaged securely and disposed of through commercial or governmental channels that are capable of handling these types of wastes.</P>
                        <P>18.4 For further information on waste management, consult The Waste Management Manual for Laboratory Personnel and Less is Better-Laboratory Chemical Management for Waste Reduction, available from the American Chemical Society's Department of Government Relations and Science Policy, 1155 16th Street NW., Washington, DC 20036, 202-872-4477.</P>
                        <HD SOURCE="HD3">19. References</HD>
                        <FP SOURCE="FP-2">1. “Sampling and Analysis Procedures for Screening of Industrial Effluents for Priority Pollutants,” U.S. Environmental Protection Agency, Environmental Monitoring and Support Laboratory, Cincinnati, Ohio 45268, March 1977, Revised April 1977.</FP>
                        <FP SOURCE="FP-2">2. “EPA Method Study 30, Method 625, Base/Neutrals, Acids, and Pesticides,” EPA 600/4-84-053, National Technical Information Service, PB84-206572, Springfield, Virginia 22161, June 1984.</FP>
                        <FP SOURCE="FP-2">
                            3. 40 CFR part 136, appendix B.
                            <PRTPAGE P="291"/>
                        </FP>
                        <FP SOURCE="FP-2">4. Olynyk, P., Budde, W.L. and Eichelberger, J.W. “Method Detection Limit for Methods 624 and 625,” Unpublished report, May 14, 1980.</FP>
                        <FP SOURCE="FP-2">5. Annual Book of ASTM Standards, Volume 11.02, D3694-96, “Standard Practices for Preparation of Sample Containers and for Preservation of Organic Constituents,” American Society for Testing and Materials, Philadelphia.</FP>
                        <FP SOURCE="FP-2">6. Solutions to Analytical Chemistry Problems with Clean Water Act Methods, EPA 821-R-07-002, March 2007.</FP>
                        <FP SOURCE="FP-2">7. “Carcinogens-Working With Carcinogens,” Department of Health, Education, and Welfare, Public Health Service, Center for Disease Control, National Institute for Occupational Safety and Health, Publication No. 77-206, August 1977.</FP>
                        <FP SOURCE="FP-2">8. “OSHA Safety and Health Standards, General Industry,” (29 CFR part 1910), Occupational Safety and Health Administration, OSHA 2206 (Revised, January 1976).</FP>
                        <FP SOURCE="FP-2">9. “Safety in Academic Chemistry Laboratories,” American Chemical Society Publication, Committee on Chemical Safety, 7th Edition, 2003.</FP>
                        <FP SOURCE="FP-2">10. Johnson, R.A., and Wichern, D.W., “Applied Multivariate Statistical Analysis,” 3rd edition, Prentice Hall, Englewood Cliffs, NJ, 1992.</FP>
                        <FP SOURCE="FP-2">11. 40 CFR 136.6(b)(4)(x).</FP>
                        <FP SOURCE="FP-2">12. 40 CFR 136.6(b)(2)(i).</FP>
                        <FP SOURCE="FP-2">13. Protocol for EPA Approval of New Methods for Organic and Inorganic Analytes in Wastewater and Drinking Water (EPA-821-B-98-003) March 1999.</FP>
                        <FP SOURCE="FP-2">14. Provost, L.P. and Elder, R.S. “Interpretation of Percent Recovery Data,” American Laboratory, 15, 58-63 (1983). (The value 2.44 used in the equation in section 8.3.3 is two times the value 1.22 derived in this report.)</FP>
                        <FP SOURCE="FP-2">15. ASTM Annual Book of Standards, Part 31, D3370-76. “Standard Practices for Sampling Water,” American Society for Testing and Materials, Philadelphia.</FP>
                        <FP SOURCE="FP-2">16. 40 CFR 136.3(a), Table IB, Chlorine—Total Residual.</FP>
                        <FP SOURCE="FP-2">17. “Manual of Analytical Methods for the Analysis of Pesticides in Human and Environmental Samples,” EPA-600/8-80-038, U.S. Environmental Protection Agency, Health Effects Research Laboratory, Research Triangle Park, North Carolina.</FP>
                        <FP SOURCE="FP-2">18. Eichelberger, J.W., Harris, L.E., and Budde, W.L. “Reference Compound to Calibrate Ion Abundance Measurement in Gas Chromatography-Mass Spectrometry,” Analytical Chemistry, 47, 995 (1975).</FP>
                        <FP SOURCE="FP-2">19. Letter of approval of acceptance criteria for DFTPP for time-of-flight mass spectrometers from William A. Telliard and Herb Brass of EPA to Jack Cochran of LECO Corporation, February 9, 2005.</FP>
                        <HD SOURCE="HD3">20. Tables</HD>
                        <GPOTABLE COLS="4" OPTS="L2" CDEF="s100,12,12,12">
                            <TTITLE>
                                Table 1—Non Pesticide/PCB Base/Neutral Extractables 
                                <SU>1</SU>
                            </TTITLE>
                            <BOXHD>
                                <CHED H="1">Analyte</CHED>
                                <CHED H="1">CAS registry</CHED>
                                <CHED H="1">
                                    MDL 
                                    <SU>4</SU>
                                    <LI>(ug/L)</LI>
                                </CHED>
                                <CHED H="1">
                                    ML 
                                    <SU>5</SU>
                                    <LI>(ug/L)</LI>
                                </CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">Acenaphthene</ENT>
                                <ENT>83-32-9</ENT>
                                <ENT>1.9</ENT>
                                <ENT>5.7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Acenaphthylene</ENT>
                                <ENT>208-96-8</ENT>
                                <ENT>3.5</ENT>
                                <ENT>10.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Anthracene</ENT>
                                <ENT>120-12-7</ENT>
                                <ENT>1.9</ENT>
                                <ENT>5.7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Benzidine 
                                    <SU>2</SU>
                                </ENT>
                                <ENT>92-87-5</ENT>
                                <ENT>44</ENT>
                                <ENT>132</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzo(a)anthracene</ENT>
                                <ENT>56-55-3</ENT>
                                <ENT>7.8</ENT>
                                <ENT>23.4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzo(a)pyrene</ENT>
                                <ENT>50-32-8</ENT>
                                <ENT>2.5</ENT>
                                <ENT>7.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzo(b)fluoranthene</ENT>
                                <ENT>205-99-2</ENT>
                                <ENT>4.8</ENT>
                                <ENT>14.4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzo(k)fluoranthene</ENT>
                                <ENT>207-08-9</ENT>
                                <ENT>2.5</ENT>
                                <ENT>7.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzo(ghi)perylene</ENT>
                                <ENT>191-24-2</ENT>
                                <ENT>4.1</ENT>
                                <ENT>12.3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzyl butyl phthalate</ENT>
                                <ENT>85-68-7</ENT>
                                <ENT>2.5</ENT>
                                <ENT>7.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">bis(2-Chloroethoxy)methane</ENT>
                                <ENT>111-91-1</ENT>
                                <ENT>5.3</ENT>
                                <ENT>15.9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">bis(2-Ethylhexyl)phthalate</ENT>
                                <ENT>117-81-7</ENT>
                                <ENT>2.5</ENT>
                                <ENT>7.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">bis(2-Chloroisopropyl) ether (2,2'-Oxybis[1-chloropropane])</ENT>
                                <ENT>108-60-1</ENT>
                                <ENT>5.7</ENT>
                                <ENT>17.1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4-Bromophenyl phenyl ether</ENT>
                                <ENT>101-55-3</ENT>
                                <ENT>1.9</ENT>
                                <ENT>5.7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-Chloronaphthalene</ENT>
                                <ENT>91-58-7</ENT>
                                <ENT>1.9</ENT>
                                <ENT>5.7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4-Chlorophenyl phenyl ether</ENT>
                                <ENT>7005-72-3</ENT>
                                <ENT>4.2</ENT>
                                <ENT>12.6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chrysene</ENT>
                                <ENT>218-01-9</ENT>
                                <ENT>2.5</ENT>
                                <ENT>7.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dibenz(a,h)anthracene</ENT>
                                <ENT>53-70-3</ENT>
                                <ENT>2.5</ENT>
                                <ENT>7.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Di-
                                    <E T="03">n</E>
                                    -butylphthalate
                                </ENT>
                                <ENT>84-74-2</ENT>
                                <ENT>2.5</ENT>
                                <ENT>7.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">3,3'-Dichlorobenzidine</ENT>
                                <ENT>91-94-1</ENT>
                                <ENT>16.5</ENT>
                                <ENT>49.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Diethyl phthalate</ENT>
                                <ENT>84-66-2</ENT>
                                <ENT>1.9</ENT>
                                <ENT>5.7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dimethyl phthalate</ENT>
                                <ENT>131-11-3</ENT>
                                <ENT>1.6</ENT>
                                <ENT>4.8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4-Dinitrotoluene</ENT>
                                <ENT>121-14-2</ENT>
                                <ENT>5.7</ENT>
                                <ENT>17.1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,6-Dinitrotoluene</ENT>
                                <ENT>606-20-2</ENT>
                                <ENT>1.9</ENT>
                                <ENT>5.7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Di-n-octylphthalate</ENT>
                                <ENT>117-84-0</ENT>
                                <ENT>2.5</ENT>
                                <ENT>7.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Fluoranthene</ENT>
                                <ENT>206-44-0</ENT>
                                <ENT>2.2</ENT>
                                <ENT>6.6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Fluorene</ENT>
                                <ENT>86-73-7</ENT>
                                <ENT>1.9</ENT>
                                <ENT>5.7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Hexachlorobenzene</ENT>
                                <ENT>118-74-1</ENT>
                                <ENT>1.9</ENT>
                                <ENT>5.7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Hexachlorobutadiene</ENT>
                                <ENT>87-68-3</ENT>
                                <ENT>0.9</ENT>
                                <ENT>2.7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Hexachloroethane</ENT>
                                <ENT>67-72-1</ENT>
                                <ENT>1.6</ENT>
                                <ENT>4.8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Indeno(1,2,3-cd)pyrene</ENT>
                                <ENT>193-39-5</ENT>
                                <ENT>3.7</ENT>
                                <ENT>11.1</ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="292"/>
                                <ENT I="01">Isophorone</ENT>
                                <ENT>78-59-1</ENT>
                                <ENT>2.2</ENT>
                                <ENT>6.6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Naphthalene</ENT>
                                <ENT>91-20-3</ENT>
                                <ENT>1.6</ENT>
                                <ENT>4.8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Nitrobenzene</ENT>
                                <ENT>98-95-3</ENT>
                                <ENT>1.9</ENT>
                                <ENT>5.7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    N-Nitrosodi-
                                    <E T="03">n</E>
                                    -propylamine 
                                    <SU>3</SU>
                                </ENT>
                                <ENT>621-64-7</ENT>
                                <ENT>—</ENT>
                                <ENT>—</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Phenanthrene</ENT>
                                <ENT>85-01-8</ENT>
                                <ENT>5.4</ENT>
                                <ENT>16.2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Pyrene</ENT>
                                <ENT>129-00-0</ENT>
                                <ENT>1.9</ENT>
                                <ENT>5.7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,4-Trichlorobenzene</ENT>
                                <ENT>120-82-1</ENT>
                                <ENT>1.9</ENT>
                                <ENT>5.7</ENT>
                            </ROW>
                            <TNOTE>
                                <SU>1</SU>
                                 All analytes in this table are Priority Pollutants (40 CFR part 423, appendix A).
                            </TNOTE>
                            <TNOTE>
                                <SU>2</SU>
                                 Included for tailing factor testing.
                            </TNOTE>
                            <TNOTE>
                                <SU>3</SU>
                                 See section 1.2.
                            </TNOTE>
                            <TNOTE>
                                <SU>4</SU>
                                 MDL values from the 1984 promulgated version of Method 625.
                            </TNOTE>
                            <TNOTE>
                                <SU>5</SU>
                                 ML = Minimum Level—see Glossary for definition and derivation.
                            </TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="4" OPTS="L2" CDEF="s100,12,12,12">
                            <TTITLE>
                                Table 2—Acid Extractables 
                                <SU>1</SU>
                            </TTITLE>
                            <BOXHD>
                                <CHED H="1">Analyte</CHED>
                                <CHED H="1">CAS registry</CHED>
                                <CHED H="1">
                                    MDL 
                                    <SU>3</SU>
                                    <LI>(ug/L)</LI>
                                </CHED>
                                <CHED H="1">
                                    ML 
                                    <SU>4</SU>
                                    <LI>(ug/L)</LI>
                                </CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">4-Chloro-3-methylphenol</ENT>
                                <ENT>59-50-7</ENT>
                                <ENT>3.0</ENT>
                                <ENT>9.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-Chlorophenol</ENT>
                                <ENT>95-57-8</ENT>
                                <ENT>3.3</ENT>
                                <ENT>9.9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4-Dichlorophenol</ENT>
                                <ENT>120-83-2</ENT>
                                <ENT>2.7</ENT>
                                <ENT>8.1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4-Dimethylphenol</ENT>
                                <ENT>105-67-9</ENT>
                                <ENT>2.7</ENT>
                                <ENT>8.1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4-Dinitrophenol</ENT>
                                <ENT>51-28-5</ENT>
                                <ENT>42</ENT>
                                <ENT>126</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-Methyl-4,6-dinitrophenol</ENT>
                                <ENT>534-52-1</ENT>
                                <ENT>24</ENT>
                                <ENT>72</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-Nitrophenol</ENT>
                                <ENT>88-75-5</ENT>
                                <ENT>3.6</ENT>
                                <ENT>10.8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4-Nitrophenol</ENT>
                                <ENT>100-02-7</ENT>
                                <ENT>2.4</ENT>
                                <ENT>7.2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Pentachlorophenol 
                                    <SU>2</SU>
                                </ENT>
                                <ENT>87-86-5</ENT>
                                <ENT>3.6</ENT>
                                <ENT>10.8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Phenol</ENT>
                                <ENT>108-95-2</ENT>
                                <ENT>1.5</ENT>
                                <ENT>4.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4,6-Trichlorophenol</ENT>
                                <ENT>88-06-2</ENT>
                                <ENT>2.7</ENT>
                                <ENT>8.1</ENT>
                            </ROW>
                            <TNOTE>
                                <SU>1</SU>
                                 All analytes in this table are Priority Pollutants (40 CFR part 423, appendix A).
                            </TNOTE>
                            <TNOTE>
                                <SU>2</SU>
                                 See section 1.2; included for tailing factor testing.
                            </TNOTE>
                            <TNOTE>
                                <SU>3</SU>
                                 MDL values from the 1984 promulgated version of Method 625.
                            </TNOTE>
                            <TNOTE>
                                <SU>4</SU>
                                 ML = Minimum Level—see Glossary for definition and derivation.
                            </TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="4" OPTS="L2" CDEF="s100,12,12,12">
                            <TTITLE>
                                Table 3—Additional Extractable Analytes 
                                <SU>1 2</SU>
                            </TTITLE>
                            <BOXHD>
                                <CHED H="1">Analyte</CHED>
                                <CHED H="1">CAS registry</CHED>
                                <CHED H="1">
                                    MDL 
                                    <SU>7</SU>
                                    <LI>(ug/L)</LI>
                                </CHED>
                                <CHED H="1">
                                    ML 
                                    <SU>8</SU>
                                    <LI>(ug/L)</LI>
                                </CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">Acetophenone</ENT>
                                <ENT>98-86-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-Acetylaminofluorene</ENT>
                                <ENT>53-96-3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1-Acetyl-2-thiourea</ENT>
                                <ENT>591-08-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Alachlor</ENT>
                                <ENT>15972-60-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Aldrin 
                                    <SU>3</SU>
                                </ENT>
                                <ENT>309-00-2</ENT>
                                <ENT>1.9</ENT>
                                <ENT>5.7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ametryn</ENT>
                                <ENT>834-12-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-Aminoanthraquinone</ENT>
                                <ENT>117-79-3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Aminoazobenzene</ENT>
                                <ENT>60-09-3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4-Aminobiphenyl</ENT>
                                <ENT>92-67-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">3-Amino-9-ethylcarbazole</ENT>
                                <ENT>132-32-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Anilazine</ENT>
                                <ENT>101-05-3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Aniline</ENT>
                                <ENT>62-53-3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">o</E>
                                    -Anisidine
                                </ENT>
                                <ENT>90-04-0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Aramite</ENT>
                                <ENT>140-57-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Atraton</ENT>
                                <ENT>1610-17-9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Atrazine</ENT>
                                <ENT>1912-24-9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Azinphos-methyl</ENT>
                                <ENT>86-50-0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Barban</ENT>
                                <ENT>101-27-9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzanthrone</ENT>
                                <ENT>82-05-3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzenethiol</ENT>
                                <ENT>108-98-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzoic acid</ENT>
                                <ENT>65-85-0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,3-Benzofluorene</ENT>
                                <ENT>243-17-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">p</E>
                                    -Benzoquinone
                                </ENT>
                                <ENT>106-51-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzyl alcohol</ENT>
                                <ENT>100-51-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">alpha</E>
                                    -BHC 
                                    <SU>3</SU>
                                     
                                    <SU>4</SU>
                                </ENT>
                                <ENT>319-84-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">beta</E>
                                    -BHC 
                                    <SU>3</SU>
                                </ENT>
                                <ENT>319-85-7</ENT>
                                <ENT>3.1</ENT>
                                <ENT>9.3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">gamma</E>
                                    -BHC (Lindane) 
                                    <SU>3</SU>
                                     
                                    <SU>4</SU>
                                </ENT>
                                <ENT>58-89-8</ENT>
                                <ENT>4.2</ENT>
                                <ENT>12.6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">delta</E>
                                    -BHC 
                                    <SU>3</SU>
                                </ENT>
                                <ENT>319-86-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Biphenyl</ENT>
                                <ENT>92-52-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Bromacil</ENT>
                                <ENT>314-40-9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-Bromochlorobenzene</ENT>
                                <ENT>694-80-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">3-Bromochlorobenzene</ENT>
                                <ENT>108-39-2</ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="293"/>
                                <ENT I="01">Bromoxynil</ENT>
                                <ENT>1689-84-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Butachlor</ENT>
                                <ENT>2318-4669</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Butylate</ENT>
                                <ENT>2008-41-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">n</E>
                                    -C10 (
                                    <E T="03">n</E>
                                    -decane)
                                </ENT>
                                <ENT>124-18-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">n</E>
                                    -C12 (
                                    <E T="03">n</E>
                                    -undecane)
                                </ENT>
                                <ENT>112-40-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">n</E>
                                    -C14 (
                                    <E T="03">n</E>
                                    -tetradecane)
                                </ENT>
                                <ENT>629-59-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">n</E>
                                    -C16 (
                                    <E T="03">n</E>
                                    -hexadecane)
                                </ENT>
                                <ENT>544-76-3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">n</E>
                                    -C18 (
                                    <E T="03">n</E>
                                    -octadecane)
                                </ENT>
                                <ENT>593-45-3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">n</E>
                                    -C20 (
                                    <E T="03">n</E>
                                    -eicosane)
                                </ENT>
                                <ENT>112-95-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">n</E>
                                    -C22 (
                                    <E T="03">n</E>
                                    -docosane)
                                </ENT>
                                <ENT>629-97-0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">n</E>
                                    -C24 (
                                    <E T="03">n</E>
                                    -tetracosane)
                                </ENT>
                                <ENT>646-31-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">n</E>
                                    -C26 (
                                    <E T="03">n</E>
                                    -hexacosane)
                                </ENT>
                                <ENT>630-01-3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">n</E>
                                    -C28 (
                                    <E T="03">n</E>
                                    -octacosane)
                                </ENT>
                                <ENT>630-02-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">n</E>
                                    -C30 (
                                    <E T="03">n</E>
                                    -triacontane)
                                </ENT>
                                <ENT>638-68-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Captafol</ENT>
                                <ENT>2425-06-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Captan</ENT>
                                <ENT>133-06-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Carbaryl</ENT>
                                <ENT>63-25-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Carbazole</ENT>
                                <ENT>86-74-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Carbofuran</ENT>
                                <ENT>1563-66-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Carboxin</ENT>
                                <ENT>5234-68 -4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Carbophenothion</ENT>
                                <ENT>786-19-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Chlordane 
                                    <SU>3 5</SU>
                                </ENT>
                                <ENT>57-74-9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    bis(2-Chloroethyl) ether 
                                    <SU>3 4</SU>
                                </ENT>
                                <ENT>111-44-4</ENT>
                                <ENT>5.7</ENT>
                                <ENT>17.1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chloroneb</ENT>
                                <ENT>2675-77-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4-Chloroaniline</ENT>
                                <ENT>106-47-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chlorobenzilate</ENT>
                                <ENT>510-15-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chlorfenvinphos</ENT>
                                <ENT>470-90-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4-Chloro-2-methylaniline</ENT>
                                <ENT>95-69-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">3-(Chloromethyl)pyridine hydrochloride</ENT>
                                <ENT>6959-48-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4-Chloro-2-nitroaniline</ENT>
                                <ENT>89-63-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chlorpropham</ENT>
                                <ENT>101-21-3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chlorothalonil</ENT>
                                <ENT>1897-45-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1-Chloronaphthalene</ENT>
                                <ENT>90-13-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">3-Chloronitrobenzene</ENT>
                                <ENT>121-73-3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4-Chloro-1,2-phenylenediamine</ENT>
                                <ENT>95-83-0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4-Chloro-1,3-phenylenediamine</ENT>
                                <ENT>5131-60-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-Chlorobiphenyl</ENT>
                                <ENT>2051-60-7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chlorpyrifos</ENT>
                                <ENT>2921-88-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Coumaphos</ENT>
                                <ENT>56-72-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">m</E>
                                     + 
                                    <E T="03">p</E>
                                    -Cresol
                                </ENT>
                                <ENT>65794-96-9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">o</E>
                                    -Cresol
                                </ENT>
                                <ENT>95-48-7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">p</E>
                                    -Cresidine
                                </ENT>
                                <ENT>120-71-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Crotoxyphos</ENT>
                                <ENT>7700-17-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-Cyclohexyl-4,6-dinitro-phenol</ENT>
                                <ENT>131-89-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Cyanazine</ENT>
                                <ENT>21725-46-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Cycloate</ENT>
                                <ENT>1134-23-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">p</E>
                                    -Cymene
                                </ENT>
                                <ENT>99-87-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dacthal (DCPA)</ENT>
                                <ENT>1861-32-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    4,4'-DDD 
                                    <SU>3</SU>
                                </ENT>
                                <ENT>72-54-8</ENT>
                                <ENT>2.8</ENT>
                                <ENT>8.4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    4,4'-DDE 
                                    <SU>3</SU>
                                </ENT>
                                <ENT>72-55-9</ENT>
                                <ENT>5.6</ENT>
                                <ENT>16.8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    4,4'-DDT 
                                    <SU>3</SU>
                                </ENT>
                                <ENT>50-29-3</ENT>
                                <ENT>4.7</ENT>
                                <ENT>14.1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Demeton-O</ENT>
                                <ENT>298-03-3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Demeton-S</ENT>
                                <ENT>126-75-0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Diallate (
                                    <E T="03">cis</E>
                                     or 
                                    <E T="03">trans</E>
                                    )
                                </ENT>
                                <ENT>2303-16-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4-Diaminotoluene</ENT>
                                <ENT>95-80-7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Diazinon</ENT>
                                <ENT>333-41-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dibenz(a,j)acridine</ENT>
                                <ENT>224-42-0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dibenzofuran</ENT>
                                <ENT>132-64-9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dibenzo(a,e)pyrene</ENT>
                                <ENT>192-65-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dibenzothiophene</ENT>
                                <ENT>132-65-0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2-Dibromo-3-chloropropane</ENT>
                                <ENT>96-12-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">3,5-Dibromo-4-hydroxybenzonitrile</ENT>
                                <ENT>1689-84-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    2,6-Di-
                                    <E T="03">tert</E>
                                    -butyl-p-benzoquinone
                                </ENT>
                                <ENT>719-22-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dichlone</ENT>
                                <ENT>117-80-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,3-Dichloroaniline</ENT>
                                <ENT>608-27-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,3-Dichlorobiphenyl</ENT>
                                <ENT>16605-91-7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,6-Dichloro-4-nitroaniline</ENT>
                                <ENT>99-30-9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,3-Dichloronitrobenzene</ENT>
                                <ENT>3209-22-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,3-Dichloro-2-propanol</ENT>
                                <ENT>96-23-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,6-Dichlorophenol</ENT>
                                <ENT>120-83-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dichlorvos</ENT>
                                <ENT>62-73-7</ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="294"/>
                                <ENT I="01">Dicrotophos</ENT>
                                <ENT>141-66-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Dieldrin 
                                    <SU>3</SU>
                                </ENT>
                                <ENT>60-57-1</ENT>
                                <ENT>2.5</ENT>
                                <ENT>7.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2:3,4-Diepoxybutane</ENT>
                                <ENT>1464-53-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Di(2-ethylhexyl) adipate</ENT>
                                <ENT>103-23-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Diethylstilbestrol</ENT>
                                <ENT>56-53-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Diethyl sulfate</ENT>
                                <ENT>64-67-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dilantin (5,5-Diphenylhydantoin)</ENT>
                                <ENT>57-41-0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dimethoate</ENT>
                                <ENT>60-51-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">3,3′-Dimethoxybenzidine</ENT>
                                <ENT>119-90-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dimethylaminoazobenzene</ENT>
                                <ENT>60-11-7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">7,12-Dimethylbenz(a)anthracene</ENT>
                                <ENT>57-97-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">3,3′-Dimethylbenzidine</ENT>
                                <ENT>119-93-7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">N,N-Dimethylformamide</ENT>
                                <ENT>68-12-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">3,6-Dimethylphenathrene</ENT>
                                <ENT>1576-67-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">alpha, alpha</E>
                                    -Dimethylphenethylamine
                                </ENT>
                                <ENT>122-09-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dimethyl sulfone</ENT>
                                <ENT>67-71-0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2-Dinitrobenzene</ENT>
                                <ENT>528-29-0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,3-Dinitrobenzene</ENT>
                                <ENT>99-65-0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,4-Dinitrobenzene</ENT>
                                <ENT>100-25-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dinocap</ENT>
                                <ENT>39300-45-3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dinoseb</ENT>
                                <ENT>88-85-7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Diphenylamine</ENT>
                                <ENT>122-39-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Diphenyl ether</ENT>
                                <ENT>101-84-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2-Diphenylhydrazine</ENT>
                                <ENT>122-66-7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Diphenamid</ENT>
                                <ENT>957-51-7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Diphenyldisulfide</ENT>
                                <ENT>882-33-7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Disulfoton</ENT>
                                <ENT>298-04-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Disulfoton sulfoxide</ENT>
                                <ENT>2497-07-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Disulfoton sulfone</ENT>
                                <ENT>2497-06-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Endosulfan I 
                                    <SU>4</SU>
                                </ENT>
                                <ENT>959-98-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Endosulfan II 
                                    <SU>3 4</SU>
                                </ENT>
                                <ENT>33213-65-9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Endosulfan sulfate 
                                    <SU>3</SU>
                                </ENT>
                                <ENT>1031-07-8</ENT>
                                <ENT>5.6</ENT>
                                <ENT>16.8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Endrin 
                                    <SU>3 4</SU>
                                </ENT>
                                <ENT>72-20-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Endrin aldehyde 
                                    <SU>3 4</SU>
                                </ENT>
                                <ENT>7421-93-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Endrin ketone 
                                    <SU>3 4</SU>
                                </ENT>
                                <ENT>53494-70-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">EPN</ENT>
                                <ENT>2104-64-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">EPTC</ENT>
                                <ENT>759-94-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ethion</ENT>
                                <ENT>563-12-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ethoprop</ENT>
                                <ENT>13194-48-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ethyl carbamate</ENT>
                                <ENT>51-79-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ethyl methanesulfonate</ENT>
                                <ENT>65-50-0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ethylenethiourea</ENT>
                                <ENT>96-45-7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Etridiazole</ENT>
                                <ENT>2593-15-9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ethynylestradiol-3-methyl ether</ENT>
                                <ENT>72-33-3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Famphur</ENT>
                                <ENT>52-85-7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Fenamiphos</ENT>
                                <ENT>22224-92-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Fenarimol</ENT>
                                <ENT>60168-88-9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Fensulfothion</ENT>
                                <ENT>115-90-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Fenthion</ENT>
                                <ENT>55-38-9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Fluchloralin</ENT>
                                <ENT>33245-39-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Fluridone</ENT>
                                <ENT>59756-60-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Heptachlor 
                                    <SU>3</SU>
                                </ENT>
                                <ENT>76-44-8</ENT>
                                <ENT>1.9</ENT>
                                <ENT>5.7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Heptachlor epoxide 
                                    <SU>3</SU>
                                </ENT>
                                <ENT>1024-57-3</ENT>
                                <ENT>2.2</ENT>
                                <ENT>6.6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,2′,3,3′,4,4′,6-Heptachlorobiphenyl</ENT>
                                <ENT>52663-71-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,2′,4,4′,5′,6-Hexachlorobiphenyl</ENT>
                                <ENT>60145-22-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Hexachlorocyclopentadiene 
                                    <SU>3 4</SU>
                                </ENT>
                                <ENT>77-47-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Hexachlorophene</ENT>
                                <ENT>70-30-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Hexachloropropene</ENT>
                                <ENT>1888-71-7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Hexamethylphosphoramide</ENT>
                                <ENT>680-31-9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Hexanoic acid</ENT>
                                <ENT>142-62-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Hexazinone</ENT>
                                <ENT>51235-04-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Hydroquinone</ENT>
                                <ENT>123-31-9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Isodrin</ENT>
                                <ENT>465-73-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-Isopropylnaphthalene</ENT>
                                <ENT>2027-17-0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Isosafrole</ENT>
                                <ENT>120-58-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Kepone</ENT>
                                <ENT>143-50-0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Leptophos</ENT>
                                <ENT>21609-90-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Longifolene</ENT>
                                <ENT>475-20-7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Malachite green</ENT>
                                <ENT>569-64-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Malathion</ENT>
                                <ENT>121-75-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Maleic anhydride</ENT>
                                <ENT>108-31-6</ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="295"/>
                                <ENT I="01">Merphos</ENT>
                                <ENT>150-50-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Mestranol</ENT>
                                <ENT>72-33-3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Methapyrilene</ENT>
                                <ENT>91-80-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Methoxychlor</ENT>
                                <ENT>72-43-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-Methylbenzothioazole</ENT>
                                <ENT>120-75-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">3-Methylcholanthrene</ENT>
                                <ENT>56-49-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4,4′-Methylenebis(2-chloroaniline)</ENT>
                                <ENT>101-14-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4,4′-Methylenebis(N,N-dimethylaniline)</ENT>
                                <ENT>101-61-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4,5-Methylenephenanthrene</ENT>
                                <ENT>203-64-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1-Methylfluorene</ENT>
                                <ENT>1730-37-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Methyl methanesulfonate</ENT>
                                <ENT>66-27-3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-Methylnaphthalene</ENT>
                                <ENT>91-57-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Methylparaoxon</ENT>
                                <ENT>950-35-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Methyl parathion</ENT>
                                <ENT>298-00-0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1-Methylphenanthrene</ENT>
                                <ENT>832-69-9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-(Methylthio)benzothiazole</ENT>
                                <ENT>615-22-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Metolachlor</ENT>
                                <ENT>5218-45-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Metribuzin</ENT>
                                <ENT>21087-64-9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Mevinphos</ENT>
                                <ENT>7786-34-7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Mexacarbate</ENT>
                                <ENT>315-18-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">MGK 264</ENT>
                                <ENT>113-48-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Mirex</ENT>
                                <ENT>2385-85-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Molinate</ENT>
                                <ENT>2212-67-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Monocrotophos</ENT>
                                <ENT>6923-22-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Naled</ENT>
                                <ENT>300-76-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Napropamide</ENT>
                                <ENT>15299-99-7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,4-Naphthoquinone</ENT>
                                <ENT>130-15-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1-Naphthylamine</ENT>
                                <ENT>134-32-7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-Naphthylamine</ENT>
                                <ENT>91-59-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,5-Naphthalenediamine</ENT>
                                <ENT>2243-62-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Nicotine</ENT>
                                <ENT>54-11-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">5-Nitroacenaphthene</ENT>
                                <ENT>602-87-9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-Nitroaniline</ENT>
                                <ENT>88-74-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">3-Nitroaniline</ENT>
                                <ENT>99-09-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4-Nitroaniline</ENT>
                                <ENT>100-01-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    5-Nitro-
                                    <E T="03">o</E>
                                    -anisidine
                                </ENT>
                                <ENT>99-59-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4-Nitrobiphenyl</ENT>
                                <ENT>92-93-3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Nitrofen</ENT>
                                <ENT>1836-75-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    5-Nitro-
                                    <E T="03">o</E>
                                    -toluidine
                                </ENT>
                                <ENT>99-55-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Nitroquinoline-1-oxide</ENT>
                                <ENT>56-57-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    N-Nitrosodi-
                                    <E T="03">n</E>
                                    -butylamine 
                                    <SU>4</SU>
                                </ENT>
                                <ENT>924-16-3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    N-Nitrosodiethylamine 
                                    <SU>4</SU>
                                </ENT>
                                <ENT>55-18-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    N-Nitrosodimethylamine 
                                    <SU>3 4</SU>
                                </ENT>
                                <ENT>62-75-9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    N-Nitrosodiphenylamine 
                                    <SU>3 4</SU>
                                </ENT>
                                <ENT>86-30-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    N-Nitrosomethylethylamine 
                                    <SU>4</SU>
                                </ENT>
                                <ENT>10595-95-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    N-Nitrosomethylphenylamine 
                                    <SU>4</SU>
                                </ENT>
                                <ENT>614-00-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    N-Nitrosomorpholine 
                                    <SU>4</SU>
                                </ENT>
                                <ENT>59-89-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    N-Nitrosopiperidine 
                                    <SU>4</SU>
                                </ENT>
                                <ENT>100-75-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    N-Nitrosopyrrolidine 
                                    <SU>4</SU>
                                </ENT>
                                <ENT>930-55-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">trans</E>
                                    -Nonachlor
                                </ENT>
                                <ENT>39765-80-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Norflurazon</ENT>
                                <ENT>27314-13-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,2′,3,3′,4,5′,6,6′-Octachlorobiphenyl</ENT>
                                <ENT>40186-71-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Octamethyl pyrophosphoramide</ENT>
                                <ENT>152-16-9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4,4'-Oxydianiline</ENT>
                                <ENT>101-80-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Parathion</ENT>
                                <ENT>56-38-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    PCB-1016 
                                    <SU>3 5</SU>
                                </ENT>
                                <ENT>12674-11-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    PCB-1221 
                                    <SU>3 5</SU>
                                </ENT>
                                <ENT>11104-28-2</ENT>
                                <ENT>30</ENT>
                                <ENT>90</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    PCB-1232 
                                    <SU>3 5</SU>
                                </ENT>
                                <ENT>11141-16-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    PCB-1242 
                                    <SU>3 5</SU>
                                </ENT>
                                <ENT>53469-21-9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    PCB-1248 
                                    <SU>3 5</SU>
                                </ENT>
                                <ENT>12672-29-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    PCB-1254 
                                    <SU>3 5</SU>
                                </ENT>
                                <ENT>11097-69-1</ENT>
                                <ENT>36</ENT>
                                <ENT>108</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    PCB-1260 
                                    <SU>3 5</SU>
                                </ENT>
                                <ENT>11098-82-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    PCB-1268 
                                    <SU>3 5</SU>
                                </ENT>
                                <ENT>11100-14-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Pebulate</ENT>
                                <ENT>1114-71-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Pentachlorobenzene</ENT>
                                <ENT>608-93-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Pentachloronitrobenzene</ENT>
                                <ENT>82-68-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,2′,3,4′,6-Pentachlorobiphenyl</ENT>
                                <ENT>68194-05-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Pentachloroethane</ENT>
                                <ENT>76-01-7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Pentamethylbenzene</ENT>
                                <ENT>700-12-9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Perylene</ENT>
                                <ENT>198-55-0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Phenacetin</ENT>
                                <ENT>62-44-2</ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="296"/>
                                <ENT I="01">
                                    <E T="03">cis</E>
                                    -Permethrin
                                </ENT>
                                <ENT>61949-76-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">trans</E>
                                    -Permethrin
                                </ENT>
                                <ENT>61949-77-7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Phenobarbital</ENT>
                                <ENT>50-06-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Phenothiazene</ENT>
                                <ENT>92-84-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,4-Phenylenediamine</ENT>
                                <ENT>624-18-0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1-Phenylnaphthalene</ENT>
                                <ENT>605-02-7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-Phenylnaphthalene</ENT>
                                <ENT>612-94-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Phorate</ENT>
                                <ENT>298-02-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Phosalone</ENT>
                                <ENT>2310-18-0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Phosmet</ENT>
                                <ENT>732-11-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Phosphamidon</ENT>
                                <ENT>13171-21-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Phthalic anhydride</ENT>
                                <ENT>85-44-9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">alpha</E>
                                    -Picoline (2-Methylpyridine)
                                </ENT>
                                <ENT>109-06-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Piperonyl sulfoxide</ENT>
                                <ENT>120-62-7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Prometon</ENT>
                                <ENT>1610-18-0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Prometryn</ENT>
                                <ENT>7287-19-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Pronamide</ENT>
                                <ENT>23950-58-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Propachlor</ENT>
                                <ENT>1918-16-7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Propazine</ENT>
                                <ENT>139-40-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Propylthiouracil</ENT>
                                <ENT>51-52-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Pyridine</ENT>
                                <ENT>110-86-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Resorcinol (1,3-Benzenediol)</ENT>
                                <ENT>108-46-3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Safrole</ENT>
                                <ENT>94-59-7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Simazine</ENT>
                                <ENT>122-34-9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Simetryn</ENT>
                                <ENT>1014-70-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Squalene</ENT>
                                <ENT>7683-64-9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Stirofos</ENT>
                                <ENT>22248-79-9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Strychnine</ENT>
                                <ENT>57-24-9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Styrene 
                                    <SU>9</SU>
                                </ENT>
                                <ENT>100-42-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Sulfallate</ENT>
                                <ENT>95-06-7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Tebuthiuron</ENT>
                                <ENT>34014-18-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Terbacil</ENT>
                                <ENT>5902-51-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Terbufos</ENT>
                                <ENT>13071-79-9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Terbutryn</ENT>
                                <ENT>886-50-0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">alpha</E>
                                    -Terpineol
                                </ENT>
                                <ENT>98-55-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,4,5-Tetrachlorobenzene</ENT>
                                <ENT>95-94-3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,2′,4,4′-Tetrachlorobiphenyl</ENT>
                                <ENT>2437-79-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    2,3,7,8-Tetrachlorodibenzo-
                                    <E T="03">p</E>
                                    -dioxin
                                </ENT>
                                <ENT>1746-01-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,3,4,6-Tetrachlorophenol</ENT>
                                <ENT>58-90-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Tetrachlorvinphos</ENT>
                                <ENT>22248-79-9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Tetraethyl dithiopyrophosphate</ENT>
                                <ENT>3689-24-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Tetraethyl pyrophosphate</ENT>
                                <ENT>107-49-3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Thianaphthene (2,3-Benzothiophene)</ENT>
                                <ENT>95-15-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Thioacetamide</ENT>
                                <ENT>62-55-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Thionazin</ENT>
                                <ENT>297-97-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Thiophenol (Benzenethiol)</ENT>
                                <ENT>108-98-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Thioxanthone</ENT>
                                <ENT>492-22-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Toluene-1,3-diisocyanate</ENT>
                                <ENT>26471-62-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Toluene-2,4-diisocyanate</ENT>
                                <ENT>584-84-9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">o</E>
                                    -Toluidine
                                </ENT>
                                <ENT>95-53-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Toxaphene 
                                    <SU>3 5</SU>
                                </ENT>
                                <ENT>8001-35-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Triadimefon</ENT>
                                <ENT>43121-43-3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3-Trichlorobenzene</ENT>
                                <ENT>87-61-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4,5-Trichlorobiphenyl</ENT>
                                <ENT>15862-07-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,3,6-Trichlorophenol</ENT>
                                <ENT>933-75-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4,5-Trichlorophenol</ENT>
                                <ENT>95-95-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Tricyclazole</ENT>
                                <ENT>41814-78-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Trifluralin</ENT>
                                <ENT>1582-09-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3-Trimethoxybenzene</ENT>
                                <ENT>634-36-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4,5-Trimethylaniline</ENT>
                                <ENT>137-17-7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Trimethyl phosphate</ENT>
                                <ENT>512-56-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Triphenylene</ENT>
                                <ENT>217-59-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Tripropyleneglycolmethyl ether</ENT>
                                <ENT>20324-33-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,3,5-Trinitrobenzene</ENT>
                                <ENT>99-35-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Tris(2,3-dibromopropyl) phosphate</ENT>
                                <ENT>126-72-7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Tri-
                                    <E T="03">p</E>
                                    -tolyl phosphate
                                </ENT>
                                <ENT>78-32-0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">O,O,O-Triethyl phosphorothioate</ENT>
                                <ENT>126-68-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Trithiane</ENT>
                                <ENT>291-29-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Vernolate</ENT>
                                <ENT>1929-77-7</ENT>
                            </ROW>
                            <TNOTE>
                                <SU>1</SU>
                                 Compounds that have been demonstrated amenable to extraction and gas chromatography.
                            </TNOTE>
                            <TNOTE>
                                <SU>2</SU>
                                 Determine each analyte in the fraction that gives the most accurate result.
                                <PRTPAGE P="297"/>
                            </TNOTE>
                            <TNOTE>
                                <SU>3</SU>
                                 Priority Pollutant (40 CFR part 423, appendix A).
                            </TNOTE>
                            <TNOTE>
                                <SU>4</SU>
                                 See section 1.2.
                            </TNOTE>
                            <TNOTE>
                                <SU>5</SU>
                                 These compounds are mixtures of various isomers.
                            </TNOTE>
                            <TNOTE>
                                <SU>6</SU>
                                 Detected as azobenzene.
                            </TNOTE>
                            <TNOTE>
                                <SU>7</SU>
                                 MDL values from the 1984 promulgated version of Method 625.
                            </TNOTE>
                            <TNOTE>
                                <SU>8</SU>
                                 ML = Minimum Level—see Glossary for definition and derivation.
                            </TNOTE>
                            <TNOTE>
                                <SU>9</SU>
                                 Styrene may be susceptible to losses during sampling, preservation, and/or extraction of full-volume (1 L) water samples. However, styrene is not regulated at 40 CFR part 136, and it is also listed as an analyte in EPA Method 624.1 and EPA Method 1625C, where such losses may be less than using Method 625.1.
                            </TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="8" OPTS="L2" CDEF="s50,10,10,10,10,10,10,10">
                            <TTITLE>
                                Table 4—Chromatographic Conditions and Characteristic 
                                <E T="01">m/z's</E>
                                 for Base/Neutral Extractables
                            </TTITLE>
                            <BOXHD>
                                <CHED H="1">Analyte</CHED>
                                <CHED H="1">
                                    Retention time
                                    <LI>
                                        (sec) 
                                        <SU>1</SU>
                                    </LI>
                                </CHED>
                                <CHED H="1">Characteristic m/z's</CHED>
                                <CHED H="2">Electron impact ionization</CHED>
                                <CHED H="3">Primary</CHED>
                                <CHED H="3">Second</CHED>
                                <CHED H="3">Second</CHED>
                                <CHED H="2">Chemical ionization</CHED>
                                <CHED H="3">Methane</CHED>
                                <CHED H="3">Methane</CHED>
                                <CHED H="3">Methane</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">N-Nitrosodimethylamine</ENT>
                                <ENT>385</ENT>
                                <ENT>42</ENT>
                                <ENT>74</ENT>
                                <ENT>44</ENT>
                                <ENT/>
                            </ROW>
                            <ROW>
                                <ENT I="01">bis(2-Chloroethyl) ether</ENT>
                                <ENT>704</ENT>
                                <ENT>93</ENT>
                                <ENT>63</ENT>
                                <ENT>95</ENT>
                                <ENT>63</ENT>
                                <ENT>107</ENT>
                                <ENT>109</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">bis(2-Chloroisopropyl) ether</ENT>
                                <ENT>799</ENT>
                                <ENT>45</ENT>
                                <ENT>77</ENT>
                                <ENT>79</ENT>
                                <ENT>77</ENT>
                                <ENT>135</ENT>
                                <ENT>137</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Hexachloroethane</ENT>
                                <ENT>823</ENT>
                                <ENT>117</ENT>
                                <ENT>201</ENT>
                                <ENT>199</ENT>
                                <ENT>199</ENT>
                                <ENT>201</ENT>
                                <ENT>203</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    N-Nitrosodi-
                                    <E T="03">n</E>
                                    -propylamine
                                </ENT>
                                <ENT>830</ENT>
                                <ENT>130</ENT>
                                <ENT>42</ENT>
                                <ENT>101</ENT>
                                <ENT/>
                            </ROW>
                            <ROW>
                                <ENT I="01">Nitrobenzene</ENT>
                                <ENT>849</ENT>
                                <ENT>77</ENT>
                                <ENT>123</ENT>
                                <ENT>65</ENT>
                                <ENT>124</ENT>
                                <ENT>152</ENT>
                                <ENT>164</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Isophorone</ENT>
                                <ENT>889</ENT>
                                <ENT>82</ENT>
                                <ENT>95</ENT>
                                <ENT>138</ENT>
                                <ENT>139</ENT>
                                <ENT>167</ENT>
                                <ENT>178</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">bis(2-Chloroethoxy) methane</ENT>
                                <ENT>939</ENT>
                                <ENT>93</ENT>
                                <ENT>95</ENT>
                                <ENT>123</ENT>
                                <ENT>65</ENT>
                                <ENT>107</ENT>
                                <ENT>137</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,4-Trichlorobenzene</ENT>
                                <ENT>958</ENT>
                                <ENT>180</ENT>
                                <ENT>182</ENT>
                                <ENT>145</ENT>
                                <ENT>181</ENT>
                                <ENT>183</ENT>
                                <ENT>209</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Naphthalene</ENT>
                                <ENT>967</ENT>
                                <ENT>128</ENT>
                                <ENT>129</ENT>
                                <ENT>127</ENT>
                                <ENT>129</ENT>
                                <ENT>157</ENT>
                                <ENT>169</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Hexachlorobutadiene</ENT>
                                <ENT>1006</ENT>
                                <ENT>225</ENT>
                                <ENT>223</ENT>
                                <ENT>227</ENT>
                                <ENT>223</ENT>
                                <ENT>225</ENT>
                                <ENT>227</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Hexachlorocyclopentadiene</ENT>
                                <ENT>1142</ENT>
                                <ENT>237</ENT>
                                <ENT>235</ENT>
                                <ENT>272</ENT>
                                <ENT>235</ENT>
                                <ENT>237</ENT>
                                <ENT>239</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-Chloronaphthalene</ENT>
                                <ENT>1200</ENT>
                                <ENT>162</ENT>
                                <ENT>164</ENT>
                                <ENT>127</ENT>
                                <ENT>163</ENT>
                                <ENT>191</ENT>
                                <ENT>203</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Acenaphthylene</ENT>
                                <ENT>1247</ENT>
                                <ENT>152</ENT>
                                <ENT>151</ENT>
                                <ENT>153</ENT>
                                <ENT>152</ENT>
                                <ENT>153</ENT>
                                <ENT>181</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dimethyl phthalate</ENT>
                                <ENT>1273</ENT>
                                <ENT>163</ENT>
                                <ENT>194</ENT>
                                <ENT>164</ENT>
                                <ENT>151</ENT>
                                <ENT>163</ENT>
                                <ENT>164</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,6-Dinitrotoluene</ENT>
                                <ENT>1300</ENT>
                                <ENT>165</ENT>
                                <ENT>89</ENT>
                                <ENT>121</ENT>
                                <ENT>183</ENT>
                                <ENT>211</ENT>
                                <ENT>223</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Acenaphthene</ENT>
                                <ENT>1304</ENT>
                                <ENT>154</ENT>
                                <ENT>153</ENT>
                                <ENT>152</ENT>
                                <ENT>154</ENT>
                                <ENT>155</ENT>
                                <ENT>183</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4-Dinitrotoluene</ENT>
                                <ENT>1364</ENT>
                                <ENT>165</ENT>
                                <ENT>63</ENT>
                                <ENT>182</ENT>
                                <ENT>183</ENT>
                                <ENT>211</ENT>
                                <ENT>223</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Fluorene</ENT>
                                <ENT>1401</ENT>
                                <ENT>166</ENT>
                                <ENT>165</ENT>
                                <ENT>167</ENT>
                                <ENT>166</ENT>
                                <ENT>167</ENT>
                                <ENT>195</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4-Chlorophenyl phenyl ether</ENT>
                                <ENT>1409</ENT>
                                <ENT>204</ENT>
                                <ENT>206</ENT>
                                <ENT>141</ENT>
                                <ENT/>
                            </ROW>
                            <ROW>
                                <ENT I="01">Diethyl phthalate</ENT>
                                <ENT>1414</ENT>
                                <ENT>149</ENT>
                                <ENT>177</ENT>
                                <ENT>150</ENT>
                                <ENT>177</ENT>
                                <ENT>223</ENT>
                                <ENT>251</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">N-Nitrosodiphenylamine</ENT>
                                <ENT>1464</ENT>
                                <ENT>169</ENT>
                                <ENT>168</ENT>
                                <ENT>167</ENT>
                                <ENT>169</ENT>
                                <ENT>170</ENT>
                                <ENT>198</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4-Bromophenyl phenyl ether</ENT>
                                <ENT>1498</ENT>
                                <ENT>248</ENT>
                                <ENT>250</ENT>
                                <ENT>141</ENT>
                                <ENT>249</ENT>
                                <ENT>251</ENT>
                                <ENT>277</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">alpha</E>
                                    -BHC
                                </ENT>
                                <ENT>1514</ENT>
                                <ENT>183</ENT>
                                <ENT>181</ENT>
                                <ENT>109</ENT>
                                <ENT/>
                            </ROW>
                            <ROW>
                                <ENT I="01">Hexachlorobenzene</ENT>
                                <ENT>1522</ENT>
                                <ENT>284</ENT>
                                <ENT>142</ENT>
                                <ENT>249</ENT>
                                <ENT>284</ENT>
                                <ENT>286</ENT>
                                <ENT>288</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">beta</E>
                                    -BHC
                                </ENT>
                                <ENT>1544</ENT>
                                <ENT>183</ENT>
                                <ENT>181</ENT>
                                <ENT>109</ENT>
                                <ENT/>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">gamma</E>
                                    -BHC
                                </ENT>
                                <ENT>1557</ENT>
                                <ENT>181</ENT>
                                <ENT>183</ENT>
                                <ENT>109</ENT>
                                <ENT/>
                            </ROW>
                            <ROW>
                                <ENT I="01">Phenanthrene</ENT>
                                <ENT>1583</ENT>
                                <ENT>178</ENT>
                                <ENT>179</ENT>
                                <ENT>176</ENT>
                                <ENT>178</ENT>
                                <ENT>179</ENT>
                                <ENT>207</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Anthracene</ENT>
                                <ENT>1592</ENT>
                                <ENT>178</ENT>
                                <ENT>179</ENT>
                                <ENT>176</ENT>
                                <ENT>178</ENT>
                                <ENT>179</ENT>
                                <ENT>207</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">delta</E>
                                    -BHC
                                </ENT>
                                <ENT>1599</ENT>
                                <ENT>183</ENT>
                                <ENT>109</ENT>
                                <ENT>181</ENT>
                                <ENT/>
                            </ROW>
                            <ROW>
                                <ENT I="01">Heptachlor</ENT>
                                <ENT>1683</ENT>
                                <ENT>100</ENT>
                                <ENT>272</ENT>
                                <ENT>274</ENT>
                                <ENT/>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Di-
                                    <E T="03">n</E>
                                    -butyl phthalate
                                </ENT>
                                <ENT>1723</ENT>
                                <ENT>149</ENT>
                                <ENT>150</ENT>
                                <ENT>104</ENT>
                                <ENT>149</ENT>
                                <ENT>205</ENT>
                                <ENT>279</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Aldrin</ENT>
                                <ENT>1753</ENT>
                                <ENT>66</ENT>
                                <ENT>263</ENT>
                                <ENT>220</ENT>
                                <ENT/>
                            </ROW>
                            <ROW>
                                <ENT I="01">Fluoranthene</ENT>
                                <ENT>1817</ENT>
                                <ENT>202</ENT>
                                <ENT>101</ENT>
                                <ENT>100</ENT>
                                <ENT>203</ENT>
                                <ENT>231</ENT>
                                <ENT>243</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Heptachlor epoxide</ENT>
                                <ENT>1820</ENT>
                                <ENT>353</ENT>
                                <ENT>355</ENT>
                                <ENT>351</ENT>
                                <ENT/>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">gamma</E>
                                    -Chlordane
                                </ENT>
                                <ENT>1834</ENT>
                                <ENT>373</ENT>
                                <ENT>375</ENT>
                                <ENT>377</ENT>
                                <ENT/>
                            </ROW>
                            <ROW>
                                <ENT I="01">Pyrene</ENT>
                                <ENT>1852</ENT>
                                <ENT>202</ENT>
                                <ENT>101</ENT>
                                <ENT>100</ENT>
                                <ENT>203</ENT>
                                <ENT>231</ENT>
                                <ENT>243</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Benzidine
                                    <SU>2</SU>
                                </ENT>
                                <ENT>1853</ENT>
                                <ENT>184</ENT>
                                <ENT>92</ENT>
                                <ENT>185</ENT>
                                <ENT>185</ENT>
                                <ENT>213</ENT>
                                <ENT>225</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">alpha</E>
                                    -Chlordane
                                </ENT>
                                <ENT>1854</ENT>
                                <ENT>373</ENT>
                                <ENT>375</ENT>
                                <ENT>377</ENT>
                                <ENT/>
                            </ROW>
                            <ROW>
                                <ENT I="01">Endosulfan I</ENT>
                                <ENT>1855</ENT>
                                <ENT>237</ENT>
                                <ENT>339</ENT>
                                <ENT>341</ENT>
                                <ENT/>
                            </ROW>
                            <ROW>
                                <ENT I="01">4,4′-DDE</ENT>
                                <ENT>1892</ENT>
                                <ENT>246</ENT>
                                <ENT>248</ENT>
                                <ENT>176</ENT>
                                <ENT/>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dieldrin</ENT>
                                <ENT>1907</ENT>
                                <ENT>79</ENT>
                                <ENT>263</ENT>
                                <ENT>279</ENT>
                                <ENT/>
                            </ROW>
                            <ROW>
                                <ENT I="01">Endrin</ENT>
                                <ENT>1935</ENT>
                                <ENT>81</ENT>
                                <ENT>263</ENT>
                                <ENT>82</ENT>
                                <ENT/>
                            </ROW>
                            <ROW>
                                <ENT I="01">Endosulfan II</ENT>
                                <ENT>2014</ENT>
                                <ENT>237</ENT>
                                <ENT>339</ENT>
                                <ENT>341</ENT>
                                <ENT/>
                            </ROW>
                            <ROW>
                                <ENT I="01">4,4′-DDD</ENT>
                                <ENT>2019</ENT>
                                <ENT>235</ENT>
                                <ENT>237</ENT>
                                <ENT>165</ENT>
                                <ENT/>
                            </ROW>
                            <ROW>
                                <ENT I="01">Endrin aldehyde</ENT>
                                <ENT>2031</ENT>
                                <ENT>67</ENT>
                                <ENT>345</ENT>
                                <ENT>250</ENT>
                                <ENT/>
                            </ROW>
                            <ROW>
                                <ENT I="01">Butyl benzyl phthalate</ENT>
                                <ENT>2060</ENT>
                                <ENT>149</ENT>
                                <ENT>91</ENT>
                                <ENT>206</ENT>
                                <ENT>149</ENT>
                                <ENT>299</ENT>
                                <ENT>327</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Endosulfan sulfate</ENT>
                                <ENT>2068</ENT>
                                <ENT>272</ENT>
                                <ENT>387</ENT>
                                <ENT>422</ENT>
                                <ENT/>
                            </ROW>
                            <ROW>
                                <ENT I="01">4,4′-DDT</ENT>
                                <ENT>2073</ENT>
                                <ENT>235</ENT>
                                <ENT>237</ENT>
                                <ENT>165</ENT>
                                <ENT/>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chrysene</ENT>
                                <ENT>2083</ENT>
                                <ENT>228</ENT>
                                <ENT>226</ENT>
                                <ENT>229</ENT>
                                <ENT>228</ENT>
                                <ENT>229</ENT>
                                <ENT>257</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">3,3′-Dichlorobenzidine</ENT>
                                <ENT>2086</ENT>
                                <ENT>252</ENT>
                                <ENT>254</ENT>
                                <ENT>126</ENT>
                                <ENT/>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzo(a)anthracene</ENT>
                                <ENT>2090</ENT>
                                <ENT>228</ENT>
                                <ENT>229</ENT>
                                <ENT>226</ENT>
                                <ENT>228</ENT>
                                <ENT>229</ENT>
                                <ENT>257</ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="298"/>
                                <ENT I="01">bis(2-Ethylhexyl) phthalate</ENT>
                                <ENT>2124</ENT>
                                <ENT>149</ENT>
                                <ENT>167</ENT>
                                <ENT>279</ENT>
                                <ENT>149</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Di-
                                    <E T="03">n</E>
                                    -octyl phthalate
                                </ENT>
                                <ENT>2240</ENT>
                                <ENT>149</ENT>
                                <ENT>43</ENT>
                                <ENT>57</ENT>
                                <ENT/>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzo(b)fluoranthene</ENT>
                                <ENT>2286</ENT>
                                <ENT>252</ENT>
                                <ENT>253</ENT>
                                <ENT>125</ENT>
                                <ENT>252</ENT>
                                <ENT>253</ENT>
                                <ENT>281</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzo(k)fluoranthene</ENT>
                                <ENT>2293</ENT>
                                <ENT>252</ENT>
                                <ENT>253</ENT>
                                <ENT>125</ENT>
                                <ENT>252</ENT>
                                <ENT>253</ENT>
                                <ENT>281</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzo(a)pyrene</ENT>
                                <ENT>2350</ENT>
                                <ENT>252</ENT>
                                <ENT>253</ENT>
                                <ENT>125</ENT>
                                <ENT>252</ENT>
                                <ENT>253</ENT>
                                <ENT>281</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Indeno(1,2,3-cd) pyrene</ENT>
                                <ENT>2650</ENT>
                                <ENT>276</ENT>
                                <ENT>138</ENT>
                                <ENT>277</ENT>
                                <ENT>276</ENT>
                                <ENT>277</ENT>
                                <ENT>305</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dibenz(a,h)anthracene</ENT>
                                <ENT>2660</ENT>
                                <ENT>278</ENT>
                                <ENT>139</ENT>
                                <ENT>279</ENT>
                                <ENT>278</ENT>
                                <ENT>279</ENT>
                                <ENT>307</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzo(ghi)perylene</ENT>
                                <ENT>2750</ENT>
                                <ENT>276</ENT>
                                <ENT>138</ENT>
                                <ENT>277</ENT>
                                <ENT>276</ENT>
                                <ENT>277</ENT>
                                <ENT>305</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Toxaphene</ENT>
                                <ENT/>
                                <ENT>159</ENT>
                                <ENT>231</ENT>
                                <ENT>233</ENT>
                                <ENT/>
                            </ROW>
                            <ROW>
                                <ENT I="01">PCB 1016</ENT>
                                <ENT/>
                                <ENT>224</ENT>
                                <ENT>260</ENT>
                                <ENT>294</ENT>
                                <ENT/>
                            </ROW>
                            <ROW>
                                <ENT I="01">PCB 1221</ENT>
                                <ENT/>
                                <ENT>190</ENT>
                                <ENT>224</ENT>
                                <ENT>260</ENT>
                                <ENT/>
                            </ROW>
                            <ROW>
                                <ENT I="01">PCB 1232</ENT>
                                <ENT/>
                                <ENT>190</ENT>
                                <ENT>224</ENT>
                                <ENT>260</ENT>
                                <ENT/>
                            </ROW>
                            <ROW>
                                <ENT I="01">PCB 1242</ENT>
                                <ENT/>
                                <ENT>224</ENT>
                                <ENT>260</ENT>
                                <ENT>294</ENT>
                                <ENT/>
                            </ROW>
                            <ROW>
                                <ENT I="01">PCB 1248</ENT>
                                <ENT/>
                                <ENT>294</ENT>
                                <ENT>330</ENT>
                                <ENT>262</ENT>
                                <ENT/>
                            </ROW>
                            <ROW>
                                <ENT I="01">PCB 1254</ENT>
                                <ENT/>
                                <ENT>294</ENT>
                                <ENT>330</ENT>
                                <ENT>362</ENT>
                                <ENT/>
                            </ROW>
                            <ROW>
                                <ENT I="01">PCB 1260</ENT>
                                <ENT/>
                                <ENT>330</ENT>
                                <ENT>362</ENT>
                                <ENT>394</ENT>
                            </ROW>
                            <TNOTE>
                                <SU>1</SU>
                                 Column: 30 m x 0.25 mm ID; 94% methyl, 5% phenyl, 1% vinyl bonded phase fused silica capillary.
                            </TNOTE>
                            <TNOTE>Conditions: 5 min at 30 °C; 30-280 at 8 °C per min; isothermal at 280 °C until benzo(ghi)perylene elutes.</TNOTE>
                            <TNOTE>Gas velocity: 30 cm/sec at 30 °C (at constant pressure).</TNOTE>
                            <TNOTE>
                                <SU>2</SU>
                                 See section 1.2; included for tailing factor testing.
                            </TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="8" OPTS="L2" CDEF="s50,10,10,10,10,10,10,10">
                            <TTITLE>
                                Table 5—Chromatographic Conditions and Characteristic 
                                <E T="01">m/z's</E>
                                 for Acid Extractables
                            </TTITLE>
                            <BOXHD>
                                <CHED H="1">Analyte</CHED>
                                <CHED H="1">
                                    Retention Time
                                    <LI>
                                        (sec) 
                                        <SU>1</SU>
                                    </LI>
                                </CHED>
                                <CHED H="1">Characteristic m/z's</CHED>
                                <CHED H="2">Electron impact ionization</CHED>
                                <CHED H="3">Prime</CHED>
                                <CHED H="3">Second</CHED>
                                <CHED H="3">Second</CHED>
                                <CHED H="2">Chemical ionization</CHED>
                                <CHED H="3">Methane</CHED>
                                <CHED H="3">Methane</CHED>
                                <CHED H="3">Methane</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">2-Chlorophenol</ENT>
                                <ENT>705</ENT>
                                <ENT>128</ENT>
                                <ENT>64</ENT>
                                <ENT>130</ENT>
                                <ENT>129</ENT>
                                <ENT>131</ENT>
                                <ENT>157</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Phenol</ENT>
                                <ENT>700</ENT>
                                <ENT>94</ENT>
                                <ENT>65</ENT>
                                <ENT>66</ENT>
                                <ENT>95</ENT>
                                <ENT>123</ENT>
                                <ENT>135</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-Nitrophenol</ENT>
                                <ENT>900</ENT>
                                <ENT>139</ENT>
                                <ENT>65</ENT>
                                <ENT>109</ENT>
                                <ENT>140</ENT>
                                <ENT>168</ENT>
                                <ENT>122</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4-Dimethylphenol</ENT>
                                <ENT>924</ENT>
                                <ENT>122</ENT>
                                <ENT>107</ENT>
                                <ENT>121</ENT>
                                <ENT>123</ENT>
                                <ENT>151</ENT>
                                <ENT>163</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4-Dichlorophenol</ENT>
                                <ENT>947</ENT>
                                <ENT>162</ENT>
                                <ENT>164</ENT>
                                <ENT>98</ENT>
                                <ENT>163</ENT>
                                <ENT>165</ENT>
                                <ENT>167</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4-Chloro-3-methylphenol</ENT>
                                <ENT>1091</ENT>
                                <ENT>142</ENT>
                                <ENT>107</ENT>
                                <ENT>144</ENT>
                                <ENT>143</ENT>
                                <ENT>171</ENT>
                                <ENT>183</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4,6-Trichlorophenol</ENT>
                                <ENT>1165</ENT>
                                <ENT>196</ENT>
                                <ENT>198</ENT>
                                <ENT>200</ENT>
                                <ENT>197</ENT>
                                <ENT>199</ENT>
                                <ENT>201</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4-Dinitrophenol</ENT>
                                <ENT>1325</ENT>
                                <ENT>184</ENT>
                                <ENT>63</ENT>
                                <ENT>154</ENT>
                                <ENT>185</ENT>
                                <ENT>213</ENT>
                                <ENT>225</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4-Nitrophenol</ENT>
                                <ENT>1354</ENT>
                                <ENT>65</ENT>
                                <ENT>139</ENT>
                                <ENT>109</ENT>
                                <ENT>140</ENT>
                                <ENT>168</ENT>
                                <ENT>122</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-Methyl-4,6-dinitrophenol</ENT>
                                <ENT>1435</ENT>
                                <ENT>198</ENT>
                                <ENT>182</ENT>
                                <ENT>77</ENT>
                                <ENT>199</ENT>
                                <ENT>227</ENT>
                                <ENT>239</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Pentachlorophenol</ENT>
                                <ENT>1561</ENT>
                                <ENT>266</ENT>
                                <ENT>264</ENT>
                                <ENT>268</ENT>
                                <ENT>267</ENT>
                                <ENT>265</ENT>
                                <ENT>269</ENT>
                            </ROW>
                            <TNOTE>Column: 30 m x 0.25 mm ID; 94% methyl, 5% phenyl, 1% vinyl bonded phase fused silica capillary.</TNOTE>
                            <TNOTE>Conditions: 5 min at 30 °C; 30-250 at 8 °C per min; isothermal at 280 °C until pentachlorophenol elutes.</TNOTE>
                            <TNOTE>Gas velocity: 30 cm/sec at 30 °C (at constant pressure).</TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="6" OPTS="L2" CDEF="s100,12,12,12,12,12">
                            <TTITLE>
                                Table 6—QC Acceptance Criteria—Method 625 
                                <SU>1</SU>
                            </TTITLE>
                            <BOXHD>
                                <CHED H="1">Analyte</CHED>
                                <CHED H="1">
                                    Range for Q
                                    <LI>
                                        (%) 
                                        <SU>2</SU>
                                    </LI>
                                </CHED>
                                <CHED H="1">
                                    Limit for s
                                    <LI>
                                        (%) 
                                        <SU>3</SU>
                                    </LI>
                                </CHED>
                                <CHED H="1">
                                    Range for
                                    <LI>
                                        <E T="7501">X</E>
                                         (%) 
                                        <SU>3</SU>
                                    </LI>
                                </CHED>
                                <CHED H="1">
                                    Range for
                                    <LI>
                                        P
                                        <E T="52">1</E>
                                        , P
                                        <E T="52">2</E>
                                        (%) 
                                        <SU>3</SU>
                                    </LI>
                                </CHED>
                                <CHED H="1">
                                    Limit for
                                    <LI>RPD (%)</LI>
                                </CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">Acenaphthene</ENT>
                                <ENT>70-130</ENT>
                                <ENT>29</ENT>
                                <ENT>60-132</ENT>
                                <ENT>47-145</ENT>
                                <ENT>48</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Acenaphthylene</ENT>
                                <ENT>60-130</ENT>
                                <ENT>45</ENT>
                                <ENT>54-126</ENT>
                                <ENT>33-145</ENT>
                                <ENT>74</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Aldrin</ENT>
                                <ENT>7-152</ENT>
                                <ENT>39</ENT>
                                <ENT>7-152</ENT>
                                <ENT>D-166</ENT>
                                <ENT>81</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Anthracene</ENT>
                                <ENT>58-130</ENT>
                                <ENT>40</ENT>
                                <ENT>43-120</ENT>
                                <ENT>27-133</ENT>
                                <ENT>66</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzo(a)anthracene</ENT>
                                <ENT>42-133</ENT>
                                <ENT>32</ENT>
                                <ENT>42-133</ENT>
                                <ENT>33-143</ENT>
                                <ENT>53</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzo(b)fluoranthene</ENT>
                                <ENT>42-140</ENT>
                                <ENT>43</ENT>
                                <ENT>42-140</ENT>
                                <ENT>24-159</ENT>
                                <ENT>71</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzo(k)fluoranthene</ENT>
                                <ENT>25-146</ENT>
                                <ENT>38</ENT>
                                <ENT>25-146</ENT>
                                <ENT>11-162</ENT>
                                <ENT>63</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzo(a)pyrene</ENT>
                                <ENT>32-148</ENT>
                                <ENT>43</ENT>
                                <ENT>32-148</ENT>
                                <ENT>17-163</ENT>
                                <ENT>72</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzo(ghi)perylene</ENT>
                                <ENT>13-195</ENT>
                                <ENT>61</ENT>
                                <ENT>D-195</ENT>
                                <ENT>D-219</ENT>
                                <ENT>97</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzyl butyl phthalate</ENT>
                                <ENT>43-140</ENT>
                                <ENT>36</ENT>
                                <ENT>D-140</ENT>
                                <ENT>D-152</ENT>
                                <ENT>60</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">beta</E>
                                    -BHC
                                </ENT>
                                <ENT>42-131</ENT>
                                <ENT>37</ENT>
                                <ENT>42-131</ENT>
                                <ENT>24-149</ENT>
                                <ENT>61</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">delta</E>
                                    -BHC
                                </ENT>
                                <ENT>D-130</ENT>
                                <ENT>77</ENT>
                                <ENT>D-120</ENT>
                                <ENT>D-120</ENT>
                                <ENT>129</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">bis(2-Chloroethyl)ether</ENT>
                                <ENT>52-130</ENT>
                                <ENT>65</ENT>
                                <ENT>43-126</ENT>
                                <ENT>12-158</ENT>
                                <ENT>108</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">bis(2-Chloroethoxy)methane</ENT>
                                <ENT>52-164</ENT>
                                <ENT>32</ENT>
                                <ENT>49-165</ENT>
                                <ENT>33-184</ENT>
                                <ENT>54</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">bis(2-Chloroisopropyl) ether</ENT>
                                <ENT>63-139</ENT>
                                <ENT>46</ENT>
                                <ENT>63-139</ENT>
                                <ENT>36-166</ENT>
                                <ENT>76</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">bis(2-Ethylhexyl) phthalate</ENT>
                                <ENT>43-137</ENT>
                                <ENT>50</ENT>
                                <ENT>29-137</ENT>
                                <ENT>8-158</ENT>
                                <ENT>82</ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="299"/>
                                <ENT I="01">4-Bromophenyl phenyl ether</ENT>
                                <ENT>70-130</ENT>
                                <ENT>26</ENT>
                                <ENT>65-120</ENT>
                                <ENT>53-127</ENT>
                                <ENT>43</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-Chloronaphthalene</ENT>
                                <ENT>70-130</ENT>
                                <ENT>15</ENT>
                                <ENT>65-120</ENT>
                                <ENT>60-120</ENT>
                                <ENT>24</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4-Chlorophenyl phenyl ether</ENT>
                                <ENT>57-145</ENT>
                                <ENT>36</ENT>
                                <ENT>38-145</ENT>
                                <ENT>25-158</ENT>
                                <ENT>61</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chrysene</ENT>
                                <ENT>44-140</ENT>
                                <ENT>53</ENT>
                                <ENT>44-140</ENT>
                                <ENT>17-168</ENT>
                                <ENT>87</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4,4′-DDD</ENT>
                                <ENT>D-135</ENT>
                                <ENT>56</ENT>
                                <ENT>D-135</ENT>
                                <ENT>D-145</ENT>
                                <ENT>93</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4,4′-DDE</ENT>
                                <ENT>19-130</ENT>
                                <ENT>46</ENT>
                                <ENT>19-120</ENT>
                                <ENT>4-136</ENT>
                                <ENT>77</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4,4′-DDT</ENT>
                                <ENT>D-171</ENT>
                                <ENT>81</ENT>
                                <ENT>D-171</ENT>
                                <ENT>D-203</ENT>
                                <ENT>135</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dibenz(a,h)anthracene</ENT>
                                <ENT>13-200</ENT>
                                <ENT>75</ENT>
                                <ENT>D-200</ENT>
                                <ENT>D-227</ENT>
                                <ENT>126</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Di-
                                    <E T="03">n</E>
                                    -butyl phthalate
                                </ENT>
                                <ENT>52-130</ENT>
                                <ENT>28</ENT>
                                <ENT>8-120</ENT>
                                <ENT>1-120</ENT>
                                <ENT>47</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">3,3′-Dichlorobenzidine</ENT>
                                <ENT>18-213</ENT>
                                <ENT>65</ENT>
                                <ENT>8-213</ENT>
                                <ENT>D-262</ENT>
                                <ENT>108</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dieldrin</ENT>
                                <ENT>70-130</ENT>
                                <ENT>38</ENT>
                                <ENT>44-119</ENT>
                                <ENT>29-136</ENT>
                                <ENT>62</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Diethyl phthalate</ENT>
                                <ENT>47-130</ENT>
                                <ENT>60</ENT>
                                <ENT>D-120</ENT>
                                <ENT>D-120</ENT>
                                <ENT>100</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dimethyl phthalate</ENT>
                                <ENT>50-130</ENT>
                                <ENT>110</ENT>
                                <ENT>D-120</ENT>
                                <ENT>D-120</ENT>
                                <ENT>183</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4-Dinitrotoluene</ENT>
                                <ENT>53-130</ENT>
                                <ENT>25</ENT>
                                <ENT>48-127</ENT>
                                <ENT>39-139</ENT>
                                <ENT>42</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,6-Dinitrotoluene</ENT>
                                <ENT>68-137</ENT>
                                <ENT>29</ENT>
                                <ENT>68-137</ENT>
                                <ENT>50-158</ENT>
                                <ENT>48</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Di-
                                    <E T="03">n</E>
                                    -octyl phthalate
                                </ENT>
                                <ENT>21-132</ENT>
                                <ENT>42</ENT>
                                <ENT>19-132</ENT>
                                <ENT>4-146</ENT>
                                <ENT>69</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Endosulfan sulfate</ENT>
                                <ENT>D-130</ENT>
                                <ENT>42</ENT>
                                <ENT>D-120</ENT>
                                <ENT>D-120</ENT>
                                <ENT>70</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Endrin aldehyde</ENT>
                                <ENT>D-189</ENT>
                                <ENT>45</ENT>
                                <ENT>D-189</ENT>
                                <ENT>D-209</ENT>
                                <ENT>75</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Fluoranthene</ENT>
                                <ENT>47-130</ENT>
                                <ENT>40</ENT>
                                <ENT>43-121</ENT>
                                <ENT>26-137</ENT>
                                <ENT>66</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Fluorene</ENT>
                                <ENT>70-130</ENT>
                                <ENT>23</ENT>
                                <ENT>70-120</ENT>
                                <ENT>59-121</ENT>
                                <ENT>38</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Heptachlor</ENT>
                                <ENT>D-172</ENT>
                                <ENT>44</ENT>
                                <ENT>D-172</ENT>
                                <ENT>D-192</ENT>
                                <ENT>74</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Heptachlor epoxide</ENT>
                                <ENT>70-130</ENT>
                                <ENT>61</ENT>
                                <ENT>71-120</ENT>
                                <ENT>26-155</ENT>
                                <ENT>101</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Hexachlorobenzene</ENT>
                                <ENT>38-142</ENT>
                                <ENT>33</ENT>
                                <ENT>8-142</ENT>
                                <ENT>D-152</ENT>
                                <ENT>55</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Hexachlorobutadiene</ENT>
                                <ENT>68-130</ENT>
                                <ENT>38</ENT>
                                <ENT>38-120</ENT>
                                <ENT>24-120</ENT>
                                <ENT>62</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Hexachloroethane</ENT>
                                <ENT>55-130</ENT>
                                <ENT>32</ENT>
                                <ENT>55-120</ENT>
                                <ENT>40-120</ENT>
                                <ENT>52</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Indeno(1,2,3-cd)pyrene</ENT>
                                <ENT>13-151</ENT>
                                <ENT>60</ENT>
                                <ENT>D-151</ENT>
                                <ENT>D-171</ENT>
                                <ENT>99</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Isophorone</ENT>
                                <ENT>52-180</ENT>
                                <ENT>56</ENT>
                                <ENT>47-180</ENT>
                                <ENT>21-196</ENT>
                                <ENT>93</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Naphthalene</ENT>
                                <ENT>70-130</ENT>
                                <ENT>39</ENT>
                                <ENT>36-120</ENT>
                                <ENT>21-133</ENT>
                                <ENT>65</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Nitrobenzene</ENT>
                                <ENT>54-158</ENT>
                                <ENT>37</ENT>
                                <ENT>54-158</ENT>
                                <ENT>35-180</ENT>
                                <ENT>62</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    N-Nitrosodi-
                                    <E T="03">n</E>
                                    -propylamine
                                </ENT>
                                <ENT>59-170</ENT>
                                <ENT>52</ENT>
                                <ENT>14-198</ENT>
                                <ENT>D-230</ENT>
                                <ENT>87</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">PCB-1260</ENT>
                                <ENT>19-130</ENT>
                                <ENT>77</ENT>
                                <ENT>19-130</ENT>
                                <ENT>D-164</ENT>
                                <ENT>128</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Phenanthrene</ENT>
                                <ENT>67-130</ENT>
                                <ENT>24</ENT>
                                <ENT>65-120</ENT>
                                <ENT>54-120</ENT>
                                <ENT>39</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Pyrene</ENT>
                                <ENT>70-130</ENT>
                                <ENT>30</ENT>
                                <ENT>70-120</ENT>
                                <ENT>52-120</ENT>
                                <ENT>49</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,4-Trichlorobenzene</ENT>
                                <ENT>61-130</ENT>
                                <ENT>30</ENT>
                                <ENT>57-130</ENT>
                                <ENT>44-142</ENT>
                                <ENT>50</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4-Chloro-3-methylphenol</ENT>
                                <ENT>68-130</ENT>
                                <ENT>44</ENT>
                                <ENT>41-128</ENT>
                                <ENT>22-147</ENT>
                                <ENT>73</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-Chlorophenol</ENT>
                                <ENT>55-130</ENT>
                                <ENT>37</ENT>
                                <ENT>36-120</ENT>
                                <ENT>23-134</ENT>
                                <ENT>61</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4-Dichlorophenol</ENT>
                                <ENT>64-130</ENT>
                                <ENT>30</ENT>
                                <ENT>53-122</ENT>
                                <ENT>39-135</ENT>
                                <ENT>50</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4-Dimethylphenol</ENT>
                                <ENT>58-130</ENT>
                                <ENT>35</ENT>
                                <ENT>42-120</ENT>
                                <ENT>32-120</ENT>
                                <ENT>58</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4-Dinitrophenol</ENT>
                                <ENT>39-173</ENT>
                                <ENT>79</ENT>
                                <ENT>D-173</ENT>
                                <ENT>D-191</ENT>
                                <ENT>132</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-Methyl-4,6-dinitrophenol</ENT>
                                <ENT>56-130</ENT>
                                <ENT>122</ENT>
                                <ENT>53-130</ENT>
                                <ENT>D-181</ENT>
                                <ENT>203</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-Nitrophenol</ENT>
                                <ENT>61-163</ENT>
                                <ENT>33</ENT>
                                <ENT>45-167</ENT>
                                <ENT>29-182</ENT>
                                <ENT>55</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4-Nitrophenol</ENT>
                                <ENT>35-130</ENT>
                                <ENT>79</ENT>
                                <ENT>13-129</ENT>
                                <ENT>D-132</ENT>
                                <ENT>131</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Pentachlorophenol</ENT>
                                <ENT>42-152</ENT>
                                <ENT>52</ENT>
                                <ENT>38-152</ENT>
                                <ENT>14-176</ENT>
                                <ENT>86</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Phenol</ENT>
                                <ENT>48-130</ENT>
                                <ENT>39</ENT>
                                <ENT>17-120</ENT>
                                <ENT>5-120</ENT>
                                <ENT>64</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4,6-Trichlorophenol</ENT>
                                <ENT>69-130</ENT>
                                <ENT>35</ENT>
                                <ENT>52-129</ENT>
                                <ENT>37-144</ENT>
                                <ENT>58</ENT>
                            </ROW>
                            <TNOTE>
                                <SU>1</SU>
                                 Acceptance criteria are based upon method performance data in Table 7 and from EPA Method 1625. Where necessary, limits for recovery have been broadened to assure applicability to concentrations below those used to develop Table 7.
                            </TNOTE>
                            <TNOTE>
                                <SU>2</SU>
                                 Test concentration = 100 µg/mL.
                            </TNOTE>
                            <TNOTE>
                                <SU>3</SU>
                                 Test concentration = 100 µg/L.
                            </TNOTE>
                            <TNOTE>Q = Calibration verification (sections 7.3.1 and 13.4).</TNOTE>
                            <TNOTE>s = Standard deviation for four recovery measurements in the DOC test (section 8.2.4).</TNOTE>
                            <TNOTE>
                                <E T="7501">X</E>
                                 = Average recovery for four recovery measurements in the DOC test (section 8.2.4).
                            </TNOTE>
                            <TNOTE>
                                P
                                <E T="52">1</E>
                                , P
                                <E T="52">2</E>
                                 = MS/MSD recovery (section 8.3.2, section 8.4.2).
                            </TNOTE>
                            <TNOTE>RPD = MS/MSD relative percent difference (RPD; section 8.3.3).</TNOTE>
                            <TNOTE>D = Detected; result must be greater than zero.</TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="4" OPTS="L2" CDEF="s100,13,13,13">
                            <TTITLE>
                                Table 7—Precision and Recovery as Functions of Concentration—Method 625 
                                <SU>1</SU>
                            </TTITLE>
                            <BOXHD>
                                <CHED H="1">Analyte</CHED>
                                <CHED H="1">
                                    Recovery, X′
                                    <LI>(µg/L)</LI>
                                </CHED>
                                <CHED H="1">
                                    Single analyst
                                    <LI>
                                        precision, s
                                        <E T="52">r</E>
                                        ′
                                    </LI>
                                    <LI>(µg/L)</LI>
                                </CHED>
                                <CHED H="1">
                                    Overall
                                    <LI>precision, S′</LI>
                                    <LI>(µg/L)</LI>
                                </CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">Acenaphthene</ENT>
                                <ENT>0.96C + 0.19</ENT>
                                <ENT>
                                    0.15 
                                    <E T="7501">X</E>
                                    −0.12
                                </ENT>
                                <ENT>
                                    0.21 
                                    <E T="7501">X</E>
                                    −0.67
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Acenaphthylene</ENT>
                                <ENT>0.89C + 0.74</ENT>
                                <ENT>
                                    0.24 
                                    <E T="7501">X</E>
                                    −1.06
                                </ENT>
                                <ENT>
                                    0.26 
                                    <E T="7501">X</E>
                                    −0.54
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Aldrin</ENT>
                                <ENT>0.78C + 1.66</ENT>
                                <ENT>
                                    0.27 
                                    <E T="7501">X</E>
                                    −1.28
                                </ENT>
                                <ENT>
                                    0.43 
                                    <E T="7501">X</E>
                                     + 1.13
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Anthracene</ENT>
                                <ENT>0.80C + 0.68</ENT>
                                <ENT>
                                    0.21 
                                    <E T="7501">X</E>
                                    −0.32
                                </ENT>
                                <ENT>
                                    0.27 
                                    <E T="7501">X</E>
                                    −0.64
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzo(a)anthracene</ENT>
                                <ENT>0.88C−0.60</ENT>
                                <ENT>
                                    0.15 
                                    <E T="7501">X</E>
                                     + 0.93
                                </ENT>
                                <ENT>
                                    0.26 
                                    <E T="7501">X</E>
                                    −0.28
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzo(b)fluoranthene</ENT>
                                <ENT>0.93C−1.80</ENT>
                                <ENT>
                                    0.22 
                                    <E T="7501">X</E>
                                     + 0.43
                                </ENT>
                                <ENT>
                                    0.29 
                                    <E T="7501">X</E>
                                     + 0.96
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzo(k)fluoranthene</ENT>
                                <ENT>0.87C−1.56</ENT>
                                <ENT>
                                    0.19 
                                    <E T="7501">X</E>
                                     + 1.03
                                </ENT>
                                <ENT>
                                    0.35 
                                    <E T="7501">X</E>
                                     + 0.40
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzo(a)pyrene</ENT>
                                <ENT>0.90C−0.13</ENT>
                                <ENT>
                                    0.22 
                                    <E T="7501">X</E>
                                     + 0.48
                                </ENT>
                                <ENT>
                                    0.32 
                                    <E T="7501">X</E>
                                     + 1.35
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzo(ghi)perylene</ENT>
                                <ENT>0.98C−0.86</ENT>
                                <ENT>
                                    0.29 
                                    <E T="7501">X</E>
                                     + 2.40
                                </ENT>
                                <ENT>
                                    0.51 
                                    <E T="7501">X</E>
                                    −0.44
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzyl butyl phthalate</ENT>
                                <ENT>0.66C−1.68</ENT>
                                <ENT>
                                    0.18 
                                    <E T="7501">X</E>
                                     + 0.94
                                </ENT>
                                <ENT>
                                    0.53 
                                    <E T="7501">X</E>
                                     + 0.92
                                </ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="300"/>
                                <ENT I="01">
                                    <E T="03">beta</E>
                                    -BHC
                                </ENT>
                                <ENT>0.87C−0.94</ENT>
                                <ENT>
                                    0.20 
                                    <E T="7501">X</E>
                                    −0.58
                                </ENT>
                                <ENT>
                                    0.30 
                                    <E T="7501">X</E>
                                    −1.94
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">delta</E>
                                    -BHC
                                </ENT>
                                <ENT>0.29C−1.09</ENT>
                                <ENT>
                                    0.34 
                                    <E T="7501">X</E>
                                     + 0.86
                                </ENT>
                                <ENT>
                                    0.93 
                                    <E T="7501">X</E>
                                    −0.17
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">bis(2-Chloroethyl) ether</ENT>
                                <ENT>0.86C−1.54</ENT>
                                <ENT>
                                    0.35 
                                    <E T="7501">X</E>
                                    −0.99
                                </ENT>
                                <ENT>
                                    0.35 
                                    <E T="7501">X</E>
                                     + 0.10
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">bis(2-Chloroethoxy) methane</ENT>
                                <ENT>1.12C−5.04</ENT>
                                <ENT>
                                    0.16 
                                    <E T="7501">X</E>
                                     + 1.34
                                </ENT>
                                <ENT>
                                    0.26 
                                    <E T="7501">X</E>
                                     + 2.01
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">bis(2-Chloroisopropyl) ether</ENT>
                                <ENT>1.03C−2.31</ENT>
                                <ENT>
                                    0.24 
                                    <E T="7501">X</E>
                                     + 0.28
                                </ENT>
                                <ENT>
                                    0.25 
                                    <E T="7501">X</E>
                                     + 1.04
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">bis(2-Ethylhexyl) phthalate</ENT>
                                <ENT>0.84C−1.18</ENT>
                                <ENT>
                                    0.26 
                                    <E T="7501">X</E>
                                     + 0.73
                                </ENT>
                                <ENT>
                                    0.36 
                                    <E T="7501">X</E>
                                     + 0.67
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4-Bromophenyl phenyl ether</ENT>
                                <ENT>0.91C−1.34</ENT>
                                <ENT>
                                    0.13 
                                    <E T="7501">X</E>
                                     + 0.66
                                </ENT>
                                <ENT>
                                    0.16 
                                    <E T="7501">X</E>
                                     + 0.66
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-Chloronaphthalene</ENT>
                                <ENT>0.89C + 0.01</ENT>
                                <ENT>
                                    0.07 
                                    <E T="7501">X</E>
                                     + 0.52
                                </ENT>
                                <ENT>
                                    0.13 
                                    <E T="7501">X</E>
                                     + 0.34
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4-Chlorophenyl phenyl ether</ENT>
                                <ENT>0.91C + 0.53</ENT>
                                <ENT>
                                    0.20 
                                    <E T="7501">X</E>
                                    −0.94
                                </ENT>
                                <ENT>
                                    0.30 
                                    <E T="7501">X</E>
                                    −0.46
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chrysene</ENT>
                                <ENT>0.93C−1.00</ENT>
                                <ENT>
                                    0.28 
                                    <E T="7501">X</E>
                                     + 0.13
                                </ENT>
                                <ENT>
                                    0.33 
                                    <E T="7501">X</E>
                                    −0.09
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4,4′-DDD</ENT>
                                <ENT>0.56C−0.40</ENT>
                                <ENT>
                                    0.29 
                                    <E T="7501">X</E>
                                    −0.32
                                </ENT>
                                <ENT>
                                    0.66 
                                    <E T="7501">X</E>
                                    −0.96
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4,4′-DDE</ENT>
                                <ENT>0.70C−0.54</ENT>
                                <ENT>
                                    0.26 
                                    <E T="7501">X</E>
                                    −1.17
                                </ENT>
                                <ENT>
                                    0.39 
                                    <E T="7501">X</E>
                                    −1.04
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4,4′-DDT</ENT>
                                <ENT>0.79C−3.28</ENT>
                                <ENT>
                                    0.42 
                                    <E T="7501">X</E>
                                     + 0.19
                                </ENT>
                                <ENT>
                                    0.65 
                                    <E T="7501">X</E>
                                    −0.58
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dibenz(a,h)anthracene</ENT>
                                <ENT>0.88C + 4.72</ENT>
                                <ENT>
                                    0.30 
                                    <E T="7501">X</E>
                                     + 8.51
                                </ENT>
                                <ENT>
                                    0.59 
                                    <E T="7501">X</E>
                                     + 0.25
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Di-
                                    <E T="03">n</E>
                                    -butyl phthalate
                                </ENT>
                                <ENT>0.59C + 0.71</ENT>
                                <ENT>
                                    0.13 
                                    <E T="7501">X</E>
                                     + 1.16
                                </ENT>
                                <ENT>
                                    0.39 
                                    <E T="7501">X</E>
                                     + 0.60
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">3,3'-Dichlorobenzidine</ENT>
                                <ENT>1.23C−12.65</ENT>
                                <ENT>
                                    0.28 
                                    <E T="7501">X</E>
                                     + 7.33
                                </ENT>
                                <ENT>
                                    0.47 
                                    <E T="7501">X</E>
                                     + 3.45
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dieldrin</ENT>
                                <ENT>0.82C−0.16</ENT>
                                <ENT>
                                    0.20 
                                    <E T="7501">X</E>
                                    −0.16
                                </ENT>
                                <ENT>
                                    0.26 
                                    <E T="7501">X</E>
                                    −0.07
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Diethyl phthalate</ENT>
                                <ENT>0.43C + 1.00</ENT>
                                <ENT>
                                    0.28 
                                    <E T="7501">X</E>
                                     + 1.44
                                </ENT>
                                <ENT>
                                    0.52 
                                    <E T="7501">X</E>
                                     + 0.22
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dimethyl phthalate</ENT>
                                <ENT>0.20C + 1.03</ENT>
                                <ENT>
                                    0.54 
                                    <E T="7501">X</E>
                                     + 0.19
                                </ENT>
                                <ENT>
                                    1.05 
                                    <E T="7501">X</E>
                                    −0.92
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4-Dinitrotoluene</ENT>
                                <ENT>0.92C−4.81</ENT>
                                <ENT>
                                    0.12 
                                    <E T="7501">X</E>
                                     + 1.06
                                </ENT>
                                <ENT>
                                    0.21 
                                    <E T="7501">X</E>
                                     + 1.50
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,6-Dinitrotoluene</ENT>
                                <ENT>1.06C−3.60</ENT>
                                <ENT>
                                    0.14 
                                    <E T="7501">X</E>
                                     + 1.26
                                </ENT>
                                <ENT>
                                    0.19 
                                    <E T="7501">X</E>
                                     + 0.35
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Di-
                                    <E T="03">n</E>
                                    -octyl phthalate
                                </ENT>
                                <ENT>0.76C−0.79</ENT>
                                <ENT>
                                    0.21 
                                    <E T="7501">X</E>
                                     + 1.19
                                </ENT>
                                <ENT>
                                    0.37 
                                    <E T="7501">X</E>
                                     + 1.19
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Endosulfan sulfate</ENT>
                                <ENT>0.39C + 0.41</ENT>
                                <ENT>
                                    0.12 
                                    <E T="7501">X</E>
                                     + 2.47
                                </ENT>
                                <ENT>
                                    0.63 
                                    <E T="7501">X</E>
                                    −1.03
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Endrin aldehyde</ENT>
                                <ENT>0.76C−3.86</ENT>
                                <ENT>
                                    0.18 
                                    <E T="7501">X</E>
                                     + 3.91
                                </ENT>
                                <ENT>
                                    0.73 
                                    <E T="7501">X</E>
                                    −0.62
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Fluoranthene</ENT>
                                <ENT>0.81C + 1.10</ENT>
                                <ENT>
                                    0.22 
                                    <E T="7501">X</E>
                                     + 0.73
                                </ENT>
                                <ENT>
                                    0.28 
                                    <E T="7501">X</E>
                                    −0.60
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Fluorene</ENT>
                                <ENT>0.90C−0.00</ENT>
                                <ENT>
                                    0.12 
                                    <E T="7501">X</E>
                                     + 0.26
                                </ENT>
                                <ENT>
                                    0.13 
                                    <E T="7501">X</E>
                                     + 0.61
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Heptachlor</ENT>
                                <ENT>0.87C−2.97</ENT>
                                <ENT>
                                    0.24 
                                    <E T="7501">X</E>
                                    −0.56
                                </ENT>
                                <ENT>
                                    0.50 
                                    <E T="7501">X</E>
                                    −0.23
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Heptachlor epoxide</ENT>
                                <ENT>0.92C−1.87</ENT>
                                <ENT>
                                    0.33 
                                    <E T="7501">X</E>
                                    −0.46
                                </ENT>
                                <ENT>
                                    0.28 
                                    <E T="7501">X</E>
                                     + 0.64
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Hexachlorobenzene</ENT>
                                <ENT>0.74C + 0.66</ENT>
                                <ENT>
                                    0.18 
                                    <E T="7501">X</E>
                                    −0.10
                                </ENT>
                                <ENT>
                                    0.43 
                                    <E T="7501">X</E>
                                    −0.52
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Hexachlorobutadiene</ENT>
                                <ENT>0.71C−1.01</ENT>
                                <ENT>
                                    0.19 
                                    <E T="7501">X</E>
                                     + 0.92
                                </ENT>
                                <ENT>
                                    0.26 
                                    <E T="7501">X</E>
                                     + 0.49
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Hexachloroethane</ENT>
                                <ENT>0.73C−0.83</ENT>
                                <ENT>
                                    0.17 
                                    <E T="7501">X</E>
                                     + 0.67
                                </ENT>
                                <ENT>
                                    0.17 
                                    <E T="7501">X</E>
                                     + 0.80
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Indeno(1,2,3-cd)pyrene</ENT>
                                <ENT>0.78C−3.10</ENT>
                                <ENT>
                                    0.29 
                                    <E T="7501">X</E>
                                     + 1.46
                                </ENT>
                                <ENT>
                                    0.50 
                                    <E T="7501">X</E>
                                     + 0.44
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Isophorone</ENT>
                                <ENT>1.12C + 1.41</ENT>
                                <ENT>
                                    0.27 
                                    <E T="7501">X</E>
                                     + 0.77
                                </ENT>
                                <ENT>
                                    0.33 
                                    <E T="7501">X</E>
                                     + 0.26
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Naphthalene</ENT>
                                <ENT>0.76C + 1.58</ENT>
                                <ENT>
                                    0.21 
                                    <E T="7501">X</E>
                                    −0.41
                                </ENT>
                                <ENT>
                                    0.30 
                                    <E T="7501">X</E>
                                    −0.68
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Nitrobenzene</ENT>
                                <ENT>1.09C−3.05</ENT>
                                <ENT>
                                    0.19 
                                    <E T="7501">X</E>
                                     + 0.92
                                </ENT>
                                <ENT>
                                    0.27 
                                    <E T="7501">X</E>
                                     + 0.21
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    N-Nitrosodi-
                                    <E T="03">n</E>
                                    -propylamine
                                </ENT>
                                <ENT>1.12C−6.22</ENT>
                                <ENT>
                                    0.27 
                                    <E T="7501">X</E>
                                     + 0.68
                                </ENT>
                                <ENT>
                                    0.44 
                                    <E T="7501">X</E>
                                     + 0.47
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">PCB-1260</ENT>
                                <ENT>0.81C−10.86</ENT>
                                <ENT>
                                    0.35 
                                    <E T="7501">X</E>
                                     + 3.61
                                </ENT>
                                <ENT>
                                    0.43 
                                    <E T="7501">X</E>
                                     + 1.82
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Phenanthrene</ENT>
                                <ENT>0.87C−0.06</ENT>
                                <ENT>
                                    0.12 
                                    <E T="7501">X</E>
                                     + 0.57
                                </ENT>
                                <ENT>
                                    0.15 
                                    <E T="7501">X</E>
                                     + 0.25
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Pyrene</ENT>
                                <ENT>0.84C−0.16</ENT>
                                <ENT>
                                    0.16 
                                    <E T="7501">X</E>
                                     + 0.06
                                </ENT>
                                <ENT>
                                    0.15 
                                    <E T="7501">X</E>
                                     + 0.31
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,4-Trichlorobenzene</ENT>
                                <ENT>0.94C−0.79</ENT>
                                <ENT>
                                    0.15 
                                    <E T="7501">X</E>
                                     + 0.85
                                </ENT>
                                <ENT>
                                    0.21 
                                    <E T="7501">X</E>
                                     + 0.39
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4-Chloro-3-methylphenol</ENT>
                                <ENT>0.84C + 0.35</ENT>
                                <ENT>
                                    0.23 
                                    <E T="7501">X</E>
                                     + 0.75
                                </ENT>
                                <ENT>
                                    0.29 
                                    <E T="7501">X</E>
                                     + 1.31
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-Chlorophenol</ENT>
                                <ENT>0.78C + 0.29</ENT>
                                <ENT>
                                    0.18 
                                    <E T="7501">X</E>
                                     + 1.46
                                </ENT>
                                <ENT>
                                    0.28 
                                    <E T="7501">X</E>
                                     + 0.97
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4-Dichlorophenol</ENT>
                                <ENT>0.87C + 0.13</ENT>
                                <ENT>
                                    0.15 
                                    <E T="7501">X</E>
                                     + 1.25
                                </ENT>
                                <ENT>
                                    0.21 
                                    <E T="7501">X</E>
                                     + 1.28
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4-Dimethylphenol</ENT>
                                <ENT>0.71C + 4.41</ENT>
                                <ENT>
                                    0.16 
                                    <E T="7501">X</E>
                                     + 1.21
                                </ENT>
                                <ENT>
                                    0.22 
                                    <E T="7501">X</E>
                                     + 1.31
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4-Dinitrophenol</ENT>
                                <ENT>0.81C−18.04</ENT>
                                <ENT>
                                    0.38 
                                    <E T="7501">X</E>
                                     + 2.36
                                </ENT>
                                <ENT>
                                    0.42 
                                    <E T="7501">X</E>
                                     + 26.29
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-Methyl-4,6-Dinitrophenol</ENT>
                                <ENT>1.04C−28.04</ENT>
                                <ENT>
                                    0.05 
                                    <E T="7501">X</E>
                                     + 42.29
                                </ENT>
                                <ENT>
                                    0.26 
                                    <E T="7501">X</E>
                                     + 23.10
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-Nitrophenol</ENT>
                                <ENT>1.07C−1.15</ENT>
                                <ENT>
                                    0.16 
                                    <E T="7501">X</E>
                                     + 1.94
                                </ENT>
                                <ENT>
                                    0.27 
                                    <E T="7501">X</E>
                                     + 2.60
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4-Nitrophenol</ENT>
                                <ENT>0.61C−1.22</ENT>
                                <ENT>
                                    0.38 
                                    <E T="7501">X</E>
                                     + 2.57
                                </ENT>
                                <ENT>
                                    0.44 
                                    <E T="7501">X</E>
                                     + 3.24
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Pentachlorophenol</ENT>
                                <ENT>0.93C + 1.99</ENT>
                                <ENT>
                                    0.24 
                                    <E T="7501">X</E>
                                     + 3.03
                                </ENT>
                                <ENT>
                                    0.30 
                                    <E T="7501">X</E>
                                     + 4.33
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Phenol</ENT>
                                <ENT>0.43C + 1.26</ENT>
                                <ENT>
                                    0.26 
                                    <E T="7501">X</E>
                                     + 0.73
                                </ENT>
                                <ENT>
                                    0.35 
                                    <E T="7501">X</E>
                                     + 0.58
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4,6-Trichlorophenol</ENT>
                                <ENT>0.91C−0.18</ENT>
                                <ENT>
                                    0.16 
                                    <E T="7501">X</E>
                                     + 2.22
                                </ENT>
                                <ENT>
                                    0.22 
                                    <E T="7501">X</E>
                                     + 1.81
                                </ENT>
                            </ROW>
                            <TNOTE>
                                <SU>1</SU>
                                 Regressions based on data from Reference 2.
                            </TNOTE>
                            <TNOTE>X′ = Expected recovery for one or more measurements of a sample containing a concentration of C, in µg/L.</TNOTE>
                            <TNOTE>
                                s
                                <E T="52">r</E>
                                ′ = Expected single analyst standard deviation of measurements at an average concentration found of 
                                <E T="7501">X</E>
                                , in µg/L.
                            </TNOTE>
                            <TNOTE>
                                S′ = Expected interlaboratory standard deviation of measurements at an average concentration found of 
                                <E T="7501">X</E>
                                , in µg/L.
                            </TNOTE>
                            <TNOTE>C = True value for the concentration, in µg/L.</TNOTE>
                            <TNOTE>
                                <E T="7501">X</E>
                                 = Average recovery found for measurements of samples containing a concentration of C, in µg/L.
                            </TNOTE>
                        </GPOTABLE>
                        <PRTPAGE P="301"/>
                        <GPOTABLE COLS="3" OPTS="L2" CDEF="s50,12,12">
                            <TTITLE>Table 8—Suggested Internal and Surrogate Standards</TTITLE>
                            <BOXHD>
                                <CHED H="1">Base/neutral fraction</CHED>
                                <CHED H="1">
                                    Range for surrogate recovery (%) 
                                    <SU>1</SU>
                                </CHED>
                                <CHED H="2">Calibration verification</CHED>
                                <CHED H="2">Recovery from samples</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">
                                    Acenaphthalene-d
                                    <E T="52">8</E>
                                </ENT>
                                <ENT>66-152</ENT>
                                <ENT>33-168</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Acenaphthene-d
                                    <E T="52">10</E>
                                </ENT>
                                <ENT>71-141</ENT>
                                <ENT>30-180</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Aniline-d
                                    <E T="52">5</E>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Anthracene-d
                                    <E T="52">10</E>
                                </ENT>
                                <ENT>58-171</ENT>
                                <ENT>23-142</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Benzo(a)anthracene-d
                                    <E T="52">12</E>
                                </ENT>
                                <ENT>28-357</ENT>
                                <ENT>22-329</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Benzo(a)pyrene-d
                                    <E T="52">12</E>
                                </ENT>
                                <ENT>32-194</ENT>
                                <ENT>32-194</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    4-Chloroaniline-d
                                    <E T="52">4</E>
                                </ENT>
                                <ENT>1-145</ENT>
                                <ENT>1-145</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    bis(2-Chloroethyl) ether-d
                                    <E T="52">8</E>
                                </ENT>
                                <ENT>52-194</ENT>
                                <ENT>25-222</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Chrysene-d
                                    <E T="52">12</E>
                                </ENT>
                                <ENT>23-290</ENT>
                                <ENT>23-290</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Decafluorobiphenyl</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4,4′-Dibromobiphenyl</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4,4′-Dibromooctafluorobiphenyl</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    1,4-Dichlorobenzene-d
                                    <E T="52">4</E>
                                </ENT>
                                <ENT>65-153</ENT>
                                <ENT>11-245</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,2′-Difluorobiphenyl</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Dimethyl phthalate-d
                                    <E T="52">6</E>
                                </ENT>
                                <ENT>47-211</ENT>
                                <ENT>1-500</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Fluoranthene-d
                                    <E T="52">10</E>
                                </ENT>
                                <ENT>47-215</ENT>
                                <ENT>30-187</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Fluorene-d
                                    <E T="52">10</E>
                                </ENT>
                                <ENT>61-164</ENT>
                                <ENT>38-172</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4-Fluoroaniline</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1-Fluoronaphthalene</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-Fluoronaphthalene</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    2-Methylnaphthalene-d
                                    <E T="52">10</E>
                                </ENT>
                                <ENT>50-150</ENT>
                                <ENT>50-150</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Naphthalene-d
                                    <E T="52">8</E>
                                </ENT>
                                <ENT>71-141</ENT>
                                <ENT>22-192</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Nitrobenzene-d
                                    <E T="52">5</E>
                                </ENT>
                                <ENT>46-219</ENT>
                                <ENT>15-314</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,3,4,5,6-Pentafluorobiphenyl</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Perylene-d
                                    <E T="52">12</E>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Phenanthrene-d
                                    <E T="52">10</E>
                                </ENT>
                                <ENT>67-149</ENT>
                                <ENT>34-168</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Pyrene-d
                                    <E T="52">10</E>
                                </ENT>
                                <ENT>48-210</ENT>
                                <ENT>28-196</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Pyridine-d
                                    <E T="52">5</E>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Acid fraction</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    2-Chlorophenol-d
                                    <E T="52">4</E>
                                </ENT>
                                <ENT>55-180</ENT>
                                <ENT>33-180</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    2,4-Dichlorophenol-d
                                    <E T="52">3</E>
                                </ENT>
                                <ENT>64-157</ENT>
                                <ENT>34-182</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    4,6-Dinitro-2-methylphenol-d
                                    <E T="52">2</E>
                                </ENT>
                                <ENT>56-177</ENT>
                                <ENT>22-307</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-Fluorophenol</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    4-Methylphenol-d
                                    <E T="52">8</E>
                                </ENT>
                                <ENT>25-111</ENT>
                                <ENT>25-111</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    2-Nitrophenol-d
                                    <E T="52">4</E>
                                </ENT>
                                <ENT>61-163</ENT>
                                <ENT>37-163</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    4-Nitrophenol-d
                                    <E T="52">4</E>
                                </ENT>
                                <ENT>35-287</ENT>
                                <ENT>6-500</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Pentafluorophenol</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-Perfluoromethylphenol</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Phenol-d
                                    <E T="52">5</E>
                                </ENT>
                                <ENT>48-208</ENT>
                                <ENT>8-424</ENT>
                            </ROW>
                            <TNOTE>
                                <SU>1</SU>
                                 Recovery from samples is the wider of the criteria in the CLP SOW for organics or in Method 1625.
                            </TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="2" OPTS="L2" CDEF="xs20,r80">
                            <TTITLE>
                                Table 9A—DFTPP Key 
                                <E T="01">m/z's</E>
                                 and Abundance Criteria for Quadrupole Instruments 
                                <SU>1</SU>
                            </TTITLE>
                            <BOXHD>
                                <CHED H="1">m/z</CHED>
                                <CHED H="1">Abundance criteria</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">51</ENT>
                                <ENT>30-60 percent of m/z 198.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">68</ENT>
                                <ENT>Less than 2 percent of m/z 69.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">70</ENT>
                                <ENT>Less than 2 percent of m/z 69.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">127</ENT>
                                <ENT>40-60 percent of base peak m/z 198.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">197</ENT>
                                <ENT>Less than 1 percent of m/z 198.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">198</ENT>
                                <ENT>Base peak, 100 percent relative abundance.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">199</ENT>
                                <ENT>5-9 percent of m/z 198.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">275</ENT>
                                <ENT>10-30 percent of m/z 198.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">365</ENT>
                                <ENT>Greater than 1 percent of m/z 198.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">441</ENT>
                                <ENT>Present but less than m/z 443.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">442</ENT>
                                <ENT>40-100 percent of m/z 198.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">443</ENT>
                                <ENT>17-23 percent of m/z 442.</ENT>
                            </ROW>
                            <TNOTE>
                                <SU>1</SU>
                                 Criteria in these tables are for quadrupole and time-of-flight instruments. Alternative tuning criteria from other published EPA reference methods may be used provided method performance is not adversely affected. Alternative tuning criteria specified by an instrument manufacturer may also be used for another type of mass spectrometer, provided method performance is not adversely affected.
                            </TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="2" OPTS="L2" CDEF="xs20,r80">
                            <TTITLE>
                                Table 9B—DFTPP Key 
                                <E T="01">m/z's</E>
                                 and Abundance Criteria for Time-of-flight Instruments 
                                <SU>1</SU>
                            </TTITLE>
                            <BOXHD>
                                <CHED H="1">m/z</CHED>
                                <CHED H="1">Abundance criteria</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">51</ENT>
                                <ENT>10-85 percent of the base peak.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">68</ENT>
                                <ENT>Less than 2 percent of m/z 69.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">70</ENT>
                                <ENT>Less than 2 percent of m/z 69.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">127</ENT>
                                <ENT>10-80 percent of the base peak.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">197</ENT>
                                <ENT>Less than 2 percent of Mass 198.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">198</ENT>
                                <ENT>Base peak, or greater than 50% of m/z 442.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">199</ENT>
                                <ENT>5-9 percent of m/z 198.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">275</ENT>
                                <ENT>10-60 percent of the base peak.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">365</ENT>
                                <ENT>Greater than 0.5 percent of m/z 198.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">441</ENT>
                                <ENT>Less than 150 percent of m/z 443.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">442</ENT>
                                <ENT>Base peak or greater than 30 percent of m/z 198.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">443</ENT>
                                <ENT>15-24 percent of m/z 442.</ENT>
                            </ROW>
                            <TNOTE>
                                <SU>1</SU>
                                 Criteria in these tables are for quadrupole and time-of-flight instruments. Alternative tuning criteria from other published EPA reference methods may be used provided method performance is not adversely affected. Alternative tuning criteria specified by an instrument manufacturer may also be used for another type of mass spectrometer, or for an alternative carrier gas, provided method performance is not adversely affected.
                            </TNOTE>
                        </GPOTABLE>
                        <HD SOURCE="HD1">21. Figures</HD>
                        <GPH SPAN="2" DEEP="459">
                            <PRTPAGE P="302"/>
                            <GID>ER28AU17.018</GID>
                        </GPH>
                        <GPH SPAN="2" DEEP="232">
                            <PRTPAGE P="303"/>
                            <GID>ER28AU17.019</GID>
                        </GPH>
                        <HD SOURCE="HD3">22. Glossary</HD>
                        <P>These definitions and purposes are specific to this method but have been conformed to common usage to the extent possible.</P>
                        <P>22.1 Units of weight and measure and their abbreviations.</P>
                        <P>22.1.1 Symbols.</P>
                        <FP SOURCE="FP-1"> °C degrees Celsius</FP>
                        <FP SOURCE="FP-1">µg microgram</FP>
                        <FP SOURCE="FP-1">µL microliter</FP>
                        <FP SOURCE="FP-1">&lt; less than</FP>
                        <FP SOURCE="FP-1">&gt; greater than</FP>
                        <FP SOURCE="FP-1">≤ less than or equal to</FP>
                        <FP SOURCE="FP-1">% percent</FP>
                        <P>22.1.2 Abbreviations (in alphabetical order).</P>
                        <FP SOURCE="FP-1">cm centimeter</FP>
                        <FP SOURCE="FP-1">g gram</FP>
                        <FP SOURCE="FP-1">h hour</FP>
                        <FP SOURCE="FP-1">ID inside diameter</FP>
                        <FP SOURCE="FP-1">in. inch</FP>
                        <FP SOURCE="FP-1">L liter</FP>
                        <FP SOURCE="FP-1">m mass or meter</FP>
                        <FP SOURCE="FP-1">mg milligram</FP>
                        <FP SOURCE="FP-1">min minute</FP>
                        <FP SOURCE="FP-1">mL milliliter</FP>
                        <FP SOURCE="FP-1">mm millimeter</FP>
                        <FP SOURCE="FP-1">ms millisecond</FP>
                        <FP SOURCE="FP-1">m/z mass-to-charge ratio</FP>
                        <FP SOURCE="FP-1">N normal; gram molecular weight of solute divided by hydrogen equivalent of solute, per liter of solution</FP>
                        <FP SOURCE="FP-1">ng nanogram</FP>
                        <FP SOURCE="FP-1">pg picogram</FP>
                        <FP SOURCE="FP-1">ppb part-per-billion</FP>
                        <FP SOURCE="FP-1">ppm part-per-million</FP>
                        <FP SOURCE="FP-1">ppt part-per-trillion</FP>
                        <FP SOURCE="FP-1">psig pounds-per-square inch gauge</FP>
                        <P>22.2 Definitions and acronyms (in alphabetical order).</P>
                        <P>Analyte—A compound or mixture of compounds (e.g., PCBs) tested for by this method. The analytes are listed in Tables 1-3.</P>
                        <P>Batch—See Extraction.</P>
                        <P>Blank—An aliquot of reagent water that is treated exactly as a sample including exposure to all glassware, equipment, solvents, reagents, internal standards, and surrogates that are used with samples. The blank is used to determine if analytes or interferences are present in the laboratory environment, the reagents, or the apparatus.</P>
                        <P>Calibration—The process of determining the relationship between the output or response of a measuring instrument and the value of an input standard. Historically, EPA has referred to a multi-point calibration as the “initial calibration,” to differentiate it from a single-point calibration verification.</P>
                        <P>
                            Calibration standard—A solution prepared from stock solutions and/or a secondary standards and containing the analytes of interest, surrogates, and internal standards. The calibration standard is used to calibrate the response of the GC/MS instrument against analyte concentration.
                            <PRTPAGE P="304"/>
                        </P>
                        <P>Calibration verification standard—The mid-point calibration standard used to verify calibration. See sections 7.3 and 13.4.</P>
                        <P>Descriptor—In SIM, the beginning and ending retention times for the RT window, the m/z's sampled in the RT window, and the dwell time at each m/z.</P>
                        <P>Extracted ion current profile (EICP)—The line described by the signal at a given m/z.</P>
                        <P>Extraction Batch—A set of up to 20 field samples (not including QC samples) started through the extraction process on a given 24-hour shift (section 3.1). Each extraction batch must be accompanied by a blank (section 8.5), a laboratory control sample (LCS, section 8.4), and a matrix spike and duplicate (MS/MSD; Section 8.3), resulting in a minimum of five analyses (1 sample, 1 blank, 1 LCS, 1 MS, and 1 MSD) and a maximum of 24 analyses (20 field samples, 1 blank, 1 LCS, 1 MS, and 1 MSD) for the batch. If greater than 20 samples are to be extracted in a 24-hour shift, the samples must be separated into extraction batches of 20 or fewer samples.</P>
                        <P>Field Duplicates—Two samples collected at the same time and placed under identical conditions, and treated identically throughout field and laboratory procedures. Results of analyses of the field duplicates provide an estimate of the precision associated with sample collection, preservation, and storage, as well as with laboratory procedures.</P>
                        <P>Field blank—An aliquot of reagent water or other reference matrix that is placed in a sample container in the field, and treated as a sample in all respects, including exposure to sampling site conditions, storage, preservation, and all analytical procedures. The purpose of the field blank is to determine if the field or sample transporting procedures and environments have contaminated the sample.</P>
                        <P>GC—Gas chromatograph or gas chromatography.</P>
                        <P>Internal standard—A compound added to an extract or standard solution in a known amount and used as a reference for quantitation of the analytes of interest and surrogates. In this method the internal standards are stable isotopically labeled analogs of selected method analytes (Table 8). Also see Internal standard quantitation.</P>
                        <P>Internal standard quantitation—A means of determining the concentration of an analyte of interest (Tables 1-3) by reference to a compound not expected to be found in a sample.</P>
                        <P>DOC—Initial demonstration of capability (section 8.2); four aliquots of reagent water spiked with the analytes of interest and analyzed to establish the ability of the laboratory to generate acceptable precision and recovery. A DOC is performed prior to the first time this method is used and any time the method or instrumentation is modified.</P>
                        <P>Laboratory Control Sample (LCS; laboratory fortified blank; section 8.4)—An aliquot of reagent water spiked with known quantities of the analytes of interest and surrogates. The LCS is analyzed exactly like a sample. Its purpose is to assure that the results produced by the laboratory remain within the limits specified in this method for precision and recovery.</P>
                        <P>Laboratory fortified sample matrix—See Matrix spike.</P>
                        <P>Laboratory reagent blank—A blank run on laboratory reagents; e.g., methylene chloride (section 11.1.5).</P>
                        <P>Matrix spike (MS) and matrix spike duplicate (MSD) (laboratory fortified sample matrix and duplicate)—Two aliquots of an environmental sample to which known quantities of the analytes of interest and surrogates are added in the laboratory. The MS/MSD are prepared and analyzed exactly like a field sample. Their purpose is to quantify any additional bias and imprecision caused by the sample matrix. The background concentrations of the analytes in the sample matrix must be determined in a separate aliquot and the measured values in the MS/MSD corrected for background concentrations.</P>
                        <P>May—This action, activity, or procedural step is neither required nor prohibited.</P>
                        <P>May not—This action, activity, or procedural step is prohibited.</P>
                        <P>Method blank—See blank.</P>
                        <P>Method detection limit (MDL)—A detection limit determined by the procedure at 40 CFR part 136, appendix B. The MDLs determined by EPA in the original version of the method are listed in Tables 1, 2 and 3. As noted in section 1.5, use the MDLs in Tables 1, 2, and 3 in conjunction with current MDL data from the laboratory actually analyzing samples to assess the sensitivity of this procedure relative to project objectives and regulatory requirements (where applicable).</P>
                        <P>Minimum level (ML)—The term “minimum level” refers to either the sample concentration equivalent to the lowest calibration point in a method or a multiple of the method detection limit (MDL), whichever is higher. Minimum levels may be obtained in several ways: They may be published in a method; they may be based on the lowest acceptable calibration point used by a laboratory; or they may be calculated by multiplying the MDL in a method, or the MDL determined by a laboratory, by a factor of 3. For the purposes of NPDES compliance monitoring, EPA considers the following terms to be synonymous: “quantitation limit,” “reporting limit,” and “minimum level.”</P>
                        <P>MS—Mass spectrometer or mass spectrometry, or matrix spike (a QC sample type).</P>
                        <P>MSD—Matrix spike duplicate (a QC sample type).</P>
                        <P>
                            Must—This action, activity, or procedural step is required.
                            <PRTPAGE P="305"/>
                        </P>
                        <P>m/z—The ratio of the mass of an ion (m) detected in the mass spectrometer to the charge (z) of that ion.</P>
                        <P>Preparation blank—See blank.</P>
                        <P>Quality control check sample (QCS)—See Laboratory Control Sample.</P>
                        <P>Reagent water—Water demonstrated to be free from the analytes of interest and potentially interfering substances at the MDLs for the analytes in this method.</P>
                        <P>Regulatory compliance limit (or regulatory concentration limit)—A limit on the concentration or amount of a pollutant or contaminant specified in a nationwide standard, in a permit, or otherwise established by a regulatory/control authority.</P>
                        <P>Relative retention time (RRT)—The ratio of the retention time of an analyte to the retention time of its associated internal standard. RRT compensates for small changes in the GC temperature program that can affect the absolute retention times of the analyte and internal standard. RRT is a unitless quantity.</P>
                        <P>Relative standard deviation (RSD)—The standard deviation times 100 divided by the mean. Also termed “coefficient of variation.”</P>
                        <P>RF—Response factor. See section 7.2.2.</P>
                        <P>RSD—See relative standard deviation.</P>
                        <P>Safety Data Sheet (SDS)—Written information on a chemical's toxicity, health hazards, physical properties, fire, and reactivity, including storage, spill, and handling precautions that meet the requirements of OSHA, 29 CFR 1910.1200(g) and appendix D to § 1910.1200. United Nations Globally Harmonized System of Classification and Labelling of Chemicals (GHS), third revised edition, United Nations, 2009.</P>
                        <P>Selected Ion Monitoring (SIM)—An MS technique in which a few m/z's are monitored. When used with gas chromatography, the m/z's monitored are usually changed periodically throughout the chromatographic run, to correlate with the characteristic m/z's of the analytes, surrogates, and internal standards as they elute from the chromatographic column. The technique is often used to increase sensitivity and minimize interferences.</P>
                        <P>Signal-to-noise ratio (S/N)—The height of the signal as measured from the mean (average) of the noise to the peak maximum divided by the width of the noise.</P>
                        <P>Should—This action, activity, or procedural step is suggested but not required.</P>
                        <P>SPE—Solid-phase extraction; an extraction technique in which an analyte is extracted from an aqueous solution by passage over or through a material capable of reversibly adsorbing the analyte. Also termed liquid-solid extraction.</P>
                        <P>Stock solution—A solution containing an analyte that is prepared using a reference material traceable to EPA, the National Institute of Science and Technology (NIST), or a source that will attest to the purity, authenticity, and concentration of the standard.</P>
                        <P>Surrogate—A compound unlikely to be found in a sample, and which is spiked into sample in a known amount before extraction or other processing, and is quantitated with the same procedures used to quantify other sample components. The purpose of the surrogate is to monitor method performance with each sample.</P>
                        <HD SOURCE="HD1">Method 1613, Revision B</HD>
                        <HD SOURCE="HD2">Tetra- Through Octa-Chlorinated Dioxins and Furans by Isotope Dilution HRGC/HRMS</HD>
                        <EAR>Pt. 136, App. A, Meth. 1613</EAR>
                        <HD SOURCE="HD2">1.0 Scope and Application</HD>
                        <P>1.1 This method is for determination of tetra- through octa-chlorinated dibenzo-p-dioxins (CDDs) and dibenzofurans (CDFs) in water, soil, sediment, sludge, tissue, and other sample matrices by high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS). The method is for use in EPA's data gathering and monitoring programs associated with the Clean Water Act, the Resource Conservation and Recovery Act, the Comprehensive Environmental Response, Compensation and Liability Act, and the Safe Drinking Water Act. The method is based on a compilation of EPA, industry, commercial laboratory, and academic methods (References 1-6).</P>
                        <P>1.2 The seventeen 2,3,7,8-substituted CDDs/CDFs listed in Table 1 may be determined by this method. Specifications are also provided for separate determination of 2,3,7,8-tetrachloro-dibenzo-p-dioxin (2,3,7,8-TCDD) and 2,3,7,8-tetrachloro-dibenzofuran (2,3,7,8-TCDF).</P>
                        <P>1.3 The detection limits and quantitation levels in this method are usually dependent on the level of interferences rather than instrumental limitations. The minimum levels (MLs) in Table 2 are the levels at which the CDDs/CDFs can be determined with no interferences present. The Method Detection Limit (MDL) for 2,3,7,8-TCDD has been determined as 4.4 pg/L (parts-per-quadrillion) using this method.</P>
                        <P>1.4 The GC/MS portions of this method are for use only by analysts experienced with HRGC/HRMS or under the close supervision of such qualified persons. Each laboratory that uses this method must demonstrate the ability to generate acceptable results using the procedure in Section 9.2.</P>
                        <P>
                            1.5 This method is “performance-based”. The analyst is permitted to modify the method to overcome interferences or lower the cost of measurements, provided that all performance criteria in this method are met. The requirements for establishing method equivalency are given in Section 9.1.2.
                            <PRTPAGE P="306"/>
                        </P>
                        <P>1.6 Any modification of this method, beyond those expressly permitted, shall be considered a major modification subject to application and approval of alternate test procedures under 40 CFR 136.4 and 136.5.</P>
                        <HD SOURCE="HD2">2.0 Summary of Method</HD>
                        <P>Flow charts that summarize procedures for sample preparation, extraction, and analysis are given in Figure 1 for aqueous and solid samples, Figure 2 for multi-phase samples, and Figure 3 for tissue samples.</P>
                        <P>2.1 Extraction.</P>
                        <P>2.1.1 Aqueous samples (samples containing less than 1% solids)—Stable isotopically labeled analogs of 15 of the 2,3,7,8-substituted CDDs/CDFs are spiked into a 1 L sample, and the sample is extracted by one of three procedures:</P>
                        <P>2.1.1.1 Samples containing no visible particles are extracted with methylene chloride in a separatory funnel or by the solid-phase extraction technique summarized in Section 2.1.1.3. The extract is concentrated for cleanup.</P>
                        <P>2.1.1.2 Samples containing visible particles are vacuum filtered through a glass-fiber filter. The filter is extracted in a Soxhlet/Dean-Stark (SDS) extractor (Reference 7), and the filtrate is extracted with methylene chloride in a separatory funnel. The methylene chloride extract is concentrated and combined with the SDS extract prior to cleanup.</P>
                        <P>2.1.1.3 The sample is vacuum filtered through a glass-fiber filter on top of a solid-phase extraction (SPE) disk. The filter and disk are extracted in an SDS extractor, and the extract is concentrated for cleanup.</P>
                        <P>2.1.2 Solid, semi-solid, and multi-phase samples (but not tissue)—The labeled compounds are spiked into a sample containing 10 g (dry weight) of solids. Samples containing multiple phases are pressure filtered and any aqueous liquid is discarded. Coarse solids are ground or homogenized. Any non-aqueous liquid from multi-phase samples is combined with the solids and extracted in an SDS extractor. The extract is concentrated for cleanup.</P>
                        <P>2.1.3 Fish and other tissue—The sample is extracted by one of two procedures:</P>
                        <P>2.1.3.1 Soxhlet or SDS extraction—A 20 g aliquot of sample is homogenized, and a 10 g aliquot is spiked with the labeled compounds. The sample is mixed with sodium sulfate, allowed to dry for 12-24 hours, and extracted for 18-24 hours using methylene chloride:hexane (1:1) in a Soxhlet extractor. The extract is evaporated to dryness, and the lipid content is determined.</P>
                        <P>2.1.3.2 HCl digestion—A 20 g aliquot is homogenized, and a 10 g aliquot is placed in a bottle and spiked with the labeled compounds. After equilibration, 200 mL of hydrochloric acid and 200 mL of methylene chloride:hexane (1:1) are added, and the bottle is agitated for 12-24 hours. The extract is evaporated to dryness, and the lipid content is determined.</P>
                        <P>
                            2.2 After extraction, 
                            <SU>37</SU>
                            Cl
                            <E T="52">4</E>
                            -labeled 2,3,7,8-TCDD is added to each extract to measure the efficiency of the cleanup process. Sample cleanups may include back-extraction with acid and/or base, and gel permeation, alumina, silica gel, Florisil and activated carbon chromatography. High-performance liquid chromatography (HPLC) can be used for further isolation of the 2,3,7,8-isomers or other specific isomers or congeners. Prior to the cleanup procedures cited above, tissue extracts are cleaned up using an anthropogenic isolation column, a batch silica gel adsorption, or sulfuric acid and base back-extraction, depending on the tissue extraction procedure used.
                        </P>
                        <P>2.3 After cleanup, the extract is concentrated to near dryness. Immediately prior to injection, internal standards are added to each extract, and an aliquot of the extract is injected into the gas chromatograph. The analytes are separated by the GC and detected by a high-resolution (≥10,000) mass spectrometer. Two exact m/z's are monitored for each analyte.</P>
                        <P>2.4 An individual CDD/CDF is identified by comparing the GC retention time and ion-abundance ratio of two exact m/z's with the corresponding retention time of an authentic standard and the theoretical or acquired ion-abundance ratio of the two exact m/z's. The non-2,3,7,8 substituted isomers and congeners are identified when retention times and ion-abundance ratios agree within predefined limits. Isomer specificity for 2,3,7,8-TCDD and 2,3,7,8-TCDF is achieved using GC columns that resolve these isomers from the other tetra-isomers.</P>
                        <P>2.5 Quantitative analysis is performed using selected ion current profile (SICP) areas, in one of three ways:</P>
                        <P>2.5.1 For the 15 2,3,7,8-substituted CDDs/CDFs with labeled analogs (see Table 1), the GC/MS system is calibrated, and the concentration of each compound is determined using the isotope dilution technique.</P>
                        <P>2.5.2 For 1,2,3,7,8,9-HxCDD, OCDF, and the labeled compounds, the GC/MS system is calibrated and the concentration of each compound is determined using the internal standard technique.</P>
                        <P>
                            2.5.3 For non-2,3,7,8-substituted isomers and for all isomers at a given level of chlorination (
                            <E T="03">i.e.</E>
                            , total TCDD), concentrations are determined using response factors from calibration of the CDDs/CDFs at the same level of chlorination.
                        </P>
                        <P>
                            2.6 The quality of the analysis is assured through reproducible calibration and testing of the extraction, cleanup, and GC/MS systems.
                            <PRTPAGE P="307"/>
                        </P>
                        <HD SOURCE="HD2">3.0 Definitions</HD>
                        <P>Definitions are given in the glossary at the end of this method.</P>
                        <HD SOURCE="HD2">4.0 Contamination and Interferences</HD>
                        <P>4.1 Solvents, reagents, glassware, and other sample processing hardware may yield artifacts and/or elevated baselines causing misinterpretation of chromatograms (References 8-9). Specific selection of reagents and purification of solvents by distillation in all-glass systems may be required. Where possible, reagents are cleaned by extraction or solvent rinse.</P>
                        <P>4.2 Proper cleaning of glassware is extremely important, because glassware may not only contaminate the samples but may also remove the analytes of interest by adsorption on the glass surface.</P>
                        <P>4.2.1 Glassware should be rinsed with solvent and washed with a detergent solution as soon after use as is practical. Sonication of glassware containing a detergent solution for approximately 30 seconds may aid in cleaning. Glassware with removable parts, particularly separatory funnels with fluoropolymer stopcocks, must be disassembled prior to detergent washing.</P>
                        <P>4.2.2 After detergent washing, glassware should be rinsed immediately, first with methanol, then with hot tap water. The tap water rinse is followed by another methanol rinse, then acetone, and then methylene chloride.</P>
                        <P>4.2.3 Do not bake reusable glassware in an oven as a routine part of cleaning. Baking may be warranted after particularly dirty samples are encountered but should be minimized, as repeated baking of glassware may cause active sites on the glass surface that will irreversibly adsorb CDDs/CDFs.</P>
                        <P>4.2.4 Immediately prior to use, the Soxhlet apparatus should be pre-extracted with toluene for approximately three hours (see Sections 12.3.1 through 12.3.3). Separatory funnels should be shaken with methylene chloride/toluene (80/20 mixture) for two minutes, drained, and then shaken with pure methylene chloride for two minutes.</P>
                        <P>4.3 All materials used in the analysis shall be demonstrated to be free from interferences by running reference matrix method blanks initially and with each sample batch (samples started through the extraction process on a given 12-hour shift, to a maximum of 20 samples).</P>
                        <P>4.3.1 The reference matrix must simulate, as closely as possible, the sample matrix under test. Ideally, the reference matrix should not contain the CDDs/CDFs in detectable amounts, but should contain potential interferents in the concentrations expected to be found in the samples to be analyzed. For example, a reference sample of human adipose tissue containing pentachloronaphthalene can be used to exercise the cleanup systems when samples containing pentachloronaphthalene are expected.</P>
                        <P>4.3.2 When a reference matrix that simulates the sample matrix under test is not available, reagent water (Section 7.6.1) can be used to simulate water samples; playground sand (Section 7.6.2) or white quartz sand (Section 7.3.2) can be used to simulate soils; filter paper (Section 7.6.3) can be used to simulate papers and similar materials; and corn oil (Section 7.6.4) can be used to simulate tissues.</P>
                        <P>4.4 Interferences coextracted from samples will vary considerably from source to source, depending on the diversity of the site being sampled. Interfering compounds may be present at concentrations several orders of magnitude higher than the CDDs/CDFs. The most frequently encountered interferences are chlorinated biphenyls, methoxy biphenyls, hydroxydiphenyl ethers, benzylphenyl ethers, polynuclear aromatics, and pesticides. Because very low levels of CDDs/CDFs are measured by this method, the elimination of interferences is essential. The cleanup steps given in Section 13 can be used to reduce or eliminate these interferences and thereby permit reliable determination of the CDDs/CDFs at the levels shown in Table 2.</P>
                        <P>4.5 Each piece of reusable glassware should be numbered to associate that glassware with the processing of a particular sample. This will assist the laboratory in tracking possible sources of contamination for individual samples, identifying glassware associated with highly contaminated samples that may require extra cleaning, and determining when glassware should be discarded.</P>
                        <P>4.6 Cleanup of tissue—The natural lipid content of tissue can interfere in the analysis of tissue samples for the CDDs/CDFs. The lipid contents of different species and portions of tissue can vary widely. Lipids are soluble to varying degrees in various organic solvents and may be present in sufficient quantity to overwhelm the column chromatographic cleanup procedures used for cleanup of sample extracts. Lipids must be removed by the lipid removal procedures in Section 13.7, followed by alumina (Section 13.4) or Florisil (Section 13.8), and carbon (Section 13.5) as minimum additional cleanup steps. If chlorodiphenyl ethers are detected, as indicated by the presence of peaks at the exact m/z's monitored for these interferents, alumina and/or Florisil cleanup must be employed to eliminate these interferences.</P>
                        <HD SOURCE="HD2">5.0 Safety</HD>
                        <P>
                            5.1 The toxicity or carcinogenicity of each compound or reagent used in this method has not been precisely determined; however, each chemical compound should be 
                            <PRTPAGE P="308"/>
                            treated as a potential health hazard. Exposure to these compounds should be reduced to the lowest possible level.
                        </P>
                        <P>5.1.1 The 2,3,7,8-TCDD isomer has been found to be acnegenic, carcinogenic, and teratogenic in laboratory animal studies. It is soluble in water to approximately 200 ppt and in organic solvents to 0.14%. On the basis of the available toxicological and physical properties of 2,3,7,8-TCDD, all of the CDDs/CDFs should be handled only by highly trained personnel thoroughly familiar with handling and cautionary procedures and the associated risks.</P>
                        <P>5.1.2 It is recommended that the laboratory purchase dilute standard solutions of the analytes in this method. However, if primary solutions are prepared, they shall be prepared in a hood, and a NIOSH/MESA approved toxic gas respirator shall be worn when high concentrations are handled.</P>
                        <P>5.2 The laboratory is responsible for maintaining a current awareness file of OSHA regulations regarding the safe handling of the chemicals specified in this method. A reference file of material safety data sheets (MSDSs) should also be made available to all personnel involved in these analyses. It is also suggested that the laboratory perform personal hygiene monitoring of each analyst who uses this method and that the results of this monitoring be made available to the analyst. Additional information on laboratory safety can be found in References 10-13. The references and bibliography at the end of Reference 13 are particularly comprehensive in dealing with the general subject of laboratory safety.</P>
                        <P>5.3 The CDDs/CDFs and samples suspected to contain these compounds are handled using essentially the same techniques employed in handling radioactive or infectious materials. Well-ventilated, controlled access laboratories are required. Assistance in evaluating the health hazards of particular laboratory conditions may be obtained from certain consulting laboratories and from State Departments of Health or Labor, many of which have an industrial health service. The CDDs/CDFs are extremely toxic to laboratory animals. Each laboratory must develop a strict safety program for handling these compounds. The practices in References 2 and 14 are highly recommended.</P>
                        <P>5.3.1 Facility—When finely divided samples (dusts, soils, dry chemicals) are handled, all operations (including removal of samples from sample containers, weighing, transferring, and mixing) should be performed in a glove box demonstrated to be leak tight or in a fume hood demonstrated to have adequate air flow. Gross losses to the laboratory ventilation system must not be allowed. Handling of the dilute solutions normally used in analytical and animal work presents no inhalation hazards except in the case of an accident.</P>
                        <P>5.3.2 Protective equipment—Disposable plastic gloves, apron or lab coat, safety glasses or mask, and a glove box or fume hood adequate for radioactive work should be used. During analytical operations that may give rise to aerosols or dusts, personnel should wear respirators equipped with activated carbon filters. Eye protection equipment (preferably full face shields) must be worn while working with exposed samples or pure analytical standards. Latex gloves are commonly used to reduce exposure of the hands. When handling samples suspected or known to contain high concentrations of the CDDs/CDFs, an additional set of gloves can also be worn beneath the latex gloves.</P>
                        <P>5.3.3 Training—Workers must be trained in the proper method of removing contaminated gloves and clothing without contacting the exterior surfaces.</P>
                        <P>5.3.4 Personal hygiene—Hands and forearms should be washed thoroughly after each manipulation and before breaks (coffee, lunch, and shift).</P>
                        <P>5.3.5 Confinement—Isolated work areas posted with signs, segregated glassware and tools, and plastic absorbent paper on bench tops will aid in confining contamination.</P>
                        <P>5.3.6 Effluent vapors—The effluents of sample splitters from the gas chromatograph (GC) and from roughing pumps on the mass spectrometer (MS) should pass through either a column of activated charcoal or be bubbled through a trap containing oil or high-boiling alcohols to condense CDD/CDF vapors.</P>
                        <P>5.3.7 Waste Handling—Good technique includes minimizing contaminated waste. Plastic bag liners should be used in waste cans. Janitors and other personnel must be trained in the safe handling of waste.</P>
                        <P>5.3.8 Decontamination</P>
                        <P>5.3.8.1 Decontamination of personnel—Use any mild soap with plenty of scrubbing action.</P>
                        <P>5.3.8.2 Glassware, tools, and surfaces—Chlorothene NU Solvent is the least toxic solvent shown to be effective. Satisfactory cleaning may be accomplished by rinsing with Chlorothene, then washing with any detergent and water. If glassware is first rinsed with solvent, then the dish water may be disposed of in the sewer. Given the cost of disposal, it is prudent to minimize solvent wastes.</P>
                        <P>5.3.9 Laundry—Clothing known to be contaminated should be collected in plastic bags. Persons who convey the bags and launder the clothing should be advised of the hazard and trained in proper handling. The clothing may be put into a washer without contact if the launderer knows of the potential problem. The washer should be run through a cycle before being used again for other clothing.</P>
                        <P>
                            5.3.10 Wipe tests—A useful method of determining cleanliness of work surfaces and 
                            <PRTPAGE P="309"/>
                            tools is to wipe the surface with a piece of filter paper. Extraction and analysis by GC with an electron capture detector (ECD) can achieve a limit of detection of 0.1 µg per wipe; analysis using this method can achieve an even lower detection limit. Less than 0.1 µg per wipe indicates acceptable cleanliness; anything higher warrants further cleaning. More than 10 µg on a wipe constitutes an acute hazard and requires prompt cleaning before further use of the equipment or work space, and indicates that unacceptable work practices have been employed.
                        </P>
                        <P>5.3.11 Table or wrist-action shaker—The use of a table or wrist-action shaker for extraction of tissues presents the possibility of breakage of the extraction bottle and spillage of acid and flammable organic solvent. A secondary containment system around the shaker is suggested to prevent the spread of acid and solvents in the event of such a breakage. The speed and intensity of shaking action should also be adjusted to minimize the possibility of breakage.</P>
                        <HD SOURCE="HD2">6.0 Apparatus and Materials</HD>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>Brand names, suppliers, and part numbers are for illustration purposes only and no endorsement is implied. Equivalent performance may be achieved using apparatus and materials other than those specified here. Meeting the performance requirements of this method is the responsibility of the laboratory.</P>
                            <P>6.1 Sampling Equipment for Discrete or Composite Sampling</P>
                            <P>6.1.1 Sample bottles and caps</P>
                            <P>6.1.1.1 Liquid samples (waters, sludges and similar materials containing 5% solids or less)—Sample bottle, amber glass, 1.1 L minimum, with screw cap.</P>
                            <P>6.1.1.2 Solid samples (soils, sediments, sludges, paper pulps, filter cake, compost, and similar materials that contain more than 5% solids)—Sample bottle, wide mouth, amber glass, 500 mL minimum.</P>
                            <P>6.1.1.3 If amber bottles are not available, samples shall be protected from light.</P>
                            <P>6.1.1.4 Bottle caps—Threaded to fit sample bottles. Caps shall be lined with fluoropolymer.</P>
                            <P>6.1.1.5 Cleaning</P>
                            <P>6.1.1.5.1 Bottles are detergent water washed, then solvent rinsed before use.</P>
                            <P>6.1.1.5.2 Liners are detergent water washed, rinsed with reagent water (Section 7.6.1) followed by solvent, and baked at approximately 200 °C for a minimum of 1 hour prior to use.</P>
                            <P>6.1.2 Compositing equipment—Automatic or manual compositing system incorporating glass containers cleaned per bottle cleaning procedure above. Only glass or fluoropolymer tubing shall be used. If the sampler uses a peristaltic pump, a minimum length of compressible silicone rubber tubing may be used in the pump only. Before use, the tubing shall be thoroughly rinsed with methanol, followed by repeated rinsing with reagent water to minimize sample contamination. An integrating flow meter is used to collect proportional composite samples.</P>
                            <P>6.2 Equipment for Glassware Cleaning—Laboratory sink with overhead fume hood.</P>
                            <P>6.3 Equipment for Sample Preparation</P>
                            <P>6.3.1 Laboratory fume hood of sufficient size to contain the sample preparation equipment listed below.</P>
                            <P>6.3.2 Glove box (optional).</P>
                            <P>6.3.3 Tissue homogenizer—VirTis Model 45 Macro homogenizer (American Scientific Products H-3515, or equivalent) with stainless steel Macro-shaft and Turbo-shear blade.</P>
                            <P>6.3.4 Meat grinder—Hobart, or equivalent, with 3-5 mm holes in inner plate.</P>
                            <P>6.3.5 Equipment for determining percent moisture</P>
                            <P>6.3.5.1 Oven—Capable of maintaining a temperature of 110 ±5 °C.</P>
                            <P>6.3.5.2 Dessicator.</P>
                            <P>6.3.6 Balances</P>
                            <P>6.3.6.1 Analytical—Capable of weighing 0.1 mg.</P>
                            <P>6.3.6.2 Top loading—Capable of weighing 10 mg.</P>
                            <P>6.4 Extraction Apparatus</P>
                            <P>6.4.1 Water samples</P>
                            <P>6.4.1.1 pH meter, with combination glass electrode.</P>
                            <P>6.4.1.2 pH paper, wide range (Hydrion Papers, or equivalent).</P>
                            <P>6.4.1.3 Graduated cylinder, 1 L capacity.</P>
                            <P>6.4.1.4 Liquid/liquid extraction—Separatory funnels, 250 mL, 500 mL, and 2000 mL, with fluoropolymer stopcocks.</P>
                            <P>6.4.1.5 Solid-phase extraction</P>
                            <P>6.4.1.5.1 One liter filtration apparatus, including glass funnel, glass frit support, clamp, adapter, stopper, filtration flask, and vacuum tubing (Figure 4). For wastewater samples, the apparatus should accept 90 or 144 mm disks. For drinking water or other samples containing low solids, smaller disks may be used.</P>
                            <P>6.4.1.5.2 Vacuum source capable of maintaining 25 in. Hg, equipped with shutoff valve and vacuum gauge.</P>
                            <P>6.4.1.5.3 Glass-fiber filter—Whatman GMF 150 (or equivalent), 1 micron pore size, to fit filtration apparatus in Section 6.4.1.5.1.</P>
                            <P>
                                6.4.1.5.4 Solid-phase extraction disk containing octadecyl (C
                                <E T="52">18</E>
                                ) bonded silica uniformly enmeshed in an inert matrix—Fisher Scientific 14-378F (or equivalent), to fit filtration apparatus in Section 6.4.1.5.1.
                            </P>
                            <P>6.4.2 Soxhlet/Dean-Stark (SDS) extractor (Figure 5)—For filters and solid/sludge samples.</P>
                            <P>
                                6.4.2.1 Soxhlet—50 mm ID, 200 mL capacity with 500 mL flask (Cal-Glass LG-6900, or equivalent, except substitute 500 mL round-bottom flask for 300 mL flat-bottom flask).
                                <PRTPAGE P="310"/>
                            </P>
                            <P>6.4.2.2 Thimble—43 × 123 to fit Soxhlet (Cal-Glass LG-6901-122, or equivalent).</P>
                            <P>6.4.2.3 Moisture trap—Dean Stark or Barret with fluoropolymer stopcock, to fit Soxhlet.</P>
                            <P>6.4.2.4 Heating mantle—Hemispherical, to fit 500 mL round-bottom flask (Cal-Glass LG-8801-112, or equivalent).</P>
                            <P>6.4.2.5 Variable transformer—Powerstat (or equivalent), 110 volt, 10 amp.</P>
                            <P>6.4.3 Apparatus for extraction of tissue.</P>
                            <P>6.4.3.1 Bottle for extraction (if digestion/extraction using HCl is used)” 500-600 mL wide-mouth clear glass, with fluoropolymer-lined cap.</P>
                            <P>6.4.3.2 Bottle for back-extraction—100-200 mL narrow-mouth clear glass with fluoropolymer-lined cap.</P>
                            <P>6.4.3.3 Mechanical shaker—Wrist-action or platform-type rotary shaker that produces vigorous agitation (Sybron Thermolyne Model LE “Big Bill” rotator/shaker, or equivalent).</P>
                            <P>6.4.3.4 Rack attached to shaker table to permit agitation of four to nine samples simultaneously.</P>
                            <P>6.4.4 Beakers—400-500 mL.</P>
                            <P>6.4.5 Spatulas—Stainless steel.</P>
                            <P>6.5 Filtration Apparatus.</P>
                            <P>6.5.1 Pyrex glass wool—Solvent-extracted by SDS for three hours minimum.</P>
                        </NOTE>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>Baking glass wool may cause active sites that will irreversibly adsorb CDDs/CDFs.</P>
                            <P>6.5.2 Glass funnel—125-250 mL.</P>
                            <P>6.5.3 Glass-fiber filter paper—Whatman GF/D (or equivalent), to fit glass funnel in Section 6.5.2.</P>
                            <P>6.5.4 Drying column—15-20 mm ID Pyrex chromatographic column equipped with coarse-glass frit or glass-wool plug.</P>
                            <P>6.5.5 Buchner funnel—15 cm.</P>
                            <P>6.5.6 Glass-fiber filter paper—to fit Buchner funnel in Section 6.5.5.</P>
                            <P>6.5.7 Filtration flasks—1.5-2.0 L, with side arm.</P>
                            <P>6.5.8 Pressure filtration apparatus—Millipore YT30 142 HW, or equivalent.</P>
                            <P>6.6 Centrifuge Apparatus.</P>
                            <P>6.6.1 Centrifuge—Capable of rotating 500 mL centrifuge bottles or 15 mL centrifuge tubes at 5,000 rpm minimum.</P>
                            <P>6.6.2 Centrifuge bottles—500 mL, with screw-caps, to fit centrifuge.</P>
                            <P>6.6.3 Centrifuge tubes—12-15 mL, with screw-caps, to fit centrifuge.</P>
                            <P>6.7 Cleanup Apparatus.</P>
                            <P>6.7.1 Automated gel permeation chromatograph (Analytical Biochemical Labs, Inc, Columbia, MO, Model GPC Autoprep 1002, or equivalent).</P>
                            <P>6.7.1.1 Column—600-700 mm long × 25 mm ID, packed with 70 g of</P>
                            <FP>SX-3 Bio-beads (Bio-Rad Laboratories, Richmond, CA, or equivalent).</FP>
                            <P>6.7.1.2 Syringe—10 mL, with Luer fitting.</P>
                            <P>6.7.1.3 Syringe filter holder—stainless steel, and glass-fiber or fluoropolymer filters (Gelman 4310, or equivalent).</P>
                            <P>6.7.1.4 UV detectors—254 nm, preparative or semi-preparative flow cell (Isco, Inc., Type 6; Schmadzu, 5 mm path length; Beckman-Altex 152W, 8 µL micro-prep flow cell, 2 mm path; Pharmacia UV-1, 3 mm flow cell; LDC Milton-Roy UV-3, monitor #1203; or equivalent).</P>
                            <P>6.7.2 Reverse-phase high-performance liquid chromatograph.</P>
                            <P>6.7.2.1 Column oven and detector—Perkin-Elmer Model LC-65T (or equivalent) operated at 0.02 AUFS at 235 nm.</P>
                            <P>6.7.2.2 Injector—Rheodyne 7120 (or equivalent) with 50 µL sample loop.</P>
                            <P>6.7.2.3 Column—Two 6.2 mm × 250 mm Zorbax-ODS columns in series (DuPont Instruments Division, Wilmington, DE, or equivalent), operated at 50 °C with 2.0 mL/min methanol isocratic effluent.</P>
                            <P>6.7.2.4 Pump—Altex 110A (or equivalent).</P>
                            <P>6.7.3 Pipets.</P>
                            <P>6.7.3.1 Disposable, pasteur—150 mm long × 5-mm ID (Fisher Scientific 13-678-6A, or equivalent).</P>
                            <P>6.7.3.2 Disposable, serological—10 mL (6 mm ID).</P>
                            <P>6.7.4 Glass chromatographic columns.</P>
                            <P>6.7.4.1 150 mm long × 8-mm ID, (Kontes K-420155, or equivalent) with coarse-glass frit or glass-wool plug and 250 mL reservoir.</P>
                            <P>6.7.4.2 200 mm long × 15 mm ID, with coarse-glass frit or glass-wool plug and 250 mL reservoir.</P>
                            <P>6.7.4.3 300 mm long × 25 mm ID, with 300 mL reservoir and glass or fluoropolymer stopcock.</P>
                            <P>6.7.5 Stirring apparatus for batch silica cleanup of tissue extracts.</P>
                            <P>6.7.5.1 Mechanical stirrer—Corning Model 320, or equivalent.</P>
                            <P>6.7.5.2 Bottle—500-600 mL wide-mouth clear glass.</P>
                            <P>6.7.6 Oven—For baking and storage of adsorbents, capable of maintaining a constant temperature (±5 °C) in the range of 105-250 °C.</P>
                            <P>6.8 Concentration Apparatus.</P>
                            <P>6.8.1 Rotary evaporator—Buchi/Brinkman-American Scientific No. E5045-10 or equivalent, equipped with a variable temperature water bath.</P>
                            <P>6.8.1.1 Vacuum source for rotary evaporator equipped with shutoff valve at the evaporator and vacuum gauge.</P>
                            <P>6.8.1.2 A recirculating water pump and chiller are recommended, as use of tap water for cooling the evaporator wastes large volumes of water and can lead to inconsistent performance as water temperatures and pressures vary.</P>
                            <P>6.8.1.3 Round-bottom flask—100 mL and 500 mL or larger, with ground-glass fitting compatible with the rotary evaporator.</P>
                            <P>
                                6.8.2 Kuderna-Danish (K-D) Concentrator.
                                <PRTPAGE P="311"/>
                            </P>
                            <P>6.8.2.1 Concentrator tube—10 mL, graduated (Kontes K-570050-1025, or equivalent) with calibration verified. Ground-glass stopper (size 19/22 joint) is used to prevent evaporation of extracts.</P>
                            <P>6.8.2.2 Evaporation flask—500 mL (Kontes K-570001-0500, or equivalent), attached to concentrator tube with springs (Kontes K-662750-0012 or equivalent).</P>
                            <P>6.8.2.3 Snyder column—Three-ball macro (Kontes K-503000-0232, or equivalent).</P>
                            <P>6.8.2.4 Boiling chips.</P>
                            <P>6.8.2.4.1 Glass or silicon carbide—Approximately 10/40 mesh, extracted with methylene chloride and baked at 450 °C for one hour minimum.</P>
                            <P>6.8.2.4.2 Fluoropolymer (optional)—Extracted with methylene chloride.</P>
                            <P>6.8.2.5 Water bath—Heated, with concentric ring cover, capable of maintaining a temperature within ±2 °C, installed in a fume hood.</P>
                            <P>6.8.3 Nitrogen blowdown apparatus—Equipped with water bath controlled in the range of 30-60 °C (N-Evap, Organomation Associates, Inc., South Berlin, MA, or equivalent), installed in a fume hood.</P>
                            <P>6.8.4 Sample vials.</P>
                            <P>6.8.4.1 Amber glass—2-5 mL with fluoropolymer-lined screw-cap.</P>
                            <P>6.8.4.2 Glass—0.3 mL, conical, with fluoropolymer-lined screw or crimp cap.</P>
                            <P>6.9 Gas Chromatograph—Shall have splitless or on-column injection port for capillary column, temperature program with isothermal hold, and shall meet all of the performance specifications in Section 10.</P>
                            <P>6.9.1 GC column for CDDs/CDFs and for isomer specificity for 2,3,7,8-TCDD—60 ±5 m long × 0.32 ±0.02 mm ID; 0.25 µm 5% phenyl, 94% methyl, 1% vinyl silicone bonded-phase fused-silica capillary column (J&amp;W DB-5, or equivalent).</P>
                            <P>6.9.2 GC column for isomer specificity for 2,3,7,8-TCDF—30 ±5 m long × 0.32 ±0.02 mm ID; 0.25 µm bonded-phase fused-silica capillary column (J&amp;W DB-225, or equivalent).</P>
                            <P>6.10 Mass Spectrometer—28-40 eV electron impact ionization, shall be capable of repetitively selectively monitoring 12 exact m/z's minimum at high resolution (≥10,000) during a period of approximately one second, and shall meet all of the performance specifications in Section 10.</P>
                            <P>6.11 GC/MS Interface—The mass spectrometer (MS) shall be interfaced to the GC such that the end of the capillary column terminates within 1 cm of the ion source but does not intercept the electron or ion beams.</P>
                            <P>6.12 Data System—Capable of collecting, recording, and storing MS data.</P>
                        </NOTE>
                        <HD SOURCE="HD2">7.0 Reagents and Standards</HD>
                        <P>7.1 pH Adjustment and Back-Extraction.</P>
                        <P>7.1.1 Potassium hydroxide—Dissolve 20 g reagent grade KOH in 100 mL reagent water.</P>
                        <P>7.1.2 Sulfuric acid—Reagent grade (specific gravity 1.84).</P>
                        <P>7.1.3 Hydrochloric acid—Reagent grade, 6N.</P>
                        <P>7.1.4 Sodium chloride—Reagent grade, prepare at 5% (w/v) solution in reagent water.</P>
                        <P>7.2 Solution Drying and Evaporation.</P>
                        <P>7.2.1 Solution drying—Sodium sulfate, reagent grade, granular, anhydrous (Baker 3375, or equivalent), rinsed with methylene chloride (20 mL/g), baked at 400 °C for one hour minimum, cooled in a dessicator, and stored in a pre-cleaned glass bottle with screw-cap that prevents moisture from entering. If, after heating, the sodium sulfate develops a noticeable grayish cast (due to the presence of carbon in the crystal matrix), that batch of reagent is not suitable for use and should be discarded. Extraction with methylene chloride (as opposed to simple rinsing) and baking at a lower temperature may produce sodium sulfate that is suitable for use.</P>
                        <P>7.2.2 Tissue drying—Sodium sulfate, reagent grade, powdered, treated and stored as above.</P>
                        <P>7.2.3 Prepurified nitrogen.</P>
                        <P>7.3 Extraction.</P>
                        <P>7.3.1 Solvents—Acetone, toluene, cyclohexane, hexane, methanol, methylene chloride, and nonane; distilled in glass, pesticide quality, lot-certified to be free of interferences.</P>
                        <P>7.3.2 White quartz sand, 60/70 mesh—For Soxhlet/Dean-Stark extraction (Aldrich Chemical, Cat. No. 27-437-9, or equivalent). Bake at 450 °C for four hours minimum.</P>
                        <P>7.4 GPC Calibration Solution—Prepare a solution containing 300 mg/mL corn oil, 15 mg/mL bis(2-ethylhexyl) phthalate, 1.4 mg/mL pentachlorophenol, 0.1 mg/mL perylene, and 0.5 mg/mL sulfur.</P>
                        <P>7.5 Adsorbents for Sample Cleanup.</P>
                        <P>7.5.1 Silica gel.</P>
                        <P>7.5.1.1 Activated silica gel—100-200 mesh, Supelco 1-3651 (or equivalent), rinsed with methylene chloride, baked at 180 °C for a minimum of one hour, cooled in a dessicator, and stored in a precleaned glass bottle with screw-cap that prevents moisture from entering.</P>
                        <P>7.5.1.2 Acid silica gel (30% w/w)—Thoroughly mix 44.0 g of concentrated sulfuric acid with 100.0 g of activated silica gel in a clean container. Break up aggregates with a stirring rod until a uniform mixture is obtained. Store in a bottle with a fluoropolymer-lined screw-cap.</P>
                        <P>7.5.1.3 Basic silica gel—Thoroughly mix 30 g of 1N sodium hydroxide with 100 g of activated silica gel in a clean container. Break up aggregates with a stirring rod until a uniform mixture is obtained. Store in a bottle with a fluoropolymer-lined screw-cap.</P>
                        <P>
                            7.5.1.4 Potassium silicate.
                            <PRTPAGE P="312"/>
                        </P>
                        <P>7.5.1.4.1 Dissolve 56 g of high purity potassium hydroxide (Aldrich, or equivalent) in 300 mL of methanol in a 750-1000 mL flat-bottom flask.</P>
                        <P>7.5.1.4.2 Add 100 g of silica gel and a stirring bar, and stir on a hot plate at 60-70 °C for one to two hours.</P>
                        <P>7.5.1.4.3 Decant the liquid and rinse the potassium silicate twice with 100 mL portions of methanol, followed by a single rinse with 100 mL of methylene chloride.</P>
                        <P>7.5.1.4.4 Spread the potassium silicate on solvent-rinsed aluminum foil and dry for two to four hours in a hood.</P>
                        <P>7.5.1.4.5 Activate overnight at 200-250 °C.</P>
                        <P>7.5.2 Alumina—Either one of two types of alumina, acid or basic, may be used in the cleanup of sample extracts, provided that the laboratory can meet the performance specifications for the recovery of labeled compounds described in Section 9.3. The same type of alumina must be used for all samples, including those used to demonstrate initial precision and recovery (Section 9.2) and ongoing precision and recovery (Section 15.5).</P>
                        <P>7.5.2.1 Acid alumina—Supelco 19996-6C (or equivalent). Activate by heating to 130 °C for a minimum of 12 hours.</P>
                        <P>7.5.2.2 Basic alumina—Supelco 19944-6C (or equivalent). Activate by heating to 600 °C for a minimum of 24 hours. Alternatively, activate by heating in a tube furnace at 650-700 °C under an air flow rate of approximately 400 cc/minute. Do not heat over 700 °C, as this can lead to reduced capacity for retaining the analytes. Store at 130 °C in a covered flask. Use within five days of baking.</P>
                        <P>7.5.3 Carbon.</P>
                        <P>7.5.3.1 Carbopak C—(Supelco 1-0258, or equivalent).</P>
                        <P>7.5.3.2 Celite 545—(Supelco 2-0199, or equivalent).</P>
                        <P>7.5.3.3 Thoroughly mix 9.0 g Carbopak C and 41.0 g Celite 545 to produce an 18% w/w mixture. Activate the mixture at 130 °C for a minimum of six hours. Store in a dessicator.</P>
                        <P>7.5.4 Anthropogenic isolation column—Pack the column in Section 6.7.4.3 from bottom to top with the following:</P>
                        <P>7.5.4.1 2 g silica gel (Section 7.5.1.1).</P>
                        <P>7.5.4.2 2 g potassium silicate (Section 7.5.1.4).</P>
                        <P>7.5.4.3 2 g granular anhydrous sodium sulfate (Section 7.2.1).</P>
                        <P>7.5.4.4 10 g acid silica gel (Section 7.5.1.2).</P>
                        <P>7.5.4.5 2 g granular anhydrous sodium sulfate.</P>
                        <P>7.5.5 Florisil column.</P>
                        <P>7.5.5.1 Florisil—60-100 mesh, Floridin Corp (or equivalent). Soxhlet extract in 500 g portions for 24 hours.</P>
                        <P>7.5.5.2 Insert a glass wool plug into the tapered end of a graduated serological pipet (Section 6.7.3.2). Pack with 1.5 g (approx 2 mL) of Florisil topped with approx 1 mL of sodium sulfate (Section 7.2.1) and a glass wool plug.</P>
                        <P>7.5.5.3 Activate in an oven at 130-150 °C for a minimum of 24 hours and cool for 30 minutes. Use within 90 minutes of cooling.</P>
                        <P>7.6 Reference Matrices—Matrices in which the CDDs/CDFs and interfering compounds are not detected by this method.</P>
                        <P>7.6.1 Reagent water—Bottled water purchased locally, or prepared by passage through activated carbon.</P>
                        <P>7.6.2 High-solids reference matrix—Playground sand or similar material. Prepared by extraction with methylene chloride and/or baking at 450 °C for a minimum of four hours.</P>
                        <P>7.6.3 Paper reference matrix—Glass-fiber filter, Gelman Type A, or equivalent. Cut paper to simulate the surface area of the paper sample being tested.</P>
                        <P>7.6.4 Tissue reference matrix—Corn or other vegetable oil. May be prepared by extraction with methylene chloride.</P>
                        <P>7.6.5 Other matrices—This method may be verified on any reference matrix by performing the tests given in Section 9.2. Ideally, the matrix should be free of the CDDs/CDFs, but in no case shall the background level of the CDDs/CDFs in the reference matrix exceed three times the minimum levels in Table 2. If low background levels of the CDDs/CDFs are present in the reference matrix, the spike level of the analytes used in Section 9.2 should be increased to provide a spike-to-background ratio in the range of 1:1 to 5:1 (Reference 15).</P>
                        <P>7.7 Standard Solutions—Purchased as solutions or mixtures with certification to their purity, concentration, and authenticity, or prepared from materials of known purity and composition. If the chemical purity is 98% or greater, the weight may be used without correction to compute the concentration of the standard. When not being used, standards are stored in the dark at room temperature in screw-capped vials with fluoropolymer-lined caps. A mark is placed on the vial at the level of the solution so that solvent loss by evaporation can be detected. If solvent loss has occurred, the solution should be replaced.</P>
                        <P>7.8 Stock Solutions.</P>
                        <P>7.8.1 Preparation—Prepare in nonane per the steps below or purchase as dilute solutions (Cambridge Isotope Laboratories (CIL), Woburn, MA, or equivalent). Observe the safety precautions in Section 5, and the recommendation in Section 5.1.2.</P>
                        <P>7.8.2 Dissolve an appropriate amount of assayed reference material in solvent. For example, weigh 1-2 mg of 2,3,7,8-TCDD to three significant figures in a 10 mL ground-glass-stoppered volumetric flask and fill to the mark with nonane. After the TCDD is completely dissolved, transfer the solution to a clean 15 mL vial with fluoropolymer-lined cap.</P>
                        <P>
                            7.8.3 Stock standard solutions should be checked for signs of degradation prior to the 
                            <PRTPAGE P="313"/>
                            preparation of calibration or performance test standards. Reference standards that can be used to determine the accuracy of calibration standards are available from CIL and may be available from other vendors.
                        </P>
                        <P>7.9 PAR Stock Solution</P>
                        <P>7.9.1 All CDDs/CDFs—Using the solutions in Section 7.8, prepare the PAR stock solution to contain the CDDs/CDFs at the concentrations shown in Table 3. When diluted, the solution will become the PAR (Section 7.14).</P>
                        <P>7.9.2 If only 2,3,7,8-TCDD and 2,3,7,8-TCDF are to be determined, prepare the PAR stock solution to contain these compounds only.</P>
                        <P>7.10 Labeled-Compound Spiking Solution.</P>
                        <P>7.10.1 All CDDs/CDFs—From stock solutions, or from purchased mixtures, prepare this solution to contain the labeled compounds in nonane at the concentrations shown in Table 3. This solution is diluted with acetone prior to use (Section 7.10.3).</P>
                        <P>7.10.2 If only 2,3,7,8-TCDD and 2,3,7,8-TCDF are to be determined, prepare the labeled-compound solution to contain these compounds only. This solution is diluted with acetone prior to use (Section 7.10.3).</P>
                        <P>7.10.3 Dilute a sufficient volume of the labeled compound solution (Section 7.10.1 or 7.10.2) by a factor of 50 with acetone to prepare a diluted spiking solution. Each sample requires 1.0 mL of the diluted solution, but no more solution should be prepared than can be used in one day.</P>
                        <P>
                            7.11 Cleanup Standard—Prepare 
                            <SU>37</SU>
                            Cl
                            <SU>4</SU>
                            -2,3,7,8-TCDD in nonane at the concentration shown in Table 3. The cleanup standard is added to all extracts prior to cleanup to measure the efficiency of the cleanup process.
                        </P>
                        <P>7.12 Internal Standard(s).</P>
                        <P>
                            7.12.1 All CDDs/CDFs—Prepare the internal standard solution to contain 
                            <SU>13</SU>
                            C
                            <SU>12</SU>
                            -1,2,3,4-TCDD and 
                            <SU>13</SU>
                            C
                            <SU>2</SU>
                            -1,2,3,7,8,9-HxCDD in nonane at the concentration shown in Table 3.
                        </P>
                        <P>
                            7.12.2 If only 2,3,7,8-TCDD and 2,3,7,8-TCDF are to be determined, prepare the internal standard solution to contain 
                            <SU>13</SU>
                            C
                            <SU>12</SU>
                            -1,2,3,4-TCDD only.
                        </P>
                        <P>7.13 Calibration Standards (CS1 through CS5)—Combine the solutions in Sections 7.9 through 7.12 to produce the five calibration solutions shown in Table 4 in nonane. These solutions permit the relative response (labeled to native) and response factor to be measured as a function of concentration. The CS3 standard is used for calibration verification (VER). If only 2,3,7,8-TCDD and 2,3,7,8-TCDF are to be determined, combine the solutions appropriate to these compounds.</P>
                        <P>7.14 Precision and Recovery (PAR) Standard—Used for determination of initial (Section 9.2) and ongoing (Section 15.5) precision and recovery. Dilute 10 µL of the precision and recovery standard (Section 7.9.1 or 7.9.2) to 2.0 mL with acetone for each sample matrix for each sample batch. One mL each are required for the blank and OPR with each matrix in each batch.</P>
                        <P>7.15 GC Retention Time Window Defining Solution and Isomer Specificity Test Standard—Used to define the beginning and ending retention times for the dioxin and furan isomers and to demonstrate isomer specificity of the GC columns employed for determination of 2,3,7,8-TCDD and 2,3,7,8-TCDF. The standard must contain the compounds listed in Table 5 (CIL EDF—4006, or equivalent), at a minimum. It is not necessary to monitor the window-defining compounds if only 2,3,7,8-TCDD and 2,3,7,8-TCDF are to be determined. In this case, an isomer-specificity test standard containing the most closely eluted isomers listed in Table 5 (CIL EDF-4033, or equivalent) may be used.</P>
                        <P>7.16 QC Check Sample—A QC Check Sample should be obtained from a source independent of the calibration standards. Ideally, this check sample would be a certified reference material containing the CDDs/CDFs in known concentrations in a sample matrix similar to the matrix under test.</P>
                        <P>7.17 Stability of Solutions—Standard solutions used for quantitative purposes (Sections 7.9 through 7.15) should be analyzed periodically, and should be assayed against reference standards (Section 7.8.3) before further use.</P>
                        <HD SOURCE="HD2">8.0 Sample Collection, Preservation, Storage, and Holding Times</HD>
                        <P>8.1 Collect samples in amber glass containers following conventional sampling practices (Reference 16). Aqueous samples that flow freely are collected in refrigerated bottles using automatic sampling equipment. Solid samples are collected as grab samples using wide-mouth jars.</P>
                        <P>8.2 Maintain aqueous samples in the dark at 0-4 °C from the time of collection until receipt at the laboratory. If residual chlorine is present in aqueous samples, add 80 mg sodium thiosulfate per liter of water. EPA Methods 330.4 and 330.5 may be used to measure residual chlorine (Reference 17). If sample pH is greater than 9, adjust to pH 7-9 with sulfuric acid.</P>
                        <P>Maintain solid, semi-solid, oily, and mixed-phase samples in the dark at &lt;4 °C from the time of collection until receipt at the laboratory.</P>
                        <P>Store aqueous samples in the dark at 0-4 °C. Store solid, semi-solid, oily, mixed-phase, and tissue samples in the dark at &lt;−10 °C.</P>
                        <P>8.3 Fish and Tissue Samples.</P>
                        <P>8.3.1 Fish may be cleaned, filleted, or processed in other ways in the field, such that the laboratory may expect to receive whole fish, fish fillets, or other tissues for analysis.</P>
                        <P>
                            8.3.2 Fish collected in the field should be wrapped in aluminum foil, and must be maintained at a temperature less than 4 °C 
                            <PRTPAGE P="314"/>
                            from the time of collection until receipt at the laboratory.
                        </P>
                        <P>8.3.3 Samples must be frozen upon receipt at the laboratory and maintained in the dark at &lt;−10 °C until prepared. Maintain unused sample in the dark at &lt;−10 °C.</P>
                        <P>8.4 Holding Times.</P>
                        <P>8.4.1 There are no demonstrated maximum holding times associated with CDDs/CDFs in aqueous, solid, semi-solid, tissues, or other sample matrices. If stored in the dark at 0-4 °C and preserved as given above (if required), aqueous samples may be stored for up to one year. Similarly, if stored in the dark at &lt;−10 °C, solid, semi-solid, multi-phase, and tissue samples may be stored for up to one year.</P>
                        <P>8.4.2 Store sample extracts in the dark at &lt;−10 °C until analyzed. If stored in the dark at &lt;−10 °C, sample extracts may be stored for up to one year.</P>
                        <HD SOURCE="HD2">9.0 Quality Assurance/Quality Control</HD>
                        <P>9.1 Each laboratory that uses this method is required to operate a formal quality assurance program (Reference 18). The minimum requirements of this program consist of an initial demonstration of laboratory capability, analysis of samples spiked with labeled compounds to evaluate and document data quality, and analysis of standards and blanks as tests of continued performance. Laboratory performance is compared to established performance criteria to determine if the results of analyses meet the performance characteristics of the method.</P>
                        <P>If the method is to be applied to sample matrix other than water (e.g., soils, filter cake, compost, tissue) the most appropriate alternate matrix (Sections 7.6.2 through 7.6.5) is substituted for the reagent water matrix (Section 7.6.1) in all performance tests.</P>
                        <P>9.1.1 The analyst shall make an initial demonstration of the ability to generate acceptable accuracy and precision with this method. This ability is established as described in Section 9.2.</P>
                        <P>9.1.2 In recognition of advances that are occurring in analytical technology, and to allow the analyst to overcome sample matrix interferences, the analyst is permitted certain options to improve separations or lower the costs of measurements. These options include alternate extraction, concentration, cleanup procedures, and changes in columns and detectors. Alternate determinative techniques, such as the substitution of spectroscopic or immuno-assay techniques, and changes that degrade method performance, are not allowed. If an analytical technique other than the techniques specified in this method is used, that technique must have a specificity equal to or better than the specificity of the techniques in this method for the analytes of interest.</P>
                        <P>9.1.2.1 Each time a modification is made to this method, the analyst is required to repeat the procedure in Section 9.2. If the detection limit of the method will be affected by the change, the laboratory is required to demonstrate that the MDL (40 CFR part 136, appendix B) is lower than one-third the regulatory compliance level or one-third the ML in this method, whichever is higher. If calibration will be affected by the change, the analyst must recalibrate the instrument per Section 10.</P>
                        <P>9.1.2.2 The laboratory is required to maintain records of modifications made to this method. These records include the following, at a minimum:</P>
                        <P>9.1.2.2.1 The names, titles, addresses, and telephone numbers of the analyst(s) who performed the analyses and modification, and of the quality control officer who witnessed and will verify the analyses and modifications.</P>
                        <P>9.1.2.2.2 A listing of pollutant(s) measured, by name and CAS Registry number.</P>
                        <P>9.1.2.2.3 A narrative stating reason(s) for the modifications.</P>
                        <P>9.1.2.2.4 Results from all quality control (QC) tests comparing the modified method to this method, including:</P>
                        <P>(a) Calibration (Section 10.5 through 10.7).</P>
                        <P>(b) Calibration verification (Section 15.3).</P>
                        <P>(c) Initial precision and recovery (Section 9.2).</P>
                        <P>(d) Labeled compound recovery (Section 9.3).</P>
                        <P>(e) Analysis of blanks (Section 9.5).</P>
                        <P>(f) Accuracy assessment (Section 9.4).</P>
                        <P>9.1.2.2.5 Data that will allow an independent reviewer to validate each determination by tracing the instrument output (peak height, area, or other signal) to the final result. These data are to include:</P>
                        <P>(a) Sample numbers and other identifiers.</P>
                        <P>(b) Extraction dates.</P>
                        <P>(c) Analysis dates and times.</P>
                        <P>(d) Analysis sequence/run chronology.</P>
                        <P>(e) Sample weight or volume (Section 11).</P>
                        <P>(f) Extract volume prior to each cleanup step (Section 13).</P>
                        <P>(g) Extract volume after each cleanup step (Section 13).</P>
                        <P>(h) Final extract volume prior to injection (Section 14).</P>
                        <P>(i) Injection volume (Section 14.3).</P>
                        <P>(j) Dilution data, differentiating between dilution of a sample or extract (Section 17.5).</P>
                        <P>(k) Instrument and operating conditions.</P>
                        <P>(l) Column (dimensions, liquid phase, solid support, film thickness, etc).</P>
                        <P>(m) Operating conditions (temperatures, temperature program, flow rates).</P>
                        <P>(n) Detector (type, operating conditions, etc).</P>
                        <P>(o) Chromatograms, printer tapes, and other recordings of raw data.</P>
                        <P>
                            (p) Quantitation reports, data system outputs, and other data to link the raw data to the results reported.
                            <PRTPAGE P="315"/>
                        </P>
                        <P>9.1.3 Analyses of method blanks are required to demonstrate freedom from contamination (Section 4.3). The procedures and criteria for analysis of a method blank are described in Sections 9.5 and 15.6.</P>
                        <P>9.1.4 The laboratory shall spike all samples with labeled compounds to monitor method performance. This test is described in Section 9.3. When results of these spikes indicate atypical method performance for samples, the samples are diluted to bring method performance within acceptable limits. Procedures for dilution are given in Section 17.5.</P>
                        <P>9.1.5 The laboratory shall, on an ongoing basis, demonstrate through calibration verification and the analysis of the ongoing precision and recovery aliquot that the analytical system is in control. These procedures are described in Sections 15.1 through 15.5.</P>
                        <P>9.1.6 The laboratory shall maintain records to define the quality of data that is generated. Development of accuracy statements is described in Section 9.4.</P>
                        <P>9.2 Initial Precision and Recovery (IPR)—To establish the ability to generate acceptable precision and recovery, the analyst shall perform the following operations.</P>
                        <P>9.2.1 For low solids (aqueous) samples, extract, concentrate, and analyze four 1 L aliquots of reagent water spiked with the diluted labeled compound spiking solution (Section 7.10.3) and the precision and recovery standard (Section 7.14) according to the procedures in Sections 11 through 18. For an alternative sample matrix, four aliquots of the alternative reference matrix (Section 7.6) are used. All sample processing steps that are to be used for processing samples, including preparation (Section 11), extraction (Section 12), and cleanup (Section 13), shall be included in this test.</P>
                        <P>9.2.2 Using results of the set of four analyses, compute the average concentration (X) of the extracts in ng/mL and the standard deviation of the concentration (s) in ng/mL for each compound, by isotope dilution for CDDs/CDFs with a labeled analog, and by internal standard for 1,2,3,7,8,9-HxCDD, OCDF, and the labeled compounds.</P>
                        <P>9.2.3 For each CDD/CDF and labeled compound, compare s and X with the corresponding limits for initial precision and recovery in Table 6. If only 2,3,7,8-TCDD and 2,3,7,8-TCDF are to be determined, compare s and X with the corresponding limits for initial precision and recovery in Table 6a. If s and X for all compounds meet the acceptance criteria, system performance is acceptable and analysis of blanks and samples may begin. If, however, any individual s exceeds the precision limit or any individual X falls outside the range for accuracy, system performance is unacceptable for that compound. Correct the problem and repeat the test (Section 9.2).</P>
                        <P>9.3 The laboratory shall spike all samples with the diluted labeled compound spiking solution (Section 7.10.3) to assess method performance on the sample matrix.</P>
                        <P>9.3.1 Analyze each sample according to the procedures in Sections 11 through 18.</P>
                        <P>9.3.2 Compute the percent recovery of the labeled compounds and the cleanup standard using the internal standard method (Section 17.2).</P>
                        <P>9.3.3 The recovery of each labeled compound must be within the limits in Table 7 when all 2,3,7,8-substituted CDDs/CDFs are determined, and within the limits in Table 7a when only 2,3,7,8-TCDD and 2,3,7,8-TCDF are determined. If the recovery of any compound falls outside of these limits, method performance is unacceptable for that compound in that sample. To overcome such difficulties, water samples are diluted and smaller amounts of soils, sludges, sediments, and other matrices are reanalyzed per Section 18.4.</P>
                        <P>9.4 Recovery of labeled compounds from samples should be assessed and records should be maintained.</P>
                        <P>
                            9.4.1 After the analysis of five samples of a given matrix type (water, soil, sludge, pulp, etc.) for which the labeled compounds pass the tests in Section 9.3, compute the average percent recovery (R) and the standard deviation of the percent recovery (SR) for the labeled compounds only. Express the assessment as a percent recovery interval from R−2S
                            <E T="52">R</E>
                             to R = 2S
                            <E T="52">R</E>
                             for each matrix. For example, if R = 90% and S
                            <E T="52">R</E>
                             = 10% for five analyses of pulp, the recovery interval is expressed as 70-110%.
                        </P>
                        <P>9.4.2 Update the accuracy assessment for each labeled compound in each matrix on a regular basis (e.g., after each 5-10 new measurements).</P>
                        <P>9.5 Method Blanks—Reference matrix method blanks are analyzed to demonstrate freedom from contamination (Section 4.3).</P>
                        <P>9.5.1 Prepare, extract, clean up, and concentrate a method blank with each sample batch (samples of the same matrix started through the extraction process on the same 12-hour shift, to a maximum of 20 samples). The matrix for the method blank shall be similar to sample matrix for the batch, e.g., a 1 L reagent water blank (Section 7.6.1), high-solids reference matrix blank (Section 7.6.2), paper matrix blank (Section 7.6.3); tissue blank (Section 7.6.4) or alternative reference matrix blank (Section 7.6.5). Analyze the blank immediately after analysis of the OPR (Section 15.5) to demonstrate freedom from contamination.</P>
                        <P>
                            9.5.2 If any 2,3,7,8-substituted CDD/CDF (Table 1) is found in the blank at greater than the minimum level (Table 2) or one-third the regulatory compliance level, whichever is greater; or if any potentially interfering compound is found in the blank at the minimum level for each level of 
                            <PRTPAGE P="316"/>
                            chlorination given in Table 2 (assuming a response factor of 1 relative to the 
                            <SU>13</SU>
                            C
                            <E T="52">12</E>
                            -1,2,3,4-TCDD internal standard for compounds not listed in Table 1), analysis of samples is halted until the blank associated with the sample batch shows no evidence of contamination at this level. All samples must be associated with an uncontaminated method blank before the results for those samples may be reported for regulatory compliance purposes.
                        </P>
                        <P>9.6 QC Check Sample—Analyze the QC Check Sample (Section 7.16) periodically to assure the accuracy of calibration standards and the overall reliability of the analytical process. It is suggested that the QC Check Sample be analyzed at least quarterly.</P>
                        <P>9.7 The specifications contained in this method can be met if the apparatus used is calibrated properly and then maintained in a calibrated state. The standards used for calibration (Section 10), calibration verification (Section 15.3), and for initial (Section 9.2) and ongoing (Section 15.5) precision and recovery should be identical, so that the most precise results will be obtained. A GC/MS instrument will provide the most reproducible results if dedicated to the settings and conditions required for the analyses of CDDs/CDFs by this method.</P>
                        <P>9.8 Depending on specific program requirements, field replicates may be collected to determine the precision of the sampling technique, and spiked samples may be required to determine the accuracy of the analysis when the internal standard method is used.</P>
                        <HD SOURCE="HD2">10.0 Calibration</HD>
                        <P>10.1 Establish the operating conditions necessary to meet the minimum retention times for the internal standards in Section 10.2.4 and the relative retention times for the CDDs/CDFs in Table 2.</P>
                        <P>10.1.1 Suggested GC operating conditions:</P>
                        <FP>Injector temperature: 270 °C</FP>
                        <FP>Interface temperature: 290 °C</FP>
                        <FP>Initial temperature: 200 °C</FP>
                        <FP>Initial time: Two minutes</FP>
                        <FP>Temperature program:</FP>
                        <FP>200-220 °C, at 5 °C/minute</FP>
                        <FP>220 °C for 16 minutes</FP>
                        <FP>220-235 °C, at 5 °C/minute</FP>
                        <FP>235 °C for seven minutes</FP>
                        <FP>235-330 °C, at 5 °C/minute</FP>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>All portions of the column that connect the GC to the ion source shall remain at or above the interface temperature specified above during analysis to preclude condensation of less volatile compounds.</P>
                        </NOTE>
                        <P>Optimize GC conditions for compound separation and sensitivity. Once optimized, the same GC conditions must be used for the analysis of all standards, blanks, IPR and OPR aliquots, and samples.</P>
                        <P>10.1.2 Mass spectrometer (MS) resolution—Obtain a selected ion current profile (SICP) of each analyte in Table 3 at the two exact m/z's specified in Table 8 and at ≥10,000 resolving power by injecting an authentic standard of the CDDs/CDFs either singly or as part of a mixture in which there is no interference between closely eluted components.</P>
                        <P>10.1.2.1 The analysis time for CDDs/CDFs may exceed the long-term mass stability of the mass spectrometer. Because the instrument is operated in the high-resolution mode, mass drifts of a few ppm (e.g., 5 ppm in mass) can have serious adverse effects on instrument performance. Therefore, a mass-drift correction is mandatory and a lock-mass m/z from PFK is used for drift correction. The lock-mass m/z is dependent on the exact m/z's monitored within each descriptor, as shown in Table 8. The level of PFK metered into the HRMS during analyses should be adjusted so that the amplitude of the most intense selected lock-mass m/z signal (regardless of the descriptor number) does not exceed 10% of the full-scale deflection for a given set of detector parameters. Under those conditions, sensitivity changes that might occur during the analysis can be more effectively monitored.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>Excessive PFK (or any other reference substance) may cause noise problems and contamination of the ion source necessitating increased frequency of source cleaning.</P>
                        </NOTE>
                        <P>10.1.2.2 If the HRMS has the capability to monitor resolution during the analysis, it is acceptable to terminate the analysis when the resolution falls below 10,000 to save reanalysis time.</P>
                        <P>10.1.2.3 Using a PFK molecular leak, tune the instrument to meet the minimum required resolving power of 10,000 (10% valley) at m/z 304.9824 (PFK) or any other reference signal close to m/z 304 (from TCDF). For each descriptor (Table 8), monitor and record the resolution and exact m/z's of three to five reference peaks covering the mass range of the descriptor. The resolution must be greater than or equal to 10,000, and the deviation between the exact m/z and the theoretical m/z (Table 8) for each exact m/z monitored must be less than 5 ppm.</P>
                        <P>
                            10.2 Ion Abundance Ratios, Minimum Levels, Signal-to-Noise Ratios, and Absolute Retention Times—Choose an injection volume of either 1 µL or 2 µL, consistent with the capability of the HRGC/HRMS instrument. Inject a 1 µL or 2 µL aliquot of the CS1 calibration solution (Table 4) using the GC conditions from Section 10.1.1. If only 2,3,7,8-TCDD and 2,3,7,8-TCDF are to be determined, the operating conditions and specifications below apply to analysis of those compounds only.
                            <PRTPAGE P="317"/>
                        </P>
                        <P>10.2.1 Measure the SICP areas for each analyte, and compute the ion abundance ratios at the exact m/z's specified in Table 8. Compare the computed ratio to the theoretical ratio given in Table 9.</P>
                        <P>10.2.1.1 The exact m/z's to be monitored in each descriptor are shown in Table 8. Each group or descriptor shall be monitored in succession as a function of GC retention time to ensure that all CDDs/CDFs are detected. Additional m/z's may be monitored in each descriptor, and the m/z's may be divided among more than the five descriptors listed in Table 8, provided that the laboratory is able to monitor the m/z's of all the CDDs/CDFs that may elute from the GC in a given retention-time window. If only 2,3,7,8-TCDD and 2,3,7,8-TCDF are to be determined, the descriptors may be modified to include only the exact m/z's for the tetra-and penta-isomers, the diphenyl ethers, and the lock m/z's.</P>
                        <P>10.2.1.2 The mass spectrometer shall be operated in a mass-drift correction mode, using perfluorokerosene (PFK) to provide lock m/z's. The lock-mass for each group of m/z's is shown in Table 8. Each lock mass shall be monitored and shall not vary by more than ±20% throughout its respective retention time window. Variations of the lock mass by more than 20% indicate the presence of coeluting interferences that may significantly reduce the sensitivity of the mass spectrometer. Reinjection of another aliquot of the sample extract will not resolve the problem. Additional cleanup of the extract may be required to remove the interferences.</P>
                        <P>10.2.2 All CDDs/CDFs and labeled compounds in the CS1 standard shall be within the QC limits in Table 9 for their respective ion abundance ratios; otherwise, the mass spectrometer shall be adjusted and this test repeated until the m/z ratios fall within the limits specified. If the adjustment alters the resolution of the mass spectrometer, resolution shall be verified (Section 10.1.2) prior to repeat of the test.</P>
                        <P>10.2.3 Verify that the HRGC/HRMS instrument meets the minimum levels in Table 2. The peaks representing the CDDs/CDFs and labeled compounds in the CS1 calibration standard must have signal-to-noise ratios (S/N) greater than or equal to 10.0. Otherwise, the mass spectrometer shall be adjusted and this test repeated until the minimum levels in Table 2 are met.</P>
                        <P>
                            10.2.4 The absolute retention time of 
                            <SU>13</SU>
                            C
                            <E T="52">12</E>
                            -1,2,3,4-TCDD (Section 7.12) shall exceed 25.0 minutes on the DB-5 column, and the retention time of 
                            <SU>13</SU>
                            C
                            <E T="52">12</E>
                            -1,2,3,4-TCDD shall exceed 15.0 minutes on the DB-225 column; otherwise, the GC temperature program shall be adjusted and this test repeated until the above-stated minimum retention time criteria are met.
                        </P>
                        <FP>2010.3 Retention-Time Windows—Analyze the window defining mixtures (Section 7.15) using the optimized temperature program in Section 10.1. Table 5 gives the elution order (first/last) of the window-defining compounds. If 2,3,7,8-TCDD and 2,3,7,8-TCDF only are to be analyzed, this test is not required.</FP>
                        <P>10.4 Isomer Specificity.</P>
                        <P>10.4.1 Analyze the isomer specificity test standards (Section 7.15) using the procedure in Section 14 and the optimized conditions for sample analysis (Section 10.1.1).</P>
                        <P>10.4.2 Compute the percent valley between the GC peaks that elute most closely to the 2,3,7,8-TCDD and TCDF isomers, on their respective columns, per Figures 6 and 7.</P>
                        <P>10.4.3 Verify that the height of the valley between the most closely eluted isomers and the 2,3,7,8-substituted isomers is less than 25% (computed as 100 x/y in Figures 6 and 7). If the valley exceeds 25%, adjust the analytical conditions and repeat the test or replace the GC column and recalibrate (Sections 10.1.2 through 10.7).</P>
                        <P>10.5 Calibration by Isotope Dilution—Isotope dilution calibration is used for the 15 2,3,7,8-substituted CDDs/CDFs for which labeled compounds are added to samples prior to extraction. The reference compound for each CDD/CDF compound is shown in Table 2.</P>
                        <P>10.5.1 A calibration curve encompassing the concentration range is prepared for each compound to be determined. The relative response (RR) (labeled to native) vs. concentration in standard solutions is plotted or computed using a linear regression. Relative response is determined according to the procedures described below. Five calibration points are employed.</P>
                        <P>10.5.2 The response of each CDD/CDF relative to its labeled analog is determined using the area responses of both the primary and secondary exact m/z's specified in Table 8, for each calibration standard, as follows:</P>
                        <GPH SPAN="1" DEEP="31">
                            <GID>ER15SE97.002</GID>
                        </GPH>
                        <FP>where:</FP>
                        <FP SOURCE="FP-2">
                            A1
                            <E T="52">n</E>
                             and A2
                            <E T="52">n</E>
                             = The areas of the primary and secondary m/z's for the CDD/CDF.
                        </FP>
                        <FP SOURCE="FP-2">
                            A1
                            <E T="52">l</E>
                             and A2
                            <E T="52">l</E>
                             = The areas of the primary and secondary m/z's for the labeled compound.
                        </FP>
                        <FP SOURCE="FP-2">
                            C
                            <E T="52">l</E>
                             = The concentration of the labeled compound in the calibration standard (Table 4).
                        </FP>
                        <FP SOURCE="FP-2">
                            C
                            <E T="52">n</E>
                             = The concentration of the native compound in the calibration standard (Table 4).
                        </FP>
                        <P>
                            10.5.3 To calibrate the analytical system by isotope dilution, inject a volume of calibration standards CS1 through CS5 (Section 7.13 and Table 4) identical to the volume chosen in Section 10.2, using the procedure in Section 14 and the conditions in Section 
                            <PRTPAGE P="318"/>
                            10.1.1 and Table 2. Compute the relative response (RR) at each concentration.
                        </P>
                        <P>10.5.4 Linearity—If the relative response for any compound is constant (less than 20% coefficient of variation) over the five-point calibration range, an averaged relative response may be used for that compound; otherwise, the complete calibration curve for that compound shall be used over the five-point calibration range.</P>
                        <P>10.6 Calibration by Internal Standard—The internal standard method is applied to determination of 1,2,3,7,8,9-HxCDD (Section 17.1.2), OCDF (Section 17.1.1), the non 2,3,7,8-substituted compounds, and to the determination of labeled compounds for intralaboratory statistics (Sections 9.4 and 15.5.4).</P>
                        <P>10.6.1 Response factors—Calibration requires the determination of response factors (RF) defined by the following equation:</P>
                        <GPH SPAN="1" DEEP="31">
                            <GID>ER15SE97.003</GID>
                        </GPH>
                        <FP>where:</FP>
                        <FP SOURCE="FP-2">
                            A1
                            <E T="52">s</E>
                             and A2
                            <E T="52">s</E>
                             = The areas of the primary and secondary m/z's for the CDD/CDF.
                        </FP>
                        <FP SOURCE="FP-2">
                            A1
                            <E T="52">is</E>
                             and A2
                            <E T="52">is</E>
                             = The areas of the primary and secondary m/z's for the internal standard.
                        </FP>
                        <FP SOURCE="FP-2">
                            C
                            <E T="52">is</E>
                             = The concentration of the internal standard (Table 4).
                        </FP>
                        <FP SOURCE="FP-2">
                            C
                            <E T="52">s</E>
                             = The concentration of the compound in the calibration standard (Table 4).
                        </FP>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>
                                There is only one m/z for 
                                <SU>37</SU>
                                Cl
                                <E T="52">4</E>
                                -2,3,7,8-TCDD. See Table 8.
                            </P>
                        </NOTE>
                        <P>10.6.2 To calibrate the analytical system by internal standard, inject 1.0 µL or 2.0 µL of calibration standards CS1 through CS5 (Section 7.13 and Table 4) using the procedure in Section 14 and the conditions in Section 10.1.1 and Table 2. Compute the response factor (RF) at each concentration.</P>
                        <P>10.6.3 Linearity—If the response factor (RF) for any compound is constant (less than 35% coefficient of variation) over the five-point calibration range, an averaged response factor may be used for that compound; otherwise, the complete calibration curve for that compound shall be used over the five-point range.</P>
                        <P>10.7 Combined Calibration—By using calibration solutions (Section 7.13 and Table 4) containing the CDDs/CDFs and labeled compounds and the internal standards, a single set of analyses can be used to produce calibration curves for the isotope dilution and internal standard methods. These curves are verified each shift (Section 15.3) by analyzing the calibration verification standard (VER, Table 4). Recalibration is required if any of the calibration verification criteria (Section 15.3) cannot be met.</P>
                        <P>10.8 Data Storage—MS data shall be collected, recorded, and stored.</P>
                        <P>10.8.1 Data acquisition—The signal at each exact m/z shall be collected repetitively throughout the monitoring period and stored on a mass storage device.</P>
                        <P>10.8.2 Response factors and multipoint calibrations—The data system shall be used to record and maintain lists of response factors (response ratios for isotope dilution) and multipoint calibration curves. Computations of relative standard deviation (coefficient of variation) shall be used to test calibration linearity. Statistics on initial performance (Section 9.2) and ongoing performance (Section 15.5) should be computed and maintained, either on the instrument data system, or on a separate computer system.</P>
                        <HD SOURCE="HD2">11.0 Sample Preparation</HD>
                        <P>11.1 Sample preparation involves modifying the physical form of the sample so that the CDDs/CDFs can be extracted efficiently. In general, the samples must be in a liquid form or in the form of finely divided solids in order for efficient extraction to take place. Table 10 lists the phases and suggested quantities for extraction of various sample matrices.</P>
                        <P>For samples known or expected to contain high levels of the CDDs/CDFs, the smallest sample size representative of the entire sample should be used (see Section 17.5).</P>
                        <P>For all samples, the blank and IPR/OPR aliquots must be processed through the same steps as the sample to check for contamination and losses in the preparation processes.</P>
                        <P>11.1.1 For samples that contain particles, percent solids and particle size are determined using the procedures in Sections 11.2 and 11.3, respectively.</P>
                        <P>11.1.2 Aqueous samples—Because CDDs/CDFs may be bound to suspended particles, the preparation of aqueous samples is dependent on the solids content of the sample.</P>
                        <P>11.1.2.1 Aqueous samples visibly absent particles are prepared per Section 11.4 and extracted directly using the separatory funnel or SPE techniques in Sections 12.1 or 12.2, respectively.</P>
                        <P>11.1.2.2 Aqueous samples containing visible particles and containing one percent suspended solids or less are prepared using the procedure in Section 11.4. After preparation, the sample is extracted directly using the SPE technique in 12.2 or filtered per Section 11.4.3. After filtration, the particles and filter are extracted using the SDS procedure in Section 12.3 and the filtrate is extracted using the separatory funnel procedure in Section 12.1.</P>
                        <P>
                            11.1.2.3 For aqueous samples containing greater than one percent solids, a sample aliquot sufficient to provide 10 g of dry solids is used, as described in Section 11.5.
                            <PRTPAGE P="319"/>
                        </P>
                        <P>11.1.3 Solid samples are prepared using the procedure described in Section 11.5 followed by extraction via the SDS procedure in Section 12.3.</P>
                        <P>11.1.4 Multiphase samples—The phase(s) containing the CDDs/CDFs is separated from the non-CDD/CDF phase using pressure filtration and centrifugation, as described in Section 11.6. The CDDs/CDFs will be in the organic phase in a multiphase sample in which an organic phase exists.</P>
                        <P>11.1.5 Procedures for grinding, homogenization, and blending of various sample phases are given in Section 11.7.</P>
                        <P>11.1.6 Tissue samples—Preparation procedures for fish and other tissues are given in Section 11.8.</P>
                        <P>11.2 Determination of Percent Suspended Solids.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>This aliquot is used for determining the solids content of the sample, not for determination of CDDs/CDFs.</P>
                        </NOTE>
                        <P>11.2.1 Aqueous liquids and multi-phase samples consisting of mainly an aqueous phase.</P>
                        <P>11.2.1.1 Dessicate and weigh a GF/D filter (Section 6.5.3) to three significant figures.</P>
                        <P>11.2.1.2 Filter 10.0 ±0.02 mL of well-mixed sample through the filter.</P>
                        <P>11.2.1.3 Dry the filter a minimum of 12 hours at 110 ±5 °C and cool in a dessicator.</P>
                        <P>11.2.1.4 Calculate percent solids as follows:</P>
                        <GPH SPAN="2" DEEP="26">
                            <GID>ER15SE97.004</GID>
                        </GPH>
                        <P>11.2.2 Non-aqueous liquids, solids, semi-solid samples, and multi-phase samples in which the main phase is not aqueous; but not tissues.</P>
                        <P>11.2.2.1 Weigh 5-10 g of sample to three significant figures in a tared beaker.</P>
                        <P>11.2.2.2 Dry a minimum of 12 hours at 110 ±5 °C, and cool in a dessicator.</P>
                        <P>11.2.2.3 Calculate percent solids as follows:</P>
                        <GPH SPAN="2" DEEP="26">
                            <GID>ER15SE97.005</GID>
                        </GPH>
                        <P>11.3 Determination of Particle Size.</P>
                        <P>11.3.1 Spread the dried sample from Section 11.2.2.2 on a piece of filter paper or aluminum foil in a fume hood or glove box.</P>
                        <P>11.3.2 Estimate the size of the particles in the sample. If the size of the largest particles is greater than 1 mm, the particle size must be reduced to 1 mm or less prior to extraction using the procedures in Section 11.7.</P>
                        <P>11.4 Preparation of Aqueous Samples Containing 1% Suspended Solids or Less.</P>
                        <P>11.4.1 Aqueous samples visibly absent particles are prepared per the procedure below and extracted directly using the separatory funnel or SPE techniques in Sections 12.1 or 12.2, respectively. Aqueous samples containing visible particles and one percent suspended solids or less are prepared using the procedure below and extracted using either the SPE technique in Section 12.2 or further prepared using the filtration procedure in Section 11.4.3. The filtration procedure is followed by SDS extraction of the filter and particles (Section 12.3) and separatory funnel extraction of the filtrate (Section 12.1). The SPE procedure is followed by SDS extraction of the filter and disk.</P>
                        <P>11.4.2 Preparation of sample and QC aliquots.</P>
                        <P>11.4.2.1 Mark the original level of the sample on the sample bottle for reference. Weigh the sample plus bottle to ±1.</P>
                        <P>11.4.2.2 Spike 1.0 mL of the diluted labeled-compound spiking solution (Section 7.10.3) into the sample bottle. Cap the bottle and mix the sample by careful shaking. Allow the sample to equilibrate for one to two hours, with occasional shaking.</P>
                        <P>11.4.2.3 For each sample or sample batch (to a maximum of 20 samples) to be extracted during the same 12-hour shift, place two 1.0 L aliquots of reagent water in clean sample bottles or flasks.</P>
                        <P>11.4.2.4 Spike 1.0 mL of the diluted labeled-compound spiking solution (Section 7.10.3) into both reagent water aliquots. One of these aliquots will serve as the method blank.</P>
                        <P>11.4.2.5 Spike 1.0 mL of the PAR standard (Section 7.14) into the remaining reagent water aliquot. This aliquot will serve as the OPR (Section 15.5).</P>
                        <P>
                            11.4.2.6 If SPE is to be used, add 5 mL of methanol to the sample, cap and shake the 
                            <PRTPAGE P="320"/>
                            sample to mix thoroughly, and proceed to Section 12.2 for extraction. If SPE is not to be used, and the sample is visibly absent particles, proceed to Section 12.1 for extraction. If SPE is not to be used and the sample contains visible particles, proceed to the following section for filtration of particles.
                        </P>
                        <P>11.4.3 Filtration of particles.</P>
                        <P>11.4.3.1 Assemble a Buchner funnel (Section 6.5.5) on top of a clean filtration flask. Apply vacuum to the flask, and pour the entire contents of the sample bottle through a glass-fiber filter (Section 6.5.6) in the Buchner funnel, swirling the sample remaining in the bottle to suspend any particles.</P>
                        <P>11.4.3.2 Rinse the sample bottle twice with approximately 5 mL portions of reagent water to transfer any remaining particles onto the filter.</P>
                        <P>11.4.3.3 Rinse any particles off the sides of the Buchner funnel with small quantities of reagent water.</P>
                        <P>11.4.3.4 Weigh the empty sample bottle to ±1 g. Determine the weight of the sample by difference. Save the bottle for further use.</P>
                        <P>11.4.3.5 Extract the filtrate using the separatory funnel procedure in Section 12.1.</P>
                        <P>11.4.3.6 Extract the filter containing the particles using the SDS procedure in Section 12.3.</P>
                        <P>11.5 Preparation of Samples Containing Greater Than 1% Solids.</P>
                        <P>11.5.1 Weigh a well-mixed aliquot of each sample (of the same matrix type) sufficient to provide 10 g of dry solids (based on the solids determination in Section 11.2) into a clean beaker or glass jar.</P>
                        <P>11.5.2 Spike 1.0 mL of the diluted labeled compound spiking solution (Section 7.10.3) into the sample.</P>
                        <P>11.5.3 For each sample or sample batch (to a maximum of 20 samples) to be extracted during the same 12-hour shift, weigh two 10 g aliquots of the appropriate reference matrix (Section 7.6) into clean beakers or glass jars.</P>
                        <P>11.5.4 Spike 1.0 mL of the diluted labeled compound spiking solution (Section 7.10.3) into each reference matrix aliquot. One aliquot will serve as the method blank. Spike 1.0 mL of the PAR standard (Section 7.14) into the other reference matrix aliquot. This aliquot will serve as the OPR (Section 15.5).</P>
                        <P>11.5.5 Stir or tumble and equilibrate the aliquots for one to two hours.</P>
                        <P>11.5.6 Decant excess water. If necessary to remove water, filter the sample through a glass-fiber filter and discard the aqueous liquid.</P>
                        <P>11.5.7 If particles &gt;1mm are present in the sample (as determined in Section 11.3.2), spread the sample on clean aluminum foil in a hood. After the sample is dry, grind to reduce the particle size (Section 11.7).</P>
                        <P>11.5.8 Extract the sample and QC aliquots using the SDS procedure in Section 12.3.</P>
                        <P>11.6 Multiphase Samples.</P>
                        <P>11.6.1 Using the percent solids determined in Section 11.2.1 or 11.2.2, determine the volume of sample that will provide 10 g of solids, up to 1 L of sample.</P>
                        <P>11.6.2 Pressure filter the amount of sample determined in Section 11.6.1 through Whatman GF/D glass-fiber filter paper (Section 6.5.3). Pressure filter the blank and OPR aliquots through GF/D papers also. If necessary to separate the phases and/or settle the solids, centrifuge these aliquots prior to filtration.</P>
                        <P>11.6.3 Discard any aqueous phase (if present). Remove any non-aqueous liquid present and reserve the maximum amount filtered from the sample (Section 11.6.1) or 10 g, whichever is less, for combination with the solid phase (Section 12.3.5).</P>
                        <P>11.6.4 If particles &gt;1mm are present in the sample (as determined in Section 11.3.2) and the sample is capable of being dried, spread the sample and QC aliquots on clean aluminum foil in a hood. After the aliquots are dry or if the sample cannot be dried, reduce the particle size using the procedures in Section 11.7 and extract the reduced particles using the SDS procedure in Section 12.3. If particles &gt;1mm are not present, extract the particles and filter in the sample and QC aliquots directly using the SDS procedure in Section 12.3.</P>
                        <P>11.7 Sample grinding, homogenization, or blending—Samples with particle sizes greater than 1 mm (as determined in Section 11.3.2) are subjected to grinding, homogenization, or blending. The method of reducing particle size to less than 1 mm is matrix-dependent. In general, hard particles can be reduced by grinding with a mortar and pestle. Softer particles can be reduced by grinding in a Wiley mill or meat grinder, by homogenization, or in a blender.</P>
                        <P>11.7.1 Each size-reducing preparation procedure on each matrix shall be verified by running the tests in Section 9.2 before the procedure is employed routinely.</P>
                        <P>11.7.2 The grinding, homogenization, or blending procedures shall be carried out in a glove box or fume hood to prevent particles from contaminating the work environment.</P>
                        <P>11.7.3 Grinding—Certain papers and pulps, slurries, and amorphous solids can be ground in a Wiley mill or heavy duty meat grinder. In some cases, reducing the temperature of the sample to freezing or to dry ice or liquid nitrogen temperatures can aid in the grinding process. Grind the sample aliquots from Section 11.5.7 or 11.6.4 in a clean grinder. Do not allow the sample temperature to exceed 50 °C. Grind the blank and reference matrix aliquots using a clean grinder.</P>
                        <P>
                            11.7.4 Homogenization or blending—Particles that are not ground effectively, or particles greater than 1 mm in size after grinding, can often be reduced in size by high speed homogenization or blending. Homogenize and/or blend the particles or filter from 
                            <PRTPAGE P="321"/>
                            Section 11.5.7 or 11.6.4 for the sample, blank, and OPR aliquots.
                        </P>
                        <P>11.7.5 Extract the aliquots using the SDS procedure in Section 12.3.</P>
                        <P>11.8 Fish and Other Tissues—Prior to processing tissue samples, the laboratory must determine the exact tissue to be analyzed. Common requests for analysis of fish tissue include whole fish—skin on, whole fish—skin removed, edible fish fillets (filleted in the field or by the laboratory), specific organs, and other portions. Once the appropriate tissue has been determined, the sample must be homogenized.</P>
                        <P>11.8.1 Homogenization.</P>
                        <P>11.8.1.1 Samples are homogenized while still frozen, where practical. If the laboratory must dissect the whole fish to obtain the appropriate tissue for analysis, the unused tissues may be rapidly refrozen and stored in a clean glass jar for subsequent use.</P>
                        <P>11.8.1.2 Each analysis requires 10 g of tissue (wet weight). Therefore, the laboratory should homogenize at least 20 g of tissue to allow for re-extraction of a second aliquot of the same homogenized sample, if re-analysis is required. When whole fish analysis is necessary, the entire fish is homogenized.</P>
                        <P>11.8.1.3 Homogenize the sample in a tissue homogenizer (Section 6.3.3) or grind in a meat grinder (Section 6.3.4). Cut tissue too large to feed into the grinder into smaller pieces. To assure homogeneity, grind three times.</P>
                        <P>11.8.1.4 Transfer approximately 10 g (wet weight) of homogenized tissue to a clean, tared, 400-500 mL beaker. For the alternate HCl digestion/extraction, transfer the tissue to a clean, tared 500-600 mL wide-mouth bottle. Record the weight to the nearest 10 mg.</P>
                        <P>11.8.1.5 Transfer the remaining homogenized tissue to a clean jar with a fluoropolymer-lined lid. Seal the jar and store the tissue at &lt;−10 °C. Return any tissue that was not homogenized to its original container and store at &lt;−10 °C.</P>
                        <P>11.8.2 QC aliquots.</P>
                        <P>11.8.2.1 Prepare a method blank by adding approximately 10 g of the oily liquid reference matrix (Section 7.6.4) to a 400-500 mL beaker. For the alternate HCl digestion/extraction, add the reference matrix to a 500-600 mL wide-mouth bottle. Record the weight to the nearest 10 mg.</P>
                        <P>11.8.2.2 Prepare a precision and recovery aliquot by adding approximately 10 g of the oily liquid reference matrix (Section 7.6.4) to a separate 400-500 mL beaker or wide-mouth bottle, depending on the extraction procedure to be used. Record the weight to the nearest 10 mg. If the initial precision and recovery test is to be performed, use four aliquots; if the ongoing precision and recovery test is to be performed, use a single aliquot.</P>
                        <P>11.8.3 Spiking</P>
                        <P>11.8.3.1 Spike 1.0 mL of the labeled compound spiking solution (Section 7.10.3) into the sample, blank, and OPR aliquot.</P>
                        <P>11.8.3.2 Spike 1.0 mL of the PAR standard (Section 7.14) into the OPR aliquot.</P>
                        <P>11.8.4 Extract the aliquots using the procedures in Section 12.4.</P>
                        <HD SOURCE="HD2">12.0 Extraction and Concentration</HD>
                        <P>Extraction procedures include separatory funnel (Section 12.1) and solid phase (Section 12.2) for aqueous liquids; Soxhlet/Dean-Stark (Section 12.3) for solids, filters, and SPE disks; and Soxhlet extraction (Section 12.4.1) and HCl digestion (Section 12.4.2) for tissues. Acid/base back-extraction (Section 12.5) is used for initial cleanup of extracts.</P>
                        <P>Macro-concentration procedures include rotary evaporation (Section 12.6.1), heating mantle (Section 12.6.2), and Kuderna-Danish (K-D) evaporation (Section 12.6.3). Micro-concentration uses nitrogen blowdown (Section 12.7).</P>
                        <P>12.1 Separatory funnel extraction of filtrates and of aqueous samples visibly absent particles.</P>
                        <P>12.1.1 Pour the spiked sample (Section 11.4.2.2) or filtrate (Section 11.4.3.5) into a 2 L separatory funnel. Rinse the bottle or flask twice with 5 mL of reagent water and add these rinses to the separatory funnel.</P>
                        <P>12.1.2 Add 60 mL methylene chloride to the empty sample bottle (Section 12.1.1), seal, and shake 60 seconds to rinse the inner surface. Transfer the solvent to the separatory funnel, and extract the sample by shaking the funnel for two minutes with periodic venting. Allow the organic layer to separate from the aqueous phase for a minimum of 10 minutes. If an emulsion forms and is more than one-third the volume of the solvent layer, employ mechanical techniques to complete the phase separation (see note below). Drain the methylene chloride extract through a solvent-rinsed glass funnel approximately one-half full of granular anhydrous sodium sulfate (Section 7.2.1) supported on clean glass-fiber paper into a solvent-rinsed concentration device (Section 12.6).</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>If an emulsion forms, the analyst must employ mechanical techniques to complete the phase separation. The optimum technique depends upon the sample, but may include stirring, filtration through glass wool, use of phase separation paper, centrifugation, use of an ultrasonic bath with ice, addition of NaCl, or other physical methods. Alternatively, solid-phase or other extraction techniques may be used to prevent emulsion formation. Any alternative technique is acceptable so long as the requirements in Section 9 are met.</P>
                        </NOTE>
                        <P>
                            Experience with aqueous samples high in dissolved organic materials (e.g., paper mill effluents) has shown that acidification of the 
                            <PRTPAGE P="322"/>
                            sample prior to extraction may reduce the formation of emulsions. Paper industry methods suggest that the addition of up to 400 mL of ethanol to a 1 L effluent sample may also reduce emulsion formation. However, studies by EPA suggest that the effect may be a result of sample dilution, and that the addition of reagent water may serve the same function. Mechanical techniques may still be necessary to complete the phase separation. If either acidification or addition of ethanol is utilized, the laboratory must perform the startup tests described in Section 9.2 using the same techniques.
                        </P>
                        <P>12.1.3 Extract the water sample two more times with 60 mL portions of methylene chloride. Drain each portion through the sodium sulfate into the concentrator. After the third extraction, rinse the separatory funnel with at least 20 mL of methylene chloride, and drain this rinse through the sodium sulfate into the concentrator. Repeat this rinse at least twice. Set aside the funnel with sodium sulfate if the extract is to be combined with the extract from the particles.</P>
                        <P>12.1.4 Concentrate the extract using one of the macro-concentration procedures in Section 12.6.</P>
                        <P>12.1.4.1 If the extract is from a sample visibly absent particles (Section 11.1.2.1), adjust the final volume of the concentrated extract to approximately 10 mL with hexane, transfer to a 250 mL separatory funnel, and back-extract using the procedure in Section 12.5.</P>
                        <P>12.1.4.2 If the extract is from the aqueous filtrate (Section 11.4.3.5), set aside the concentration apparatus for addition of the SDS extract from the particles (Section 12.3.9.1.2).</P>
                        <P>12.2 SPE of Samples Containing Less Than 1% Solids (References 19-20).</P>
                        <P>12.2.1 Disk preparation.</P>
                        <P>12.2.1.1 Place an SPE disk on the base of the filter holder (Figure 4) and wet with toluene. While holding a GMF 150 filter above the SPE disk with tweezers, wet the filter with toluene and lay the filter on the SPE disk, making sure that air is not trapped between the filter and disk. Clamp the filter and SPE disk between the 1 L glass reservoir and the vacuum filtration flask.</P>
                        <P>12.2.1.2 Rinse the sides of the filtration flask with approx 15 mL of toluene using a squeeze bottle or syringe. Apply vacuum momentarily until a few drops appear at the drip tip. Release the vacuum and allow the filter/disk to soak for approx one minute. Apply vacuum and draw all of the toluene through the filter/disk. Repeat the wash step with approx 15 mL of acetone and allow the filter/disk to air dry.</P>
                        <P>12.2.1.3 Re-wet the filter/disk with approximately 15 mL of methanol, allowing the filter/disk to soak for approximately one minute. Pull the methanol through the filter/disk using the vacuum, but retain a layer of methanol approximately 1 mm thick on the filter. Do not allow the disk to go dry from this point until the end of the extraction.</P>
                        <P>12.2.1.4 Rinse the filter/disk with two 50-mL portions of reagent water by adding the water to the reservoir and pulling most through, leaving a layer of water on the surface of the filter.</P>
                        <P>12.2.2 Extraction.</P>
                        <P>12.2.2.1 Pour the spiked sample (Section 11.4.2.2), blank (Section 11.4.2.4), or IPR/OPR aliquot (Section 11.4.2.5) into the reservoir and turn on the vacuum to begin the extraction. Adjust the vacuum to complete the extraction in no less than 10 minutes. For samples containing a high concentration of particles (suspended solids), filtration times may be eight hours or longer.</P>
                        <P>12.2.2.2 Before all of the sample has been pulled through the filter/disk, rinse the sample bottle with approximately 50 mL of reagent water to remove any solids, and pour into the reservoir. Pull through the filter/disk. Use additional reagent water rinses until all visible solids are removed.</P>
                        <P>12.2.2.3 Before all of the sample and rinses have been pulled through the filter/disk, rinse the sides of the reservoir with small portions of reagent water.</P>
                        <P>12.2.2.4 Allow the filter/disk to dry, then remove the filter and disk and place in a glass Petri dish. Extract the filter and disk per Section 12.3.</P>
                        <P>12.3 SDS Extraction of Samples Containing Particles, and of Filters and/or Disks.</P>
                        <P>12.3.1 Charge a clean extraction thimble (Section 6.4.2.2) with 5.0 g of 100/200 mesh silica (Section 7.5.1.1) topped with 100 g of quartz sand (Section 7.3.2).</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>Do not disturb the silica layer throughout the extraction process.</P>
                        </NOTE>
                        <P>12.3.2 Place the thimble in a clean extractor. Place 30-40 mL of toluene in the receiver and 200-250 mL of toluene in the flask.</P>
                        <P>12.3.3 Pre-extract the glassware by heating the flask until the toluene is boiling. When properly adjusted, one to two drops of toluene will fall per second from the condenser tip into the receiver. Extract the apparatus for a minimum of three hours.</P>
                        <P>12.3.4 After pre-extraction, cool and disassemble the apparatus. Rinse the thimble with toluene and allow to air dry.</P>
                        <P>12.3.5 Load the wet sample, filter, and/or disk from Section 11.4.3.6, 11.5.8, 11.6.4, 11.7.3, 11.7.4, or 12.2.2.4 and any nonaqueous liquid from Section 11.6.3 into the thimble and manually mix into the sand layer with a clean metal spatula, carefully breaking up any large lumps of sample.</P>
                        <P>
                            12.3.6 Reassemble the pre-extracted SDS apparatus, and add a fresh charge of toluene to the receiver and reflux flask. Apply power 
                            <PRTPAGE P="323"/>
                            to the heating mantle to begin refluxing. Adjust the reflux rate to match the rate of percolation through the sand and silica beds until water removal lessens the restriction to toluene flow. Frequently check the apparatus for foaming during the first two hours of extraction. If foaming occurs, reduce the reflux rate until foaming subsides.
                        </P>
                        <P>12.3.7 Drain the water from the receiver at one to two hours and eight to nine hours, or sooner if the receiver fills with water. Reflux the sample for a total of 16-24 hours. Cool and disassemble the apparatus. Record the total volume of water collected.</P>
                        <P>12.3.8 Remove the distilling flask. Drain the water from the Dean-Stark receiver and add any toluene in the receiver to the extract in the flask.</P>
                        <P>12.3.9 Concentrate the extract using one of the macro-concentration procedures in Section 12.6 per the following:</P>
                        <P>12.3.9.1 Extracts from the particles in an aqueous sample containing less than 1% solids (Section 11.4.3.6).</P>
                        <P>12.3.9.1.1 Concentrate the extract to approximately 5 mL using the rotary evaporator or heating mantle procedures in Section 12.6.1 or 12.6.2.</P>
                        <P>12.3.9.1.2 Quantitatively transfer the extract through the sodium sulfate (Section 12.1.3) into the apparatus that was set aside (Section 12.1.4.2) and reconcentrate to the level of the toluene.</P>
                        <P>12.3.9.1.3 Adjust to approximately 10 mL with hexane, transfer to a 250 mL separatory funnel, and proceed with back-extraction (Section 12.5).</P>
                        <P>12.3.9.2 Extracts from particles (Sections 11.5 through 11.6) or from the SPE filter and disk (Section 12.2.2.4)—Concentrate to approximately 10 mL using the rotary evaporator or heating mantle (Section 12.6.1 or 12.6.2), transfer to a 250 mL separatory funnel, and proceed with back-extraction (Section 12.5).</P>
                        <P>12.4 Extraction of Tissue—Two procedures are provided for tissue extraction.</P>
                        <P>12.4.1 Soxhlet extraction (Reference 21).</P>
                        <P>12.4.1.1 Add 30-40 g of powdered anhydrous sodium sulfate to each of the beakers (Section 11.8.4) and mix thoroughly. Cover the beakers with aluminum foil and allow to equilibrate for 12-24 hours. Remix prior to extraction to prevent clumping.</P>
                        <P>12.4.1.2 Assemble and pre-extract the Soxhlet apparatus per Sections 12.3.1 through 12.3.4, except use the methylene chloride:hexane (1:1) mixture for the pre-extraction and rinsing and omit the quartz sand. The Dean-Stark moisture trap may also be omitted, if desired.</P>
                        <P>12.4.1.3 Reassemble the pre-extracted Soxhlet apparatus and add a fresh charge of methylene chloride:hexane to the reflux flask.</P>
                        <P>12.4.1.4 Transfer the sample/sodium sulfate mixture (Section 12.4.1.1) to the Soxhlet thimble, and install the thimble in the Soxhlet apparatus.</P>
                        <P>12.4.1.5 Rinse the beaker with several portions of solvent mixture and add to the thimble. Fill the thimble/receiver with solvent. Extract for 18-24 hours.</P>
                        <P>12.4.1.6 After extraction, cool and disassemble the apparatus.</P>
                        <P>12.4.1.7 Quantitatively transfer the extract to a macro-concentration device (Section 12.6), and concentrate to near dryness. Set aside the concentration apparatus for re-use.</P>
                        <P>12.4.1.8 Complete the removal of the solvent using the nitrogen blowdown procedure (Section 12.7) and a water bath temperature of 60 °C. Weigh the receiver, record the weight, and return the receiver to the blowdown apparatus, concentrating the residue until a constant weight is obtained.</P>
                        <P>12.4.1.9 Percent lipid determination—The lipid content is determined by extraction of tissue with the same solvent system (methylene chloride:hexane) that was used in EPA's National Dioxin Study (Reference 22) so that lipid contents are consistent with that study.</P>
                        <P>12.4.1.9.1 Redissolve the residue in the receiver in hexane and spike 1.0 mL of the cleanup standard (Section 7.11) into the solution.</P>
                        <P>12.4.1.9.2 Transfer the residue/hexane to the anthropogenic isolation column (Section 13.7.1) or bottle for the acidified silica gel batch cleanup (Section 13.7.2), retaining the boiling chips in the concentration apparatus. Use several rinses to assure that all material is transferred. If necessary, sonicate or heat the receiver slightly to assure that all material is re-dissolved. Allow the receiver to dry. Weigh the receiver and boiling chips.</P>
                        <P>12.4.1.9.3 Calculate the lipid content to the nearest three significant figures as follows:</P>
                        <GPH SPAN="1" DEEP="25">
                            <GID>ER15SE97.006</GID>
                        </GPH>
                        <P>12.4.1.9.4 It is not necessary to determine the lipid content of the blank, IPR, or OPR aliquots.</P>
                        <P>12.4.2 HCl digestion/extraction and concentration (References 23-26).</P>
                        <P>12.4.2.1 Add 200 mL of 6 N HCl and 200 mL of methylene chloride:hexane (1:1) to the sample and QC aliquots (Section 11.8.4).</P>
                        <P>12.4.2.2 Cap and shake each bottle one to three times. Loosen the cap in a hood to vent excess pressure. Shake each bottle for 10-30 seconds and vent.</P>
                        <P>
                            12.4.2.3 Tightly cap and place on shaker. Adjust the shaker action and speed so that the acid, solvent, and tissue are in constant motion. However, take care to avoid such violent action that the bottle may be dislodged from the shaker. Shake for 12-24 hours.
                            <PRTPAGE P="324"/>
                        </P>
                        <P>12.4.2.4 After digestion, remove the bottles from the shaker. Allow the bottles to stand so that the solvent and acid layers separate.</P>
                        <P>12.4.2.5 Decant the solvent through a glass funnel with glass-fiber filter (Sections 6.5.2 through 6.5.3) containing approximately 10 g of granular anhydrous sodium sulfate (Section 7.2.1) into a macro-concentration apparatus (Section 12.6). Rinse the contents of the bottle with two 25 mL portions of hexane and pour through the sodium sulfate into the apparatus.</P>
                        <P>12.4.2.6 Concentrate the solvent to near dryness using a macro-concentration procedure (Section 12.6).</P>
                        <P>12.4.2.7 Complete the removal of the solvent using the nitrogen blowdown apparatus (Section 12.7) and a water bath temperature of 60 °C. Weigh the receiver, record the weight, and return the receiver to the blowdown apparatus, concentrating the residue until a constant weight is obtained.</P>
                        <P>12.4.2.8 Percent lipid determination—The lipid content is determined in the same solvent system [methylene chloride:hexane (1:1)] that was used in EPA's National Dioxin Study (Reference 22) so that lipid contents are consistent with that study.</P>
                        <P>12.4.2.8.1 Redissolve the residue in the receiver in hexane and spike 1.0 mL of the cleanup standard (Section 7.11) into the solution.</P>
                        <P>12.4.2.8.2 Transfer the residue/hexane to the narrow-mouth 100-200 mL bottle retaining the boiling chips in the receiver. Use several rinses to assure that all material is transferred, to a maximum hexane volume of approximately 70 mL. Allow the receiver to dry. Weigh the receiver and boiling chips.</P>
                        <P>12.4.2.8.3 Calculate the percent lipid per Section 12.4.1.9.3. It is not necessary to determine the lipid content of the blank, IPR, or OPR aliquots.</P>
                        <P>12.4.2.9 Clean up the extract per Section 13.7.3.</P>
                        <P>12.5 Back-Extraction with Base and Acid.</P>
                        <P>12.5.1 Spike 1.0 mL of the cleanup standard (Section 7.11) into the separatory funnels containing the sample and QC extracts from Section 12.1.4.1, 12.3.9.1.3, or 12.3.9.2.</P>
                        <P>12.5.2 Partition the extract against 50 mL of potassium hydroxide solution (Section 7.1.1). Shake for two minutes with periodic venting into a hood. Remove and discard the aqueous layer. Repeat the base washing until no color is visible in the aqueous layer, to a maximum of four washings. Minimize contact time between the extract and the base to prevent degradation of the CDDs/CDFs. Stronger potassium hydroxide solutions may be employed for back-extraction, provided that the laboratory meets the specifications for labeled compound recovery and demonstrates acceptable performance using the procedure in Section 9.2.</P>
                        <P>12.5.3 Partition the extract against 50 mL of sodium chloride solution (Section 7.1.4) in the same way as with base. Discard the aqueous layer.</P>
                        <P>12.5.4 Partition the extract against 50 mL of sulfuric acid (Section 7.1.2) in the same way as with base. Repeat the acid washing until no color is visible in the aqueous layer, to a maximum of four washings.</P>
                        <P>12.5.5 Repeat the partitioning against sodium chloride solution and discard the aqueous layer.</P>
                        <P>12.5.6 Pour each extract through a drying column containing 7-10 cm of granular anhydrous sodium sulfate (Section 7.2.1). Rinse the separatory funnel with 30-50 mL of solvent, and pour through the drying column. Collect each extract in a round-bottom flask. Re-concentrate the sample and QC aliquots per Sections 12.6 through 12.7, and clean up the samples and QC aliquots per Section 13.</P>
                        <P>12.6 Macro-Concentration—Extracts in toluene are concentrated using a rotary evaporator or a heating mantle; extracts in methylene chloride or hexane are concentrated using a rotary evaporator, heating mantle, or Kuderna-Danish apparatus.</P>
                        <P>12.6.1 Rotary evaporation—Concentrate the extracts in separate round-bottom flasks.</P>
                        <P>12.6.1.1 Assemble the rotary evaporator according to manufacturer's instructions, and warm the water bath to 45 °C. On a daily basis, preclean the rotary evaporator by concentrating 100 mL of clean extraction solvent through the system. Archive both the concentrated solvent and the solvent in the catch flask for a contamination check if necessary. Between samples, three 2-3 mL aliquots of solvent should be rinsed down the feed tube into a waste beaker.</P>
                        <P>12.6.1.2 Attach the round-bottom flask containing the sample extract to the rotary evaporator. Slowly apply vacuum to the system, and begin rotating the sample flask.</P>
                        <P>12.6.1.3 Lower the flask into the water bath, and adjust the speed of rotation and the temperature as required to complete concentration in 15-20 minutes. At the proper rate of concentration, the flow of solvent into the receiving flask will be steady, but no bumping or visible boiling of the extract will occur.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>If the rate of concentration is too fast, analyte loss may occur.</P>
                        </NOTE>
                        <P>
                            12.6.1.4 When the liquid in the concentration flask has reached an apparent volume of approximately 2 mL, remove the flask from the water bath and stop the rotation. Slowly and carefully admit air into the system. Be sure not to open the valve so quickly that the sample is blown out of the flask. Rinse the feed tube with approximately 2 mL of solvent.
                            <PRTPAGE P="325"/>
                        </P>
                        <P>12.6.1.5 Proceed to Section 12.6.4 for preparation for back-extraction or micro-concentration and solvent exchange.</P>
                        <P>12.6.2 Heating mantle—Concentrate the extracts in separate round-bottom flasks.</P>
                        <P>12.6.2.1 Add one or two clean boiling chips to the round-bottom flask, and attach a three-ball macro Snyder column. Prewet the column by adding approximately 1 mL of solvent through the top. Place the round-bottom flask in a heating mantle, and apply heat as required to complete the concentration in 15-20 minutes. At the proper rate of distillation, the balls of the column will actively chatter, but the chambers will not flood.</P>
                        <P>12.6.2.2 When the liquid has reached an apparent volume of approximately 10 mL, remove the round-bottom flask from the heating mantle and allow the solvent to drain and cool for at least 10 minutes. Remove the Snyder column and rinse the glass joint into the receiver with small portions of solvent.</P>
                        <P>12.6.2.3 Proceed to Section 12.6.4 for preparation for back-extraction or micro-concentration and solvent exchange.</P>
                        <P>12.6.3 Kuderna-Danish (K-D)—Concentrate the extracts in separate 500 mL K-D flasks equipped with 10 mL concentrator tubes. The K-D technique is used for solvents such as methylene chloride and hexane. Toluene is difficult to concentrate using the K-D technique unless a water bath fed by a steam generator is used.</P>
                        <P>12.6.3.1 Add one to two clean boiling chips to the receiver. Attach a three-ball macro Snyder column. Prewet the column by adding approximately 1 mL of solvent through the top. Place the K-D apparatus in a hot water bath so that the entire lower rounded surface of the flask is bathed with steam.</P>
                        <P>12.6.3.2 Adjust the vertical position of the apparatus and the water temperature as required to complete the concentration in 15-20 minutes. At the proper rate of distillation, the balls of the column will actively chatter but the chambers will not flood.</P>
                        <P>12.6.3.3 When the liquid has reached an apparent volume of 1 mL, remove the K-D apparatus from the bath and allow the solvent to drain and cool for at least 10 minutes. Remove the Snyder column and rinse the flask and its lower joint into the concentrator tube with 1-2 mL of solvent. A 5 mL syringe is recommended for this operation.</P>
                        <P>12.6.3.4 Remove the three-ball Snyder column, add a fresh boiling chip, and attach a two-ball micro Snyder column to the concentrator tube. Prewet the column by adding approximately 0.5 mL of solvent through the top. Place the apparatus in the hot water bath.</P>
                        <P>12.6.3.5 Adjust the vertical position and the water temperature as required to complete the concentration in 5-10 minutes. At the proper rate of distillation, the balls of the column will actively chatter but the chambers will not flood.</P>
                        <P>12.6.3.6 When the liquid reaches an apparent volume of 0.5 mL, remove the apparatus from the water bath and allow to drain and cool for at least 10 minutes.</P>
                        <P>12.6.3.7 Proceed to 12.6.4 for preparation for back-extraction or micro-concentration and solvent exchange.</P>
                        <P>12.6.4 Preparation for back-extraction or micro-concentration and solvent exchange.</P>
                        <P>12.6.4.1 For back-extraction (Section 12.5), transfer the extract to a 250 mL separatory funnel. Rinse the concentration vessel with small portions of hexane, adjust the hexane volume in the separatory funnel to 10-20 mL, and proceed to back-extraction (Section 12.5).</P>
                        <P>12.6.4.2 For determination of the weight of residue in the extract, or for clean-up procedures other than back-extraction, transfer the extract to a blowdown vial using two to three rinses of solvent. Proceed with micro-concentration and solvent exchange (Section 12.7).</P>
                        <P>12.7 Micro-Concentration and Solvent Exchange.</P>
                        <P>12.7.1 Extracts to be subjected to GPC or HPLC cleanup are exchanged into methylene chloride. Extracts to be cleaned up using silica gel, alumina, carbon, and/or Florisil are exchanged into hexane.</P>
                        <P>12.7.2 Transfer the vial containing the sample extract to a nitrogen blowdown device. Adjust the flow of nitrogen so that the surface of the solvent is just visibly disturbed.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>A large vortex in the solvent may cause analyte loss.</P>
                        </NOTE>
                        <P>12.7.3 Lower the vial into a 45 °C water bath and continue concentrating.</P>
                        <P>12.7.3.1 If the extract is to be concentrated to dryness for weight determination (Sections 12.4.1.8, 12.4.2.7, and 13.7.1.4), blow dry until a constant weight is obtained.</P>
                        <P>12.7.3.2 If the extract is to be concentrated for injection into the GC/MS or the solvent is to be exchanged for extract cleanup, proceed as follows:</P>
                        <P>12.7.4 When the volume of the liquid is approximately 100 L, add 2-3 mL of the desired solvent (methylene chloride for GPC and HPLC, or hexane for the other cleanups) and continue concentration to approximately 100 µL. Repeat the addition of solvent and concentrate once more.</P>
                        <P>12.7.5 If the extract is to be cleaned up by GPC, adjust the volume of the extract to 5.0 mL with methylene chloride. If the extract is to be cleaned up by HPLC, further concentrate the extract to 30 µL. Proceed with GPC or HPLC cleanup (Section 13.2 or 13.6, respectively).</P>
                        <P>
                            12.7.6 If the extract is to be cleaned up by column chromatography (alumina, silica gel, Carbopak/Celite, or Florisil), bring the final 
                            <PRTPAGE P="326"/>
                            volume to 1.0 mL with hexane. Proceed with column cleanups (Sections 13.3 through 13.5 and 13.8).
                        </P>
                        <P>12.7.7 If the extract is to be concentrated for injection into the GC/MS (Section 14), quantitatively transfer the extract to a 0.3 mL conical vial for final concentration, rinsing the larger vial with hexane and adding the rinse to the conical vial. Reduce the volume to approximately 100 µL. Add 10 µL of nonane to the vial, and evaporate the solvent to the level of the nonane. Seal the vial and label with the sample number. Store in the dark at room temperature until ready for GC/MS analysis. If GC/MS analysis will not be performed on the same day, store the vial at &lt;−10 °C.</P>
                        <HD SOURCE="HD2">13.0 Extract Cleanup</HD>
                        <P>13.1 Cleanup may not be necessary for relatively clean samples (e.g., treated effluents, groundwater, drinking water). If particular circumstances require the use of a cleanup procedure, the analyst may use any or all of the procedures below or any other appropriate procedure. Before using a cleanup procedure, the analyst must demonstrate that the requirements of Section 9.2 can be met using the cleanup procedure. If only 2,3,7,8-TCDD and 2,3,7,8-TCDF are to be determined, the cleanup procedures may be optimized for isolation of these two compounds.</P>
                        <P>13.1.1 Gel permeation chromatography (Section 13.2) removes high molecular weight interferences that cause GC column performance to degrade. It should be used for all soil and sediment extracts and may be used for water extracts that are expected to contain high molecular weight organic compounds (e.g., polymeric materials, humic acids).</P>
                        <P>13.1.2 Acid, neutral, and basic silica gel (Section 13.3), alumina (Section 13.4), and Florisil (Section 13.8) are used to remove nonpolar and polar interferences. Alumina and Florisil are used to remove chlorodiphenyl ethers.</P>
                        <P>13.1.3 Carbopak/Celite (Section 13.5) is used to remove nonpolar interferences.</P>
                        <P>13.1.4 HPLC (Section 13.6) is used to provide specificity for the 2,3,7,8-substituted and other CDD and CDF isomers.</P>
                        <P>13.1.5 The anthropogenic isolation column (Section 13.7.1), acidified silica gel batch adsorption procedure (Section 13.7.2), and sulfuric acid and base back-extraction (Section 13.7.3) are used for removal of lipids from tissue samples.</P>
                        <P>13.2 Gel Permeation Chromatography (GPC).</P>
                        <P>13.2.1 Column packing.</P>
                        <P>13.2.1.1 Place 70-75 g of SX-3 Bio-beads (Section 6.7.1.1) in a 400-500 mL beaker.</P>
                        <P>13.2.1.2 Cover the beads with methylene chloride and allow to swell overnight (a minimum of 12 hours).</P>
                        <P>13.2.1.3 Transfer the swelled beads to the column (Section 6.7.1.1) and pump solvent through the column, from bottom to top, at 4.5-5.5 mL/minute prior to connecting the column to the detector.</P>
                        <P>13.2.1.4 After purging the column with solvent for one to two hours, adjust the column head pressure to 7-10 psig and purge for four to five hours to remove air. Maintain a head pressure of 7-10 psig. Connect the column to the detector (Section 6.7.1.4).</P>
                        <P>13.2.2 Column calibration.</P>
                        <P>13.2.2.1 Load 5 mL of the calibration solution (Section 7.4) into the sample loop.</P>
                        <P>13.2.2.2 Inject the calibration solution and record the signal from the detector. The elution pattern will be corn oil, bis(2-ethyl hexyl)phthalate, pentachlorophenol, perylene, and sulfur.</P>
                        <P>13.2.2.3 Set the “dump time” to allow &gt;85% removal of the corn oil and &gt;85% collection of the phthalate.</P>
                        <P>13.2.2.4 Set the “collect time” to the peak minimum between perylene and sulfur.</P>
                        <P>13.2.2.5 Verify the calibration with the calibration solution after every 20 extracts. Calibration is verified if the recovery of the pentachlorophenol is greater than 85%. If calibration is not verified, the system shall be recalibrated using the calibration solution, and the previous 20 samples shall be re-extracted and cleaned up using the calibrated GPC system.</P>
                        <P>13.2.3 Extract cleanup—GPC requires that the column not be overloaded. The column specified in this method is designed to handle a maximum of 0.5 g of high molecular weight material in a 5 mL extract. If the extract is known or expected to contain more than 0.5 g, the extract is split into aliquots for GPC, and the aliquots are combined after elution from the column. The residue content of the extract may be obtained gravimetrically by evaporating the solvent from a 50 µL aliquot.</P>
                        <P>13.2.3.1 Filter the extract or load through the filter holder (Section 6.7.1.3) to remove the particles. Load the 5.0 mL extract onto the column.</P>
                        <P>13.2.3.2 Elute the extract using the calibration data determined in Section 13.2.2. Collect the eluate in a clean 400-500 mL beaker.</P>
                        <P>13.2.3.3 Rinse the sample loading tube thoroughly with methylene chloride between extracts to prepare for the next sample.</P>
                        <P>13.2.3.4 If a particularly dirty extract is encountered, a 5.0 mL methylene chloride blank shall be run through the system to check for carry-over.</P>
                        <P>13.2.3.5 Concentrate the eluate per Sections 12.6 and 12.7 for further cleanup or injection into the GC/MS.</P>
                        <P>13.3 Silica Gel Cleanup.</P>
                        <P>
                            13.3.1 Place a glass-wool plug in a 15 mm ID chromatography column (Section 6.7.4.2). Pack the column bottom to top with: 1 g silica gel (Section 7.5.1.1), 4 g basic silica gel (Section 7.5.1.3), 1 g silica gel, 8 g acid silica 
                            <PRTPAGE P="327"/>
                            gel (Section 7.5.1.2), 2 g silica gel, and 4 g granular anhydrous sodium sulfate (Section 7.2.1). Tap the column to settle the adsorbents.
                        </P>
                        <P>13.3.2 Pre-elute the column with 50-100 mL of hexane. Close the stopcock when the hexane is within 1 mm of the sodium sulfate. Discard the eluate. Check the column for channeling. If channeling is present, discard the column and prepare another.</P>
                        <P>13.3.3 Apply the concentrated extract to the column. Open the stopcock until the extract is within 1 mm of the sodium sulfate.</P>
                        <P>13.3.4 Rinse the receiver twice with 1 mL portions of hexane, and apply separately to the column. Elute the CDDs/CDFs with 100 mL hexane, and collect the eluate.</P>
                        <P>13.3.5 Concentrate the eluate per Sections 12.6 and 12.7 for further cleanup or injection into the HPLC or GC/MS.</P>
                        <P>13.3.6 For extracts of samples known to contain large quantities of other organic compounds (such as paper mill effluents), it may be advisable to increase the capacity of the silica gel column. This may be accomplished by increasing the strengths of the acid and basic silica gels. The acid silica gel (Section 7.5.1.2) may be increased in strength to as much as 44% w/w (7.9 g sulfuric acid added to 10 g silica gel). The basic silica gel (Section 7.5.1.3) may be increased in strength to as much as 33% w/w (50 mL 1N NaOH added to 100 g silica gel), or the potassium silicate (Section 7.5.1.4) may be used.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>The use of stronger acid silica gel (44% w/w) may lead to charring of organic compounds in some extracts. The charred material may retain some of the analytes and lead to lower recoveries of CDDs/CDFs. Increasing the strengths of the acid and basic silica gel may also require different volumes of hexane than those specified above to elute the analytes off the column. Therefore, the performance of the method after such modifications must be verified by the procedure in Section 9.2.</P>
                        </NOTE>
                        <P>13.4 Alumina Cleanup.</P>
                        <P>13.4.1 Place a glass-wool plug in a 15 mm ID chromatography column (Section 6.7.4.2).</P>
                        <P>13.4.2 If using acid alumina, pack the column by adding 6 g acid alumina (Section 7.5.2.1). If using basic alumina, substitute 6 g basic alumina (Section 7.5.2.2). Tap the column to settle the adsorbents.</P>
                        <P>13.4.3 Pre-elute the column with 50-100 mL of hexane. Close the stopcock when the hexane is within 1 mm of the alumina.</P>
                        <P>13.4.4 Discard the eluate. Check the column for channeling. If channeling is present, discard the column and prepare another.</P>
                        <P>13.4.5 Apply the concentrated extract to the column. Open the stopcock until the extract is within 1 mm of the alumina.</P>
                        <P>13.4.6 Rinse the receiver twice with 1 mL portions of hexane and apply separately to the column. Elute the interfering compounds with 100 mL hexane and discard the eluate.</P>
                        <P>13.4.7 The choice of eluting solvents will depend on the choice of alumina (acid or basic) made in Section 13.4.2.</P>
                        <P>13.4.7.1 If using acid alumina, elute the CDDs/CDFs from the column with 20 mL methylene chloride:hexane (20:80 v/v). Collect the eluate.</P>
                        <P>13.4.7.2 If using basic alumina, elute the CDDs/CDFs from the column with 20 mL methylene chloride:hexane (50:50 v/v). Collect the eluate.</P>
                        <P>13.4.8 Concentrate the eluate per Sections 12.6 and 12.7 for further cleanup or injection into the HPLC or GC/MS.</P>
                        <P>13.5 Carbon Column.</P>
                        <P>13.5.1 Cut both ends from a 10 mL disposable serological pipet (Section 6.7.3.2) to produce a 10 cm column. Fire-polish both ends and flare both ends if desired. Insert a glass-wool plug at one end, and pack the column with 0.55 g of Carbopak/Celite (Section 7.5.3.3) to form an adsorbent bed approximately 2 cm long. Insert a glass-wool plug on top of the bed to hold the adsorbent in place.</P>
                        <P>13.5.2 Pre-elute the column with 5 mL of toluene followed by 2 mL of methylene chloride: methanol:toluene (15:4:1 v/v), 1 mL of methylene chloride:cyclohexane (1:1 v/v), and 5 mL of hexane. If the flow rate of eluate exceeds 0.5 mL/minute, discard the column.</P>
                        <P>13.5.3 When the solvent is within 1 mm of the column packing, apply the sample extract to the column. Rinse the sample container twice with 1 mL portions of hexane and apply separately to the column. Apply 2 mL of hexane to complete the transfer.</P>
                        <P>13.5.4 Elute the interfering compounds with two 3 mL portions of hexane, 2 mL of methylene chloride:cyclohexane (1:1 v/v), and 2 mL of methylene chloride:methanol:toluene (15:4:1 v/v). Discard the eluate.</P>
                        <P>13.5.5 Invert the column, and elute the CDDs/CDFs with 20 mL of toluene. If carbon particles are present in the eluate, filter through glass-fiber filter paper.</P>
                        <P>13.5.6 Concentrate the eluate per Sections 12.6 and 12.7 for further cleanup or injection into the HPLC or GC/MS.</P>
                        <P>13.6 HPLC (Reference 6).</P>
                        <P>13.6.1 Column calibration.</P>
                        <P>13.6.1.1 Prepare a calibration standard containing the 2,3,7,8-substituted isomers and/or other isomers of interest at a concentration of approximately 500 pg/µL in methylene chloride.</P>
                        <P>13.6.1.2 Inject 30 µL of the calibration solution into the HPLC and record the signal from the detector. Collect the eluant for reuse. The elution order will be the tetra- through octa-isomers.</P>
                        <P>
                            13.6.1.3 Establish the collection time for the tetra-isomers and for the other isomers of interest. Following calibration, flush the injection system with copious quantities of 
                            <PRTPAGE P="328"/>
                            methylene chloride, including a minimum of five 50 µL injections while the detector is monitored, to ensure that residual CDDs/CDFs are removed from the system.
                        </P>
                        <P>13.6.1.4 Verify the calibration with the calibration solution after every 20 extracts. Calibration is verified if the recovery of the CDDs/CDFs from the calibration standard (Section 13.6.1.1) is 75-125% compared to the calibration (Section 13.6.1.2). If calibration is not verified, the system shall be recalibrated using the calibration solution, and the previous 20 samples shall be re-extracted and cleaned up using the calibrated system.</P>
                        <P>13.6.2 Extract cleanup—HPLC requires that the column not be overloaded. The column specified in this method is designed to handle a maximum of 30 µL of extract. If the extract cannot be concentrated to less than 30 µL, it is split into fractions and the fractions are combined after elution from the column.</P>
                        <P>13.6.2.1 Rinse the sides of the vial twice with 30 µL of methylene chloride and reduce to 30 µL with the evaporation apparatus (Section 12.7).</P>
                        <P>13.6.2.2 Inject the 30 µL extract into the HPLC.</P>
                        <P>13.6.2.3 Elute the extract using the calibration data determined in Section 13.6.1. Collect the fraction(s) in a clean 20 mL concentrator tube containing 5 mL of hexane:acetone (1:1 v/v).</P>
                        <P>13.6.2.4 If an extract containing greater than 100 ng/mL of total CDD or CDF is encountered, a 30 µL methylene chloride blank shall be run through the system to check for carry-over.</P>
                        <P>13.6.2.5 Concentrate the eluate per Section 12.7 for injection into the GC/MS.</P>
                        <P>13.7 Cleanup of Tissue Lipids—Lipids are removed from the Soxhlet extract using either the anthropogenic isolation column (Section 13.7.1) or acidified silica gel (Section 13.7.2), or are removed from the HCl digested extract using sulfuric acid and base back-extraction (Section 13.7.3).</P>
                        <P>13.7.1 Anthropogenic isolation column (References 22 and 27)—Used for removal of lipids from the Soxhlet/SDS extraction (Section 12.4.1).</P>
                        <P>13.7.1.1 Prepare the column as given in Section 7.5.4.</P>
                        <P>13.7.1.2 Pre-elute the column with 100 mL of hexane. Drain the hexane layer to the top of the column, but do not expose the sodium sulfate.</P>
                        <P>13.7.1.3 Load the sample and rinses (Section 12.4.1.9.2) onto the column by draining each portion to the top of the bed. Elute the CDDs/CDFs from the column into the apparatus used for concentration (Section 12.4.1.7) using 200 mL of hexane.</P>
                        <P>13.7.1.4 Concentrate the cleaned up extract (Sections 12.6 through 12.7) to constant weight per Section 12.7.3.1. If more than 500 mg of material remains, repeat the cleanup using a fresh anthropogenic isolation column.</P>
                        <P>13.7.1.5 Redissolve the extract in a solvent suitable for the additional cleanups to be used (Sections 13.2 through 13.6 and 13.8).</P>
                        <P>13.7.1.6 Spike 1.0 mL of the cleanup standard (Section 7.11) into the residue/solvent.</P>
                        <P>13.7.1.7 Clean up the extract using the procedures in Sections 13.2 through 13.6 and 13.8. Alumina (Section 13.4) or Florisil (Section 13.8) and carbon (Section 13.5) are recommended as minimum additional cleanup steps.</P>
                        <P>13.7.1.8 Following cleanup, concentrate the extract to 10 µL as described in Section 12.7 and proceed with the analysis in Section 14.</P>
                        <P>13.7.2 Acidified silica gel (Reference 28)—Procedure alternate to the anthropogenic isolation column (Section 13.7.1) that is used for removal of lipids from the Soxhlet/SDS extraction (Section 12.4.1).</P>
                        <P>13.7.2.1 Adjust the volume of hexane in the bottle (Section 12.4.1.9.2) to approximately 200 mL.</P>
                        <P>13.7.2.2 Spike 1.0 mL of the cleanup standard (Section 7.11) into the residue/solvent.</P>
                        <P>13.7.2.3 Drop the stirring bar into the bottle, place the bottle on the stirring plate, and begin stirring.</P>
                        <P>13.7.2.4 Add 30-100 g of acid silica gel (Section 7.5.1.2) to the bottle while stirring, keeping the silica gel in motion. Stir for two to three hours.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>30 grams of silica gel should be adequate for most samples and will minimize contamination from this source.</P>
                        </NOTE>
                        <P>13.7.2.5 After stirring, pour the extract through approximately 10 g of granular anhydrous sodium sulfate (Section 7.2.1) contained in a funnel with glass-fiber filter into a macro contration device (Section 12.6). Rinse the bottle and sodium sulfate with hexane to complete the transfer.</P>
                        <P>13.7.2.6 Concentrate the extract per Sections 12.6 through 12.7 and clean up the extract using the procedures in Sections 13.2 through 13.6 and 13.8. Alumina (Section 13.4) or Florisil (Section 13.8) and carbon (Section 13.5) are recommended as minimum additional cleanup steps.</P>
                        <P>13.7.3 Sulfuric acid and base back-extraction. Used with HCl digested extracts (Section 12.4.2).</P>
                        <P>13.7.3.1 Spike 1.0 mL of the cleanup standard (Section 7.11) into the residue/solvent (Section 12.4.2.8.2).</P>
                        <P>13.7.3.2 Add 10 mL of concentrated sulfuric acid to the bottle. Immediately cap and shake one to three times. Loosen cap in a hood to vent excess pressure. Cap and shake the bottle so that the residue/solvent is exposed to the acid for a total time of approximately 45 seconds.</P>
                        <P>
                            13.7.3.3 Decant the hexane into a 250 mL separatory funnel making sure that no acid 
                            <PRTPAGE P="329"/>
                            is transferred. Complete the quantitative transfer with several hexane rinses.
                        </P>
                        <P>13.7.3.4 Back extract the solvent/residue with 50 mL of potassium hydroxide solution per Section 12.5.2, followed by two reagent water rinses.</P>
                        <P>13.7.3.5 Drain the extract through a filter funnel containing approximately 10 g of granular anhydrous sodium sulfate in a glass-fiber filter into a macro concentration device (Section 12.6).</P>
                        <P>13.7.3.6 Concentrate the cleaned up extract to a volume suitable for the additional cleanups given in Sections 13.2 through 13.6 and 13.8. Gel permeation chromatography (Section 13.2), alumina (Section 13.4) or Florisil (Section 13.8), and Carbopak/Celite (Section 13.5) are recommended as minimum additional cleanup steps.</P>
                        <P>13.7.3.7 Following cleanup, concentrate the extract to 10 L as described in Section 12.7 and proceed with analysis per Section 14.</P>
                        <P>13.8 Florisil Cleanup (Reference 29).</P>
                        <P>13.8.1 Pre-elute the activated Florisil column (Section 7.5.3) with 10 mL of methylene chloride followed by 10 mL of hexane:methylene chloride (98:2 v/v) and discard the solvents.</P>
                        <P>13.8.2 When the solvent is within 1 mm of the packing, apply the sample extract (in hexane) to the column. Rinse the sample container twice with 1 mL portions of hexane and apply to the column.</P>
                        <P>13.8.3 Elute the interfering compounds with 20 mL of hexane:methylene chloride (98:2) and discard the eluate.</P>
                        <P>13.8.4 Elute the CDDs/CDFs with 35 mL of methylene chloride and collect the eluate. Concentrate the eluate per Sections 12.6 through 12.7 for further cleanup or for injection into the HPLC or GC/MS.</P>
                        <HD SOURCE="HD2">14.0 HRGC/HRMS Analysis</HD>
                        <P>14.1 Establish the operating conditions given in Section 10.1.</P>
                        <P>14.2 Add 10 uL of the appropriate internal standard solution (Section 7.12) to the sample extract immediately prior to injection to minimize the possibility of loss by evaporation, adsorption, or reaction. If an extract is to be reanalyzed and evaporation has occurred, do not add more instrument internal standard solution. Rather, bring the extract back to its previous volume (e.g., 19 L) with pure nonane only (18 L if 2 L injections are used).</P>
                        <P>14.3 Inject 1.0 µL or 2.0 µL of the concentrated extract containing the internal standard solution, using on-column or splitless injection. The volume injected must be identical to the volume used for calibration (Section 10). Start the GC column initial isothermal hold upon injection. Start MS data collection after the solvent peak elutes. Stop data collection after the OCDD and OCDF have eluted. If only 2,3,7,8-TCDD and 2,3,7,8-TCDF are to be determined, stop data collection after elution of these compounds. Return the column to the initial temperature for analysis of the next extract or standard.</P>
                        <HD SOURCE="HD2">15.0 System and Laboratory Performance</HD>
                        <P>15.1 At the beginning of each 12-hour shift during which analyses are performed, GC/MS system performance and calibration are verified for all CDDs/CDFs and labeled compounds. For these tests, analysis of the CS3 calibration verification (VER) standard (Section 7.13 and Table 4) and the isomer specificity test standards (Section 7.15 and Table 5) shall be used to verify all performance criteria. Adjustment and/or recalibration (Section 10) shall be performed until all performance criteria are met. Only after all performance criteria are met may samples, blanks, IPRs, and OPRs be analyzed.</P>
                        <P>15.2 MS Resolution—A static resolving power of at least 10,000 (10% valley definition) must be demonstrated at the appropriate m/z before any analysis is performed. Static resolving power checks must be performed at the beginning and at the end of each 12-hour shift according to procedures in Section 10.1.2. Corrective actions must be implemented whenever the resolving power does not meet the requirement.</P>
                        <P>15.3 Calibration Verification.</P>
                        <P>15.3.1 Inject the VER standard using the procedure in Section 14.</P>
                        <P>15.3.2 The m/z abundance ratios for all CDDs/CDFs shall be within the limits in Table 9; otherwise, the mass spectrometer shall be adjusted until the m/z abundance ratios fall within the limits specified, and the verification test shall be repeated. If the adjustment alters the resolution of the mass spectrometer, resolution shall be verified (Section 10.1.2) prior to repeat of the verification test.</P>
                        <P>15.3.3 The peaks representing each CDD/CDF and labeled compound in the VER standard must be present with S/N of at least 10; otherwise, the mass spectrometer shall be adjusted and the verification test repeated.</P>
                        <P>15.3.4 Compute the concentration of each CDD/CDF compound by isotope dilution (Section 10.5) for those compounds that have labeled analogs (Table 1). Compute the concentration of the labeled compounds by the internal standard method (Section 10.6). These concentrations are computed based on the calibration data in Section 10.</P>
                        <P>
                            15.3.5 For each compound, compare the concentration with the calibration verification limit in Table 6. If only 2,3,7,8-TCDD and 2,3,7,8-TCDF are to be determined, compare the concentration to the limit in Table 6a. If all compounds meet the acceptance criteria, calibration has been verified and analysis of standards and sample extracts may proceed. If, however, any compound fails its respective limit, the measurement system is not performing properly for 
                            <PRTPAGE P="330"/>
                            that compound. In this event, prepare a fresh calibration standard or correct the problem causing the failure and repeat the resolution (Section 15.2) and verification (Section 15.3) tests, or recalibrate (Section 10).
                        </P>
                        <P>15.4 Retention Times and GC Resolution.</P>
                        <P>15.4.1 Retention times.</P>
                        <P>
                            15.4.1.1 Absolute—The absolute retention times of the 
                            <SU>13</SU>
                            C
                            <E T="52">12</E>
                            -1,2,3,4-TCDD and 
                            <SU>13</SU>
                            C
                            <E T="52">12</E>
                            -1,2,3,7,8,9-HxCDD GCMS internal standards in the verification test (Section 15.3) shall be within ±15 seconds of the retention times obtained during calibration (Sections 10.2.1 and 10.2.4).
                        </P>
                        <P>15.4.1.2 Relative—The relative retention times of CDDs/CDFs and labeled compounds in the verification test (Section 15.3) shall be within the limits given in Table 2.</P>
                        <P>15.4.2 GC resolution.</P>
                        <P>15.4.2.1 Inject the isomer specificity standards (Section 7.15) on their respective columns.</P>
                        <P>15.4.2.2 The valley height between 2,3,7,8-TCDD and the other tetra-dioxin isomers at m/z 319.8965, and between 2,3,7,8-TCDF and the other tetra-furan isomers at m/z 303.9016 shall not exceed 25% on their respective columns (Figures 6 and 7).</P>
                        <P>15.4.3 If the absolute retention time of any compound is not within the limits specified or if the 2,3,7,8-isomers are not resolved, the GC is not performing properly. In this event, adjust the GC and repeat the verification test (Section 15.3) or recalibrate (Section 10), or replace the GC column and either verify calibration or recalibrate.</P>
                        <P>15.5 Ongoing Precision and Recovery.</P>
                        <P>15.5.1 Analyze the extract of the ongoing precision and recovery (OPR) aliquot (Section 11.4.2.5, 11.5.4, 11.6.2, 11.7.4, or 11.8.3.2) prior to analysis of samples from the same batch.</P>
                        <P>15.5.2 Compute the concentration of each CDD/CDF by isotope dilution for those compounds that have labeled analogs (Section 10.5). Compute the concentration of 1,2,3,7,8,9-HxCDD, OCDF, and each labeled compound by the internal standard method (Section 10.6).</P>
                        <P>15.5.3 For each CDD/CDF and labeled compound, compare the concentration to the OPR limits given in Table 6. If only 2,3,7,8-TCDD and 2,3,7,8-TCDF are to be determined, compare the concentration to the limits in Table 6a. If all compounds meet the acceptance criteria, system performance is acceptable and analysis of blanks and samples may proceed. If, however, any individual concentration falls outside of the range given, the extraction/concentration processes are not being performed properly for that compound. In this event, correct the problem, re-prepare, extract, and clean up the sample batch and repeat the ongoing precision and recovery test (Section 15.5).</P>
                        <P>
                            15.5.4 Add results that pass the specifications in Section 15.5.3 to initial and previous ongoing data for each compound in each matrix. Update QC charts to form a graphic representation of continued laboratory performance. Develop a statement of laboratory accuracy for each CDD/CDF in each matrix type by calculating the average percent recovery (R) and the standard deviation of percent recovery (S
                            <E T="52">R</E>
                            ). Express the accuracy as a recovery interval from R−2S
                            <E T="52">R</E>
                             to R = 2S
                            <E T="52">R</E>
                            . For example, if R = 95% and S
                            <E T="52">R</E>
                             = 5%, the accuracy is 85-105%.
                        </P>
                        <P>15.6 Blank—Analyze the method blank extracted with each sample batch immediately following analysis of the OPR aliquot to demonstrate freedom from contamination and freedom from carryover from the OPR analysis. The results of the analysis of the blank must meet the specifications in Section 9.5.2 before sample analyses may proceed.</P>
                        <HD SOURCE="HD2">16.0 Qualitative Determination</HD>
                        <P>A CDD, CDF, or labeled compound is identified in a standard, blank, or sample when all of the criteria in Sections 16.1 through 16.4 are met.</P>
                        <P>16.1 The signals for the two exact m/z's in Table 8 must be present and must maximize within the same two seconds.</P>
                        <P>16.2 The signal-to-noise ratio (S/N) for the GC peak at each exact m/z must be greater than or equal to 2.5 for each CDD or CDF detected in a sample extract, and greater than or equal to 10 for all CDDs/CDFs in the calibration standard (Sections 10.2.3 and 15.3.3).</P>
                        <P>16.3 The ratio of the integrated areas of the two exact m/z's specified in Table 8 must be within the limit in Table 9, or within ±10% of the ratio in the midpoint (CS3) calibration or calibration verification (VER), whichever is most recent.</P>
                        <P>16.4 The relative retention time of the peak for a 2,3,7,8-substituted CDD or CDF must be within the limit in Table 2. The retention time of peaks representing non-2,3,7,8-substituted CDDs/CDFs must be within the retention time windows established in Section 10.3.</P>
                        <P>16.5 Confirmatory Analysis—Isomer specificity for 2,3,7,8-TCDF cannot be achieved on the DB-5 column. Therefore, any sample in which 2,3,7,8-TCDF is identified by analysis on a DB-5 column must have a confirmatory analysis performed on a DB-225, SP-2330, or equivalent GC column. The operating conditions in Section 10.1.1 may be adjusted to optimize the analysis on the second GC column, but the GC/MS must meet the mass resolution and calibration specifications in Section 10.</P>
                        <P>
                            16.6 If the criteria for identification in Sections 16.1 through 16.5 are not met, the CDD or CDF has not been identified and the results may not be reported for regulatory compliance purposes. If interferences preclude identification, a new aliquot of sample 
                            <PRTPAGE P="331"/>
                            must be extracted, further cleaned up, and analyzed.
                        </P>
                        <P>17.0 Quantitative Determination</P>
                        <P>17.1 Isotope Dilution Quantitation—By adding a known amount of a labeled compound to every sample prior to extraction, correction for recovery of the CDD/CDF can be made because the CDD/CDF and its labeled analog exhibit similar effects upon extraction, concentration, and gas chromatography. Relative response (RR) values are used in conjunction with the initial calibration data described in Section 10.5 to determine concentrations directly, so long as labeled compound spiking levels are constant, using the following equation:</P>
                        <GPH SPAN="1" DEEP="30">
                            <GID>ER15SE97.007</GID>
                        </GPH>
                        <FP>where:</FP>
                        <FP SOURCE="FP-2">
                            C
                            <E T="52">ex</E>
                             = The concentration of the CDD/CDF in the extract, and the other terms are as defined in Section 10.5.2.
                        </FP>
                        <P>17.1.1 Because of a potential interference, the labeled analog of OCDF is not added to the sample. Therefore, OCDF is quantitated against labeled OCDD. As a result, the concentration of OCDF is corrected for the recovery of the labeled OCDD. In instances where OCDD and OCDF behave differently during sample extraction, concentration, and cleanup procedures, this may decrease the accuracy of the OCDF results. However, given the low toxicity of this compound relative to the other dioxins and furans, the potential decrease in accuracy is not considered significant.</P>
                        <P>
                            17.1.2 Because 
                            <SU>13</SU>
                            C
                            <E T="52">12</E>
                            -1,2,3,7,8,9-HxCDD is used as an instrument internal standard (
                            <E T="03">i.e.</E>
                            , not added before extraction of the sample), it cannot be used to quantitate the 1,2,3,7,8,9-HxCDD by strict isotope dilution procedures. Therefore, 1,2,3,7,8,9-HxCDD is quantitated using the averaged response of the labeled analogs of the other two 2,3,7,8-substituted HxCDD's: 1,2,3,4,7,8-HxCDD and 1,2,3,6,7,8-HxCDD. As a result, the concentration of 1,2,3,7,8,9-HxCDD is corrected for the average recovery of the other two HxCDD's.
                        </P>
                        <P>17.1.3 Any peaks representing non-2,3,7,8-substituted CDDs/CDFs are quantitated using an average of the response factors from all of the labeled 2,3,7,8-isomers at the same level of chlorination.</P>
                        <P>17.2 Internal Standard Quantitation and Labeled Compound Recovery.</P>
                        <P>
                            17.2.1 Compute the concentrations of 1,2,3,7,8,9-HxCDD, OCDF, the 
                            <SU>13</SU>
                            C-labeled analogs and the 
                            <SU>37</SU>
                            C-labeled cleanup standard in the extract using the response factors determined from the initial calibration data (Section 10.6) and the following equation:
                        </P>
                        <GPH SPAN="1" DEEP="31">
                            <GID>ER15SE97.008</GID>
                        </GPH>
                        <FP>where:</FP>
                        <FP SOURCE="FP-2">
                            C
                            <E T="52">ex</E>
                             = The concentration of the CDD/CDF in the extract, and the other terms are as defined in Section 10.6.1.
                        </FP>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>
                                There is only one m/z for the 
                                <SU>37</SU>
                                Cl-labeled standard.
                            </P>
                        </NOTE>
                        <P>
                            17.2.2 Using the concentration in the extract determined above, compute the percent recovery of the 
                            <SU>13</SU>
                            C-labeled compounds and the 
                            <SU>37</SU>
                            C-labeled cleanup standard using the following equation:
                        </P>
                        <GPH SPAN="2" DEEP="26">
                            <GID>ER15SE97.009</GID>
                        </GPH>
                        <P>17.3 The concentration of a CDD/CDF in the solid phase of the sample is computed using the concentration of the compound in the extract and the weight of the solids (Section 11.5.1), as follows:</P>
                        <GPH SPAN="2" DEEP="34">
                            <GID>ER15SE97.010</GID>
                        </GPH>
                        <FP>where:</FP>
                        <FP SOURCE="FP-2">
                            C
                            <E T="52">ex</E>
                             = The concentration of the compound in the extract.
                        </FP>
                        <FP SOURCE="FP-2">
                            V
                            <E T="52">ex</E>
                             = The extract volume in mL.
                        </FP>
                        <FP SOURCE="FP-2">
                            W
                            <E T="52">s</E>
                             = The sample weight (dry weight) in kg.
                        </FP>
                        <P>
                            17.4 The concentration of a CDD/CDF in the aqueous phase of the sample is computed using the concentration of the compound in 
                            <PRTPAGE P="332"/>
                            the extract and the volume of water extracted (Section 11.4 or 11.5), as follows:
                        </P>
                        <GPH SPAN="2" DEEP="34">
                            <GID>ER15SE97.011</GID>
                        </GPH>
                        <FP>where:</FP>
                        <FP SOURCE="FP-2">
                            C
                            <E T="52">ex</E>
                             = The concentration of the compound in the extract.
                        </FP>
                        <FP SOURCE="FP-2">
                            V
                            <E T="52">ex</E>
                             = The extract volume in mL.
                        </FP>
                        <FP SOURCE="FP-2">
                            V
                            <E T="52">s</E>
                             = The sample volume in liters.
                        </FP>
                        <P>17.5 If the SICP area at either quantitation m/z for any compound exceeds the calibration range of the system, a smaller sample aliquot is extracted.</P>
                        <P>17.5.1 For aqueous samples containing 1% solids or less, dilute 100 mL, 10 mL, etc., of sample to 1 L with reagent water and re-prepare, extract, clean up, and analyze per Sections 11 through 14.</P>
                        <P>
                            17.5.2 For samples containing greater than 1% solids, extract an amount of sample equal to 
                            <FR>1/10</FR>
                            , 
                            <FR>1/100</FR>
                            , etc., of the amount used in Section 11.5.1. Re-prepare, extract, clean up, and analyze per Sections 11 through 14.
                        </P>
                        <P>17.5.3 If a smaller sample size will not be representative of the entire sample, dilute the sample extract by a factor of 10, adjust the concentration of the instrument internal standard to 100 pg/µL in the extract, and analyze an aliquot of this diluted extract by the internal standard method.</P>
                        <P>17.6 Results are reported to three significant figures for the CDDs/CDFs and labeled compounds found in all standards, blanks, and samples.</P>
                        <P>17.6.1 Reporting units and levels.</P>
                        <P>17.6.1.1 Aqueous samples—Report results in pg/L (parts-per-quadrillion).</P>
                        <P>17.6.1.2 Samples containing greater than 1% solids (soils, sediments, filter cake, compost)—Report results in ng/kg based on the dry weight of the sample. Report the percent solids so that the result may be corrected.</P>
                        <P>17.6.1.3 Tissues—Report results in ng/kg of wet tissue, not on the basis of the lipid content of the sample. Report the percent lipid content, so that the data user can calculate the concentration on a lipid basis if desired.</P>
                        <P>17.6.1.4 Reporting level.</P>
                        <P>17.6.1.4.1 Standards (VER, IPR, OPR) and samples—Report results at or above the minimum level (Table 2). Report results below the minimum level as not detected or as required by the regulatory authority.</P>
                        <P>17.6.1.4.2 Blanks—Report results above one-third the ML.</P>
                        <P>17.6.2 Results for CDDs/CDFs in samples that have been diluted are reported at the least dilute level at which the areas at the quantitation m/z's are within the calibration range (Section 17.5).</P>
                        <P>17.6.3 For CDDs/CDFs having a labeled analog, results are reported at the least dilute level at which the area at the quantitation m/z is within the calibration range (Section 17.5) and the labeled compound recovery is within the normal range for the method (Section 9.3 and Tables 6, 6a, 7, and 7a).</P>
                        <P>
                            17.6.4 Additionally, if requested, the total concentration of all isomers in an individual level of chlorination (
                            <E T="03">i.e.</E>
                            , total TCDD, total TCDF, total Paced, etc.) may be reported by summing the concentrations of all isomers identified in that level of chlorination, including both 2,3,7,8-substituted and non-2,3,7,8-substituted isomers.
                        </P>
                        <HD SOURCE="HD2">18.0 Analysis of Complex Samples</HD>
                        <P>18.1 Some samples may contain high levels (&gt;10 ng/L; &gt;1000 ng/kg) of the compounds of interest, interfering compounds, and/or polymeric materials. Some extracts will not concentrate to 10 µL (Section 12.7); others may overload the GC column and/or mass spectrometer.</P>
                        <P>18.2 Analyze a smaller aliquot of the sample (Section 17.5) when the extract will not concentrate to 10 µL after all cleanup procedures have been exhausted.</P>
                        <P>18.3 Chlorodiphenyl Ethers—If chromatographic peaks are detected at the retention time of any CDDs/CDFs in any of the m/z channels being monitored for the chlorodiphenyl ethers (Table 8), cleanup procedures must be employed until these interferences are removed. Alumina (Section 13.4) and Florisil (Section 13.8) are recommended for removal of chlorodiphenyl ethers.</P>
                        <P>18.4 Recovery of Labeled Compounds—In most samples, recoveries of the labeled compounds will be similar to those from reagent water or from the alternate matrix (Section 7.6).</P>
                        <P>18.4.1 If the recovery of any of the labeled compounds is outside of the normal range (Table 7), a diluted sample shall be analyzed (Section 17.5).</P>
                        <P>
                            18.4.2 If the recovery of any of the labeled compounds in the diluted sample is outside of normal range, the calibration verification standard (Section 7.13) shall be analyzed and calibration verified (Section 15.3).
                            <PRTPAGE P="333"/>
                        </P>
                        <P>18.4.3 If the calibration cannot be verified, a new calibration must be performed and the original sample extract reanalyzed.</P>
                        <P>18.4.4 If the calibration is verified and the diluted sample does not meet the limits for labeled compound recovery, the method does not apply to the sample being analyzed and the result may not be reported for regulatory compliance purposes. In this case, alternate extraction and cleanup procedures in this method must be employed to resolve the interference. If all cleanup procedures in this method have been employed and labeled compound recovery remains outside of the normal range, extraction and/or cleanup procedures that are beyond this scope of this method will be required to analyze these samples.</P>
                        <HD SOURCE="HD2">19.0 Pollution Prevention</HD>
                        <P>19.1 The solvents used in this method pose little threat to the environment when managed properly. The solvent evaporation techniques used in this method are amenable to solvent recovery, and it is recommended that the laboratory recover solvents wherever feasible.</P>
                        <P>19.2 Standards should be prepared in volumes consistent with laboratory use to minimize disposal of standards.</P>
                        <HD SOURCE="HD2">20.0 Waste Management</HD>
                        <P>20.1 It is the laboratory's responsibility to comply with all federal, state, and local regulations governing waste management, particularly the hazardous waste identification rules and land disposal restrictions, and to protect the air, water, and land by minimizing and controlling all releases from fume hoods and bench operations. Compliance is also required with any sewage discharge permits and regulations.</P>
                        <P>20.2 Samples containing HCl to pH &lt;2 are hazardous and must be neutralized before being poured down a drain or must be handled as hazardous waste.</P>
                        <P>20.3 The CDDs/CDFs decompose above 800 °C. Low-level waste such as absorbent paper, tissues, animal remains, and plastic gloves may be burned in an appropriate incinerator. Gross quantities (milligrams) should be packaged securely and disposed of through commercial or governmental channels that are capable of handling extremely toxic wastes.</P>
                        <P>20.4 Liquid or soluble waste should be dissolved in methanol or ethanol and irradiated with ultraviolet light with a wavelength shorter than 290 nm for several days. Use F40 BL or equivalent lamps. Analyze liquid wastes, and dispose of the solutions when the CDDs/CDFs can no longer be detected.</P>
                        <P>20.5 For further information on waste management, consult “The Waste Management Manual for Laboratory Personnel” and “Less is Better—Laboratory Chemical Management for Waste Reduction,” available from the American Chemical Society's Department of Government Relations and Science Policy, 1155 16th Street N.W., Washington, D.C. 20036.</P>
                        <HD SOURCE="HD2">21.0 Method Performance</HD>
                        <P>Method performance was validated and performance specifications were developed using data from EPA's international interlaboratory validation study (References 30-31) and the EPA/paper industry Long-Term Variability Study of discharges from the pulp and paper industry (58 FR 66078).</P>
                        <HD SOURCE="HD2">22.0 References</HD>
                        <P>
                            1. Tondeur, Yves. “Method 8290: Analytical Procedures and Quality Assurance for Multimedia Analysis of Polychlorinated Dibenzo-
                            <E T="03">p</E>
                            -dioxins and Dibenzofurans by High Resolution Gas Chromatography/High Resolution Mass Spectrometry,” USEPA EMSL, Las Vegas, Nevada, June 1987.
                        </P>
                        <P>
                            2. “Measurement of 2,3,7,8-Tetrachlorinated Dibenzo-
                            <E T="03">p</E>
                            -dioxin (TCDD) and 2,3,7,8-Tetrachlorinated Dibenzofuran (TCDF) in Pulp, Sludges, Process Samples and Wastewaters from Pulp and Paper Mills,” Wright State University, Dayton, OH 45435, June 1988.
                        </P>
                        <P>3. “NCASI Procedures for the Preparation and Isomer Specific Analysis of Pulp and Paper Industry Samples for 2,3,7,8-TCDD and 2,3,7,8-TCDF,” National Council of the Paper Industry for Air and Stream Improvement Inc., 260 Madison Avenue, New York, NY 10016, Technical Bulletin No. 551, Pre-Release Copy, July 1988.</P>
                        <P>4. “Analytical Procedures and Quality Assurance Plan for the Determination of PCDD/PCDF in Fish,” USEPA, Environmental Research Laboratory, 6201 Congdon Boulevard, Duluth, MN 55804, April 1988.</P>
                        <P>5. Tondeur, Yves. “Proposed GC/MS Methodology for the Analysis of PCDDs and PCDFs in Special Analytical Services Samples,” Triangle Laboratories, Inc., 801-10 Capitola Dr, Research Triangle Park, NC 27713, January 1988; updated by personal communication September 1988.</P>
                        <P>
                            6. Lamparski, L.L. and Nestrick, T.J. “Determination of Tetra-, Hexa-, Hepta-, and Octachlorodibenzo-
                            <E T="03">p</E>
                            -dioxin Isomers in Particulate Samples at Parts per Trillion Levels,” Analytical Chemistry, 52: 2045-2054, 1980.
                        </P>
                        <P>
                            7. Lamparski, L.L. and Nestrick, T.J. “Novel Extraction Device for the Determination of Chlorinated Dibenzo-
                            <E T="03">p</E>
                            -dioxins (PCDDs) and Dibenzofurans (PCDFs) in Matrices Containing Water,” Chemosphere, 19:27-31, 1989.
                        </P>
                        <P>
                            8. Patterson, D.G., et. al. “Control of Interferences in the Analysis of Human Adipose Tissue for 2,3,7,8-Tetrachlorodibenzo-
                            <E T="03">p</E>
                            -
                            <PRTPAGE P="334"/>
                            dioxin,” Environmental Toxicological Chemistry, 5:355-360, 1986.
                        </P>
                        <P>
                            9. Stanley, John S. and Sack, Thomas M. “Protocol for the Analysis of 2,3,7,8-Tetrachlorodibenzo-
                            <E T="03">p</E>
                            -dioxin by High Resolution Gas Chromatography/High Resolution Mass Spectrometry,” USEPA EMSL, Las Vegas, Nevada 89114, EPA 600/4-86-004, January 1986.
                        </P>
                        <P>10. “Working with Carcinogens,” Department of Health, Education, &amp; Welfare, Public Health Service, Centers for Disease Control, NIOSH, Publication 77-206, August 1977, NTIS PB-277256.</P>
                        <P>11. “OSHA Safety and Health Standards, General Industry,” OSHA 2206, 29 CFR 1910.</P>
                        <P>12. “Safety in Academic Chemistry Laboratories,” ACS Committee on Chemical Safety, 1979.</P>
                        <P>13. “Standard Methods for the Examination of Water and Wastewater,” 18th edition and later revisions, American Public Health Association, 1015 15th St, N.W., Washington, DC 20005, 1-35: Section 1090 (Safety), 1992.</P>
                        <P>14. “Method 613—2,3,7,8-Tetrachlorodibenzo-p-dioxin,” 40 CFR 136 (49 FR 43234), October 26, 1984, Section 4.1.</P>
                        <P>15. Provost, L.P. and Elder, R.S. “Interpretation of Percent Recovery Data,” American Laboratory, 15: 56-83, 1983.</P>
                        <P>16. “Standard Practice for Sampling Water,” ASTM Annual Book of Standards, ASTM, 1916 Race Street, Philadelphia, PA 19103-1187, 1980.</P>
                        <P>17. “Methods 330.4 and 330.5 for Total Residual Chlorine,” USEPA, EMSL, Cincinnati, OH 45268, EPA 600/4-79-020, March 1979.</P>
                        <P>18. “Handbook of Analytical Quality Control in Water and Wastewater Laboratories,” USEPA EMSL, Cincinnati, OH 45268, EPA-600/4-79-019, March 1979.</P>
                        <P>19. Williams, Rick. Letter to Bill Telliard, June 4, 1993, available from the EPA Sample Control Center operated by DynCorp Viar, Inc., 300 N Lee St, Alexandria, VA 22314, 703-519-1140.</P>
                        <P>20. Barkowski, Sarah. Fax to Sue Price, August 6, 1992, available from the EPA Sample Control Center operated by DynCorp Viar, Inc., 300 N Lee St, Alexandria VA 22314, 703-519-1140.</P>
                        <P>21. “Analysis of Multi-media, Multi-concentration Samples for Dioxins and Furans, PCDD/PCDF Analyses Data Package”, Narrative for Episode 4419, MRI Project No. 3091-A, op.cit. February 12, 1993, Available from the EPA Sample Control Center operated by DynCorp Viar Inc, 300 N Lee St, Alexandria, VA 22314 (703-519-1140).</P>
                        <P>22. “Analytical Procedures and Quality Assurance Plan for the Determination of PCDD/PCDF in Fish”, U.S. Environmental Protection Agency, Environmental Research Laboratory, Duluth, MN 55804, EPA/600/3-90/022, March 1990.</P>
                        <P>23. Afghan, B.K., Carron, J., Goulden, P.D., Lawrence, J., Leger, D., Onuska, F., Sherry, J., and Wilkenson, R.J., “Recent Advances in Ultratrace Analysis of Dioxins and Related Halogenated Hydrocarbons”, Can J. Chem., 65: 1086-1097, 1987.</P>
                        <P>24. Sherry, J.P. and Tse, H. “A Procedure for the Determination of Polychlorinated Dibenzo-p-dioxins in Fish”, Chemosphere, 20: 865-872, 1990.</P>
                        <P>25. “Preliminary Fish Tissue Study”, Results of Episode 4419, available from the EPA Sample Control Center operated by DynCorp Viar, Inc., 300 N Lee St, Alexandria, VA 22314, 703-519-1140.</P>
                        <P>26. Nestrick, Terry L. DOW Chemical Co., personal communication with D.R. Rushneck, April 8, 1993. Details available from the U.S. Environmental Protection Agency Sample Control Center operated by DynCorp Viar Inc, 300 N Lee St, Alexandria, VA 22314, 703-519-1140.</P>
                        <P>27. Barnstadt, Michael. “Big Fish Column”, Triangle Laboratories of RTP, Inc., SOP 129-90, 27 March 27, 1992.</P>
                        <P>28. “Determination of Polychlorinated Dibenzo-p-Dioxins (PCDD) and Dibenzofurans (PCDF) in Environmental Samples Using EPA Method 1613”, Chemical Sciences Department, Midwest Research Institute, 425 Volker Boulevard, Kansas City, MO 44110-2299, Standard Operating Procedure No. CS-153, January 15, 1992.</P>
                        <P>29. Ryan, John J. Raymonde Lizotte and William H. Newsome, J. Chromatog. 303 (1984) 351-360.</P>
                        <P>30. Telliard, William A., McCarty, Harry B., and Riddick, Lynn S. “Results of the Interlaboratory Validation Study of USEPA Method 1613 for the Analysis of Tetra-through Octachlorinated Dioxins and Furans by Isotope Dilution GC/MS,” Chemosphere, 27, 41-46 (1993).</P>
                        <P>31. “Results of the International Interlaboratory Validation Study of USEPA Method 1613”, October 1994, available from the EPA Sample Control Center operated by DynCorp Viar, Inc., 300 N Lee St, Alexandria, VA 22314, 703-519-1140.</P>
                        <HD SOURCE="HD2">23.0 Tables and Figures</HD>
                        <PRTPAGE P="335"/>
                        <GPOTABLE COLS="4" OPTS="L2" CDEF="s50,12,r50,12">
                            <TTITLE>Table 1—Chlorinated Dibenzo-p-Dioxins and Furans Determined by Isotope Dilution and Internal Standard High Resolution Gas Chromatography (HRGC)/High Resolution Mass Spectrometry (HRMS)</TTITLE>
                            <BOXHD>
                                <CHED H="1">
                                    CDDs/CDFs 
                                    <SU>1</SU>
                                </CHED>
                                <CHED H="1">CAS registry</CHED>
                                <CHED H="1">Labeled analog</CHED>
                                <CHED H="1">CAS registry</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">2,3,7,8-TCDD</ENT>
                                <ENT>1746-01-6</ENT>
                                <ENT>
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -2,3,7,8-TCDD
                                    <LI>
                                        <SU>37</SU>
                                        Cl
                                        <E T="52">4</E>
                                        -2,3,7,8-TCDD
                                    </LI>
                                </ENT>
                                <ENT>
                                    76523-40-5
                                    <LI>85508-50-5</LI>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Total TCDD</ENT>
                                <ENT>41903-57-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,3,7,8-TCDF</ENT>
                                <ENT>51207-31-9</ENT>
                                <ENT>
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -2,3,7,8-TCDF
                                </ENT>
                                <ENT>89059-46-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Total-TCDF</ENT>
                                <ENT>55722-27-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3,7,8-PeCDD</ENT>
                                <ENT>40321-76-4</ENT>
                                <ENT>
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -1,2,3,7,8-PeCDD
                                </ENT>
                                <ENT>109719-79-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Total-PeCDD</ENT>
                                <ENT>36088-22-9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3,7,8-PeCDF</ENT>
                                <ENT>57117-41-6</ENT>
                                <ENT>
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -1,2,3,7,8-PeCDF
                                </ENT>
                                <ENT>109719-77-9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,3,4,7,8-PeCDF</ENT>
                                <ENT>57117-31-4</ENT>
                                <ENT>
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -2,3,4,7,8-PeCDF
                                </ENT>
                                <ENT>116843-02-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Total-PeCDF</ENT>
                                <ENT>30402-15-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3,4,7,8-HxCDD</ENT>
                                <ENT>39227-28-6</ENT>
                                <ENT>
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -1,2,3,4,7,8-HxCDD
                                </ENT>
                                <ENT>109719-80-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3,6,7,8-HxCDD</ENT>
                                <ENT>57653-85-7</ENT>
                                <ENT>
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -1,2,3,6,7,8-HxCDD
                                </ENT>
                                <ENT>109719-81-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3,7,8,9-HxCDD</ENT>
                                <ENT>19408-74-3</ENT>
                                <ENT>
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -1,2,3,7,8,9-HxCDD
                                </ENT>
                                <ENT>109719-82-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Total-HxCDD</ENT>
                                <ENT>34465-46-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3,4,7,8-HxCDF</ENT>
                                <ENT>70648-26-9</ENT>
                                <ENT>
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -1,2,3,4,7,8-HxCDF
                                </ENT>
                                <ENT>114423-98-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3,6,7,8-HxCDF</ENT>
                                <ENT>57117-44-9</ENT>
                                <ENT>
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -1,2,3,6,7,8-HxCDF
                                </ENT>
                                <ENT>116843-03-9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3,7,8,9-HxCDF</ENT>
                                <ENT>72918-21-9</ENT>
                                <ENT>
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -1,2,3,7,8,9-HxCDF
                                </ENT>
                                <ENT>116843-04-0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,3,4,6,7,8-HxCDF</ENT>
                                <ENT>60851-34-5</ENT>
                                <ENT>
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -2,3,4,6,7,8-HxCDF
                                </ENT>
                                <ENT>116843-05-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Total-HxCDF</ENT>
                                <ENT>55684-94-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3,4,6,7,8-HpCDD</ENT>
                                <ENT>35822-46-9</ENT>
                                <ENT>
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -1,2,3,4,6,7,8-HpCDD
                                </ENT>
                                <ENT>109719-83-7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Total-HpCDD</ENT>
                                <ENT>37871-00-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3,4,6,7,8-HpCDF</ENT>
                                <ENT>67562-39-4</ENT>
                                <ENT>
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -1,2,3,4,6,7,8-HpCDF
                                </ENT>
                                <ENT>109719-84-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3,4,7,8,9-HpCDF</ENT>
                                <ENT>55673-89-7</ENT>
                                <ENT>
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -1,2,3,4,7,8,9-HpCDF
                                </ENT>
                                <ENT>109719-94-0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Total-HpCDF</ENT>
                                <ENT>38998-75-3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">OCDD</ENT>
                                <ENT>3268-87-9</ENT>
                                <ENT>
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -OCDD
                                </ENT>
                                <ENT>114423-97-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">OCDF</ENT>
                                <ENT>39001-02-0</ENT>
                                <ENT>Not used</ENT>
                            </ROW>
                            <TNOTE>
                                <SU>1</SU>
                                 Chlorinated dibenzo-p-dioxins and chlorinated dibenzofurans.
                            </TNOTE>
                            <TNOTE> TCDD = Tetrachlorodibenzo-p-dioxin.</TNOTE>
                            <TNOTE> TCDF = Tetrachlorodibenzofuran.</TNOTE>
                            <TNOTE> PeCDD = Pentachlorodibenzo-p-dioxin.</TNOTE>
                            <TNOTE> PeCDF = Pentachlorodibenzofuran.</TNOTE>
                            <TNOTE> HxCDD = Hexachlorodibenzo-p-dioxin.</TNOTE>
                            <TNOTE> HxCDF = Hexachlorodibenzofuran.</TNOTE>
                            <TNOTE> HpCDD = Heptachlorodibenzo-p-dioxin.</TNOTE>
                            <TNOTE> HpCDF = Heptachlorodibenzofuran.</TNOTE>
                            <TNOTE> OCDD = Octachlorodibenzo-p-dioxin.</TNOTE>
                            <TNOTE> OCDF = Octachlorodibenzofuran.</TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="6" OPTS="L2" CDEF="s50,r50,12,8,8,8">
                            <TTITLE>Table 2—Retention Time References, Quantitation References, Relative Retention Times, and Minimum Levels for CDDS and DCFS</TTITLE>
                            <BOXHD>
                                <CHED H="1">CDD/CDF</CHED>
                                <CHED H="1">
                                    Retention time and quantitation
                                    <LI>reference</LI>
                                </CHED>
                                <CHED H="1">Relative retention time</CHED>
                                <CHED H="1">
                                    Minimum level 
                                    <SU>1</SU>
                                </CHED>
                                <CHED H="2">Water (pg/L; ppq)</CHED>
                                <CHED H="2">Solid (ng/kg; ppt)</CHED>
                                <CHED H="2">Extract (pg/µL; ppb)</CHED>
                            </BOXHD>
                            <ROW EXPSTB="05" RUL="s">
                                <ENT I="21">
                                    <E T="02">Compounds using</E>
                                     
                                    <SU>13</SU>
                                     
                                    <E T="02">C12-1,2,3,4-TCDD as the Injection Internal Standard</E>
                                </ENT>
                            </ROW>
                            <ROW EXPSTB="00">
                                <ENT I="01">2,3,7,8-TCDF</ENT>
                                <ENT>
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    -2,3,7,8-TCDF
                                </ENT>
                                <ENT>0.999-1.003</ENT>
                                <ENT>10</ENT>
                                <ENT>1</ENT>
                                <ENT>0.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,3,7,8-TCDD</ENT>
                                <ENT>
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    -2,3,7,8-TCDD
                                </ENT>
                                <ENT>0.999-1.002</ENT>
                                <ENT>10</ENT>
                                <ENT>1</ENT>
                                <ENT>0.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3,7,8-Pe</ENT>
                                <ENT>
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    -1,2,3,7,8-PeCDF
                                </ENT>
                                <ENT>0.999-1.002</ENT>
                                <ENT>50</ENT>
                                <ENT>5</ENT>
                                <ENT>2.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,3,4,7,8-PeCDF</ENT>
                                <ENT>
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    -2,3,4,7,8-PeCDF
                                </ENT>
                                <ENT>0.999-1.002</ENT>
                                <ENT>50</ENT>
                                <ENT>5</ENT>
                                <ENT>2.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3,7,8-PeCDD</ENT>
                                <ENT>
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    -1,2,3,7,8-PeCDD
                                </ENT>
                                <ENT>0.999-1.002</ENT>
                                <ENT>50</ENT>
                                <ENT>5</ENT>
                                <ENT>2.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    -2,3,7,8-TCDF
                                </ENT>
                                <ENT>
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    -1,2,3,4-TCDD
                                </ENT>
                                <ENT>0.923-1.103</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    -2,3,7,8-TCDD
                                </ENT>
                                <ENT>
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    -1,2,3,4-TCDD
                                </ENT>
                                <ENT>0.976-1.043</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    -2,3,7,8-TCDD
                                </ENT>
                                <ENT>
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    -1,2,3,4-TCDD
                                </ENT>
                                <ENT>0.989-1.052</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    -1,2,3,7,8-PeCDF
                                </ENT>
                                <ENT>
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    -1,2,3,4-TCDD
                                </ENT>
                                <ENT>1.000-1.425</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    -2,3,4,7,8-PeCDF
                                </ENT>
                                <ENT>
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    -1,2,3,4-TCDD
                                </ENT>
                                <ENT>1.001-1.526</ENT>
                            </ROW>
                            <ROW RUL="s">
                                <ENT I="01">
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    -1,2,3,7,8-PeCDF
                                </ENT>
                                <ENT>
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    -1,2,3,4-TCDD
                                </ENT>
                                <ENT>1.000-1.567</ENT>
                            </ROW>
                            <ROW EXPSTB="05" RUL="s">
                                <ENT I="21">
                                    <E T="02">Compounds using</E>
                                     
                                    <SU>13</SU>
                                     
                                    <E T="02">C12-1,2,3,7,8,9-HxCDD as the Injection Internal Standard</E>
                                </ENT>
                            </ROW>
                            <ROW EXPSTB="00">
                                <ENT I="01">1,2,3,4,7,8-HxCDF</ENT>
                                <ENT>
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    -1,2,3,4,7,8-HxCDF
                                </ENT>
                                <ENT>0.999-1.001</ENT>
                                <ENT>50</ENT>
                                <ENT>5</ENT>
                                <ENT>2.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3,6,7,8-HxCDF</ENT>
                                <ENT>
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    -1,2,3,6,7,8-HxCDF
                                </ENT>
                                <ENT>0.997-1.005</ENT>
                                <ENT>50</ENT>
                                <ENT>5</ENT>
                                <ENT>2.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3,7,8,9-HxCDF</ENT>
                                <ENT>
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    -1,2,3,7,8,9-HxCDF
                                </ENT>
                                <ENT>0.999-1.001</ENT>
                                <ENT>50</ENT>
                                <ENT>5</ENT>
                                <ENT>2.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,3,4,6,7,8-HxCDF</ENT>
                                <ENT>
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    -2,3,4,6,7,8-HxCDF
                                </ENT>
                                <ENT>0.999-1.001</ENT>
                                <ENT>50</ENT>
                                <ENT>5</ENT>
                                <ENT>2.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3,4,7,8-HxCDD</ENT>
                                <ENT>
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    -1,2,3,4,7,8-HxCDD
                                </ENT>
                                <ENT>0.999-1.001</ENT>
                                <ENT>50</ENT>
                                <ENT>5</ENT>
                                <ENT>2.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3,6,7,8-HxCDD</ENT>
                                <ENT>
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    -1,2,3,6,7,8-HxCDD
                                </ENT>
                                <ENT>0.998-1.004</ENT>
                                <ENT>50</ENT>
                                <ENT>5</ENT>
                                <ENT>2.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3,7,8,9-HxCDD</ENT>
                                <ENT>
                                    (
                                    <SU>2</SU>
                                    )
                                </ENT>
                                <ENT>1.000-1.019</ENT>
                                <ENT>50</ENT>
                                <ENT>5</ENT>
                                <ENT>2.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3,4,6,7,8-HpCDF</ENT>
                                <ENT>
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    -1,2,3,4,6,7,8-HpCDF
                                </ENT>
                                <ENT>0.999-1.001</ENT>
                                <ENT>50</ENT>
                                <ENT>5</ENT>
                                <ENT>2.5</ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="336"/>
                                <ENT I="01">1,2,3,4,7,8,9-HpCDF</ENT>
                                <ENT>
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    -1,2,3,4,7,8,9-HpCDF
                                </ENT>
                                <ENT>0.999-1.001</ENT>
                                <ENT>50</ENT>
                                <ENT>5</ENT>
                                <ENT>2.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3,4,6,7,8-HpCDD</ENT>
                                <ENT>
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    -1,2,3,4,6,7,8-HpCDD
                                </ENT>
                                <ENT>0.999-1.001</ENT>
                                <ENT>50</ENT>
                                <ENT>5</ENT>
                                <ENT>2.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">OCDF</ENT>
                                <ENT>
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    -OCDD
                                </ENT>
                                <ENT>0.999-1.001</ENT>
                                <ENT>100</ENT>
                                <ENT>10</ENT>
                                <ENT>5.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">OCDD</ENT>
                                <ENT>
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    -OCDD
                                </ENT>
                                <ENT>0.999-1.001</ENT>
                                <ENT>100</ENT>
                                <ENT>10</ENT>
                                <ENT>5.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3,4,6,7,8,-HxCDF</ENT>
                                <ENT>
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    -1,2,3,7,8,9-HpCDD
                                </ENT>
                                <ENT>0.949-0.975</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    1,2,3,7,8,9-HxCDF
                                </ENT>
                                <ENT>
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    -1,2,3,7,8,9-HpCDD
                                </ENT>
                                <ENT>0.977-1.047</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    2,3,4,6,7,8,-HxCDF
                                </ENT>
                                <ENT>
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    -1,2,3,7,8,9-HpCDD
                                </ENT>
                                <ENT>0.959-1.021</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    1,2,3,4,7,8,-HxCDF
                                </ENT>
                                <ENT>
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    -1,2,3,7,8,9-HpCDD
                                </ENT>
                                <ENT>0.977-1.000</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    1,2,3,6,7,8,-HxCDF
                                </ENT>
                                <ENT>
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    -1,2,3,7,8,9-HpCDD
                                </ENT>
                                <ENT>0.981-1.003</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    1,2,3,4,6,7,8-HxCDF
                                </ENT>
                                <ENT>
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    -1,2,3,7,8,9-HpCDD
                                </ENT>
                                <ENT>1.043-1.085</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    1,2,3,4,7,8,9-HxCDF
                                </ENT>
                                <ENT>
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    -1,2,3,7,8,9-HpCDD
                                </ENT>
                                <ENT>1.057-1.151</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    1,2,3,4,6,7,8-HxCDF
                                </ENT>
                                <ENT>
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    -1,2,3,7,8,9-HpCDD
                                </ENT>
                                <ENT>1.086-1.110</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    OCDD
                                </ENT>
                                <ENT>
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    -1,2,3,7,8,9-HpCDD
                                </ENT>
                                <ENT>1.032-1.311</ENT>
                            </ROW>
                            <TNOTE>
                                <SU>1</SU>
                                 The Minimum Level (ML) for each analyte is defined as the level at which the entire analytical system must give a recognizable signal and acceptable calibration point. It is equivalent to the concentration of the lowest calibration standard, assuming that all method-specified sample weights, volumes, and cleanup procedures have been employed.
                            </TNOTE>
                            <TNOTE>
                                <SU>2</SU>
                                 The retention time reference for 1,2,3,7,8,9-HxCDD is 
                                <SU>13</SU>
                                C
                                <E T="52">12</E>
                                -1,2,3,6,7,8-HxCDD, and 1,2,3,7,8,9-HxCDD is quantified using the averaged responses for 
                                <SU>13</SU>
                                C
                                <E T="52">12</E>
                                -1,2,3,4,7,8-HxCDD and 
                                <SU>13</SU>
                                C
                                <E T="52">12</E>
                                -1,2,3,6,7,8-HxCDD.
                            </TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="5" OPTS="L2" CDEF="s100,9.1,10,10,9.1">
                            <TTITLE>Table 3—Concentration of Stock and Spiking Solutions Containing CDDS/CDFS and Labeled Compounds</TTITLE>
                            <BOXHD>
                                <CHED H="1">CDD/CDF</CHED>
                                <CHED H="1">
                                    Labeled compound stock solution 
                                    <SU>1</SU>
                                    <LI>(ng/mL)</LI>
                                </CHED>
                                <CHED H="1">
                                    Labeled compound spiking solution 
                                    <SU>2</SU>
                                    <LI>(ng/mL)</LI>
                                </CHED>
                                <CHED H="1">
                                    PAR stock solution 
                                    <SU>3</SU>
                                     (ng/mL)
                                </CHED>
                                <CHED H="1">
                                    PAR spiking solution 
                                    <SU>4</SU>
                                    <LI>(ng/mL)</LI>
                                </CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">2,3,7,8-TCDD</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>40</ENT>
                                <ENT>0.8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,3,7,8-TCDF</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>40</ENT>
                                <ENT>0.8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3,7,8-PeCDD</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>200</ENT>
                                <ENT>4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3,7,8-PeCDF</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>200</ENT>
                                <ENT>4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,3,4,7,8-PeCDF</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>200</ENT>
                                <ENT>4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3,4,7,8-HxCDD</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>200</ENT>
                                <ENT>4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3,6,7,8-HxCDD</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>200</ENT>
                                <ENT>4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3,7,8,9-HxCDD</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>200</ENT>
                                <ENT>4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3,4,7,8-HxCDF</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>200</ENT>
                                <ENT>4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3,6,7,8-HxCDF</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>200</ENT>
                                <ENT>4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3,7,8,9-HxCDF</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>200</ENT>
                                <ENT>4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,3,4,6,7,8-HxCDF</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>200</ENT>
                                <ENT>4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3,4,6,7,8-HpCDD</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>200</ENT>
                                <ENT>4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3,4,6,7,8-HpCDF</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>200</ENT>
                                <ENT>4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3,4,7,8,9-HpCDF</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>200</ENT>
                                <ENT>4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">OCDD</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>400</ENT>
                                <ENT>8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">OCDF</ENT>
                                <ENT/>
                                <ENT/>
                                <ENT>400</ENT>
                                <ENT>8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -2,3,7,8-TCDD
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -2,3,7,8-TCDF
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -1,2,3,7,8-PeCDD
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -1,2,3,7,8-PeCDF
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -2,3,4,7,8-PeCDF
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -1,2,3,4,7,8-HxCDD
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -1,2,3,6,7,8-HxCDD
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -1,2,3,4,7,8-HxCDF
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -1,2,3,6,7,8-HxCDF
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -1,2,3,7,8,9-HxCDF
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -2,3,4,6,7,8-HxCDF
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -1,2,3,4,6,7,8-HpCDD
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -1,2,3,4,6,7,8-HpCDF
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -1,2,3,4,7,8,9-HpCDF
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -OCDD
                                </ENT>
                                <ENT>200</ENT>
                                <ENT>4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22">
                                    Cleanup Standard 
                                    <SU>5</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">
                                    <SU>37</SU>
                                    Cl
                                    <E T="52">4</E>
                                    -2,3,7,8-TCDD
                                </ENT>
                                <ENT>0.8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22">
                                    Internal Standards 
                                    <SU>6</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -1,2,3,4-TCDD
                                </ENT>
                                <ENT>200</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -1,2,3,7,8,9-HxCDD
                                </ENT>
                                <ENT>200</ENT>
                            </ROW>
                            <TNOTE>
                                <SU>1</SU>
                                 Section 7.10—prepared in nonane and diluted to prepare spiking solution.
                            </TNOTE>
                            <TNOTE>
                                <SU>2</SU>
                                 Section 7.10.3—prepared in acetone from stock solution daily.
                                <PRTPAGE P="337"/>
                            </TNOTE>
                            <TNOTE>
                                <SU>3</SU>
                                 Section 7.9—prepared in nonane and diluted to prepare spiking solution.
                            </TNOTE>
                            <TNOTE>
                                <SU>4</SU>
                                 Section 7.14—prepared in acetone from stock solution daily.
                            </TNOTE>
                            <TNOTE>
                                <SU>5</SU>
                                 Section 7.11—prepared in nonane and added to extract prior to cleanup.
                            </TNOTE>
                            <TNOTE>
                                <SU>6</SU>
                                 Section 7.12—prepared in nonane and added to the concentrated extract immediately prior to injection into the GC (Section 14.2).
                            </TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="6" OPTS="L2" CDEF="s100,9.1,10,10,10,10">
                            <TTITLE>
                                Table 4—Concentration of CDDS/CDFS in Calibration and Calibration Verification Solutions 
                                <SU>1</SU>
                                 (Section 15.3)
                            </TTITLE>
                            <BOXHD>
                                <CHED H="1"> </CHED>
                                <CHED H="1">CDD/CDF</CHED>
                                <CHED H="1">
                                    CS2
                                    <LI>(ng/mL)</LI>
                                </CHED>
                                <CHED H="1">
                                    CS3
                                    <LI>(ng/mL)</LI>
                                </CHED>
                                <CHED H="1">
                                    CS4
                                    <LI>(ng/mL)</LI>
                                </CHED>
                                <CHED H="1">
                                    CS5
                                    <LI>(ng/mL)</LI>
                                </CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">2,3,7,8-TCDD</ENT>
                                <ENT>0.5</ENT>
                                <ENT>2</ENT>
                                <ENT>10</ENT>
                                <ENT>40</ENT>
                                <ENT>200</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,3,7,8-TCDF</ENT>
                                <ENT>0.5</ENT>
                                <ENT>2</ENT>
                                <ENT>10</ENT>
                                <ENT>40</ENT>
                                <ENT>200</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3,7,8-PeCDD</ENT>
                                <ENT>2.5</ENT>
                                <ENT>10</ENT>
                                <ENT>50</ENT>
                                <ENT>200</ENT>
                                <ENT>1000</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3,7,8-PeCDF</ENT>
                                <ENT>2.5</ENT>
                                <ENT>10</ENT>
                                <ENT>50</ENT>
                                <ENT>200</ENT>
                                <ENT>1000</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,3,4,7,8-PeCDF</ENT>
                                <ENT>2.5</ENT>
                                <ENT>10</ENT>
                                <ENT>50</ENT>
                                <ENT>200</ENT>
                                <ENT>1000</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3,4,7,8-HxCDD</ENT>
                                <ENT>2.5</ENT>
                                <ENT>10</ENT>
                                <ENT>50</ENT>
                                <ENT>200</ENT>
                                <ENT>1000</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3,6,7,8-HxCDD</ENT>
                                <ENT>2.5</ENT>
                                <ENT>10</ENT>
                                <ENT>50</ENT>
                                <ENT>200</ENT>
                                <ENT>1000</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3,7,8,9-HxCDD</ENT>
                                <ENT>2.5</ENT>
                                <ENT>10</ENT>
                                <ENT>50</ENT>
                                <ENT>200</ENT>
                                <ENT>1000</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3,4,7,8-HxCDF</ENT>
                                <ENT>2.5</ENT>
                                <ENT>10</ENT>
                                <ENT>50</ENT>
                                <ENT>200</ENT>
                                <ENT>1000</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3,6,7,8-HxCDF</ENT>
                                <ENT>2.5</ENT>
                                <ENT>10</ENT>
                                <ENT>50</ENT>
                                <ENT>200</ENT>
                                <ENT>1000</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3,7,8,9-HxCDF</ENT>
                                <ENT>2.5</ENT>
                                <ENT>10</ENT>
                                <ENT>50</ENT>
                                <ENT>200</ENT>
                                <ENT>1000</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,3,4,6,7,8-HxCDF</ENT>
                                <ENT>2.5</ENT>
                                <ENT>10</ENT>
                                <ENT>50</ENT>
                                <ENT>200</ENT>
                                <ENT>1000</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3,4,6,7,8-HpCDD</ENT>
                                <ENT>2.5</ENT>
                                <ENT>10</ENT>
                                <ENT>50</ENT>
                                <ENT>200</ENT>
                                <ENT>1000</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3,4,6,7,8-HpCDF</ENT>
                                <ENT>2.5</ENT>
                                <ENT>10</ENT>
                                <ENT>50</ENT>
                                <ENT>200</ENT>
                                <ENT>1000</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3,4,7,8,9-HpCDF</ENT>
                                <ENT>2.5</ENT>
                                <ENT>10</ENT>
                                <ENT>50</ENT>
                                <ENT>200</ENT>
                                <ENT>1000</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">OCDD</ENT>
                                <ENT>5.0</ENT>
                                <ENT>20</ENT>
                                <ENT>100</ENT>
                                <ENT>400</ENT>
                                <ENT>2000</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">OCDF</ENT>
                                <ENT>5.0</ENT>
                                <ENT>20</ENT>
                                <ENT>100</ENT>
                                <ENT>400</ENT>
                                <ENT>2000</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    -2,3,7,8-TCDD
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    -2,3,7,8-TCDF
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    -1,2,3,7,8-PeCDD
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    -PeCDF
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    -2,3,4,7,8-PeCDF
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    -1,2,3,4,7,8-HxCDD
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    -1,2,3,6,7,8-HxCDD
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    -1,2,3,4,7,8-HxCDF
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    -1,2,3,6,7,8-HxCDF
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    -1,2,3,7,8,9-HxCDF
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    -1,2,3,4,6,7,8-HpCDD
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    -1,2,3,4,6,7,8-HpCDF
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    -1,2,3,4,7,8,9-Hp CDF
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    -OCDD
                                </ENT>
                                <ENT>200</ENT>
                                <ENT>200</ENT>
                                <ENT>200</ENT>
                                <ENT>200</ENT>
                                <ENT>200</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22">Cleanup Standard:</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">
                                    <SU>37</SU>
                                     C1
                                    <E T="52">4</E>
                                    -2,3,7,8-TCDD
                                </ENT>
                                <ENT>0.5</ENT>
                                <ENT>2</ENT>
                                <ENT>10</ENT>
                                <ENT>40</ENT>
                                <ENT>200</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22">Internal Standards:</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    -1,2,3,4-TCDD
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                     C
                                    <E T="52">12</E>
                                    -1,2,3,7,8,9-HxCDD
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                            </ROW>
                        </GPOTABLE>
                        <GPOTABLE COLS="3" OPTS="L2" CDEF="s100,xs100,xs60">
                            <TTITLE>Table 5—GC Retention Time Window Defining Solution and Isomer Specificity Test Standard (Section 7.15)</TTITLE>
                            <BOXHD>
                                <CHED H="1">DB-5 column GC retention-time window defining solution</CHED>
                                <CHED H="2">CDD/CDF</CHED>
                                <CHED H="2">First eluted</CHED>
                                <CHED H="2">Last eluted</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">TCDF</ENT>
                                <ENT>1,3,6,8-</ENT>
                                <ENT>1,2,8,9-</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">TCDD</ENT>
                                <ENT>1,3,6,8-</ENT>
                                <ENT>1,2,8,9-</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">PeCDF</ENT>
                                <ENT>1,3,4,6,8-</ENT>
                                <ENT>1,2,3,8,9-</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">PeCDD</ENT>
                                <ENT>1,2,4,7,9-</ENT>
                                <ENT>1,2,3,8,9-</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">HxCDF</ENT>
                                <ENT>1,2,3,4,6,8-</ENT>
                                <ENT>1,2,3,4,8,9-</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">HxCDD</ENT>
                                <ENT>1,2,4,6,7,9-</ENT>
                                <ENT>1,2,3,4,6,7-</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">HpCDF</ENT>
                                <ENT>1,2,3,4,6,7,8-</ENT>
                                <ENT>1,2,3,4,7,8,9-</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">HpCDD</ENT>
                                <ENT>1,2,3,4,6,7,9-</ENT>
                                <ENT>1,2,3,4,6,7,8-</ENT>
                            </ROW>
                        </GPOTABLE>
                        <GPOTABLE COLS="1" OPTS="L0,8/9" CDEF="s200">
                            <ROW>
                                <ENT I="21">
                                    <E T="02">DB-5 Column TCDD Specificity Test Standard</E>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="21">1,2,3,7 = 1,2,3,8-TCDD</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="21">2,3,7,8-TCDD</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="21">1,2,3,9-TCDD</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="21">
                                    <E T="02">DB-225 Column TCDF Isomer Specificity Test Standard</E>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="21">2,3,4,7-TCDF</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="21">2,3,7,8-TCDF</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="21">1,2,3,9-TCDF</ENT>
                            </ROW>
                        </GPOTABLE>
                        <PRTPAGE P="338"/>
                        <GPOTABLE COLS="6" OPTS="L2" CDEF="s100,10,9.1,6-4,6-4,6-4">
                            <TTITLE>
                                Table 6—Acceptance Criteria for Performance Tests When All CDDS/CDFS Are Tested 
                                <SU>1</SU>
                            </TTITLE>
                            <BOXHD>
                                <CHED H="1">CDD/CDF</CHED>
                                <CHED H="1">Test conc. (ng/mL)</CHED>
                                <CHED H="1">
                                    IPR 
                                    <SU>2 3</SU>
                                </CHED>
                                <CHED H="2">
                                    s
                                    <LI>(ng/mL)</LI>
                                </CHED>
                                <CHED H="2">
                                    X
                                    <LI>(ng/mL)</LI>
                                </CHED>
                                <CHED H="1">
                                    OPR
                                    <LI>(ng/mL)</LI>
                                </CHED>
                                <CHED H="1">
                                    VER
                                    <LI>(ng/mL)</LI>
                                </CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">2,3,7,8-TCDD</ENT>
                                <ENT>10</ENT>
                                <ENT>2.8</ENT>
                                <ENT>8.3-12.9</ENT>
                                <ENT>6.7-15.8</ENT>
                                <ENT>7.8-12.9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,3,7,8-TCDF</ENT>
                                <ENT>10</ENT>
                                <ENT>2.0</ENT>
                                <ENT>8.7-13.7</ENT>
                                <ENT>7.5-15.8</ENT>
                                <ENT>8.4-12.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3,7,8-PeCDD</ENT>
                                <ENT>50</ENT>
                                <ENT>7.5</ENT>
                                <ENT>38-66</ENT>
                                <ENT>35-71</ENT>
                                <ENT>39-65</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3,7,8-PeCDF</ENT>
                                <ENT>50</ENT>
                                <ENT>7.5</ENT>
                                <ENT>43-62</ENT>
                                <ENT>40-67</ENT>
                                <ENT>41-60</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,3,4,7,8-PeCDF</ENT>
                                <ENT>50</ENT>
                                <ENT>8.6</ENT>
                                <ENT>36-75</ENT>
                                <ENT>34-80</ENT>
                                <ENT>41-61</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3,4,7,8-HxCDD</ENT>
                                <ENT>50</ENT>
                                <ENT>9.4</ENT>
                                <ENT>39-76</ENT>
                                <ENT>35-82</ENT>
                                <ENT>39-64</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3,6,7,8-HxCDD</ENT>
                                <ENT>50</ENT>
                                <ENT>7.7</ENT>
                                <ENT>42-62</ENT>
                                <ENT>38-67</ENT>
                                <ENT>39-64</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3,7,8,9-HxCDD</ENT>
                                <ENT>50</ENT>
                                <ENT>11.1</ENT>
                                <ENT>37-71</ENT>
                                <ENT>32-81</ENT>
                                <ENT>41-61</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3,4,7,8-HxCDF</ENT>
                                <ENT>50</ENT>
                                <ENT>8.7</ENT>
                                <ENT>41-59</ENT>
                                <ENT>36-67</ENT>
                                <ENT>45-56</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3,6,7,8-HxCDF</ENT>
                                <ENT>50</ENT>
                                <ENT>6.7</ENT>
                                <ENT>46-60</ENT>
                                <ENT>42-65</ENT>
                                <ENT>44-57</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3,7,8,9-HxCDF</ENT>
                                <ENT>50</ENT>
                                <ENT>6.4</ENT>
                                <ENT>42-61</ENT>
                                <ENT>39-65</ENT>
                                <ENT>45-56</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,3,4,6,7,8-HxCDF</ENT>
                                <ENT>50</ENT>
                                <ENT>7.4</ENT>
                                <ENT>37-74</ENT>
                                <ENT>35-78</ENT>
                                <ENT>44-57</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3,4,6,7,8-HpCDD</ENT>
                                <ENT>50</ENT>
                                <ENT>7.7</ENT>
                                <ENT>38-65</ENT>
                                <ENT>35-70</ENT>
                                <ENT>43-58</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3,4,6,7,8-HpCDF</ENT>
                                <ENT>50</ENT>
                                <ENT>6.3</ENT>
                                <ENT>45-56</ENT>
                                <ENT>41-61</ENT>
                                <ENT>45-55</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3,4,7,8,9-HpCDF</ENT>
                                <ENT>50</ENT>
                                <ENT>8.1</ENT>
                                <ENT>43-63</ENT>
                                <ENT>39-69</ENT>
                                <ENT>43-58</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">OCDD</ENT>
                                <ENT>100</ENT>
                                <ENT>19</ENT>
                                <ENT>89-127</ENT>
                                <ENT>78-144</ENT>
                                <ENT>79-126</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">OCDF</ENT>
                                <ENT>100</ENT>
                                <ENT>27</ENT>
                                <ENT>74-146</ENT>
                                <ENT>63-170</ENT>
                                <ENT>63-159</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -2,3,7,8-TCDD
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>37</ENT>
                                <ENT>28-134</ENT>
                                <ENT>20-175</ENT>
                                <ENT>82-121</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -2,3,7,8-TCDF
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>35</ENT>
                                <ENT>31-113</ENT>
                                <ENT>22-152</ENT>
                                <ENT>71-140</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -1,2,3,7,8-PeCDD
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>39</ENT>
                                <ENT>27-184</ENT>
                                <ENT>21-227</ENT>
                                <ENT>62-160</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -1,2,3,7,8-PeCDF
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>34</ENT>
                                <ENT>27-156</ENT>
                                <ENT>21-192</ENT>
                                <ENT>76-130</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -2,3,4,7,8-PeCDF
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>38</ENT>
                                <ENT>16-279</ENT>
                                <ENT>13-328</ENT>
                                <ENT>77-130</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -1,2,3,4,7,8-HxCDD
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>41</ENT>
                                <ENT>29-147</ENT>
                                <ENT>21-193</ENT>
                                <ENT>85-117</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -1,2,3,6,7,8-HxCDD
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>38</ENT>
                                <ENT>34-122</ENT>
                                <ENT>25-163</ENT>
                                <ENT>85-118</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -1,2,3,4,7,8-HxCDF
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>43</ENT>
                                <ENT>27-152</ENT>
                                <ENT>19-202</ENT>
                                <ENT>76-131</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -1,2,3,6,7,8-HxCDF
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>35</ENT>
                                <ENT>30-122</ENT>
                                <ENT>21-159</ENT>
                                <ENT>70-143</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -1,2,3,7,8,9-HxCDF
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>40</ENT>
                                <ENT>24-157</ENT>
                                <ENT>17-205</ENT>
                                <ENT>74-135</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -2,3,4,6,7,8,-HxCDF
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>37</ENT>
                                <ENT>29-136</ENT>
                                <ENT>22-176</ENT>
                                <ENT>73-137</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -1,2,3,4,6,7,8-HpCDD
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>35</ENT>
                                <ENT>34-129</ENT>
                                <ENT>26-166</ENT>
                                <ENT>72-138</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -1,2,3,4,6,7,8-HpCDF
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>41</ENT>
                                <ENT>32-110</ENT>
                                <ENT>21-158</ENT>
                                <ENT>78-129</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -1,2,3,4,7,8,9-HpCDF
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>40</ENT>
                                <ENT>28-141</ENT>
                                <ENT>20-186</ENT>
                                <ENT>77-129</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -OCDD
                                </ENT>
                                <ENT>200</ENT>
                                <ENT>95</ENT>
                                <ENT>41-276</ENT>
                                <ENT>26-397</ENT>
                                <ENT>96-415</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>37</SU>
                                    Cl
                                    <E T="52">4</E>
                                    -2,3,7,8-TCDD
                                </ENT>
                                <ENT>10</ENT>
                                <ENT>3.6</ENT>
                                <ENT>3.9-15.4</ENT>
                                <ENT>3.1-19.1</ENT>
                                <ENT>7.9-12.7</ENT>
                            </ROW>
                            <TNOTE>
                                <SU>1</SU>
                                 All specifications are given as concentration in the final extract, assuming a 20 µL volume.
                            </TNOTE>
                            <TNOTE>
                                <SU>2</SU>
                                 s = standard deviation of the concentration.
                            </TNOTE>
                            <TNOTE>
                                <SU>3</SU>
                                 X = average concentration.
                            </TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="6" OPTS="L2" CDEF="s100,10,10,6-4,6-4,6-4">
                            <TTITLE>
                                Table 6a—Acceptance Criteria for Performance Tests When Only Tetra Compounds are Tested 
                                <SU>1</SU>
                            </TTITLE>
                            <BOXHD>
                                <CHED H="1">CDD/CDF</CHED>
                                <CHED H="1">Test Conc. (ng/mL)</CHED>
                                <CHED H="1">
                                    IPR 
                                    <SU>2 3</SU>
                                </CHED>
                                <CHED H="2">s (ng/mL)</CHED>
                                <CHED H="2">X (ng/mL)</CHED>
                                <CHED H="1">
                                    OPR
                                    <LI>(ng/mL)</LI>
                                </CHED>
                                <CHED H="1">
                                    VER
                                    <LI>(ng/mL)</LI>
                                </CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">2,3,7,8-TCDD</ENT>
                                <ENT>10</ENT>
                                <ENT>2.7</ENT>
                                <ENT>8.7-12.4</ENT>
                                <ENT>7.314.6</ENT>
                                <ENT>8.2-12.3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,3,7,8-TCDF</ENT>
                                <ENT>10</ENT>
                                <ENT>2.0</ENT>
                                <ENT>9.1-13.1</ENT>
                                <ENT>8.0-14.7</ENT>
                                <ENT>8.6-11.6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -2,3,7,8-TCDD
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>35</ENT>
                                <ENT>32-115</ENT>
                                <ENT>25-141</ENT>
                                <ENT>85-117</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -2,3,7,8-TCDF
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>34</ENT>
                                <ENT>35-99</ENT>
                                <ENT>26-126</ENT>
                                <ENT>76-131</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>37</SU>
                                    C
                                    <E T="52">l4</E>
                                    -2,3,7,8-TCDD
                                </ENT>
                                <ENT>10</ENT>
                                <ENT>3.4</ENT>
                                <ENT>4.5-13.4</ENT>
                                <ENT>3.7-15.8</ENT>
                                <ENT>8.3-12.1</ENT>
                            </ROW>
                            <TNOTE>
                                <SU>1</SU>
                                 All specifications are given as concentration in the final extract, assuming a 20 µL volume.
                            </TNOTE>
                            <TNOTE>
                                <SU>2</SU>
                                 s = standard deviation of the concentration.
                            </TNOTE>
                            <TNOTE>
                                <SU>3</SU>
                                 X = average concentration.
                            </TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="4" OPTS="L2" CDEF="s100,10,6-4,10">
                            <TTITLE>Table 7—Labeled Compounds Recovery in Samples When all CDDS/CDFS are Tested</TTITLE>
                            <BOXHD>
                                <CHED H="1">Compound</CHED>
                                <CHED H="1">Test conc. (ng/mL)</CHED>
                                <CHED H="1">
                                    Labeled compound
                                    <LI>recovery</LI>
                                </CHED>
                                <CHED H="2">
                                    (ng/mL) 
                                    <SU>1</SU>
                                </CHED>
                                <CHED H="2">(%)</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -2,3,7,8-TCDD
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>25-164</ENT>
                                <ENT>25-164</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -2,3,7,8-TCDF
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>24-169</ENT>
                                <ENT>24-169</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -1,2,3,7,8-PeCDD
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>25-181</ENT>
                                <ENT>25-181</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -1,2,3,7,8-PeCDF
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>24-185</ENT>
                                <ENT>24-185</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -2,3,4,7,8-PeCDF
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>21-178</ENT>
                                <ENT>21-178</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -1,2,3,4,7,8-HxCDD
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>32-141</ENT>
                                <ENT>32-141</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -1,2,3,6,7,8-HxCDD
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>28-130</ENT>
                                <ENT>28-130</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -1,2,3,4,7,8-HxCDF
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>26-152</ENT>
                                <ENT>26-152</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -1,2,3,6,7,8-HxCDF
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>26-123</ENT>
                                <ENT>26-123</ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="339"/>
                                <ENT I="01">
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -1,2,3,7,8,9-HxCDF
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>29-147</ENT>
                                <ENT>29-147</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -2,3,4,6,7,8-HxCDF
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>28-136</ENT>
                                <ENT>28-136</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -1,2,3,4,6,7,8-HpCDD
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>23-140</ENT>
                                <ENT>23-140</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -1,2,3,4,6,7,8-HpCDF
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>28-143</ENT>
                                <ENT>28-143</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -1,2,3,4,7,8,9-HpCDF
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>26-138</ENT>
                                <ENT>26-138</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -OCDD
                                </ENT>
                                <ENT>200</ENT>
                                <ENT>34-313</ENT>
                                <ENT>17-157</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>37</SU>
                                    Cl
                                    <E T="52">4</E>
                                    -2,3,7,8-TCDD
                                </ENT>
                                <ENT>10</ENT>
                                <ENT>3.5-19.7</ENT>
                                <ENT>35-197</ENT>
                            </ROW>
                            <TNOTE>
                                <SU>1</SU>
                                 Specification given as concentration in the final extract, assuming a 20-µL volume.
                            </TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="4" OPTS="L2" CDEF="s100,10,6-4,10">
                            <TTITLE>Table 7a—Labeled Compound Recovery in Samples When Only Tetra Compounds are Tested</TTITLE>
                            <BOXHD>
                                <CHED H="1">Compound</CHED>
                                <CHED H="1">Test conc. (ng/mL)</CHED>
                                <CHED H="1">
                                    Labeled compound
                                    <LI>recovery</LI>
                                </CHED>
                                <CHED H="2">
                                    (ng/mL) 
                                    <SU>1</SU>
                                </CHED>
                                <CHED H="2">(%)</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -2,3,7,8-TCDD
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>31-137</ENT>
                                <ENT>31-137</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    -2,3,7,8-TCDF
                                </ENT>
                                <ENT>100</ENT>
                                <ENT>29-140</ENT>
                                <ENT>29-140</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <SU>37</SU>
                                    Cl
                                    <E T="52">4</E>
                                    -2,3,7,8-TCDD
                                </ENT>
                                <ENT>10</ENT>
                                <ENT>4.2-16.4</ENT>
                                <ENT>42-164</ENT>
                            </ROW>
                            <TNOTE>
                                <SU>1</SU>
                                 Specification given as concentration in the final extract, assuming a 20 µL volume.
                            </TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="5" OPTS="L2" CDEF="xs60,10,xls60,r100,xs40">
                            <TTITLE>Table 8—Descriptors, Exact M/Z's, M/Z Types, and Elemental Compositions of the CDDs and CDFs</TTITLE>
                            <BOXHD>
                                <CHED H="1">Descriptor</CHED>
                                <CHED H="1">
                                    Exact M/Z 
                                    <SU>1</SU>
                                </CHED>
                                <CHED H="1">M/Z type</CHED>
                                <CHED H="1">Elemental composition</CHED>
                                <CHED H="1">
                                    Substance 
                                    <SU>2</SU>
                                </CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">1</ENT>
                                <ENT>292.9825</ENT>
                                <ENT>Lock</ENT>
                                <ENT>
                                    C
                                    <E T="52">7</E>
                                    F
                                    <E T="52">11</E>
                                </ENT>
                                <ENT>PFK</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>303.9016</ENT>
                                <ENT>M</ENT>
                                <ENT>
                                    C
                                    <E T="52">12</E>
                                    H
                                    <E T="52">4</E>
                                    <SU>35</SU>
                                    Cl
                                    <E T="52">4</E>
                                    O
                                </ENT>
                                <ENT>TCDF</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>305.8987</ENT>
                                <ENT>M = 2</ENT>
                                <ENT>
                                    C
                                    <E T="52">12</E>
                                    H
                                    <E T="52">4</E>
                                    <SU>35</SU>
                                    Cl
                                    <E T="52">3</E>
                                    <SU>37</SU>
                                    ClO
                                </ENT>
                                <ENT>TCDF</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>315.9419</ENT>
                                <ENT>M</ENT>
                                <ENT>
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    H
                                    <E T="52">4</E>
                                    <SU>35</SU>
                                    Cl
                                    <E T="52">4</E>
                                    O
                                </ENT>
                                <ENT>
                                    TCDF 
                                    <SU>3</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>317.9389</ENT>
                                <ENT>M = 2</ENT>
                                <ENT>
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    H
                                    <E T="52">4</E>
                                    <SU>35</SU>
                                    Cl
                                    <E T="52">3</E>
                                    <SU>37</SU>
                                    ClO
                                </ENT>
                                <ENT>
                                    TCDF 
                                    <SU>3</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>319.8965</ENT>
                                <ENT>M</ENT>
                                <ENT>
                                    C
                                    <E T="52">12</E>
                                    H
                                    <E T="52">4</E>
                                    <SU>35</SU>
                                    Cl
                                    <E T="52">4</E>
                                    O
                                    <E T="52">2</E>
                                </ENT>
                                <ENT>TCDD</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>321.8936</ENT>
                                <ENT>M = 2</ENT>
                                <ENT>
                                    C
                                    <E T="52">12</E>
                                    H
                                    <E T="52">4</E>
                                    <SU>35</SU>
                                    Cl
                                    <E T="52">3</E>
                                    <SU>37</SU>
                                    ClO
                                    <E T="52">2</E>
                                </ENT>
                                <ENT>TCDD</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>327.8847</ENT>
                                <ENT>M</ENT>
                                <ENT>
                                    C
                                    <E T="52">12</E>
                                    H
                                    <E T="52">4</E>
                                    <SU>37</SU>
                                    Cl
                                    <E T="52">4</E>
                                    O
                                    <E T="52">2</E>
                                </ENT>
                                <ENT>
                                    TCDD 
                                    <SU>4</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>330.9792</ENT>
                                <ENT>QC</ENT>
                                <ENT>
                                    C
                                    <E T="52">7</E>
                                    F
                                    <E T="52">13</E>
                                </ENT>
                                <ENT>PFK</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>331.9368</ENT>
                                <ENT>M</ENT>
                                <ENT>
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    H
                                    <E T="52">4</E>
                                    <SU>35</SU>
                                    Cl
                                    <E T="52">4</E>
                                    O
                                    <E T="52">2</E>
                                </ENT>
                                <ENT>
                                    TCDD 
                                    <SU>3</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>333.9339</ENT>
                                <ENT>M = 2</ENT>
                                <ENT>
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    H
                                    <E T="52">4</E>
                                    <SU>35</SU>
                                    Cl
                                    <E T="52">3</E>
                                    <SU>37</SU>
                                    ClO
                                    <E T="52">2</E>
                                </ENT>
                                <ENT>
                                    TCDD 
                                    <SU>3</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>375.8364</ENT>
                                <ENT>M = 2</ENT>
                                <ENT>
                                    C
                                    <E T="52">12</E>
                                    H
                                    <E T="52">4</E>
                                    <SU>35</SU>
                                    Cl
                                    <E T="52">5</E>
                                    <SU>37</SU>
                                    ClO
                                </ENT>
                                <ENT>HxCDPE</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2</ENT>
                                <ENT>339.8597</ENT>
                                <ENT>M = 2</ENT>
                                <ENT>
                                    C
                                    <E T="52">12</E>
                                    H
                                    <E T="52">3</E>
                                    <SU>35</SU>
                                    Cl
                                    <E T="52">4</E>
                                    <SU>37</SU>
                                    ClO
                                </ENT>
                                <ENT>PeCDF</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>341.8567</ENT>
                                <ENT>M = 4</ENT>
                                <ENT>
                                    C
                                    <E T="52">12</E>
                                    H
                                    <E T="52">3</E>
                                    <SU>35</SU>
                                    Cl
                                    <E T="52">3</E>
                                    <SU>37</SU>
                                    Cl
                                    <E T="52">2</E>
                                    O
                                </ENT>
                                <ENT>PeCDF</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>351.9000</ENT>
                                <ENT>M = 2</ENT>
                                <ENT>
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    H
                                    <E T="52">3</E>
                                    <SU>35</SU>
                                    Cl
                                    <E T="52">4</E>
                                    <SU>37</SU>
                                    ClO
                                </ENT>
                                <ENT>PeCDF</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>353.8970</ENT>
                                <ENT>M = 4</ENT>
                                <ENT>
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    H
                                    <E T="52">3</E>
                                    <SU>35</SU>
                                    Cl
                                    <E T="52">3</E>
                                    <SU>37</SU>
                                    Cl
                                    <E T="52">2</E>
                                    O
                                </ENT>
                                <ENT>
                                    PeCDF 
                                    <SU>3</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>354.9792</ENT>
                                <ENT>Lock</ENT>
                                <ENT>
                                    C
                                    <E T="52">9</E>
                                    F
                                    <E T="52">13</E>
                                </ENT>
                                <ENT>PFK</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>355.8546</ENT>
                                <ENT>M = 2</ENT>
                                <ENT>
                                    C
                                    <E T="52">12</E>
                                    H
                                    <E T="52">3</E>
                                    <SU>35</SU>
                                    Cl
                                    <E T="52">4</E>
                                    <SU>37</SU>
                                    ClO
                                    <E T="52">2</E>
                                </ENT>
                                <ENT>PeCDD</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>357.8516</ENT>
                                <ENT>M = 4</ENT>
                                <ENT>
                                    C
                                    <E T="52">12</E>
                                    H
                                    <E T="52">3</E>
                                    <SU>35</SU>
                                    Cl
                                    <E T="52">3</E>
                                    <SU>37</SU>
                                    Cl
                                    <E T="52">2</E>
                                    O
                                    <E T="52">2</E>
                                </ENT>
                                <ENT>PeCDD</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>367.8949</ENT>
                                <ENT>M = 2</ENT>
                                <ENT>
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    H
                                    <E T="52">3</E>
                                    <SU>35</SU>
                                    Cl
                                    <E T="52">4</E>
                                    <SU>37</SU>
                                    ClO
                                    <E T="52">2</E>
                                </ENT>
                                <ENT>
                                    PeCDD 
                                    <SU>3</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>369.8919</ENT>
                                <ENT>M = 4</ENT>
                                <ENT>
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    H
                                    <E T="52">3</E>
                                    <SU>35</SU>
                                    Cl
                                    <E T="52">3</E>
                                    <SU>37</SU>
                                    Cl
                                    <E T="52">2</E>
                                    O
                                    <E T="52">2</E>
                                </ENT>
                                <ENT>
                                    PeCDD 
                                    <SU>3</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>409.7974</ENT>
                                <ENT>M = 2</ENT>
                                <ENT>
                                    C
                                    <E T="52">12</E>
                                    H
                                    <E T="52">3</E>
                                    <SU>35</SU>
                                    Cl
                                    <E T="52">6</E>
                                    <SU>37</SU>
                                    ClO
                                </ENT>
                                <ENT>HpCDPE</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">3</ENT>
                                <ENT>373.8208</ENT>
                                <ENT>M = 2</ENT>
                                <ENT>
                                    C
                                    <E T="52">12</E>
                                    H
                                    <E T="52">2</E>
                                    <SU>35</SU>
                                    Cl
                                    <E T="52">5</E>
                                    <SU>37</SU>
                                    ClO
                                </ENT>
                                <ENT>HxCDF</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>375.8178</ENT>
                                <ENT>M = 4</ENT>
                                <ENT>
                                    C
                                    <E T="52">12</E>
                                    H
                                    <E T="52">2</E>
                                    <SU>35</SU>
                                    Cl
                                    <E T="52">4</E>
                                    <SU>37</SU>
                                    Cl
                                    <E T="52">2</E>
                                    O
                                </ENT>
                                <ENT>HxCDF</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>383.8639</ENT>
                                <ENT>M</ENT>
                                <ENT>
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    H
                                    <E T="52">2</E>
                                    <SU>35</SU>
                                    Cl
                                    <E T="52">6</E>
                                    O
                                </ENT>
                                <ENT>
                                    HxCDF 
                                    <SU>3</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>385.8610</ENT>
                                <ENT>M = 2</ENT>
                                <ENT>
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    H
                                    <E T="52">2</E>
                                    <SU>35</SU>
                                    Cl
                                    <E T="52">5</E>
                                    <SU>37</SU>
                                    ClO
                                </ENT>
                                <ENT>
                                    HxCDF 
                                    <SU>3</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>389.8157</ENT>
                                <ENT>M = 2</ENT>
                                <ENT>
                                    C
                                    <E T="52">12</E>
                                    H
                                    <E T="52">2</E>
                                    <SU>35</SU>
                                    Cl
                                    <E T="52">5</E>
                                    <SU>37</SU>
                                    ClO
                                    <E T="52">2</E>
                                </ENT>
                                <ENT>HxCDD</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>391.8127</ENT>
                                <ENT>M = 4</ENT>
                                <ENT>
                                    C
                                    <E T="52">12</E>
                                    H
                                    <E T="52">2</E>
                                    <SU>35</SU>
                                    Cl
                                    <E T="52">4</E>
                                    <SU>37</SU>
                                    Cl
                                    <E T="52">2</E>
                                    O
                                    <E T="52">2</E>
                                </ENT>
                                <ENT>HxCDD</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>392.9760</ENT>
                                <ENT>Lock</ENT>
                                <ENT>
                                    C
                                    <E T="52">9</E>
                                    F
                                    <E T="52">15</E>
                                </ENT>
                                <ENT>PFK</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>401.8559</ENT>
                                <ENT>M = 2</ENT>
                                <ENT>
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    H
                                    <E T="52">2</E>
                                    <SU>35</SU>
                                    Cl
                                    <E T="52">5</E>
                                    <SU>37</SU>
                                    ClO
                                    <E T="52">2</E>
                                </ENT>
                                <ENT>
                                    HxCDD 
                                    <SU>3</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>403.8529</ENT>
                                <ENT>M = 4</ENT>
                                <ENT>
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    H
                                    <E T="52">2</E>
                                    <SU>35</SU>
                                    Cl
                                    <E T="52">4</E>
                                    <SU>37</SU>
                                    Cl
                                    <E T="52">2</E>
                                    O
                                    <E T="52">2</E>
                                </ENT>
                                <ENT>
                                    HxCDD 
                                    <SU>3</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>430.9729</ENT>
                                <ENT>QC</ENT>
                                <ENT>
                                    C
                                    <E T="52">9</E>
                                    F
                                    <E T="52">17</E>
                                </ENT>
                                <ENT>PFK</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>445.7555</ENT>
                                <ENT>M = 4</ENT>
                                <ENT>
                                    C
                                    <E T="52">12</E>
                                    H
                                    <E T="52">2</E>
                                    <SU>35</SU>
                                    Cl
                                    <E T="52">6</E>
                                    <SU>37</SU>
                                    Cl
                                    <E T="52">2</E>
                                    O
                                </ENT>
                                <ENT>OCDPE</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4</ENT>
                                <ENT>407.7818</ENT>
                                <ENT>M = 2</ENT>
                                <ENT>
                                    C
                                    <E T="52">12</E>
                                    H
                                    <SU>35</SU>
                                    Cl
                                    <E T="52">6</E>
                                    <SU>37</SU>
                                    ClO
                                </ENT>
                                <ENT>HpCDF</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>409.7789</ENT>
                                <ENT>M = 4</ENT>
                                <ENT>
                                    C
                                    <E T="52">12</E>
                                    H
                                    <SU>35</SU>
                                    Cl
                                    <E T="52">5</E>
                                    <SU>37</SU>
                                    Cl
                                    <E T="52">2</E>
                                    O
                                </ENT>
                                <ENT>HpCDF</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>417.8253</ENT>
                                <ENT>M</ENT>
                                <ENT>
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    H
                                    <SU>35</SU>
                                    Cl
                                    <E T="52">7</E>
                                    O
                                </ENT>
                                <ENT>
                                    HpCDF 
                                    <SU>3</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>419.8220</ENT>
                                <ENT>M = 2</ENT>
                                <ENT>
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    H
                                    <SU>35</SU>
                                    Cl
                                    <E T="52">6</E>
                                    <SU>37</SU>
                                    ClO
                                </ENT>
                                <ENT>
                                    HpCDF 
                                    <SU>3</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>423.7766</ENT>
                                <ENT>M = 2</ENT>
                                <ENT>
                                    C
                                    <E T="52">12</E>
                                    H
                                    <SU>35</SU>
                                    Cl
                                    <E T="52">6</E>
                                    <SU>37</SU>
                                    ClO
                                    <E T="52">2</E>
                                </ENT>
                                <ENT>HpCDD</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>425.7737</ENT>
                                <ENT>M = 4</ENT>
                                <ENT>
                                    C
                                    <E T="52">12</E>
                                    H
                                    <SU>35</SU>
                                    Cl
                                    <E T="52">5</E>
                                    <SU>37</SU>
                                    Cl
                                    <E T="52">2</E>
                                    O
                                    <E T="52">2</E>
                                </ENT>
                                <ENT>HpCDD</ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="340"/>
                                <ENT I="22"> </ENT>
                                <ENT>430.9729</ENT>
                                <ENT>Lock</ENT>
                                <ENT>
                                    C
                                    <E T="52">9</E>
                                    F
                                    <E T="52">17</E>
                                </ENT>
                                <ENT>PFK</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>435.8169</ENT>
                                <ENT>M = 2</ENT>
                                <ENT>
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    H
                                    <SU>35</SU>
                                    Cl
                                    <E T="52">6</E>
                                    <SU>37</SU>
                                    ClO
                                    <E T="52">2</E>
                                </ENT>
                                <ENT>
                                    HpCDD 
                                    <SU>3</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>437.8140</ENT>
                                <ENT>M = 4</ENT>
                                <ENT>
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    H
                                    <SU>35</SU>
                                    Cl
                                    <E T="52">5</E>
                                    <SU>37</SU>
                                    Cl
                                    <E T="52">2</E>
                                    O
                                    <E T="52">2</E>
                                </ENT>
                                <ENT>
                                    HpCDD 
                                    <SU>3</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>479.7165</ENT>
                                <ENT>M = 4</ENT>
                                <ENT>
                                    C
                                    <E T="52">12</E>
                                    H
                                    <SU>35</SU>
                                    Cl
                                    <E T="52">7</E>
                                    <SU>37</SU>
                                    Cl
                                    <E T="52">2</E>
                                    O
                                </ENT>
                                <ENT>NCDPE</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">5</ENT>
                                <ENT>441.7428</ENT>
                                <ENT>M = 2</ENT>
                                <ENT>
                                    C
                                    <E T="52">12</E>
                                    <SU>35</SU>
                                    Cl
                                    <E T="52">7</E>
                                    <SU>37</SU>
                                    ClO
                                </ENT>
                                <ENT>OCDF</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>442.9728</ENT>
                                <ENT>Lock</ENT>
                                <ENT>
                                    C
                                    <E T="52">10</E>
                                    F
                                    <E T="52">17</E>
                                </ENT>
                                <ENT>PFK</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>443.7399</ENT>
                                <ENT>M = 4</ENT>
                                <ENT>
                                    C
                                    <E T="52">12</E>
                                    <SU>35</SU>
                                    Cl
                                    <E T="52">6</E>
                                    <SU>37</SU>
                                    Cl
                                    <E T="52">2</E>
                                    O
                                </ENT>
                                <ENT>OCDF</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>457.7377</ENT>
                                <ENT>M = 2</ENT>
                                <ENT>
                                    C
                                    <E T="52">12</E>
                                    <SU>35</SU>
                                    Cl
                                    <E T="52">7</E>
                                    <SU>37</SU>
                                    ClO
                                    <E T="52">2</E>
                                </ENT>
                                <ENT>OCDD</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>459.7348</ENT>
                                <ENT>M = 4</ENT>
                                <ENT>
                                    C
                                    <E T="52">12</E>
                                    <SU>35</SU>
                                    Cl
                                    <E T="52">6</E>
                                    <SU>37</SU>
                                    Cl
                                    <E T="52">2</E>
                                    O
                                    <E T="52">2</E>
                                </ENT>
                                <ENT>OCDD</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>469.7779</ENT>
                                <ENT>M = 2</ENT>
                                <ENT>
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    <SU>35</SU>
                                    Cl
                                    <E T="52">7</E>
                                    <SU>37</SU>
                                    ClO
                                    <E T="52">2</E>
                                </ENT>
                                <ENT>
                                    OCDD 
                                    <SU>3</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>471.7750</ENT>
                                <ENT>M = 4</ENT>
                                <ENT>
                                    <SU>13</SU>
                                    C
                                    <E T="52">12</E>
                                    <SU>35</SU>
                                    Cl
                                    <E T="52">6</E>
                                    <SU>37</SU>
                                    Cl
                                    <E T="52">2</E>
                                    O
                                    <E T="52">2</E>
                                </ENT>
                                <ENT>
                                    OCDD 
                                    <SU>3</SU>
                                </ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>513.6775</ENT>
                                <ENT>M = 4</ENT>
                                <ENT>
                                    C
                                    <E T="52">12</E>
                                    <SU>35</SU>
                                    Cl
                                    <E T="52">8</E>
                                    <SU>37</SU>
                                    Cl
                                    <E T="52">2</E>
                                    O
                                </ENT>
                                <ENT>DCDPE</ENT>
                            </ROW>
                            <TNOTE>
                                <SU>1</SU>
                                 Nuclidic masses used:
                            </TNOTE>
                            <TNOTE> H = 1.007825.</TNOTE>
                            <TNOTE> O = 15.994915.</TNOTE>
                            <TNOTE> C = 12.00000.</TNOTE>
                            <TNOTE>
                                 
                                <SU>35</SU>
                                Cl = 34.968853.
                            </TNOTE>
                            <TNOTE>
                                 
                                <SU>13</SU>
                                C = 13.003355.
                            </TNOTE>
                            <TNOTE>
                                 
                                <SU>37</SU>
                                Cl = 36.965903.
                            </TNOTE>
                            <TNOTE> F = 18.9984.</TNOTE>
                            <TNOTE>
                                <SU>2</SU>
                                 TCDD = Tetrachlorodibenzo-p-dioxin.
                            </TNOTE>
                            <TNOTE> PeCDD = Pentachlorodibenzo-p-dioxin.</TNOTE>
                            <TNOTE> HxCDD = Hexachlorodibenzo-p-dioxin.</TNOTE>
                            <TNOTE> HpCDD = Heptachlorodibenzo-p-dioxin.</TNOTE>
                            <TNOTE> OCDD = Octachlorodibenzo-p-dioxin.</TNOTE>
                            <TNOTE> HxCDPE = Hexachlorodiphenyl ether.</TNOTE>
                            <TNOTE> OCDPE = Octachlorodiphenyl ether.</TNOTE>
                            <TNOTE> DCDPE = Decachlorodiphenyl ether.</TNOTE>
                            <TNOTE> TCDF = Tetrachlorodibenzofuran.</TNOTE>
                            <TNOTE> PeCDF = Pentachlorodibenzofuran.</TNOTE>
                            <TNOTE> HxCDF = Hexachlorodibenzofuran.</TNOTE>
                            <TNOTE> HpCDF = Heptachlorodibenzofuran.</TNOTE>
                            <TNOTE> OCDF = Octachlorodibenzofuran.</TNOTE>
                            <TNOTE> HpCDPE = Heptachlorodiphenyl ether.</TNOTE>
                            <TNOTE> NCDPE = Nonachlorodiphenyl ether.</TNOTE>
                            <TNOTE> PFK = Perfluorokerosene.</TNOTE>
                            <TNOTE>
                                <SU>3</SU>
                                 Labeled compound.
                            </TNOTE>
                            <TNOTE>
                                <SU>4</SU>
                                 There is only one m/z for 
                                <SU>37</SU>
                                Cl
                                <E T="52">4</E>
                                -2,3,7,8,-TCDD (cleanup standard).
                            </TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="5" OPTS="L2" CDEF="s100,r100,10,10,10">
                            <TTITLE>Table 9—Theoretical Ion Abundance Ratios and QC Limits</TTITLE>
                            <BOXHD>
                                <CHED H="1">Number of chlorine atoms</CHED>
                                <CHED H="1">M/Z's forming ratio</CHED>
                                <CHED H="1">Theoretical ratio</CHED>
                                <CHED H="1">
                                    QC limit 
                                    <SU>1</SU>
                                </CHED>
                                <CHED H="2">Lower</CHED>
                                <CHED H="2">Upper</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">
                                    4 
                                    <SU>2</SU>
                                </ENT>
                                <ENT>M/(M = 2)</ENT>
                                <ENT>0.77</ENT>
                                <ENT>0.65</ENT>
                                <ENT>0.89</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">5</ENT>
                                <ENT>(M = 2)/(M = 4)</ENT>
                                <ENT>1.55</ENT>
                                <ENT>1.32</ENT>
                                <ENT>1.78</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">6</ENT>
                                <ENT>(M = 2)/(M = 4)</ENT>
                                <ENT>1.24</ENT>
                                <ENT>1.05</ENT>
                                <ENT>1.43</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    6 
                                    <SU>3</SU>
                                </ENT>
                                <ENT>M/(M = 2)</ENT>
                                <ENT>0.51</ENT>
                                <ENT>0.43</ENT>
                                <ENT>0.59</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">7</ENT>
                                <ENT>(M = 2)/(M = 4)</ENT>
                                <ENT>1.05</ENT>
                                <ENT>0.88</ENT>
                                <ENT>1.20</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    7 
                                    <SU>4</SU>
                                </ENT>
                                <ENT>M/(M = 2)</ENT>
                                <ENT>0.44</ENT>
                                <ENT>0.37</ENT>
                                <ENT>0.51</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">8</ENT>
                                <ENT>(M = 2)/(M = 4)</ENT>
                                <ENT>0.89</ENT>
                                <ENT>0.76</ENT>
                                <ENT>1.02</ENT>
                            </ROW>
                            <TNOTE>
                                <SU>1</SU>
                                 QC limits represent ±15% windows around the theoretical ion abundance ratios.
                            </TNOTE>
                            <TNOTE>
                                <SU>2</SU>
                                 Does not apply to 
                                <SU>37</SU>
                                Cl
                                <E T="52">4</E>
                                -2,3,7,8-TCDD (cleanup standard).
                            </TNOTE>
                            <TNOTE>
                                <SU>3</SU>
                                 Used for 
                                <SU>13</SU>
                                C
                                <E T="52">12</E>
                                -HxCDF only.
                            </TNOTE>
                            <TNOTE>
                                <SU>4</SU>
                                 Used for 
                                <SU>13</SU>
                                C
                                <E T="52">12</E>
                                -HpCDF only.
                            </TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="5" OPTS="L2" CDEF="s50,r50,12,r50,xs40">
                            <TTITLE>
                                Table 10—Suggested Sample Quantities To Be Extracted for Various Matrices 
                                <SU>1</SU>
                            </TTITLE>
                            <BOXHD>
                                <CHED H="1">
                                    Sample Matrix 
                                    <SU>2</SU>
                                </CHED>
                                <CHED H="1">Example</CHED>
                                <CHED H="1">Percent solids</CHED>
                                <CHED H="1">Phase</CHED>
                                <CHED H="1">Quantity extracted</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="22">Single-phase:</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">Aqueous</ENT>
                                <ENT>Drinking water</ENT>
                                <ENT>&lt;1</ENT>
                                <ENT>
                                    (
                                    <SU>3</SU>
                                    )
                                </ENT>
                                <ENT>1000 mL.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT O="xl">Groundwater</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT O="xl">Treated wastewater</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">Solid</ENT>
                                <ENT>Dry soil</ENT>
                                <ENT>&gt;20</ENT>
                                <ENT>Solid</ENT>
                                <ENT>10 g.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT O="xl">Compost</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT O="xl">Ash</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">Organic</ENT>
                                <ENT>Waste solvent</ENT>
                                <ENT>&lt;1</ENT>
                                <ENT>Organic</ENT>
                                <ENT>10 g.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT O="xl">Waste oil</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT O="xl">Organic polymer</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="03">Tissue</ENT>
                                <ENT>Fish</ENT>
                                <ENT/>
                                <ENT>Organic</ENT>
                                <ENT>10 g.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT O="xl">Human adipose</ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="341"/>
                                <ENT I="22">Multi-phase:</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="13">Liquid/Solid:</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="05">Aqueous/Solid</ENT>
                                <ENT>Wet soil</ENT>
                                <ENT>1-30</ENT>
                                <ENT>Solid</ENT>
                                <ENT>10 g.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Untreated effluent</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Digested municipal sludge</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Filter cake</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT>Paper pulp</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="05">Organic/solid</ENT>
                                <ENT>Industrial sludge</ENT>
                                <ENT>1-100</ENT>
                                <ENT>Both</ENT>
                                <ENT>10 g.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT O="xl">Oily waste</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="13">Liquid/Liquid:</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="05">Aqueous/organic</ENT>
                                <ENT>In-process effluent</ENT>
                                <ENT>&lt;1</ENT>
                                <ENT>Organic</ENT>
                                <ENT>10 g.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT O="xl">Untreated effluent</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT O="xl">Drum waste</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="05">Aqueous/organic/solid</ENT>
                                <ENT>Untreated effluent</ENT>
                                <ENT>&gt;1</ENT>
                                <ENT>Organic and solid</ENT>
                                <ENT>10 g.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT O="xl">Drum waste</ENT>
                            </ROW>
                            <TNOTE>
                                <SU>1</SU>
                                 The quantity of sample to be extracted is adjusted to provide 10 g of solids (dry weight). One liter of aqueous samples containing 1% solids will contain 10 g of solids. For aqueous samples containing greater than 1% solids, a lesser volume is used so that 10 g of solids (dry weight) will be extracted.
                            </TNOTE>
                            <TNOTE>
                                <SU>2</SU>
                                 The sample matrix may be amorphous for some samples. In general, when the CDDs/CDFs are in contact with a multiphase system in which one of the phases is water, they will be preferentially dispersed in or adsorbed on the alternate phase because of their low solubility in water.
                            </TNOTE>
                            <TNOTE>
                                <SU>3</SU>
                                 Aqueous samples are filtered after spiking with the labeled compounds. The filtrate and the materials trapped on the filter are extracted separately, and the extracts are combined for cleanup and analysis.
                            </TNOTE>
                        </GPOTABLE>
                        <GPH SPAN="2" DEEP="470">
                            <PRTPAGE P="342"/>
                            <GID>ER15SE97.012</GID>
                        </GPH>
                        <GPH SPAN="2" DEEP="470">
                            <PRTPAGE P="343"/>
                            <GID>ER15SE97.013</GID>
                        </GPH>
                        <GPH SPAN="2" DEEP="470">
                            <PRTPAGE P="344"/>
                            <GID>ER15SE97.014</GID>
                        </GPH>
                        <GPH SPAN="2" DEEP="470">
                            <PRTPAGE P="345"/>
                            <GID>ER15SE97.015</GID>
                        </GPH>
                        <GPH SPAN="2" DEEP="470">
                            <PRTPAGE P="346"/>
                            <GID>ER15SE97.016</GID>
                        </GPH>
                        <GPH SPAN="2" DEEP="404">
                            <PRTPAGE P="347"/>
                            <GID>ER15SE97.017</GID>
                        </GPH>
                        <GPH SPAN="2" DEEP="382">
                            <PRTPAGE P="348"/>
                            <GID>ER15SE97.018</GID>
                        </GPH>
                        <HD SOURCE="HD2">24.0 Glossary of Definitions and Purposes</HD>
                        <P>These definitions and purposes are specific to this method but have been conformed to common usage as much as possible.</P>
                        <P>24.1 Units of weight and Measure and Their Abbreviations.</P>
                        <P>24.1.1 Symbols:</P>
                        <FP SOURCE="FP-2">°C—degrees Celsius</FP>
                        <FP SOURCE="FP-2">µL—microliter</FP>
                        <FP SOURCE="FP-2">µm—micrometer</FP>
                        <FP SOURCE="FP-2">&lt;—less than</FP>
                        <FP SOURCE="FP-2">&gt;—greater than</FP>
                        <FP SOURCE="FP-2">%—percent</FP>
                        <FP SOURCE="FP-2">24.1.2 Alphabetical abbreviations:</FP>
                        <FP SOURCE="FP-2">amp—ampere</FP>
                        <FP SOURCE="FP-2">cm—centimeter</FP>
                        <FP SOURCE="FP-2">g—gram</FP>
                        <FP SOURCE="FP-2">h—hour</FP>
                        <FP SOURCE="FP-2">D—inside diameter</FP>
                        <FP SOURCE="FP-2">in.—inch</FP>
                        <FP SOURCE="FP-2">L—liter</FP>
                        <FP SOURCE="FP-2">M—Molecular ion</FP>
                        <FP SOURCE="FP-2">m—meter</FP>
                        <FP SOURCE="FP-2">mg—milligram</FP>
                        <FP SOURCE="FP-2">min—minute</FP>
                        <FP SOURCE="FP-2">mL—milliliter</FP>
                        <FP SOURCE="FP-2">mm—millimeter</FP>
                        <FP SOURCE="FP-2">
                            m/z—mass-to-charge ratio
                            <PRTPAGE P="349"/>
                        </FP>
                        <FP SOURCE="FP-2">N—normal; gram molecular weight of solute divided by hydrogen equivalent of solute, per liter of solution</FP>
                        <FP SOURCE="FP-2">OD—outside diameter</FP>
                        <FP SOURCE="FP-2">pg—picogram</FP>
                        <FP SOURCE="FP-2">ppb—part-per-billion</FP>
                        <FP SOURCE="FP-2">ppm—part-per-million</FP>
                        <FP SOURCE="FP-2">ppq—part-per-quadrillion</FP>
                        <FP SOURCE="FP-2">ppt—part-per-trillion</FP>
                        <FP SOURCE="FP-2">psig—pounds-per-square inch gauge</FP>
                        <FP SOURCE="FP-2">v/v—volume per unit volume</FP>
                        <FP SOURCE="FP-2">w/v—weight per unit volume</FP>
                        <P>24.2 Definitions and Acronyms (in Alphabetical Order).</P>
                        <P>Analyte—A CDD or CDF tested for by this method. The analytes are listed in Table 1.</P>
                        <P>Calibration Standard (CAL)—A solution prepared from a secondary standard and/or stock solutions and used to calibrate the response of the instrument with respect to analyte concentration.</P>
                        <P>Calibration Verification Standard (VER)—The mid-point calibration standard (CS3) that is used in to verify calibration. See Table 4.</P>
                        <P>CDD—Chlorinated Dibenzo-p-ioxin—The isomers and congeners of tetra-through octa-chlorodibenzo-p-dioxin.</P>
                        <P>CDF—Chlorinated Dibenzofuran—The isomers and congeners of tetra-through octa-chlorodibenzofuran.</P>
                        <P>CS1, CS2, CS3, CS4, CS5—See Calibration standards and Table 4.</P>
                        <P>Field Blank—An aliquot of reagent water or other reference matrix that is placed in a sample container in the laboratory or the field, and treated as a sample in all respects, including exposure to sampling site conditions, storage, preservation, and all analytical procedures. The purpose of the field blank is to determine if the field or sample transporting procedures and environments have contaminated the sample.</P>
                        <P>GC—Gas chromatograph or gas chromatography.</P>
                        <P>GPC—Gel permeation chromatograph or gel permeation chromatography.</P>
                        <P>HPLC—High performance liquid chromatograph or high performance liquid chromatography.</P>
                        <P>HRGC—High resolution GC.</P>
                        <P>HRMS—High resolution MS.</P>
                        <P>IPR—Initial precision and recovery; four aliquots of the diluted PAR standard analyzed to establish the ability to generate acceptable precision and accuracy. An IPR is performed prior to the first time this method is used and any time the method or instrumentation is modified.</P>
                        <P>K-D—Kuderna-Danish concentrator; a device used to concentrate the analytes in a solvent.</P>
                        <P>Laboratory Blank—See method blank.</P>
                        <P>Laboratory Control sample (LCS)—See ongoing precision and recovery standard (OPR).</P>
                        <P>Laboratory Reagent Blank—See method blank.</P>
                        <P>May—This action, activity, or procedural step is neither required nor prohibited.</P>
                        <P>May Not—This action, activity, or procedural step is prohibited.</P>
                        <P>Method Blank—An aliquot of reagent water that is treated exactly as a sample including exposure to all glassware, equipment, solvents, reagents, internal standards, and surrogates that are used with samples. The method blank is used to determine if analytes or interferences are present in the laboratory environment, the reagents, or the apparatus.</P>
                        <P>Minimum Level (ML)—The level at which the entire analytical system must give a recognizable signal and acceptable calibration point for the analyte. It is equivalent to the concentration of the lowest calibration standard, assuming that all method-specified sample weights, volumes, and cleanup procedures have been employed.</P>
                        <P>MS—Mass spectrometer or mass spectrometry.</P>
                        <P>Must—This action, activity, or procedural step is required.</P>
                        <P>OPR—Ongoing precision and recovery standard (OPR); a laboratory blank spiked with known quantities of analytes. The OPR is analyzed exactly like a sample. Its purpose is to assure that the results produced by the laboratory remain within the limits specified in this method for precision and recovery.</P>
                        <P>PAR—Precision and recovery standard; secondary standard that is diluted and spiked to form the IPR and OPR.</P>
                        <P>PFK—Perfluorokerosene; the mixture of compounds used to calibrate the exact m/z scale in the HRMS.</P>
                        <P>Preparation Blank—See method blank.</P>
                        <P>Primary Dilution Standard—A solution containing the specified analytes that is purchased or prepared from stock solutions and diluted as needed to prepare calibration solutions and other solutions.</P>
                        <P>Quality Control Check Sample (QCS)—A sample containing all or a subset of the analytes at known concentrations. The QCS is obtained from a source external to the laboratory or is prepared from a source of standards different from the source of calibration standards. It is used to check laboratory performance with test materials prepared external to the normal preparation process.</P>
                        <P>Reagent Water—Water demonstrated to be free from the analytes of interest and potentially interfering substances at the method detection limit for the analyte.</P>
                        <P>Relative Standard Deviation (RSD)—The standard deviation times 100 divided by the mean. Also termed “coefficient of variation.”</P>
                        <P>RF—Response factor. See Section 10.6.1.</P>
                        <P>RR—Relative response. See Section 10.5.2.</P>
                        <P>
                            RSD—See relative standard deviation.
                            <PRTPAGE P="350"/>
                        </P>
                        <P>SDS—Soxhlet/Dean-Stark extractor; an extraction device applied to the extraction of solid and semi-solid materials (Reference 7).</P>
                        <P>Should—This action, activity, or procedural step is suggested but not required.</P>
                        <P>SICP—Selected ion current profile; the line described by the signal at an exact m/z.</P>
                        <P>SPE—Solid-phase extraction; an extraction technique in which an analyte is extracted from an aqueous sample by passage over or through a material capable of reversibly adsorbing the analyte. Also termed liquid-solid extraction.</P>
                        <P>Stock Solution—A solution containing an analyte that is prepared using a reference material traceable to EPA, the National Institute of Science and Technology (NIST), or a source that will attest to the purity and authenticity of the reference material.</P>
                        <P>TCDD—Tetrachlorodibenzo-p-dioxin.</P>
                        <P>TCDF—Tetrachlorodibenzofuran.</P>
                        <P>VER—See calibration verification standard.</P>
                        <HD SOURCE="HD1">Method 1624 Revision B—Volatile Organic Compounds by Isotope Dilution GC/MS</HD>
                        <EAR>Pt. 136, App. A, Meth. 1624</EAR>
                        <HD SOURCE="HD2">1. Scope and Application</HD>
                        <P>1.1 This method is designed to determine the volatile toxic organic pollutants associated with the 1976 Consent Decree and additional compounds amenable to purge and trap gas chromatography-mass spectrometry (GC/MS).</P>
                        <P>1.2 The chemical compounds listed in table 1 may be determined in municipal and industrial discharges by this method. The methmd is designed to meet the survey requirements of Effluent Guidelines Division (EGD) and the National Pollutants Discharge Elimination System (NPDES) under 40 CFR 136.1 and 136.5. Any modifications of this method, beyond those expressly permitted, shall be considered as major modifications subject to application and approval of alternate test procedures under 40 CFR 136.4 and 136.5.</P>
                        <P>1.3 The detection limit of this method is usually dependent on the level of interferences rather than instrumental limitations. The limits in table 2 represent the minimum quantity that can be detected with no interferences present.</P>
                        <P>1.4 The GC/MS portions of this method are for use only by analysts experienced with GC/MS or under the close supervision of such qualified persons. Laboratories unfamiliar with the analyses of environmental samples by GC/MS should run the performance tests in reference 1 before beginning.</P>
                        <HD SOURCE="HD2">2. Summary of Method</HD>
                        <P>2.1 Stable isotopically labeled analogs of the compounds of interest are added to a 5 mL water sample. The sample is purged at 20-25 °C with an inert gas in a specially designed chamber. The volatile organic compounds are transferred from the aqueous phase into the gaseous phase where they are passed into a sorbent column and trapped. After purging is completed, the trap is backflushed and heated rapidly to desorb the compounds into a gas chromatograph (GC). The compounds are separated by the GC and detected by a mass spectrometer (MS) (references 2 and 3). The labeled compounds serve to correct the variability of the analytical technique.</P>
                        <P>2.2 Identification of a compound (qualitative analysis) is performed by comparing the GC retention time and the background corrected characteristic spectral masses with those of authentic standards.</P>
                        <P>2.3 Quantitative analysis is performed by GC/MS using extracted ion current profile (EICP) areas. Isotope dilution is used when labeled compounds are available; otherwise, an internal standard method is used.</P>
                        <P>2.4 Quality is assured through reproducible calibration and testing of the purge and trap and GC/MS systems.</P>
                        <HD SOURCE="HD2">3. Contamination and Interferences</HD>
                        <P>3.1 Impurities in the purge gas, organic compounds out-gassing from the plumbing upstream of the trap, and solvent vapors in the laboratory account for the majority of contamination problems. The analytical system is demonstrated to be free from interferences under conditions of the analysis by analyzing blanks initially and with each sample lot (samples analyzed on the same 8 hr shift), as described in Section 8.5.</P>
                        <P>3.2 Samples can be contaminated by diffusion of volatile organic compounds (particularly methylene chloride) through the bottle seal during shipment and storage. A field blank prepared from reagent water and carried through the sampling and handling protocol serves as a check on such contamination.</P>
                        <P>3.3 Contamination by carry-over can occur when high level and low level samples are analyzed sequentially. To reduce carry-over, the purging device and sample syringe are rinsed between samples with reagent water. When an unusually concentrated sample is encountered, it is followed by analysis of a reagent water blank to check for carry-over. For samples containing large amounts of water soluble materials, suspended solids, high boiling compounds, or high levels or purgeable compounds, the purge device is washed with soap solution, rinsed with tap and distilled water, and dried in an oven at 100-125 °C. The trap and other parts of the system are also subject to contamination; therefore, frequent bakeout and purging of the entire system may be required.</P>
                        <P>
                            3.4 Interferences resulting from samples will vary considerably from source to source, depending on the diversity of the industrial complex or municipality being sampled.
                            <PRTPAGE P="351"/>
                        </P>
                        <HD SOURCE="HD2">4. Safety</HD>
                        <P>4.1 The toxicity or carcinogenicity of each compound or reagent used in this method has not been precisely determined; however, each chemical compound should be treated as a potential health hazard. Exposure to these compounds should be reduced to the lowest possible level. The laboratory is responsible for maintaining a current awareness file of OSHA regulations regarding the safe handling of the chemicals specified in this method. A reference file of data handling sheets should also be made available to all personnel involved in these analyses. Additional information on laboratory safety can be found in references 4-6.</P>
                        <P>4.2 The following compounds covered by this method have been tentatively classified as known or suspected human or mammalian carcinogens: benzene, carbon tetrachloride, chloroform, and vinyl chloride. Primary standards of these toxic compounds should be prepared in a hood, and a NIOSH/MESA approved toxic gas respirator should be worn when high concentrations are handled.</P>
                        <HD SOURCE="HD2">5. Apparatus and Materials</HD>
                        <P>5.1 Sample bottles for discrete sampling.</P>
                        <P>5.1.1 Bottle—25 to 40 mL with screw cap (Pierce 13075, or equivalent). Detergent wash, rinse with tap and distilled water, and dry at &gt;105 °C for one hr minimum before use.</P>
                        <P>5.1.2 Septum—Teflon-faced silicone (Pierce 12722, or equivalent), cleaned as above and baked at 100-200 °C, for one hour minimum.</P>
                        <P>5.2 Purge and trap device—consists of purging device, trap, and desorber. Complete devices are commercially available.</P>
                        <P>5.2.1 Purging device—designed to accept 5 mL samples with water column at least 3 cm deep. The volume of the gaseous head space between the water and trap shall be less than 15 mL. The purge gas shall be introduced less than 5 mm from the base of the water column and shall pass through the water as bubbles with a diameter less than 3 mm. The purging device shown in Figure 1 meets these criteria.</P>
                        <P>5.2.2 Trap—25 to 30 cm × 2.5 mm i.d. minimum, containing the following:</P>
                        <P>5.2.2.1 Methyl silicone packing—one ±0.2 cm, 3 percent OV-1 on 60/80 mesh Chromosorb W, or equivalent.</P>
                        <P>5.2.2.2 Porous polymer—15 ±1.0 cm, Tenax GC (2,6-diphenylene oxide polymer), 60/80 mesh, chromatographic grade, or equivalent.</P>
                        <P>5.2.2.3 Silica gel—8 ±1.0 cm, Davison Chemical, 35/60 mesh, grade 15, or equivalent. The trap shown in Figure 2 meets these specifications.</P>
                        <P>5.2.3 Desorber—shall heat the trap to 175 ±5 °C in 45 seconds or less. The polymer section of the trap shall not exceed 180 °C, and the remaining sections shall not exceed 220 °C. The desorber shown in Figure 2 meets these specifications.</P>
                        <P>5.2.4 The purge and trap device may be a separate unit or coupled to a GC as shown in Figures 3 and 4.</P>
                        <P>5.3 Gas chromatograph—shall be linearly temperature programmable with initial and final holds, shall contain a glass jet separator as the MS interface, and shall produce results which meet the calibration (Section 7), quality assurance (Section 8), and performance tests (Section 11) of this method.</P>
                        <P>5.3.1 Column—2.8 ±0.4 m × 2 ±0.5 mm i. d. glass, packekd with one percent SP-1000 on Carbopak B, 60/80 mesh, or equivalent.</P>
                        <P>5.4 Mass spectrometer—70 eV electron impact ionization; shall repetitively scan from 20 to 250 amu every 2-3 seconds, and produce a unit resolution (valleys between m/z 174-176 less than 10 percent of the height of the m/z 175 peak), background corrected mass spectrum from 50 ng 4-bromo-fluorobenzene (BFB) injected into the GC. The BFB spectrum shall meet the mass-intensity criteria in Table 3. All portions of the GC column, transfer lines, and separator which connect the GC column to the ion source shall remain at or above the column temperature during analysis to preclude condensation of less volatile compounds.</P>
                        <P>5.5 Data system—shall collect and record MS data, store mass intensity data in spectral libraries, process GC/MS data and generate reports, and shall calculate and record response factors.</P>
                        <P>5.5.1 Data acquisition—mass spectra shall be collected continuously throughout the analysis and stored on a mass storage device.</P>
                        <P>5.5.2 Mass spectral libraries—user created libraries containing mass spectra obtained from analysis of authentic standards shall be employed to reverse search GC/MS runs for the compounds of interest (Section 7.2).</P>
                        <P>5.5.3 Data processing—the data system shall be used to search, locate, identify, and quantify the compounds of interest in each GC/MS analysis. Software routines shall be employed to compute retention times and EICP areas. Displays of spectra, mass chromatograms, and library comparisons are required to verify results.</P>
                        <P>5.5.4 Response factors and multipoint calibrations—the data system shall be used to record and maintain lists of response factors (response ratios for isotope dilution) and generate multi-point calibration curves (Section 7). Computations of relative standard deviation (coefficient of variation) are useful for testing calibration linearity. Statistics on initial and on-going performance shall be maintained (Sections 8 and 11).</P>
                        <P>5.6 Syringes—5 mL glass hypodermic, with Luer-lok tips.</P>
                        <P>5.7 Micro syringes—10, 25, and 100 uL.</P>
                        <P>
                            5.8 Syringe valves—2-way, with Luer ends (Telfon or Kel-F).
                            <PRTPAGE P="352"/>
                        </P>
                        <P>5.9 Syringe—5 mL, gas-tight, with shut-off valve.</P>
                        <P>5.10 Bottles—15 mL., screw-cap with Telfon liner.</P>
                        <P>5.11 Balance—analytical, capable of weighing 0.1 mg.</P>
                        <HD SOURCE="HD2">6. Reagents and Standards</HD>
                        <P>6.1 Reagent water—water in which the compounds of interest and interfering compounds are not detected by this method (Section 11.7). It may be generated by any of the following methods:</P>
                        <P>6.1.1 Activated carbon—pass tap water through a carbon bed (Calgon Filtrasorb-300, or equivalent).</P>
                        <P>6.1.2 Water purifier—pass tap water through a purifier (Millipore Super Q, or equivalent).</P>
                        <P>6.1.3 Boil and purge—heat tap water to 90-100 °C and bubble contaminant free inert gas through it for approx one hour. While still hot, transfer the water to screw-cap bottles and seal with a Teflon-lined cap.</P>
                        <P>6.2 Sodium thiosulfate—ACS granular.</P>
                        <P>6.3 Methanol—pesticide quality or equivalent.</P>
                        <P>6.4 Standard solutions—purchased as solution or mixtures with certification to their purity, concentration, and authenticity, or prepared from materials of known purity and composition. If compound purity is 96 percent or greater, the weight may be used without correction to calculate the concentration of the standard.</P>
                        <P>6.5 Preparation of stock solutions—prepare in methanol using liquid or gaseous standards per the steps below. Observe the safety precautions given in Section 4.</P>
                        <P>6.5.1 Place approx 9.8 mL of methanol in a 10 mL ground glass stoppered volumetric flask. Allow the flask to stand unstoppered for approximately 10 minutes or until all methanol wetted surfaces have dried. In each case, weigh the flask, immediately add the compound, then immediately reweigh to prevent evaporation losses from affecting the measurement.</P>
                        <P>6.5.1.1 Liquids—using a 100 µL syringe, permit 2 drops of liquid to fall into the methanol without contacting the leck of the flask. Alternatively, inject a known volume of the compound into the methanol in the flask using a micro-syringe.</P>
                        <P>6.5.1.2 Gases (chloromethane, bromomethane, chloroethane, vinyl chloride)—fill a valved 5 mL gas-tight syringe with the compound. Lower the needle to approximately 5 mm above the methanol meniscus. Slowly introduce the compound above the surface of the meniscus. The gas will dissolve rapidly in the methanol.</P>
                        <P>6.5.2 Fill the flask to volume, stopper, then mix by inverting several times. Calculate the concentration in mg/mL (µg/µL) from the weight gain (or density if a known volume was injected).</P>
                        <P>6.5.3 Transfer the stock solution to a Teflon sealed screw-cap-bottle. Store, with minimal headspace, in the dark at −10 to −20 °C.</P>
                        <P>6.5.4 Prepare fresh standards weekly for the gases and 2-chloroethylvinyl ether. All other standards are replaced after one month, or sooner if comparison with check standards indicate a change in concentration. Quality control check standards that can be used to determine the accuracy of calibration standards are available from the US Environmental Protection Agency, Environmental Monitoring and Support Laboratory, Cincinnati, Ohio.</P>
                        <P>6.6 Labeled compound spiking solution—from stock standard solutions prepared as above, or from mixtures, prepare the spiking solution to contain a concentration such that a 5-10 µL spike into each 5 mL sample, blank, or aqueous standard analyzed will result in a concentration of 20 µg/L of each labeled compound. For the gases and for the water soluble compounds (acrolein, acrylonitrile, acetone, diethyl ether, and MEK), a concentration of 100 µg/L may be used. Include the internal standards (Section 7.5) in this solution so that a concentration of 20 µg/L in each sample, blank, or aqueous standard will be produced.</P>
                        <P>6.7 Secondary standards—using stock solutions, prepare a secondary standard in methanol to contain each pollutant at a concentration of 500 µg/mL For the gases and water soluble compounds (Section 6.6), a concentration of 2.5 mg/mL may be used.</P>
                        <P>6.7.1 Aqueous calibration standards—using a 25 µL syringe, add 20 µL of the secondary standard (Section 6.7) to 50, 100, 200, 500, and 1000 mL of reagent water to produce concentrations of 200, 100, 50, 20, and 10 µg/L, respectively. If the higher concentration standard for the gases and water soluble compounds was chosen (Section 6.6), these compounds will be at concentrations of 1000, 500, 250, 100, and 50 µg/L in the aqueous calibration standards.</P>
                        <P>6.7.2 Aqueous performance standard—an aqueous standard containing all pollutants, internal standards, labeled compounds, and BFB is prepared daily, and analyzed each shift to demonstrate performance (Section 11). This standard shall contain either 20 or 100 µg/L of the labeled and pollutant gases and water soluble compounds, 10 µg/L BFB, and 20 µg/L of all other pollutants, labeled compounds, and internal standards. It may be the nominal 20 µg/L aqueous calibration standard (Section 6.7.1).</P>
                        <P>
                            6.7.3 A methanolic standard containing all pollutants and internal standards is prepared to demonstrate recovery of these compounds when syringe injection and purge and trap analyses are compared. This standard shall contain either 100 µg/mL or 500 µg/mL of the gases and water soluble compounds, and 100 µg/mL of the remaining pollutants 
                            <PRTPAGE P="353"/>
                            and internal standards (consistent with the amounts in the aqueous performance standard in 6.7.2).
                        </P>
                        <P>6.7.4 Other standards which may be needed are those for test of BFB performance (Section 7.1) and for collection of mass spectra for storage in spectral libraries (Section 7.2).</P>
                        <HD SOURCE="HD2">7. Calibration</HD>
                        <P>7.1 Assemble the gas chromatographic apparatus and establish operating conditions given in table 2. By injecting standards into the GC, demonstrate that the analytical system meets the detection limits in table 2 and the mass-intensity criteria in table 3 for 50 ng BFB.</P>
                        <P>7.2 Mass spectral libraries—detection and identification of the compound of interest are dependent upon the spectra stored in user created libraries.</P>
                        <P>7.2.1 Obtain a mass spectrum of each pollutant and labeled compound and each internal standard by analyzing an authentic standard either singly or as part of a mixture in which there is no interference between closely eluted components. That only a single compound is present is determined by examination of the spectrum. Fragments not attributable to the compound under study indicate the presence of an interfering compound. Adjust the analytical conditions and scan rate (for this test only) to produce an undistorted spectrum at the GC peak maximum. An undistorted spectrum will usually be obtained if five complete spectra are collected across the upper half of the GC peak. Software algorithms designed to “enhance” the spectrum may eliminate distortion, but may also eliminate authentic m/z's or introduce other distortion.</P>
                        <P>7.2.3 The authentic reference spectrum is obtained under BFB tuning conditions (Section 7.1 and table 3) to normalize it to spectra from other instruments.</P>
                        <P>7.2.4 The spectrum is edited by saving the 5 most intense mass spectral peaks and all other mass spectral peaks greater than 10 percent of the base peak. This spectrum is stored for reverse search and for compound confirmation.</P>
                        <P>7.3 Assemble the purge and trap device. Pack the trap as shown in Figure 2 and condition overnight at 170-180 °C by backflushing with an inert gas at a flow rate of 20-30 mL/min. Condition traps daily for a minimum of 10 minutes prior to use.</P>
                        <P>7.3.1 Analyze the aqueous performance standard (Section 6.7.2) according to the purge and trap procedure in Section 10. Compute the area at the primary m/z (table 4) for each compound. Compare these areas to those obtained by injecting one µL of the methanolic standard (Section 6.7.3) to determine compound recovery. The recovery shall be greater than 20 percent for the water soluble compounds, and 60-110 percent for all other compounds. This recovery is demonstrated initially for each purge and trap GC/MS system. The test is repeated only if the purge and trap or GC/MS systems are modified in any way that might result in a change in recovery.</P>
                        <P>7.3.2 Demonstrate that 100 ng toluene (or toluene-d8) produces an area at m/z 91 (or 99) approx one-tenth that required to exceed the linear range of the system. The exact value must be determined by experience for each instrument. It is used to match the calibration range of the instrument to the analytical range and detection limits required.</P>
                        <P>7.4 Calibration by isotope dilution—the isotope dilution approach is used for the purgeable organic compounds when appropriate labeled compounds are available and when interferences do not preclude the analysis. If labeled compounds are not available, or interferences are present, internal standard methods (Section 7.5 or 7.6) are used. A calibration curve encompassing the concentration range of interest is prepared for each compound determined. The relative response (RR) vs concentration (µg/L) is plotted or computed using a linear regression. An example of a calibration curve for toluene using toluene-d8 is given in figure 5. Also shown are the ±10 percent error limits (dotted lines). Relative response is determined according to the procedures described below. A minimum of five data points are required for calibration (Section 7.4.4).</P>
                        <P>7.4.1 The relative response (RR) of pollutant to labeled compound is determined from isotope ratio values calculated from acquired data. Three isotope ratios are used in this process:</P>
                        <FP SOURCE="FP1-2">
                            R
                            <E T="52">X</E>
                             = the isotope ratio measured in the pure pollutant (figure 6A).
                        </FP>
                        <FP SOURCE="FP1-2">
                            R
                            <E T="52">y</E>
                             = the isotope ratio of pure labeled compound (figure 6B).
                        </FP>
                        <FP SOURCE="FP1-2">
                            R
                            <E T="52">m</E>
                             = the isotope ratio measured in the analytical mixture of the pollutant and labeled compounds (figure 6C).
                        </FP>
                        <P>
                            The correct way to calculate RR is: RR = (R
                            <E T="52">y</E>
                            −R
                            <E T="52">m</E>
                            ) (R
                            <E T="52">X</E>
                             + 1)/(R
                            <E T="52">m</E>
                            −R
                            <E T="52">X</E>
                            )(R
                            <E T="52">y</E>
                             + 1) If R
                            <E T="52">m</E>
                             is not between 2R
                            <E T="52">y</E>
                             and 0.5R
                            <E T="52">X</E>
                            , the method does not apply and the sample is analyzed by internal or external standard methods (Section 7.5 or 7.6).
                        </P>
                        <P>
                            7.4.2 In most cases, the retention times of the pollutant and labeled compound are the same and isotope ratios (R's) can be calculated from the EICP areas, where: R = (area at m
                            <E T="52">1</E>
                            /z)/(area at m
                            <E T="52">2</E>
                            /z) If either of the areas is zero, it is assigned a value of one in the calculations; that is, if: area of m
                            <E T="52">1</E>
                            /z = 50721, and area of m
                            <E T="52">2</E>
                            /z = 0, then R = 50721/1 = 50720. The m/z's are always selected such that R
                            <E T="52">X</E>
                            &gt;R
                            <E T="52">y</E>
                            . When there is a difference in retention times (RT) between the pollutant and labeled compounds, special precautions are required to determine the isotope ratios.
                        </P>
                        <P>
                            R
                            <E T="52">X</E>
                            , R
                            <E T="52">y</E>
                            , and R
                            <E T="52">m</E>
                             are defined as follows:
                            <PRTPAGE P="354"/>
                        </P>
                        <FP SOURCE="FP1-2">
                            R
                            <E T="52">X</E>
                            =[area m
                            <E T="52">1</E>
                            /z (at RT
                            <E T="52">1</E>
                            )]/1
                        </FP>
                        <FP SOURCE="FP1-2">
                            R
                            <E T="52">y</E>
                             = 1/[area m
                            <E T="52">2</E>
                            /z (at RT
                            <E T="52">2</E>
                            )]
                        </FP>
                        <FP SOURCE="FP1-2">
                            R
                            <E T="52">m</E>
                            =[area m
                            <E T="52">1</E>
                            /z (at RT
                            <E T="52">1</E>
                            )]/[area m
                            <E T="52">2</E>
                            /z (at RT
                            <E T="52">2</E>
                            )]
                        </FP>
                        <P>
                            7.4.3 An example of the above calculations can be taken from the data plotted in figure 6 for toluene and toluene-d8. For these data, R
                            <E T="52">X</E>
                             = 168920/1 = 168900, R
                            <E T="52">y</E>
                             = 1/60960 = 0.00001640, and R
                            <E T="52">m</E>
                             = 96868/82508 = 1.174. The RR for the above data is then calculated using the equation given in Section 7.4.1. For the example, RR = 1.174.
                        </P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>Not all labeled compounds elute before their pollutant analogs.</P>
                        </NOTE>
                        <P>7.4.4 To calibrate the analytical system by isotope dilution, analyze a 5 mL aliquot of each of the aqueous calibration standards (Section 6.7.1) spiked with an appropriate constant amount of the labeled compound spiking solution (Section 6.6), using the purge and trap procedure in section 10. Compute the RR at each concentration.</P>
                        <P>7.4.5 Linearity—if the ratio of relative response to concentration for any compound is constant (less than 20 percent coefficient of variation) over the 5 point calibration range, an averaged relative response/concentration ratio may be used for that compound; otherwise, the complete calibration curve for that compound shall be used over the 5 point calibration range.</P>
                        <P>7.5 Calibration by internal standard—used when criteria for isotope dilution (Section 7.4) cannot be met. The method is applied to pollutants having no labeled analog and to the labeled compounds. The internal standards used for volatiles analyses are bromochloromethane, 2-bromo-1-chloropropane, and 1,4-dichlorobutane. Concentrations of the labeled compounds and pollutants without labeled analogs are computed relative to the nearest eluted internal standard, as shown in table 2.</P>
                        <P>7.5.1 Response factors—calibration requires the determination of response factors (RF) which are defined by the following equation:</P>
                        <P>
                            RF = (A
                            <E T="52">s</E>
                            xC
                            <E T="52">is</E>
                            )/(A
                            <E T="52">is</E>
                            xC
                            <E T="52">s</E>
                            ), where A
                            <E T="52">s</E>
                             is the EICP area at the characteristic m/z for the compound in the daily standard. A
                            <E T="52">is</E>
                             is the EICP area at the characteristic m/z for the internal standard.
                        </P>
                        <P>
                            C
                            <E T="52">is</E>
                             is the concentration (ug/L) of the internal standard
                        </P>
                        <P>
                            C
                            <E T="52">s</E>
                             is the concentration of the pollutant in the daily standard.
                        </P>
                        <P>
                            7.5.2 The response factor is determined at 10, 20, 50, 100, and 200 ug/L for the pollutants (optionally at five times these concentrations for gases and water soluble pollutants—see Section 6.7), in a way analogous to that for calibration by isotope dilution (Section 7.4.4). The RF is plotted against concentration for each compound in the standard (C
                            <E T="52">s</E>
                            ) to produce a calibration curve.
                        </P>
                        <P>7.5.3 Linearity—if the response factor (RF) for any compound is constant (less than 35 percent coefficient of variation) over the 5 point calibration range, an averaged response factor may be used for that compound; otherwise, the complete calibration curve for that compound shall be used over the 5 point range.</P>
                        <P>7.6 Combined calibration—by adding the isotopically labeled compounds and internal standards (Section 6.6) to the aqueous calibration standards (Section 6.7.1), a single set of analyses can be used to produce calibration curves for the isotope dilution and internal standard methods. These curves are verified each shift (Section 11.5) by purging the aqueous performance standard (Section 6.7.2). Recalibration is required only if calibration and on-going performance (Section 11.5) criteria cannot be met.</P>
                        <HD SOURCE="HD2">8. Quality Assurance/Quality Control</HD>
                        <P>8.1 Each laboratory that uses this method is required to operate a formal quality assurance program. The minimum requirements of this program consist of an initial demonstration of laboratory capability, analysis of samples spiked with labeled compounds to evaluate and document data quality, and analysis of standards and blanks as tests of continued performance. Laboratory performance is compared to established performance criteria to determine if the results of analyses meet the performance characteristics of the method.</P>
                        <P>8.1.1 The analyst shall make an initial demonstration of the ability to generate acceptable accuracy and precision with this method. This ability is established as described in Section 8.2.</P>
                        <P>8.1.2 The analyst is permitted to modify this method to improve separations or lower the costs of measurements, provided all performance specifications are met. Each time a modification is made to the method, the analyst is required to repeat the procedure in Section 8.2 to demonstrate method performance.</P>
                        <P>8.1.3 Analyses of blanks are required to demonstrate freedom from contamination and that the compounds of interest and interfering compounds have not been carried over from a previous analysis (Section 3). The procedures and criteria for analysis of a blank are described in Sections 8.5 and 11.7.</P>
                        <P>8.1.4 The laboratory shall spike all samples with labeled compounds to monitor method performance. This test is described in Section 8.3. When results of these spikes indicate atypical method performance for samples, the samples are diluted to bring method performance within acceptable limits (Section 14.2).</P>
                        <P>
                            8.1.5 The laboratory shall, on an on-going basis, demonstrate through the analysis of the aqueous performance standard (Section 6.7.2) that the analysis system is in control. This procedure is described in Sections 11.1 and 11.5.
                            <PRTPAGE P="355"/>
                        </P>
                        <P>8.1.6 The laboratory shall maintain records to define the quality of data that is generated. Development of accuracy statements is described in Sections 8.4 and 11.5.2.</P>
                        <P>8.2 Initial precision and accuracy—to establish the ability to generate acceptable precision and accuracy, the analyst shall perform the following operations:</P>
                        <P>8.2.1 Analyze two sets of four 5-mL aliquots (8 aliquots total) of the aqueous performance standard (Section 6.7.2) according to the method beginning in Section 10.</P>
                        <P>
                            8.2.2 Using results of the first set of four analyses in Section 8.2.1, compute the average recovery (X
                            <AC T="8"/>
                            ) in µg/L and the standard deviation of the recovery (s) in µg/L for each compound, by isotope dilution for polluitants with a labeled analog, and by internal standard for labeled compounds and pollutants with no labeled analog.
                        </P>
                        <P>
                            8.2.3 For each compound, compare s and X
                            <AC T="8"/>
                             with the corresponding limits for initial precision and accuracy found in table 5. If s and X
                            <AC T="8"/>
                             for all compounds meet the acceptance criteria, system performance is acceptable and analysis of blanks and samples may begin. If individual X
                            <AC T="8"/>
                             falls outside the range for accuracy, system performance is unacceptable for that compound.
                        </P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>The large number of compounds in table 5 present a substantial probability that one or more will fail one of the acceptance criteria when all compoulds are analyzed. To determine if the analytical system is out of control, or if the failure can be attributed to probability, proceed as follows:</P>
                        </NOTE>
                        <P>
                            8.2.4 Using the results of the second set of four analyses, compute s and X
                            <AC T="8"/>
                             for only those compounds which failed the test of the first set of four analyses (Section 8.2.3). If these compounds now pass, system performance is acceptable for all compounds and analysis of blanks and samples may begin. If, however, any of the same compounds fail again, the analysis system is not performing properly for the compound(s) in question. In this event, correct the problem and repeat the entire test (Section 8.2.1).
                        </P>
                        <P>8.3 The laboratory shall spike all samples with labeled compounds to assess method performance on the sample matrix.</P>
                        <P>8.3.1 Spike and analyze each sample according to the method beginning in Section 10.</P>
                        <P>8.3.2 Compute the percent recovery (P) of the labeled compounds using the internal standard method (Section 7.5).</P>
                        <P>8.3.3 Compare the percent recovery for each compound with the corresponding labeled compound recovery limit in table 5. If the recovery of any compound falls outside its warning limit, method performance is unacceptable for that compound in that sample. Therefore, the sample matrix is complex and the sample is to be diluted and reanalyzed, per Section 14.2.</P>
                        <P>
                            8.4 As part of the QA program for the laboratory, method accuracy for wastewater samples shall be assessed and records shall be maintained. After the analysis of five wastewater samples for which the labeled compounds pass the tests in Section 8.3.3, compute the average percent recovery (P) and the standard deviation of the percent recovery (s
                            <E T="52">p</E>
                            ) for the labeled compounds only. Express the accuracy assessment as a percent recovery interval from P−2s
                            <E T="52">p</E>
                             to P + 2s
                            <E T="52">p</E>
                            . For example, if P = 90% and s
                            <E T="52">p</E>
                             = 10%, the accuracy interval is expressed as 70-110%. Update the accuracy assessment for each compound on a regular basis (e.g. after each 5-10 new accuracy measurements).
                        </P>
                        <P>8.5 Blanks—reagent water blanks are analyzed to demonstrate freedom from carry-over (Section 3) and contamination.</P>
                        <P>8.5.1 The level at which the purge and trap system will carry greater than 5 µg/L of a pollutant of interest (table 1) into a succeeding blank shall be determined by analyzing successively larger concentrations of these compounds. When a sample contains this concentration or more, a blank shall be analyzed immediately following this sample to demonstrate no carry-over at the 5 µg/L level.</P>
                        <P>8.5.2 With each sample lot (samples analyzed on the same 8 hr shift), a blank shall be analyzed immediately after analysis of the aqueous performance standard (Section 11.1) to demonstrate freedom from contamination. If any of the compounds of interest (table 1) or any potentially interfering compound is found in a blank at greater than 10 µg/L (assuming a response factor of 1 relative to the nearest eluted internal standard for compounds not listed in table 1), analysis of samples is halted until the source of contamination is eliminated and a blank shows no evidence of contamination at this level.</P>
                        <P>8.6 The specifications contained in this method can be met if the apparatus used is calibrated properly, then maintained in a calibrated state.</P>
                        <P>The standards used for calibration (Section 7), calibration verification (Section 11.5) and for initial (Section 8.2) and on-going (Section 11.5) precision and accuracy should be identical, so that the most precise results will be obtained. The GC/MS instrument in particular will provide the most reproducible results if dedicated to the settings and conditions required for the analyses of volatiles by this method.</P>
                        <P>
                            8.7 Depending on specific program requirements, field replicates may be collected to determine the precision of the sampling technique, and spiked samples may be required to determine the accuracy of the analysis when internal or external standard methods are used.
                            <PRTPAGE P="356"/>
                        </P>
                        <HD SOURCE="HD2">9. Sample Collection, Preservation, and Handling</HD>
                        <P>9.1 Grab samples are collected in glass containers having a total volume greater than 20 mL. Fill sample bottles so that no air bubbles pass through the sample as the bottle is filled. Seal each bottle so that no air bubbles are entrapped. Maintain the hermetic seal on the sample bottle until time of analysis.</P>
                        <P>9.2 Samples are maintained at 0-4 °C from the time of collection until analysis. If the sample contains residual chlorine, add sodium thiosulfate preservative (10 mg/40 mL) to the empty sample bottles just prior to shipment to the sample site. EPA Methods 330.4 and 330.5 may be used for measurement of residual chlorine (Reference 8). If preservative has been added, shake bottle vigorously for one minute immediately after filling.</P>
                        <P>9.3 Experimental evidence indicates that some aromatic compounds, notably benzene, toluene, and ethyl benzene are susceptible to rapid biological degradation under certain environmental conditions. Refrigeration alone may not be adequate to preserve these compounds in wastewaters for more than seven days. For this reason, a separate sample should be collected, acidified, and analyzed when these aromatics are to be determined. Collect about 500 mL of sample in a clean container.</P>
                        <P>Adjust the pH of the sample to about 2 by adding HCl (1 + 1) while stirring. Check pH with narrow range (1.4 to 2.8) pH paper. Fill a sample container as described in Section 9.1. If residual chlorine is present, add sodium thiosulfate to a separate sample container and fill as in Section 9.1.</P>
                        <P>9.4 All samples shall be analyzed within 14 days of collection.</P>
                        <HD SOURCE="HD2">10. Purge, Trap, and GC/MS Analysis</HD>
                        <P>10.1 Remove standards and samples from cold storage and bring to 20-25 °.</P>
                        <P>10.2 Adjust the purge gas flow rate to 40 ±4 mL/min. Attach the trap inlet to the purging device and set the valve to the purge mode (figure 3). Open the syringe valve located on the purging device sample introduction needle (figure 1).</P>
                        <P>10.3 Remove the plunger from a 5-mL syringe and attach a closed syringe valve. Open the sample bottle and carefully pour the sample into the syringe barrel until it overflows. Replace the plunger and compress the sample. Open the syringe valve and vent any residual air while adjusting the sample volume to 5.0 mL. Because this process of taking an aliquot destroys the validity of the sample for future analysis, fill a second syringe at this time to protect against possible loss of data. Add an appropriate amount of the labeled compound spiking solution (Section 6.6) through the valve bore, then close the valve.</P>
                        <P>10.4 Attach the syringe valve assembly to the syringe valve on the purging device. Open both syringe valves and inject the sample into the purging chamber.</P>
                        <P>10.5 Close both valves and purge the sample for 11.0 ±0.1 minutes at 20-25 °C.</P>
                        <P>10.6 After the 11 minute purge time, attach the trap to the chromatograph and set the purge and trap apparatus to the desorb mode (figure 4). Desorb the trapped compounds into the GC column by heating the trap to 170-180 °C while backflushing with carrier gas at 20-60 mL/min for four minutes. Start MS data acquisition upon start of the desorb cycle, and start the GC column temperature program 3 minutes later. Table 1 summarizes the recommended operating conditions for the gas chromatograph. Included in this table are retention times and detection limits that were achieved under these conditions. Other columns may be used provided the requirements in Section 8 can be met. If the priority pollutant gases produce GC peaks so broad that the precision and recovery specifications (Section 8.2) cannot be met, the column may be cooled to ambient or sub-ambient temperatures to sharpen these peaks.</P>
                        <P>10.7 While analysis of the desorbed compounds proceeds, empty the purging chamber using the sample introduction syringe. Wash the chamber with two 5-mL portions of reagent water. After the purging device has been emptied, allow the purge gas to vent through the chamber until the frit is dry, so that it is ready for the next sample.</P>
                        <P>10.8 After desorbing the sample for four minutes, recondition the trap by returning to the purge mode. Wait 15 seconds, then close the syringe valve on the purging device to begin gas flow through the trap. Maintain the trap temperature at 170-180 °C. After approximately seven minutes, turn off the trap heater and open the syringe valve to stop the gas flow through the trap. When cool, the trap is ready for the next sample.</P>
                        <HD SOURCE="HD2">11. System Performance</HD>
                        <P>11.1 At the beginning of each 8 hr shift during which analyses are performed, system calibration and performance shall be verified for all pollutants and labeled compounds. For these tests, analysis of the aqueous performance standard (Section 6.7.2) shall be used to verify all performance criteria. Adjustment and/or recalibration (per Section 7) shall be performed until all performance criteria are met. Only after all performance criteria are met may blanks and samples be analyzed.</P>
                        <P>11.2 BFB spectrum validity—the criteria in table 3 shall be met.</P>
                        <P>
                            11.3 Retention times—the absolute retention times of all compounds shall approximate those given in Table 2.
                            <PRTPAGE P="357"/>
                        </P>
                        <P>11.4 GC resolution—the valley height between toluene and toluene-d8 (at m/z 91 and 99 plotted on the same graph) shall be less than 10 percent of the taller of the two peaks.</P>
                        <P>11.5 Calibration verification and on-going precision and accuracy—compute the concentration of each polutant (Table 1) by isotope dilution (Section 7.4) for those compmunds which have labeled analogs. Compute the concentration of each pollutant (Table 1) which has no labeled analog by the internal standard method (Section 7.5). Compute the concentration of the labeled compounds by the internal standard method. These concentrations are computed based on the calibration data determined in Section 7.</P>
                        <P>11.5.1 For each pollutant and labeled compound, compare the concentration with the corresponding limit for on-going accuracy in Table 5. If all compmunds meet the acceptance criteria, system performance is acceptable and analysis of blanks and samples may continue. If any individual value falls outside the range given, system performance is unacceptable for that compound.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>The large number of compounds in Table 5 present a substantial probability that one or more will fail the acceptance criteria when all compounds are analyzed. To determine if the analytical system is out of control, or if the failure may be attributed to probability, proceed as follows:</P>
                        </NOTE>
                        <P>11.5.1.1 Analyze a second aliquot of the aqueous performance standard (Section 6.7.2).</P>
                        <P>11.5.1.2 Compute the concentration for only those compounds which failed the first test (Section 11.5.1). If these compounds now pass, system performance is acceptable for all compounds and analyses of blanks and samples may proceed. If, however, any of the compounds fail again, the measurement system is not performing properly for these compounds. In this event, locate and correct the problem or recalibrate the system (Section 7), and repeat the entire test (Section 11.1) for all compounds.</P>
                        <P>
                            11.5.2 Add results which pass the specification in 11.5.1.2 to initial (Section 8.2) and previous on-going data. Update QC charts to form a graphic representation of laboratory performance (Figure 7). Develop a statement of accuracy for each pollutant and labeled compound by calculating the average percentage recovery (R) and the standard deviation of percent recovery (s
                            <E T="52">r</E>
                            ). Express the accuracy as a recovery interval from R−2s
                            <E T="52">r</E>
                             to R + 2s
                            <E T="52">r</E>
                            . For example, if R = 95% and s
                            <E T="52">r</E>
                             = 5%, the accuracy is 85-105 percent.
                        </P>
                        <HD SOURCE="HD2">12. Qualitative Determination—Accomplished by Comparison of Data from Analysis of a Sample or Blank with Data from Analysis of the Shift Standard (Section 11.1). Identification is Confirmed When Spectra and Retention Times Agree Per the Criteria Below</HD>
                        <P>12.1 Labeled compounds and pollutants having no labeled analog:</P>
                        <P>12.1.1 The signals for all characteristic masses stored in the spectral library (Section 7.2.4) shall be present and shall maximize within the same two consecutive scans.</P>
                        <P>12.1.2 Either (1) the background corrected EICP areas, or (2) the corrected relative intensities of the mass spectral peaks at the GC peak maximum shall agree within a factor of two (0.5 to 2 times) for all masses stored in the library.</P>
                        <P>12.1.3 The retention time relative to the nearest eluted internal standard shall be within ±7 scans or ±20 seconds, whichever is greater.</P>
                        <P>12.2 Pollutants having a labeled analog:</P>
                        <P>12.2.1 The signals for all characteristic masses stored in the spectral library (Section 7.2.4) shall be present and shall maximize within the same two consecutive scans.</P>
                        <P>12.2.2 Either (1) the background corrected EICP areas, or (2) the corrected relative intensities of the mass spectral peaks at the GC peak maximum shall agree within a factor of two for all masses stored in the spectral library.</P>
                        <P>12.2.3 The retention time difference between the pollutant and its labeled analog shall agree within ±2 scans or ±6 seconds (whichever is greater) of this difference in the shift standard (Section 11.1).</P>
                        <P>12.3 Masses present in the experimental mass spectrum that are not present in the reference mass spectrum shall be accounted for by contaminant or background ions. If the experimental mass spectrum is contaminated, an experienced spectrometrist (Section 1.4) is to determine the presence or absence of the compound.</P>
                        <HD SOURCE="HD2">13. Quantitative Determination</HD>
                        <P>
                            13.1 Isotope dilution—by adding a known amount of a labeled compound to every sample prior to purging, correction for recovery of the pollutant can be made because the pollutant and its labeled analog exhibit the same effects upon purging, desorption, and gas chromatography. Relative response (RR) values for sample mixtures are used in conjunction with calibration curves described in Section 7.4 to determine concentrations directly, so long as labeled compound spiking levels are constant. For the toluene example given in Figure 6 (Section 7.4.3), RR would be equal to 1.174. For this RR value, the toluene calibration curve given in Figure 5 indicates a concentration of 31.8 µg/L.
                            <PRTPAGE P="358"/>
                        </P>
                        <P>13.2 Internal standard—calculate the concentration using the response factor determined from calibration data (Section 7.5) and the following equation:</P>
                        <P>
                            Concentration = (A
                            <E T="52">s</E>
                             × C
                            <E T="52">is</E>
                            )/(A
                            <E T="52">is</E>
                             × RF) where the terms are as defined in Section 7.5.1.
                        </P>
                        <P>13.3 If the EICP area at the quantitation mass for any compound exceeds the calibration range of the system, the sample is diluted by successive factors of 10 and these dilutions are analyzed until the area is within the calibration range.</P>
                        <P>13.4 Report results for all pollutants and labeled compounds (Table 1) found in all standards, blanks, and samples, in µg/L to three significant figures. Results for samples which have been diluted are reported at the least dilute level at which the area at the quantitation mass is within the calibration range (Section 13.3) and the labeled compound recovery is within the normal range for the Method (Section 14.2).</P>
                        <HD SOURCE="HD2">14. Analysis of Complex Samples</HD>
                        <P>14.1 Untreated effluents and other samples frequently contain high levels (&gt;1000 µg/L) of the compounds of interest and of interfering compounds. Some samples will foam excessively when purged; others will overload the trap/or GC column.</P>
                        <P>14.2 Dilute 0.5 mL of sample with 4.5 mL of reagent water and analyze this diluted sample when labeled compound recovery is outside the range given in Table 5. If the recovery remains outside of the range for this diluted sample, the aqueous performance standard shall be analyzed (Section 11) and calibration verified (Section 11.5). If the recovery for the labeled compmund in the aqueous performance standard is outside the range given in Table 5, the analytical system is out of control. In this case, the instrumelt shall be repaired, the performance specifications in Section 11 shall be met, and the analysis of the undiluted sample shall be repeated. If the recovery for the aqueous performance standard is within the range given in Table 5, the method does not work on the sample being analyzed and the result may not be reported for regulatory compliance purposes.</P>
                        <P>14.3 Reverse search computer programs can misinterpret the spectrum of chromatographically unresolved pollutant and labeled compound pairs with overlapping spectra when a high level of the pollutant is present. Examine each chromatogram for peaks greater than the height of the internal standard peaks. These peaks can obscure the compounds of interest.</P>
                        <HD SOURCE="HD2">15. Method Performance</HD>
                        <P>15.1 The specifications for this method were taken from the inter-laboratory validation of EPA Method 624 (reference 9). Method 1624 has been shown to yield slightly better performance on treated effluents than Method 624. Additional method performance data can be found in Reference 10.</P>
                        <HD SOURCE="HD2">References</HD>
                        <P>1. “Performance Tests for the Evaluation of Computerized Gas Chromatography/Mass Spectrometry Equipment and Laboratories,” USEPA, EMSL/Cincinnati, OH 45268, EPA-600/4-80-025 (April 1980).</P>
                        <P>
                            2. Bellar, T.A. and Lichtenberg, J.J., “Journal American Water Works Association,” 
                            <E T="03">66,</E>
                             739 (1974).
                        </P>
                        <P>
                            3. Bellar, T.A. and Lichtenberg, J.J., “Semi-automated Headspace Analysis of Drinking Waters and Industrial Waters for Purgeable Volatile Organic Compounds,” in 
                            <E T="03">Measurement of Organic Pollutants Water and Wastewater,</E>
                             C.E. VanHall, ed., American Society for Testing Materials, Philadelphia, PA, Special Technical Publication 686, (1978).
                        </P>
                        <P>4. “Working with Carcinogens,” DHEW, PHS, NIOSH, Publication 77-206 (1977).</P>
                        <P>5. “OSHA Safety and Health Standards, General Industry,” 29 CFR part 1910, OSHA 2206, (1976).</P>
                        <P>6. “Safety in Academic Chemistry Laboratories,” American Chemical Society Publication, Committee on Chemical Safety (1979).</P>
                        <P>7. “Handbook of Analytical Quality Control in Water and Wastewater Laboratories,” USEPA, EMSL/Cincinnati, OH 45268, EPA-4-79-019 (March 1979).</P>
                        <P>8. “Methods 330.4 and 330.5 for Total Residual Chlorine,” USEPA, EMSL/Cincinnati, OH 45268, EPA-4-79-020 (March 1979).</P>
                        <P>9. “EPA Method Study 29 EPA Method 624—Purgeables,” EPA 600/4-84-054, National Technical Information Service, PB84-209915, Springfield, Virginia 22161, June 1984.</P>
                        <P>10. “Colby, B.N., Beimer, R.G., Rushneck, D.R., and Telliard, W.A., “Isotope Dilution Gas Chromatography-Mass Spectrometry for the Determination of Priority Pollutants in Industrial Effluents,” USEPA, Effluent Guidelines Division, Washington, DC 20460 (1980).</P>
                        <GPOTABLE COLS="5" OPTS="L2" CDEF="s80,7,10,7,7">
                            <TTITLE>Table 1—Volatile Organic Compounds Analyzed by Isotope Dilution Gc/MS</TTITLE>
                            <BOXHD>
                                <CHED H="1">Compound</CHED>
                                <CHED H="1">Storet</CHED>
                                <CHED H="1">CAS registry</CHED>
                                <CHED H="1">EPA-EGD</CHED>
                                <CHED H="1">NPDES</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">Acetone</ENT>
                                <ENT>81552</ENT>
                                <ENT>67-64-1</ENT>
                                <ENT>516 V</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Acrolein</ENT>
                                <ENT>34210</ENT>
                                <ENT>107-02-8</ENT>
                                <ENT>002 V</ENT>
                                <ENT>001 V</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Acrylonitrile</ENT>
                                <ENT>34215</ENT>
                                <ENT>107-13-1</ENT>
                                <ENT>003 V</ENT>
                                <ENT>002 V</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzene</ENT>
                                <ENT>34030</ENT>
                                <ENT>71-43-2</ENT>
                                <ENT>004 V</ENT>
                                <ENT>003 V</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Bromodichloromethane</ENT>
                                <ENT>32101</ENT>
                                <ENT>75-27-4</ENT>
                                <ENT>048 V</ENT>
                                <ENT>012 V</ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="359"/>
                                <ENT I="01">Bromoform</ENT>
                                <ENT>32104</ENT>
                                <ENT>75-25-2</ENT>
                                <ENT>047 V</ENT>
                                <ENT>005 V</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Bromomethane</ENT>
                                <ENT>34413</ENT>
                                <ENT>74-83-9</ENT>
                                <ENT>046 V</ENT>
                                <ENT>020 V</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Carbon tetrachloride</ENT>
                                <ENT>32102</ENT>
                                <ENT>56-23-5</ENT>
                                <ENT>006 V</ENT>
                                <ENT>006 V</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chlorobenzene</ENT>
                                <ENT>34301</ENT>
                                <ENT>108-90-7</ENT>
                                <ENT>007 V</ENT>
                                <ENT>007 V</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chloroethane</ENT>
                                <ENT>34311</ENT>
                                <ENT>75-00-3</ENT>
                                <ENT>016 V</ENT>
                                <ENT>009 V</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-chloroethylvinyl ether</ENT>
                                <ENT>34576</ENT>
                                <ENT>110-75-8</ENT>
                                <ENT>019 V</ENT>
                                <ENT>010 V</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chloroform</ENT>
                                <ENT>32106</ENT>
                                <ENT>67-66-1</ENT>
                                <ENT>023 V</ENT>
                                <ENT>011 V</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chloromethane</ENT>
                                <ENT>34418</ENT>
                                <ENT>74-87-3</ENT>
                                <ENT>045 V</ENT>
                                <ENT>021 V</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dibromochloromethane</ENT>
                                <ENT>32105</ENT>
                                <ENT>124-48-1</ENT>
                                <ENT>051 V</ENT>
                                <ENT>008 V</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1-dichloroethane</ENT>
                                <ENT>34496</ENT>
                                <ENT>75-34-3</ENT>
                                <ENT>013 V</ENT>
                                <ENT>014 V</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2-dichloroethane</ENT>
                                <ENT>34536</ENT>
                                <ENT>107-06-2</ENT>
                                <ENT>010 V</ENT>
                                <ENT>015 V</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1-dichloroethene</ENT>
                                <ENT>34501</ENT>
                                <ENT>75-35-4</ENT>
                                <ENT>029 V</ENT>
                                <ENT>016 V</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Trans-1,2-dichloroethane</ENT>
                                <ENT>34546</ENT>
                                <ENT>156-60-5</ENT>
                                <ENT>030 V</ENT>
                                <ENT>026 V</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2-dichloropropane</ENT>
                                <ENT>34541</ENT>
                                <ENT>78-87-5</ENT>
                                <ENT>032 V</ENT>
                                <ENT>017 V</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Cis-1,3-dichloropropene</ENT>
                                <ENT>34704</ENT>
                                <ENT>10061-01-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Trans-1,3-dichloropropene</ENT>
                                <ENT>34699</ENT>
                                <ENT>10061-02-6</ENT>
                                <ENT>033 V</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Diethyl ether</ENT>
                                <ENT>81576</ENT>
                                <ENT>60-29-7</ENT>
                                <ENT>515 V</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">P-dioxane</ENT>
                                <ENT>81582</ENT>
                                <ENT>123-91-1</ENT>
                                <ENT>527 V</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ethylbenzene</ENT>
                                <ENT>34371</ENT>
                                <ENT>100-41-4</ENT>
                                <ENT>038 V</ENT>
                                <ENT>019 V</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Methylene chloride</ENT>
                                <ENT>34423</ENT>
                                <ENT>75-09-2</ENT>
                                <ENT>044 V</ENT>
                                <ENT>022 V</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Methyl ethyl ketone</ENT>
                                <ENT>81595</ENT>
                                <ENT>78-93-3</ENT>
                                <ENT>514 V</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1,2,2-tetrachloroethane</ENT>
                                <ENT>34516</ENT>
                                <ENT>79-34-5</ENT>
                                <ENT>015 V</ENT>
                                <ENT>023 V</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Tetrachlorethene</ENT>
                                <ENT>34475</ENT>
                                <ENT>127-18-4</ENT>
                                <ENT>085 V</ENT>
                                <ENT>024 V</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Toluene</ENT>
                                <ENT>34010</ENT>
                                <ENT>108-88-3</ENT>
                                <ENT>086 V</ENT>
                                <ENT>025 V</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1,1-trichloroethane</ENT>
                                <ENT>34506</ENT>
                                <ENT>71-55-6</ENT>
                                <ENT>011 V</ENT>
                                <ENT>027 V</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1,2-trichloroethane</ENT>
                                <ENT>34511</ENT>
                                <ENT>79-00-5</ENT>
                                <ENT>014 V</ENT>
                                <ENT>028 V</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Trichloroethene</ENT>
                                <ENT>39180</ENT>
                                <ENT>79-01-6</ENT>
                                <ENT>087 V</ENT>
                                <ENT>029 V</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Vinyl chloride</ENT>
                                <ENT>39175</ENT>
                                <ENT>75-01-4</ENT>
                                <ENT>088 V</ENT>
                                <ENT>031 V</ENT>
                            </ROW>
                        </GPOTABLE>
                        <GPOTABLE COLS="5" OPTS="L2" CDEF="3,r10,3,4,4">
                            <TTITLE>Table 2—Gas Chromatography of Purgeable Organic Compounds by Isotope Dilution GC/MS</TTITLE>
                            <BOXHD>
                                <CHED H="1">EGD No. (1)</CHED>
                                <CHED H="1">Compound</CHED>
                                <CHED H="1">Ref EGD No.</CHED>
                                <CHED H="1">Mean retention time (sec)</CHED>
                                <CHED H="1">Minimum level (2) (µg/L)</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">181</ENT>
                                <ENT>Bromochloromethane (I.S.)</ENT>
                                <ENT>181</ENT>
                                <ENT>730</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">245</ENT>
                                <ENT>Chloromethane-d3</ENT>
                                <ENT>181</ENT>
                                <ENT>147</ENT>
                                <ENT>50</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">345</ENT>
                                <ENT>Chloromethane</ENT>
                                <ENT>245</ENT>
                                <ENT>148</ENT>
                                <ENT>50</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">246</ENT>
                                <ENT>Bromomethane-d3</ENT>
                                <ENT>181</ENT>
                                <ENT>243</ENT>
                                <ENT>50</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">346</ENT>
                                <ENT>Bromomethane</ENT>
                                <ENT>246</ENT>
                                <ENT>246</ENT>
                                <ENT>50</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">288</ENT>
                                <ENT>Vinyl chloride-d3</ENT>
                                <ENT>181</ENT>
                                <ENT>301</ENT>
                                <ENT>50</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">388</ENT>
                                <ENT>Vinyl chloride</ENT>
                                <ENT>288</ENT>
                                <ENT>304</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">216</ENT>
                                <ENT>Chloroethane-d5</ENT>
                                <ENT>181</ENT>
                                <ENT>378</ENT>
                                <ENT>50</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">316</ENT>
                                <ENT>Chloroethane</ENT>
                                <ENT>216</ENT>
                                <ENT>386</ENT>
                                <ENT>50</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">244</ENT>
                                <ENT>Methylene chloride-d2</ENT>
                                <ENT>181</ENT>
                                <ENT>512</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">344</ENT>
                                <ENT>Methylene chloride</ENT>
                                <ENT>244</ENT>
                                <ENT>517</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">616</ENT>
                                <ENT>Acetone-d6</ENT>
                                <ENT>181</ENT>
                                <ENT>554</ENT>
                                <ENT>50</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">716</ENT>
                                <ENT>Acetone</ENT>
                                <ENT>616</ENT>
                                <ENT>565</ENT>
                                <ENT>50</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">002</ENT>
                                <ENT>Acrolein</ENT>
                                <ENT>181</ENT>
                                <ENT>566</ENT>
                                <ENT>50</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">203</ENT>
                                <ENT>Acrylonitrile-d3</ENT>
                                <ENT>181</ENT>
                                <ENT>606</ENT>
                                <ENT>50</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">303</ENT>
                                <ENT>Acrylonitrile</ENT>
                                <ENT>203</ENT>
                                <ENT>612</ENT>
                                <ENT>50</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">229</ENT>
                                <ENT>1,1-dichloroethene-d2</ENT>
                                <ENT>181</ENT>
                                <ENT>696</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">329</ENT>
                                <ENT>1,1-dichloroethene</ENT>
                                <ENT>229</ENT>
                                <ENT>696</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">213</ENT>
                                <ENT>1,1-dichloroethane-d3</ENT>
                                <ENT>181</ENT>
                                <ENT>778</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">313</ENT>
                                <ENT>1,1-dichloroethane</ENT>
                                <ENT>213</ENT>
                                <ENT>786</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">615</ENT>
                                <ENT>Diethyl ether-d10</ENT>
                                <ENT>181</ENT>
                                <ENT>804</ENT>
                                <ENT>50</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">715</ENT>
                                <ENT>Diethyl ether</ENT>
                                <ENT>615</ENT>
                                <ENT>820</ENT>
                                <ENT>50</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">230</ENT>
                                <ENT>Trans-1,2-dichloroethene-d2</ENT>
                                <ENT>181</ENT>
                                <ENT>821</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">330</ENT>
                                <ENT>Trans-1,2-dichloroethene</ENT>
                                <ENT>230</ENT>
                                <ENT>821</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">614</ENT>
                                <ENT>Methyl ethyl ketone-d3</ENT>
                                <ENT>181</ENT>
                                <ENT>840</ENT>
                                <ENT>50</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">714</ENT>
                                <ENT>Methyl ethyl ketone</ENT>
                                <ENT>614</ENT>
                                <ENT>848</ENT>
                                <ENT>50</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">223</ENT>
                                <ENT>Chloroform-13C1</ENT>
                                <ENT>181</ENT>
                                <ENT>861</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">323</ENT>
                                <ENT>Chloroform</ENT>
                                <ENT>223</ENT>
                                <ENT>861</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">210</ENT>
                                <ENT>1,2-dichloroethane-d4</ENT>
                                <ENT>181</ENT>
                                <ENT>901</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">310</ENT>
                                <ENT>1,2-dichloroethane</ENT>
                                <ENT>210</ENT>
                                <ENT>910</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">211</ENT>
                                <ENT>1,1,1-trichloroethane-13C2</ENT>
                                <ENT>181</ENT>
                                <ENT>989</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">311</ENT>
                                <ENT>1,1,1-trichloroethane</ENT>
                                <ENT>211</ENT>
                                <ENT>999</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">527</ENT>
                                <ENT>p-dioxane</ENT>
                                <ENT>181</ENT>
                                <ENT>1001</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">206</ENT>
                                <ENT>Carbon tetrachloride-13C1</ENT>
                                <ENT>182</ENT>
                                <ENT>1018</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">306</ENT>
                                <ENT>Carbon tetrachloride</ENT>
                                <ENT>206</ENT>
                                <ENT>1018</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">248</ENT>
                                <ENT>Bromodichloromethane-13C1</ENT>
                                <ENT>182</ENT>
                                <ENT>1045</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">348</ENT>
                                <ENT>Bromodichloromethane</ENT>
                                <ENT>248</ENT>
                                <ENT>1045</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">232</ENT>
                                <ENT>1,2-dichloropropane-d6</ENT>
                                <ENT>182</ENT>
                                <ENT>1123</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">332</ENT>
                                <ENT>1.2-dichloropropane</ENT>
                                <ENT>232</ENT>
                                <ENT>1134</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">233</ENT>
                                <ENT>Trans-1,3-dichloropropene-d4</ENT>
                                <ENT>182</ENT>
                                <ENT>1138</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">333</ENT>
                                <ENT>Trans-1,3-dichloropropene</ENT>
                                <ENT>233</ENT>
                                <ENT>1138</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">287</ENT>
                                <ENT>Trichloroethene-13C1</ENT>
                                <ENT>182</ENT>
                                <ENT>1172</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">387</ENT>
                                <ENT>Trichloroethene</ENT>
                                <ENT>287</ENT>
                                <ENT>1187</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">204</ENT>
                                <ENT>Benzene-d6</ENT>
                                <ENT>182</ENT>
                                <ENT>1200</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">304</ENT>
                                <ENT>Benzene</ENT>
                                <ENT>204</ENT>
                                <ENT>1212</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">251</ENT>
                                <ENT>Chlorodibromemethane-13C1</ENT>
                                <ENT>182</ENT>
                                <ENT>1222</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">351</ENT>
                                <ENT>Chlorodibromomethane</ENT>
                                <ENT>251</ENT>
                                <ENT>1222</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">214</ENT>
                                <ENT>1,1,2-trichloroethane-13C2</ENT>
                                <ENT>182</ENT>
                                <ENT>1224</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">314</ENT>
                                <ENT>1,1,2-trichloroethane</ENT>
                                <ENT>214</ENT>
                                <ENT>1224</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">019</ENT>
                                <ENT>2-chloroethylvinyl ether</ENT>
                                <ENT>182</ENT>
                                <ENT>1278</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">182</ENT>
                                <ENT>2-bromo-1-chloropropane (I.S.)</ENT>
                                <ENT>182</ENT>
                                <ENT>1306</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">247</ENT>
                                <ENT>Bromoform-13C1</ENT>
                                <ENT>182</ENT>
                                <ENT>1386</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">347</ENT>
                                <ENT>Bromoform</ENT>
                                <ENT>247</ENT>
                                <ENT>1386</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">215</ENT>
                                <ENT>1,1,2,2-tetrachloroethane-d2</ENT>
                                <ENT>183</ENT>
                                <ENT>1525</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">315</ENT>
                                <ENT>1,1,2,2-tetrachloroethane</ENT>
                                <ENT>215</ENT>
                                <ENT>1525</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">285</ENT>
                                <ENT>Tetrachloroethene-13C2</ENT>
                                <ENT>183</ENT>
                                <ENT>1528</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">385</ENT>
                                <ENT>Tetrachloroethene</ENT>
                                <ENT>285</ENT>
                                <ENT>1528</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">183</ENT>
                                <ENT>1,4-dichlorobutale (int std)</ENT>
                                <ENT>183</ENT>
                                <ENT>1555</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">286</ENT>
                                <ENT>Toluene-d8</ENT>
                                <ENT>183</ENT>
                                <ENT>1603</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">386</ENT>
                                <ENT>Toluene</ENT>
                                <ENT>286</ENT>
                                <ENT>1619</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="360"/>
                                <ENT I="01">207</ENT>
                                <ENT>Chlorobenzene-d5</ENT>
                                <ENT>183</ENT>
                                <ENT>1679</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">307</ENT>
                                <ENT>Chlorobenzene</ENT>
                                <ENT>207</ENT>
                                <ENT>1679</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">238</ENT>
                                <ENT>Ethylbenzene-d10</ENT>
                                <ENT>183</ENT>
                                <ENT>1802</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">338</ENT>
                                <ENT>Ethylbenzene</ENT>
                                <ENT>238</ENT>
                                <ENT>1820</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">185</ENT>
                                <ENT>Bromofluorobenzene</ENT>
                                <ENT>183</ENT>
                                <ENT>1985</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <TNOTE>(1) Reference numbers beginning with 0, 1 or 5 indicate a pollutant quantified by the internal standard method; reference numbers beginning with 2 or 6 indicate a labeled compound quantified by the internal standard method; reference numbers beginning with 3 or 7 indicate a pollutant quantified by isotope dilution.</TNOTE>
                            <TNOTE>(2) This is a minimum level at which the analytical system shall give recognizable mass spectra (background corrected) and acceptable calibration points. Column: 2.4m (8 ft) × 2 mm i.d. glass, packed with one percent SP-1000 coated on 60/80 Carbopak B. Carrier gas: helium at 40 mL/min. Temperature program: 3 min at 45 °C, 8 °C per min to 240 °C, hold at 240 °C for 15 minutes.</TNOTE>
                            <TNOTE>
                                <E T="04">Note:</E>
                                 The specifications in this table were developed from data collected from three wastewater laboratories.
                            </TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="2" OPTS="L2" CDEF="4,r10">
                            <TTITLE>Table 3—BFB Mass-Intensity Specifications</TTITLE>
                            <BOXHD>
                                <CHED H="1">Mass</CHED>
                                <CHED H="1">Intensity required</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">50</ENT>
                                <ENT>15 to 40 percent of mass 95.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">75</ENT>
                                <ENT>30 to 60 percent of mass 95.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">95</ENT>
                                <ENT>base peak, 100 percent.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">96</ENT>
                                <ENT>5 to 9 percent of mass 95.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">173</ENT>
                                <ENT>&lt;2 percent of mass 174.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">174</ENT>
                                <ENT>&gt;50 percent of mass 95.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">175</ENT>
                                <ENT>5 to 9 percent of mass 174.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">176</ENT>
                                <ENT>95 to 101 percent of mass 174.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">177</ENT>
                                <ENT>5 to 9 percent of mass 176.</ENT>
                            </ROW>
                        </GPOTABLE>
                        <GPOTABLE COLS="3" OPTS="L2" CDEF="s10,6,9">
                            <TTITLE>Table 4—Volatile Organic Compound Characteristic Masses</TTITLE>
                            <BOXHD>
                                <CHED H="1">Labeled compound</CHED>
                                <CHED H="1">Analog</CHED>
                                <CHED H="1">Primary m/z's</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">Acetone</ENT>
                                <ENT>d6</ENT>
                                <ENT>58/64</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Acrolein</ENT>
                                <ENT>d2</ENT>
                                <ENT>56/58</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Acrylonitrile</ENT>
                                <ENT>d3</ENT>
                                <ENT>53/56</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzene</ENT>
                                <ENT>d6</ENT>
                                <ENT>78/84</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Bromodichloromethane</ENT>
                                <ENT>13C</ENT>
                                <ENT>83/86</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Bromoform</ENT>
                                <ENT>13C</ENT>
                                <ENT>173/176</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Bromomethale</ENT>
                                <ENT>d3</ENT>
                                <ENT>96/99</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Carbon tetrachloride</ENT>
                                <ENT>13C</ENT>
                                <ENT>47/48</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chlorobenzene</ENT>
                                <ENT>d5</ENT>
                                <ENT>112/117</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chloroethane</ENT>
                                <ENT>d5</ENT>
                                <ENT>64/71</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-chloroethylvinyl ether</ENT>
                                <ENT>d7</ENT>
                                <ENT>106/113</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chloroform</ENT>
                                <ENT>13C</ENT>
                                <ENT>85/86</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chloromethane</ENT>
                                <ENT>d3</ENT>
                                <ENT>50/53</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dibromochloromethane</ENT>
                                <ENT>13C</ENT>
                                <ENT>129/130</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1-dichloroethane</ENT>
                                <ENT>d3</ENT>
                                <ENT>63/66</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2-dichloroethane</ENT>
                                <ENT>d4</ENT>
                                <ENT>62/67</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1-dichloroethene</ENT>
                                <ENT>d2</ENT>
                                <ENT>61/65</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Trans-1,2-dichloroethene</ENT>
                                <ENT>d2</ENT>
                                <ENT>61/65</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2-dichloropropane</ENT>
                                <ENT>d6</ENT>
                                <ENT>63/67</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Cis-1,3-dichloropropene</ENT>
                                <ENT>d4</ENT>
                                <ENT>75/79</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Trans-1,3-dichloropropene</ENT>
                                <ENT>d4</ENT>
                                <ENT>75/79</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Diethyl ether</ENT>
                                <ENT>d10</ENT>
                                <ENT>74/84</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">p-dioxane</ENT>
                                <ENT>d8</ENT>
                                <ENT>88/96</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ethylbenzene</ENT>
                                <ENT>d10</ENT>
                                <ENT>106/116</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Methylene chloride</ENT>
                                <ENT>d2</ENT>
                                <ENT>84/88</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Methyl ethyl ketone</ENT>
                                <ENT>d3</ENT>
                                <ENT>72/75</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1,2,2-tetrachloroethane</ENT>
                                <ENT>d2</ENT>
                                <ENT>83/84</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Tetrachloroethene</ENT>
                                <ENT>13C2</ENT>
                                <ENT>166/172</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Toluene</ENT>
                                <ENT>d8</ENT>
                                <ENT>92/99</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1,1-trichloroethane</ENT>
                                <ENT>d3</ENT>
                                <ENT>97/102</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1,2-trichloroethane</ENT>
                                <ENT>13C2</ENT>
                                <ENT>83/84</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Trichloroethene</ENT>
                                <ENT>13C</ENT>
                                <ENT>95/133</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Vinyl chloride</ENT>
                                <ENT>d3</ENT>
                                <ENT>62/65</ENT>
                            </ROW>
                        </GPOTABLE>
                        <GPOTABLE COLS="5" OPTS="L1" CDEF="s50,10,12,10,10">
                            <TTITLE>Table 5—Acceptance Criteria for Performance Tests</TTITLE>
                            <BOXHD>
                                <CHED H="1">Compound</CHED>
                                <CHED H="1">Acceptance criteria at 20 µg/L</CHED>
                                <CHED H="2">Initial precision and accuracy section 8.2.3</CHED>
                                <CHED H="3">s (µg/L)</CHED>
                                <CHED H="3">
                                    X
                                    <AC T="8"/>
                                     (µg/L)
                                </CHED>
                                <CHED H="2">Labeled compound recovery sec. 8.3 and 14.2</CHED>
                                <CHED H="3">P (percent)</CHED>
                                <CHED H="2">On-going accuracy sec. 11.5</CHED>
                                <CHED H="3">R (µg/L)</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">Acetone</ENT>
                                <ENT A="03">Note 1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Acrolein</ENT>
                                <ENT A="03">Note 2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Acrylonitrile</ENT>
                                <ENT A="03">Note 2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzene</ENT>
                                <ENT>9.0</ENT>
                                <ENT>13.0-28.2</ENT>
                                <ENT>ns-196</ENT>
                                <ENT>4-33</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Bromodichloromethane</ENT>
                                <ENT>8.2</ENT>
                                <ENT>6.5-31.5</ENT>
                                <ENT>ns-199</ENT>
                                <ENT>4-34</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Bromoform</ENT>
                                <ENT>7.0</ENT>
                                <ENT>7.4-35.1</ENT>
                                <ENT>ns-214</ENT>
                                <ENT>6-36</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Bromomethane</ENT>
                                <ENT>25.0</ENT>
                                <ENT>d-54.3</ENT>
                                <ENT>ns-414</ENT>
                                <ENT>d-61</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Carbon tetrachloride</ENT>
                                <ENT>6.9</ENT>
                                <ENT>15.9-24.8</ENT>
                                <ENT>42-165</ENT>
                                <ENT>12-30</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chlorobenzene</ENT>
                                <ENT>8.2</ENT>
                                <ENT>14.2-29.6</ENT>
                                <ENT>ns-205</ENT>
                                <ENT>4-35</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chloroethane</ENT>
                                <ENT>14.8</ENT>
                                <ENT>2.1-46.7</ENT>
                                <ENT>ns-308</ENT>
                                <ENT>d-51</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-chloroethylvinyl ether</ENT>
                                <ENT>36.0</ENT>
                                <ENT>d-69.8</ENT>
                                <ENT>ns-554</ENT>
                                <ENT>d-79</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chloroform</ENT>
                                <ENT>7.9</ENT>
                                <ENT>11.6-26.3</ENT>
                                <ENT>18-172</ENT>
                                <ENT>8-30</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chloromethane</ENT>
                                <ENT>26.0</ENT>
                                <ENT>d-55.5</ENT>
                                <ENT>ns-410</ENT>
                                <ENT>d-64</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dibromochloromethane</ENT>
                                <ENT>7.9</ENT>
                                <ENT>11.2-29.1</ENT>
                                <ENT>16-185</ENT>
                                <ENT>8-32</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1-dichloroethane</ENT>
                                <ENT>6.7</ENT>
                                <ENT>11.4-31.4</ENT>
                                <ENT>23-191</ENT>
                                <ENT>9-33</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2-dichloroethane</ENT>
                                <ENT>7.7</ENT>
                                <ENT>11.6-30.1</ENT>
                                <ENT>12-192</ENT>
                                <ENT>8-33</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1-dichloroethene</ENT>
                                <ENT>11.7</ENT>
                                <ENT>d-49.8</ENT>
                                <ENT>ns-315</ENT>
                                <ENT>d-52</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Trans-1,2-dichloroethene</ENT>
                                <ENT>7.4</ENT>
                                <ENT>10.5-31.5</ENT>
                                <ENT>15-195</ENT>
                                <ENT>8-34</ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="361"/>
                                <ENT I="01">1,2-dichloropropane</ENT>
                                <ENT>19.2</ENT>
                                <ENT>d-46.8</ENT>
                                <ENT>ns-343</ENT>
                                <ENT>d-51</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Cis-1,3-dichloropropene</ENT>
                                <ENT>22.1</ENT>
                                <ENT>d-51.0</ENT>
                                <ENT>ns-381</ENT>
                                <ENT>d-56</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Trans-1,3-dichloropropene</ENT>
                                <ENT>14.5</ENT>
                                <ENT>d-40.2</ENT>
                                <ENT>ns-284</ENT>
                                <ENT>d-44</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Diethyl ether</ENT>
                                <ENT A="03">Note 1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">P-dioxane</ENT>
                                <ENT A="03">Note 1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ethyl benzene</ENT>
                                <ENT>9.6</ENT>
                                <ENT>15.6-28.5</ENT>
                                <ENT>ns-203</ENT>
                                <ENT>5-35</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Methylene chloride</ENT>
                                <ENT>9.7</ENT>
                                <ENT>d-49.8</ENT>
                                <ENT>ns-316</ENT>
                                <ENT>d-50</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Methyl ethyl ketone</ENT>
                                <ENT A="03">Note 1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1,2,2-tetrachloroethane</ENT>
                                <ENT>9.6</ENT>
                                <ENT>10.7-30.0</ENT>
                                <ENT>5-199</ENT>
                                <ENT>7-34</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Tetrachloroethene</ENT>
                                <ENT>6.6</ENT>
                                <ENT>15.1-28.5</ENT>
                                <ENT>31-181</ENT>
                                <ENT>11-32</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Toluene</ENT>
                                <ENT>6.3</ENT>
                                <ENT>14.5-28.7</ENT>
                                <ENT>4-193</ENT>
                                <ENT>6-33</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1,1-trichloroethane</ENT>
                                <ENT>5.9</ENT>
                                <ENT>10.5-33.4</ENT>
                                <ENT>12-200</ENT>
                                <ENT>8-35</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,1,2-trichloroethane</ENT>
                                <ENT>7.1</ENT>
                                <ENT>11.8-29.7</ENT>
                                <ENT>21-184</ENT>
                                <ENT>9-32</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Trichloroethene</ENT>
                                <ENT>8.9</ENT>
                                <ENT>16.6-29.5</ENT>
                                <ENT>35-196</ENT>
                                <ENT>12-34</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Vinyl chloride</ENT>
                                <ENT>27.9</ENT>
                                <ENT>d-58.5</ENT>
                                <ENT>ns-452</ENT>
                                <ENT>d-65</ENT>
                            </ROW>
                            <TNOTE>d = detected; result must be greater than zero.</TNOTE>
                            <TNOTE>ns = no specification; limit would be below detection limit.</TNOTE>
                            <TNOTE>
                                <E T="04">Note 1:</E>
                                 Specifications not available for these compounds at time of release of this method.
                            </TNOTE>
                            <TNOTE>
                                <E T="04">Note 2:</E>
                                 Specifications not developed for these compounds; use method 603.
                            </TNOTE>
                        </GPOTABLE>
                        <GPH SPAN="2" DEEP="440">
                            <PRTPAGE P="362"/>
                            <GID>EC02JY92.055</GID>
                        </GPH>
                        <GPH SPAN="2" DEEP="440">
                            <PRTPAGE P="363"/>
                            <GID>EC02JY92.056</GID>
                        </GPH>
                        <HD SOURCE="HD1">Method 1625 Revision B—Semivolatile Organic Compounds by Isotope Dilution GC/MS</HD>
                        <EAR>Pt. 136, App. A, Meth. 1625</EAR>
                        <HD SOURCE="HD2">1. Scope and Application</HD>
                        <P>1.1 This method is designed to determine the semivolatile toxic organic pollutants associated with the 1976 Consent Decree and additional compounds amenable to extraction and analysis by capillary column gas chromatography-mass spectrometry (GC/MS).</P>
                        <P>
                            1.2 The chemical compounds listed in Tables 1 and 2 may be determined in municipal and industrial discharges by this method. The method is designed to meet the survey 
                            <PRTPAGE P="364"/>
                            requirements of Effluent Guidelines Division (EGD) and the National Pollutants Discharge Elimination System (NPDES) under 40 CFR 136.1. Any modifications of this method, beyond those expressly permitted, shall be considered as major modifications subject to application and approval of alternate test procedures under 40 CFR 136.4 and 136.5.
                        </P>
                        <P>1.3 The detection limit of this method is usually dependent on the level of interferences rather than instrumental limitations. The limits listed in Tables 3 and 4 represent the minimum quantity that can be detected with no interferences present.</P>
                        <P>1.4 The GC/MS portions of this method are for use only by analysts experienced with GC/MS or under the close supervision of such qualified persons. Laboratories unfamiliar with analyses of environmental samples by GC/MS should run the performance tests in reference 1 before beginning.</P>
                        <HD SOURCE="HD2">2. Summary of Method</HD>
                        <P>2.1 Stable isotopically labeled analogs of the compounds of interest are added to a one liter wastewater sample. The sample is extracted at pH 12-13, then at pH &lt;2 with methylene chloride using continuous extraction techniques. The extract is dried over sodium sulfate and concentrated to a volume of one mL. An internal standard is added to the extract, and the extract is injected into the gas chromatograph (GC). The compounds are separated by GC and detected by a mass spectrometer (MS). The labeled compounds serve to correct the variability of the analytical technique.</P>
                        <P>2.2 Identification of a compound (qualitative analysis) is performed by comparing the GC retention time and background corrected characteristic spectral masses with those of authentic standards.</P>
                        <P>2.3 Quantitative analysis is performed by GC/MS using extracted ion current profile (EICP) areas. Isotope dilution is used when labeled compounds are available; otherwise, an internal standard method is used.</P>
                        <P>2.4 Quality is assured through reproducible calibration and testing of the extraction and GC/MS systems.</P>
                        <HD SOURCE="HD2">3. Contamination and Interferences</HD>
                        <P>3.1 Solvents, reagents, glassware, and other sample processing hardware may yield artifacts and/or elevated baselines causing misinterpretation of chromatograms and spectra. All materials shall be demonstrated to be free from interferences under the conditions of analysis by running method blanks initially and with each sample lot (samples started through the extraction process on a given 8 hr shift, to a maximum of 20). Specific selection of reagents and purification of solvents by distillation in all-glass systems may be required. Glassware and, where possible, reagents are cleaned by solvent rinse and baking at 450 °C for one hour minimum.</P>
                        <P>3.2 Interferences coextracted from samples will vary considerably from source to source, depending on the diversity of the industrial complex or municipality being samples.</P>
                        <HD SOURCE="HD2">4. Safety</HD>
                        <P>4.1 The toxicity or carcinogenicity of each compound or reagent used in this method has not been precisely determined; however, each chemical compound should be treated as a potential health hazard. Exposure to these compounds should be reduced to the lowest possible level. The laboratory is responsible for maintaining a current awareness file of OSHA regulations regarding the safe handling of the chemicals specified in this method. A reference file of data handling sheets should also be made available to all personnel involved in these analyses. Additional information on laboratory safety can be found in references 2-4.</P>
                        <P>4.2 The following compounds covered by this method have been tentatively classified as known or suspected human or mammalian carcinogens: benzidine benzo(a)anthracene, 3,3′-dichlorobenzidine, benzo(a)pyrene, dibenzo(a,h)anthracene, N-nitrosodimethylamine, and β-naphtylamine. Primary standards of these compounds shall be prepared in a hood, and a NIOSH/MESA approved toxic gas respirator should be worn when high concentrations are handled.</P>
                        <HD SOURCE="HD2">5. Apparatus and Materials</HD>
                        <P>5.1 Sampling equipment for discrete or composite sampling.</P>
                        <P>5.1.1 Sample bottle, amber glass, 1.1 liters minimum. If amber bottles are not available, samples shall be protected from light. Bottles are detergent water washed, then solvent rinsed or baked at 450 °C for one hour minimum before use.</P>
                        <P>5.1.2 Bottle caps—threaded to fit sample bottles. Caps are lined with Teflon. Aluminum foil may be substituted if the sample is not corrosive. Liners are detergent water washed, then reagent water (Section 6.5) and solvent rinsed, and baked at approximately 200 °C for one hour minimum before use.</P>
                        <P>
                            5.1.3 Compositing equipment—automatic or manual compositing system incorporating glass containers for collection of a minimum 1.1 liters. Sample containers are kept at 0 to 4 °C during sampling. Glass or Teflon tubing only shall be used. If the sampler uses a peristaltic pump, a minimum length of compressible silicone rubber tubing may be used in the pump only. Before use, the tubing is thoroughly rinsed with methanol, followed by repeated rinsings with reagent water (Section 6.5) to minimize sample contamination. An integrating flow meter is used to collect proportional composite samples.
                            <PRTPAGE P="365"/>
                        </P>
                        <P>5.2 Continuous liquid-liquid extractor—Teflon or glass conncecting joints and stopcocks without lubrication (Hershberg-Wolf Extractor) one liter capacity, Ace Glass 6841-10, or equivalent.</P>
                        <P>5.3 Drying column—15 to 20 mm i.d. Pyrex chromatographic column equipped with coarse glass frit or glass wool plug.</P>
                        <P>5.4 Kuderna-Danish (K-D) apparatus</P>
                        <P>5.4.1 Concentrator tube—10mL, graduated (Kontes K-570050-1025, or equivalent) with calibration verified. Ground glass stopper (size 19/22 joint) is used to prevent evaporation of extracts.</P>
                        <P>5.4.2 Evaporation flask—500 mL (Kontes K-570001-0500, or equivalent), attached to concentrator tube with springs (Kontes K-662750-0012).</P>
                        <P>5.4.3 Snyder column—three ball macro (Kontes K-503000-0232, or equivalent).</P>
                        <P>5.4.4 Snyder column—two ball micro (Kontes K-469002-0219, or equivalent).</P>
                        <P>5.4.5 Boiling chips—approx 10/40 mesh, extracted with methylene chloride and baked at 450 °C for one hr minimum.</P>
                        <P>5.5 Water bath—heated, with concentric ring cover, capable of temperature control ±2 °C, installed in a fume hood.</P>
                        <P>5.6 Sample vials—amber glass, 2-5 mL with Teflon-lined screw cap.</P>
                        <P>5.7 Analytical balance—capable of weighing 0.1 mg.</P>
                        <P>5.8 Gas chromatograph—shall have splitless or on-column injection port for capillary column, temperature program with 30 °C hold, and shall meet all of the performance specifications in Section 12.</P>
                        <P>5.8.1 Column—30 ±5 m × 0.25 ±0.02 mm i.d. 5% phenyl, 94% methyl, 1% vinyl silicone bonded phase fused silica capillary column (J &amp; W DB-5, or equivalent).</P>
                        <P>5.9 Mass spectrometer—70 eV electron impact ionization, shall repetitively scan from 35 to 450 amu in 0.95 to 1.00 second, and shall produce a unit resolution (valleys between m/z 441-442 less than 10 percent of the height of the 441 peak), backgound corrected mass spectrum from 50 ng decafluorotriphenylphosphine (DFTPP) introduced through the GC inlet. The spectrum shall meet the mass-intensity criteria in Table 5 (reference 5). The mass spectrometer shall be interfaced to the GC such that the end of the capillary column terminates within one centimeter of the ion source but does not intercept the electron or ion beams. All portions of the column which connect the GC to the ion source shall remain at or above the column temperature during analysis to preclude condensation of less volatile compounds.</P>
                        <P>5.10 Data system—shall collect and record MS data, store mass-intensity data in spectral libraries, process GC/MS data, generate reports, and shall compute and record response factors.</P>
                        <P>5.10.1 Data acquisition—mass spectra shall be collected continuously throughout the analysis and stored on a mass storage device.</P>
                        <P>5.10.2 Mass spectral libraries—user created libraries containing mass spectra obtained from analysis of authentic standards shall be employed to reverse search GC/MS runs for the compounds of interest (Section 7.2).</P>
                        <P>5.10.3 Data processing—the data system shall be used to search, locate, identify, and quantify the compounds of interest in each GC/MS analysis. Software routines shall be employed to compute retention times and peak areas. Displays of spectra, mass chromatograms, and library comparisons are required to verify results.</P>
                        <P>5.10.4 Response factors and multipoint calibrations—the data system shall be used to record and maintain lists of response factors (response ratios for isotope dilution) and multipoint calibration curves (Section 7). Computations of relative standard deviation (coefficient of variation) are useful for testing calibration linearity. Statistics on initial (Section 8.2) and on-going (Section 12.7) performance shall be computed and maintained.</P>
                        <HD SOURCE="HD2">6. Reagents and Standards</HD>
                        <P>6.1 Sodium hydroxide—reagent grade, 6N in reagent water.</P>
                        <P>6.2 Sulfuric acid—reagent grade, 6N in reagent water.</P>
                        <P>6.3 Sodium sulfate—reagent grade, granular anhydrous, rinsed with methylene chloride (20 mL/g) and conditioned at 450 °C for one hour minimum.</P>
                        <P>6.4 Methylene chloride—distilled in glass (Burdick and Jackson, or equivalent).</P>
                        <P>6.5 Reagent water—water in which the compounds of interest and interfering compounds are not detected by this method.</P>
                        <P>6.6 Standard solutions—purchased as solutions or mixtures with certification to their purity, concentration, and authenticity, or prepared from materials of known purity and composition. If compound purity is 96 percent or greater, the weight may be used without correction to compute the concentration of the standard. When not being used, standards are stored in the dark at −20 to −10 °C in screw-capped vials with Teflon-lined lids. A mark is placed on the vial at the level of the solution so that solvent evaporation loss can be detected. The vials are brought to room temperature prior to use. Any precipitate is redissolved and solvent is added if solvent loss has occurred.</P>
                        <P>
                            6.7 Preparation of stock solutions—prepare in methylene chloride, benzene, p-dioxane, or a mixture of these solvents per the steps below. Observe the safety precautions in Section 4. The large number of labeled and unlabeled acid, base/neutral, and Appendix C compounds used for combined 
                            <PRTPAGE P="366"/>
                            calibration (Section 7) and calibration verification (12.5) require high concentratimns (approx 40 mg/mL) when individual stock solutions are prepared, so that dilutions of mixtures will permit calibration with all compounds in a single set of solutions. The working range for most compounds is 10-200 µg/mL. Compounds with a reduced MS response may be prepared at higher concentrations.
                        </P>
                        <P>6.7.1 Dissolve an appropriate amount of assayed reference material in a suitable solvent. For example, weigh 400 mg naphthalene in a 10 mL ground glass stoppered volumetric flask and fill to the mark with benzene. After the naphthalene is completely dissolved, transfer the solution to a 15 mL vial with Teflon-lined cap.</P>
                        <P>6.7.2 Stock standard solutions should be checked for signs of degradation prior to the preparation of calibration or performance test standards. Quality control check samples that can be used to determine the accuracy of calibration standards are available from the US Environmental Protection Agency, Environmental Monitoring and Support Laboratory, Cincinnati, Ohio 45268.</P>
                        <P>6.7.3 Stock standard solutions shall be replaced after six months, or sooner if comparison with quality control check samples indicates a change in concentration.</P>
                        <P>6.8 Labeled compound spiking solution—from stock standard solutions prepared as above, or from mixtures, prepare the spiking solution at a concentration of 200 µg/mL, or at a concentration appropriate to the MS response of each compound.</P>
                        <P>6.9 Secondary standard—using stock solutions (Section 6.7), prepare a secondary standard containing all of the compounds in Tables 1 and 2 at a concentration of 400 µg/mL, or higher concentration appropriate to the MS response of the compound.</P>
                        <P>6.10 Internal standard solution—prepare 2,2′-difluorobiphenyl (DFB) at a concentration of 10 mg/mL in benzene.</P>
                        <P>6.11 DFTPP solution—prepare at 50 µg/mL in acetone.</P>
                        <P>6.12 Solutions for obtaining authentic mass spectra (Section 7.2)—prepare mixtures of compounds at concentrations which will assure authentic spectra are obtained for storage in libraries.</P>
                        <P>6.13 Calibration solutions—combine 0.5 mL of the solution in Section 6.8 with 25, 50, 125, 250, and 500 uL of the solution in section 6.9 and bring to 1.00 mL total volume each. This will produce calibration solutions of nominal 10, 20, 50, 100, and 200 µg/mL of the pollutants and a constant nominal 100 µg/mL of the labeled compounds. Spike each solution with 10 µL of the internal standard solution (Section 6.10). These solutions permit the relative response (labeled to unlabeled) to be measured as a function of concentration (Section 7.4).</P>
                        <P>6.14 Precision and recovery standard—used for determination of initial (Section 8.2) and on-going (Section 12.7) precision and recovery. This solution shall contain the pollutants and labeled compounds at a nominal concentration of 100 µg/mL.</P>
                        <P>6.15 Stability of solutions—all standard solutions (Sections 6.8-6.14) shall be analyzed within 48 hours of preparation and on a monthly basis thereafter for signs of degradation. Standards will remain acceptable if the peak area at the quantitation mass relative to the DFB internal standard remains within ±15 percent of the area obtained in the initial analysis of the standard.</P>
                        <HD SOURCE="HD2">7. Calibration</HD>
                        <P>7.1 Assemble the GC/MS and establish the operating conditions in Table 3. Analyze standards per the procedure in Section 11 to demonstrate that the analytical system meets the detection limits in Tables 3 and 4, and the mass-intensity criteria in Table 5 for 50 ng DFTPP.</P>
                        <P>7.2 Mass spectral libraries—detection and identification of compounds of interest are dependent upon spectra stored in user created libraries.</P>
                        <P>7.2.1 Obtain a mass spectrum of each pollutant, labeled compound, and the internal standard by analyzing an authentic standard either singly or as part of a mixture in which there is no interference between closely eluted components. That only a single compound is present is determined by examination of the spectrum. Fragments not attributable to the compound under study indicate the presence of an interfering compound.</P>
                        <P>7.2.2 Adjust the analytical conditions and scan rate (for this test only) to produce an undistorted spectrum at the GC peak maximum. An undistorted spectrum will usually be obtained if five complete spectra are collected across the upper half of the GC peak. Software algorithms designed to “enhance” the spectrum may eliminate distortion, but may also eliminate authentic masses or introduce other distortion.</P>
                        <P>7.2.3 The authentic reference spectrum is obtained under DFTPP tuning conditions (Section 7.1 and Table 5) to normalize it to spectra from other instruments.</P>
                        <P>7.2.4 The spectrum is edited by saving the 5 most intense mass spectral peaks and all other mass spectral peaks greater than 10 percent of the base peak. This edited spectrum is stored for reverse search and for compound confirmation.</P>
                        <P>
                            7.3 Analytical range—demonstrate that 20 ng anthracene or phenanthrene produces an area at m/z 178 approx one-tenth that required to exceed the linear range of the system. The exact value must be determined by experience for each instrument. It is used to match the calibration range of the instrument to the analytical range and detection limits required, and to diagnose instrument 
                            <PRTPAGE P="367"/>
                            sensitivity problems (Section 15.4). The 20 ug/mL calibration standard (Section 6.13) can be used to demonstrate this performance.
                        </P>
                        <P>7.3.1 Polar compound detection—demonstrate that unlabeled pentachlorophenol and benzidine are detectable at the 50 µg/mL level (per all criteria in Section 13). The 50 µg/mL calibration standard (Section 6.13) can be used to demonstrate this performance.</P>
                        <P>7.4 Calibration with isotope dilution—isotope dilution is used when (1) labeled compounds are available, (2) interferences do not preclude its use, and (3) the quantitation mass extracted ion current profile (EICP) area for the compound is in the calibration range. If any of these conditions preclude isotope dilution, internal standard methods (Section 7.5 or 7.6) are used.</P>
                        <P>7.4.1 A calibration curve encompassing the concentration range is prepared for each compound to be determined. The relative response (pollutant to labeled) vs concentration in standard solutions is plotted or computed using a linear regression. The example in Figure 1 shows a calibration curve for phenol using phenol-d5 as the isotopic diluent. Also shown are the ±10 percent error limits (dotted lines). Relative Reponse (RR) is determined according to the procedures described below. A minimum of five data points are employed for calibration.</P>
                        <P>7.4.2 The relative response of a pollutant to its labeled analog is determined from isotope ratio values computed from acquired data. Three isotope ratios are used in this process:</P>
                        <P>
                            R
                            <E T="52">X</E>
                             = the isotope ratio measured for the pure pollutant.
                        </P>
                        <P>
                            R
                            <E T="52">y</E>
                             = the isotope ratio measured for the labeled compound.
                        </P>
                        <P>
                            R
                            <E T="52">m</E>
                             = the isotope ratio of an analytical mixture of pollutant and labeled compounds.
                        </P>
                        <P>
                            The m/z's are selected such that R
                            <E T="52">X</E>
                            &gt;R
                            <E T="52">y</E>
                            . If R
                            <E T="52">m</E>
                             is not between 2R
                            <E T="52">y</E>
                             and 0.5R
                            <E T="52">X</E>
                            , the method does not apply and the sample is analyzed by internal or external standard methods.
                        </P>
                        <P>
                            7.4.3 Capillary columns usually separate the pollutant-labeled pair, with the labeled compound eluted first (Figure 2). For this case, R
                            <E T="52">X</E>
                             = [area m
                            <E T="52">1</E>
                            /z]/1, at the retention time of the pollutant (RT
                            <E T="52">2</E>
                            ). R
                            <E T="52">y</E>
                             = 1/[area m
                            <E T="52">2</E>
                            /z, at the retention time of the labeled compound RT
                            <E T="52">1</E>
                            ). R
                            <E T="52">m</E>
                             = [area at m
                            <E T="52">1</E>
                            /z (at RT
                            <E T="52">2</E>
                            )]/[area at RT
                            <E T="52">1</E>
                            )], as measured in the mixture of the pollutant and labeled compounds (Figure 2), and RR = R
                            <E T="52">m</E>
                            .
                        </P>
                        <P>7.4.4 Special precautions are taken when the pollutant-labeled pair is not separated, or when another labeled compound with interfering spectral masses overlaps the pollutant (a case which can occur with isomeric compounds). In this case, it is necessary to determine the respective contributions of the pollutant and labeled compounds to the respective EICP areas. If the peaks are separated well enough to permit the data system or operator to remove the contributions of the compounds to each other, the equations in Section 7.4.3 apply. This usually occurs when the height of the valley between the two GC peaks at the same m/z is less than 10 percent of the height of the shorter of the two peaks. If significant GC and spectral overlap occur, RR is computed using the following equation:</P>
                        <P>
                            RR = (R
                            <E T="52">y</E>
                             − R
                            <E T="52">m</E>
                            ) (R
                            <E T="52">X</E>
                             + 1)/(R
                            <E T="52">m</E>
                             − R
                            <E T="52">X</E>
                            ) (R
                            <E T="52">y</E>
                             + 1), where R
                            <E T="52">X</E>
                             is measured as shown in Figure 3A, R
                            <E T="52">y</E>
                             is measured as shown in Figure 3B, and R
                            <E T="52">m</E>
                             is measured as shown in Figure 3C. For example, R
                            <E T="52">X</E>
                             = 46100/4780 = 9.644, R
                            <E T="52">y</E>
                             = 2650/43600 = 0.0608, R
                            <E T="52">m</E>
                             = 49200/48300 = 1.019. amd RR = 1.114.
                        </P>
                        <P>7.4.5 To calibrate the analytical system by isotope dilution, analyze a 1.0 µL aliquot of each of the calibration standards (Section 6.13) using the procedure in Section 11. Compute the RR at each concentration.</P>
                        <P>7.4.6 Linearity—if the ratio of relative response to concentration for any compound is constant (less than 20 percent coefficient of variation) over the 5 point calibration range, and averaged relative response/concentration ratio may be used for that compound; otherwise, the complete calibration curve for that compound shall be used over the 5 point calibration range.</P>
                        <P>7.5 Calibration by internal standard—used when criteria for istope dilution (Section 7.4) cannot be met. The internal standard to be used for both acid and base/neutral analyses is 2,2′-difluorobiphenyl. The internal standard method is also applied to determination of compounds having no labeled analog, and to measurement of labeled compounds for intra-laboratory statistics (Sections 8.4 and 12.7.4).</P>
                        <P>7.5.1 Response factors—calibration requires the determination of response factors (RF) which are defined by the following equation:</P>
                        <FP SOURCE="FP1-2">
                            RF = (A
                            <E T="52">s</E>
                             × C
                            <E T="52">is</E>
                            )/(A
                            <E T="52">is</E>
                             × C
                            <E T="52">s</E>
                            ), where
                        </FP>
                        <FP SOURCE="FP1-2">
                            A
                            <E T="52">s</E>
                             is the area of the characteristic mass for the compmund in the daily standard
                        </FP>
                        <FP SOURCE="FP1-2">
                            A
                            <E T="52">is</E>
                             is the area of the characteristic mass for the internal standard
                        </FP>
                        <FP SOURCE="FP1-2">
                            C
                            <E T="52">is</E>
                             is the concentration of the internal standard (µg/mL)
                        </FP>
                        <FP SOURCE="FP1-2">
                            C
                            <E T="52">s</E>
                             is the concentration of the compound in the daily standard (µg/mL)
                        </FP>
                        <P>
                            7.5.1.1 The response factor is determined for at least five concentrations appropriate to the response of each compound (Section 6.13); nominally, 10, 20, 50, 100, and 200 µg/mL. The amount of internal standard added to each extract is the same (100 µg/mL) so that C
                            <E T="52">is</E>
                             remains constant. The RF is plotted vs concentration for each compound in the standard (C
                            <E T="52">s</E>
                            ) to produce a calibration curve.
                        </P>
                        <P>
                            7.5.1.2 Linearity—if the response factor (RF) for any compound is constant (less than 35 percent coefficient of variation) over the 5 
                            <PRTPAGE P="368"/>
                            point calibration range, an averaged response factor may be used for that compound; otherwise, the complete calibration curve for that compound shall be used over the 5 point range.
                        </P>
                        <P>7.6 Combined calibration—by using calibration solutions (Section 6.13) containing the pollutants, labeled compounds, and the internal standard, a single set of analyses can be used to produce calibration curves for the isotope dilution and internal standard methods. These curves are verified each shift (Section 12.5) by analyzing the 100 µg/mL calibration standard (Section 6.13). Recalibration is required only if calibration verification (Section 12.5) criteria cannot be met.</P>
                        <HD SOURCE="HD2">8. Quality Assurance/Quality Control</HD>
                        <P>8.1 Each laboratory that uses this method is required to operate a formal quality assurance program. The minimum requirements of this program consist of an initial demonstration of laboratory capability, analysis of samples spiked with labeled compounds to evaluate and document data quality, and analysis of standards and blanks as tests of continued performance. Laboratory performance is compared to established performance criteria to determine if the results of analyses meet the performance characteristics of the method.</P>
                        <P>8.1.1 The analyst shall make an initial demonstration of the ability to generate acceptable accuracy and precision with this method. This ability is established as described in Section 8.2.</P>
                        <P>8.1.2 The analyst is permitted to modify this method to improve separations or lower the costs of measurements, provided all performance specifications are met. Each time a modification is made to the method, the analyst is required to repeat the procedure in Section 8.2 to demonstrate method performance.</P>
                        <P>8.1.3 Analyses of blanks are required to demonstrate freedom from contamination. The procedures and criteria for analysis of a blank are described in Section 8.5.</P>
                        <P>8.1.4 The laboratory shall spike all samples with labeled compounds to monitor method performance. This test is described in Section 8.3. When results of these spikes indicate atypical method performance for samples, the samples are diluted to bring method performance within acceptable limits (Section 15).</P>
                        <P>8.1.5 The laboratory shall, on an on-going basis, demonstrate through calibration verification and the analysis of the precision and recovery standard (Section 6.14) that the analysis system is in control. These procedures are described in Sections 12.1, 12.5, and 12.7.</P>
                        <P>8.1.6 The laboratory shall maintain records to define the quality of data that is generated. Development of accuracy statements is described in Section 8.4.</P>
                        <P>8.2 Initial precision and accuracy—to establish the ability to generate acceptable precision and accuracy, the analyst shall perform the following operations:</P>
                        <P>8.2.1 Extract, concentrate, and analyze two sets of four one-liter aliquots (8 aliquots total) of the precision and recovery standard (Section 6.14) according to the procedure in Section 10.</P>
                        <P>
                            8.2.2 Using results of the first set of four analyses, compute the average recovery (X
                            <AC T="8"/>
                            ) in µg/mL and the standard deviation of the recovery (s) in θg/µL for each compound, by isotope dilution for pollutants with a labeled analog, and by internal standard for labeled compounds and pollutants with no labeled analog.
                        </P>
                        <P>
                            8.2.3 For each compound, compare s and X
                            <AC T="8"/>
                             with the corresponding limits for initial precision and accuracy in Table 8. If s and X
                            <AC T="8"/>
                             for all compounds meet the acceptance criteria, system performance is acceptable and analysis of blanks and samples may begin. If, however, any individual s exceeds the precision limit or any individual X
                            <AC T="8"/>
                             falls outside the range for accuracy, system performance is unacceptable for that compound.
                        </P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>The large number of compounds in Table 8 present a substantial probability that one or more will fail the acceptance criteria when all compounds are analyzed. To determine if the analytical system is out of control, or if the failure can be attributed to probability, proceed as follows:</P>
                        </NOTE>
                        <P>
                            8.2.4 Using the results of the second set of four analyses, compute s and X
                            <AC T="8"/>
                             for only those compounds which failed the test of the first set of four analyses (Section 8.2.3). If these compounds now pass, system performance is acceptable for all compounds and analysis of blanks and samples may begin. If, however, any of the same compoulds fail again, the analysis system is not performing properly for these compounds. In this event, correct the problem and repeat the entire test (Section 8.2.1).
                        </P>
                        <P>8.3 The laboratory shall spike all samples with labeled compounds to assess method performance on the sample matrix.</P>
                        <P>8.3.1 Analyze each sample according to the method in Section 10.</P>
                        <P>8.3.2 Compute the percent recovery (P) of the labeled compounds using the internal standard methmd (Section 7.5).</P>
                        <P>8.3.3 Compare the labeled compound recovery for each compound with the corresponding limits in Table 8. If the recovery of any compounds falls outside its warning limit, method performance is unacceptable for that compound in that sample, Therefore, the sample is complex and is to be diluted and reanalyzed per Section 15.4.</P>
                        <P>
                            the QA program for the laboratory, method accuracy for wastewater samples shall be assessed and records shall be maintained. After 
                            <PRTPAGE P="369"/>
                            the analysis of five wastewater samples for which the labeled compounds pass the tests in Section 8.3, compute the average percent recovery (P) and the standard deviation of the percent recovery (s
                            <E T="52">p</E>
                            ) for the labeled compounds only. Express the accuracy assessment as a percent recovery interval from P—2 
                            <E T="52">sp</E>
                             to P + 2
                            <E T="52">sp</E>
                            . For example, if P = 90% and s
                            <E T="52">p</E>
                             = 10%, the accuracy interval is expressed as 70-100%. Update the accuracy assessment for each compound on a regular basis (e.g. after each 5-10 new accuracy measurements).
                        </P>
                        <P>8.5 Blanks—reagent water blanks are analyzed to demonstrate freedom from contamination.</P>
                        <P>8.5.1 Extract and concentrate a blank with each sample lot (samples started through the extraction process on the same 8 hr shift, to a maximum of 20 samples). Analyze the blank immediately after analysis of the precision and recovery standard (Section 6.14) to demonstrate freedom from contamination.</P>
                        <P>8.5.2 If any of the compounds of interest (Tables 1 and 2) or any potentially interfering compound is found in a blank at greater than 10 µg/L (assuming a response factor of 1 relative to the internal standard for compounds not listed in Tables 1 and 2), analysis of samples is halted until the source of contamination is eliminated and a blank shows no evidence of contamination at this level.</P>
                        <P>8.6 The specifications contained in this method can be met if the apparatus used is calibrated properly, then maintained in a calibrated state. The standards used for calibration (Section 7), calibration verification (Section 12.5), and for initial (Section 8.2) and on-going (Section 12.7) precision and recovery should be identical, so that the most precise results will be obtained. The GC/MS instrument in particular will provide the most reproducible results if dedicated to the settings and conditions required for the analysis of semi-volatiles by this method.</P>
                        <P>8.7 Depending on specific program requirements, field replicates may be collected to determine the precision of the sampling technique, and spiked samples may be required to determine the accuracy of the analysis when internal or external standard methods are used.</P>
                        <HD SOURCE="HD2">9. Sample Collection, Preservation, and Handling</HD>
                        <P>9.1 Collect samples in glass containers following conventional sampling practices (Reference 7). Composite samples are collected in refrigerated glass containers (Section 5.1.3) in accordance with the requirements of the sampling program.</P>
                        <P>9.2 Maintain samples at 0-4 °C from the time collectimn until extraction. If residual chlorine is present, add 80 mg sodium thiosulfate per liter of water. EPA Methods 330.4 and 330.5 may be used to measure residual chlorine (Reference 8).</P>
                        <P>9.3 Begin sample extraction within seven days of collection, and analyze all extracts within 40 days of extraction.</P>
                        <HD SOURCE="HD2">10. Sample Extraction and Concentration (See Figure 4)</HD>
                        <P>10.1 Labeled compound spiking—measure 1.00 ±0.01 liter of sample into a glass container. For untreated effluents, and samples which are expected to be difficult to extract and/or concentrate, measure an additional 10.0 ±0.1 mL and dilute to a final volume of 1.00 ±0.01 liter with reagent water in a glass container.</P>
                        <P>10.1.1 For each sample or sample lot (to a maximum of 20) to be extracted at the same time, place three 1.00 ±0.10 liter aliquots of reagent water in glass containers.</P>
                        <P>10.1.2 Spike 0.5 mL of the labeled compound spiking solution (Section 6.8) into all samples and one reagant water aliquot.</P>
                        <P>10.1.3 Spike 1.0 mL of the precision and recovery standard (Section 6.14) into the two remaining reagent water aliquots.</P>
                        <P>10.1.4 Stir and equilibrate all solutions for 1-2 hr.</P>
                        <P>10.2 Base/neutral extraction—place 100-150 mL methylene chloride in each continuous extractor and 200-300 in each distilling flask.</P>
                        <P>10.2.1 Pour the sample(s), blank, and standard aliquots into the extractors. Rinse the glass containers with 50-100 mL methylene chloride and add to the respective extractor.</P>
                        <P>10.2.2 Adjust the pH of the waters in the extractors to 12-13 with 6N NaOH while monitoring with a pH meter. Begin the extraction by heating the flask until the methylene chloride is boiling. When properly adjusted, 1-2 drops of methylene chloride per second will fall from the condensor tip into the water. After 1-2 hours of extraction, test the pH and readjust to 12-13 if required. Extract for 18-24 hours.</P>
                        <P>10.2.3 Remove the distilling flask, estimate and record the volume of extract (to the nearest 100 mL), and pour the contents through a drying column containing 7 to 10 cm anhydrous sodium sulfate. Rinse the distilling flask with 30-50 mL of methylene chloride and pour through the drying column. Collect the solution in a 500 mL K-D evaporator flask equipped with a 10 mL concentrator tube. Seal, label as the base/neutral fraction, and concentrate per Sections 10.4 to 10.5.</P>
                        <P>10.3 Acid extraction—adjust the pH of the waters in the extractors to 2 or less using 6N sulfuric acid. Charge clean distilling flasks with 300-400 mL of methylene chloride. Test and adjust the pH of the waters after the first 1-2 hr of extraction. Extract for 18-24 hours.</P>
                        <P>
                            10.3.1 Repeat Section 10.2.3, except label as the acid fraction.
                            <PRTPAGE P="370"/>
                        </P>
                        <P>10.4 Concentration—concentrate the extracts in separate 500 mL K-D flasks equipped with 10 mL concentrator tubes.</P>
                        <P>10.4.1 Add 1 to 2 clean boiling chips to the flask and attach a three-ball macro Snyder column. Prewet the column by adding approximately one mL of methylene chloride through the top. Place the K-D apparatus in a hot water bath so that the entire lower rounded surface of the flask is bathed with steam. Adjust the vertical position of the apparatus and the water temperature as required to complete the concentration in 15 to 20 minutes. At the proper rate of distillation, the balls of the column will actively chatter but the chambers will not flood. When the liquid has reached an apparent volume of 1 mL, remove the K-D apparatus from the bath and allow the solvent to drain and cool for at least 10 minutes. Remove the Snyder column and rinse the flask and its lower joint into the concentrator tube with 1-2 mL of methylene chloride. A 5-mL syringe is recommended for this operation.</P>
                        <P>10.4.2 For performance standards (Sections 8.2 and 12.7) and for blanks (Section 8.5), combine the acid and base/neutral extracts for each at this point. Do not combine the acid and base/neutral extracts for samples.</P>
                        <P>10.5 Add a clean boiling chip and attach a two ball micro Snyder column to the concentrator tube. Prewet the column by adding approx 0.5 mL methylene chloride through the top. Place the apparatus in the hot water bath. Adjust the vertical position and the water temperature as required to complete the concentration in 5-10 minutes. At the proper rate of distillation, the balls of the column will actively chatter but the chambers will not flood. When the liquid reaches an apparent volume of approx 0.5 mL, remove the apparatus from the water bath and allow to drain and cool for at least 10 minutes. Remove the micro Snyder column and rinse its lower joint into the concentrator tube with approx 0.2 mL of methylene chloride. Adjust the final volume to 1.0 mL.</P>
                        <P>10.6 Transfer the concentrated extract to a clean screw-cap vial. Seal the vial with a Teflon-lined lid, and mark the level on the vial. Label with the sample number and fraction, and store in the dark at −20 to −10 °C until ready for analysis.</P>
                        <HD SOURCE="HD2">11. GC/MS Analysis</HD>
                        <P>11.1 Establish the operating conditions given in Table 3 or 4 for analysis of the base/neutral or acid extracts, respectively. For analysis of combined extracts (Section 10.4.2), use the operating conditions in Table 3.</P>
                        <P>11.2 Bring the concentrated extract (Section 10.6) or standard (Sections 6.13 through 6.14) to room temperature and verify that any precipitate has redissolved. Verify the level on the extract (Sections 6.6 and 10.6) and bring to the mark with solvent if required.</P>
                        <P>11.3 Add the internal standard solution (Section 6.10) to the extract (use 1.0 uL of solution per 0.1 mL of extract) immediately prior to injection to minimize the possibility of loss by evaporation, adsorption, or reaction. Mix thoroughly.</P>
                        <P>11.4 Inject a volume of the standard solution or extract such that 100 ng of the internal standard will be injected, using on-column or splitless injection. For 1 mL extracts, this volume will be 1.0 uL. Start the GC column initial isothermal hold upon injection. Start MS data collection after the solvent peak elutes. Stop data collection after the benzo (ghi) perylene or pentachlorophenol peak elutes for the base/neutral or acid fraction, respectively. Return the column to the initial temperature for analysis of the next sample.</P>
                        <HD SOURCE="HD2">12. System and Laboratory Performance</HD>
                        <P>12.1 At the beginning of each 8 hr shift during which analyses are performed, GC/MS system performance and calibration are verified for all pollutants and labeled compounds. For these tests, analysis of the 100 µg/mL calibration standard (Section 6.13) shall be used to verify all performance criteria. Adjustment and/or recalibration (per Section 7) shall be performed until all performance criteria are met. Only after all performance criteria are met may samples, blanks, and precision and recovery standards be analyzed.</P>
                        <P>12.2 DFTPP spectrum validity—inject 1 µL of the DFTPP solution (Section 6.11) either separately or within a few seconds of injection of the standard (Section 12.1) analyzed at the beginning of each shift. The criteria in Table 5 shall be met.</P>
                        <P>12.3 Retention times—the absolute retention time of 2,2′-difluorobiphenyl shall be within the range of 1078 to 1248 seconds and the relative retention times of all pollutants and labeled compounds shall fall within the limits given in Tables 3 and 4.</P>
                        <P>12.4 GC resolution—the valley height between anthracene and phenanthrene at m/z 178 (or the analogs at m/z 188) shall not exceed 10 percent of the taller of the two peaks.</P>
                        <P>12.5 Calibration verification—compute the concentration of each pollutant (Tables 1 and 2) by isotope dilution (Section 7.4) for those compounds which have labeled analogs. Compute the concentration of each pollutant which has no labeled analog by the internal standard method (Section 7.5). Compute the concentration of the labeled compounds by the internal standard method. These concentrations are computed based on the calibration data determined in Section 7.</P>
                        <P>
                            12.5.1 For each pollutant and labeled compound being tested, compare the concentration with the calibration verification limit 
                            <PRTPAGE P="371"/>
                            in Table 8. If all compounds meet the acceptance criteria, calibration has been verified and analysis of blanks, samples, and precision and recovery standards may proceed. If, however, any compound fails, the measurement system is not performing properly for that compound. In this event, prepare a fresh calibration standard or correct the problem causing the failure and repeat the test (Section 12.1), or recalibrate (Section 7).
                        </P>
                        <P>12.6 Multiple peaks—each compound injected shall give a single, distinct GC peak.</P>
                        <P>12.7 On-going precision and accuracy.</P>
                        <P>12.7.1 Analyze the extract of one of the pair of precision and recovery standards (Section 10.1.3) prior to analysis of samples from the same lot.</P>
                        <P>12.7.2 Compute the concentration of each pollutant (Tables 1 and 2) by isotope dilution (Section 7.4) for those compounds which have labeled analogs. Compute the concentration of each pollutant which has no labeled analog by the internal standard method (Section 7.5). Compute the concentration of the labeled compounds by the internal standard method.</P>
                        <P>12.7.3 For each pollutant and labeled compound, compare the concentration with the limits for on-going accuracy in Table 8. If all compounds meet the acceptance criteria, system performance is acceptable and analysis of blanks and samples may proceed. If, however, any individual concentration falls outside of the range given, system performance is unacceptable for that compound.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>The large number of compounds in Table 8 present a substantial probability that one or more will fail when all compounds are analyzed. To determine if the extraction/concentration system is out of control or if the failure is caused by probability, proceed as follows:</P>
                        </NOTE>
                        <P>12.7.3.1 Analyze the second aliquot of the pair of precision and recovery standard (Section 10.1.3).</P>
                        <P>12.7.3.2 Compute the concentration of only those pollutants or labeled compounds that failed the previous test (Section 12.7.3). If these compounds now pass, the extraction/concentration processes are in control and analysis of blanks and samples may proceed. If, however, any of the same compounds fail again, the extraction/concentration processes are not being performed properly for these compounds. In this event, correct the problem, re-extract the sample lot (Section 10) and repeat the on-going precision and recovery test (Section 12.7).</P>
                        <P>
                            12.7.4 Add results which pass the specifications in Section 12.7.2 to initial and previous on-going data. Update QC charts to perform a graphic representation of continued laboratory performance (Figure 5). Develop a statement of laboratory accuracy for each pollutant and labeled compound by calculating the average percent recovery (R) and the standard deviation of percent recovery (s
                            <E T="52">r</E>
                            ). Express the accuracy as a recovery interval from R−2s
                            <E T="52">r</E>
                             to R + 2s
                            <E T="52">r</E>
                            . For example, if R = 95% and s
                            <E T="52">r</E>
                             = 5%, the accuracy is 85−105%.
                        </P>
                        <HD SOURCE="HD2">13. Qualitative Determination</HD>
                        <P>13.1 Qualititative determination is accomplished by comparison of data from analysis of a sample or blank with data from analysis of the shift standard (Section 12.1) and with data stored in the spectral libraries (Section 7.2.4). Identification is confirmed when spectra and retention times agree per the criteria below.</P>
                        <P>13.2 Labeled compounds and pollutants having no labeled analog:</P>
                        <P>13.2.1 The signals for all characteristic masses stored in the spectral library (Section 7.2.4) shall be present and shall maximize within the same two consecutive scans.</P>
                        <P>13.2.2 Either (1) the background corrected EICP areas, or (2) the corrected relative intensities of the mass spectral peaks at the GC peak maximum shall agree within a factor of two (0.5 to 2 times) for all masses stored in the library.</P>
                        <P>13.2.3 The retention time relative to the nearest eluted internal standard shall be within ±15 scans or ±15 seconds, whichever is greater of this difference in the shift standard (Section 12.1).</P>
                        <P>13.3 Pollutants having a labled analog:</P>
                        <P>13.3.1 The signals for all characteristic masses stored in the spectral library (Section 7.2.4) shall be present and shall maximize within the same two consecutive scans.</P>
                        <P>13.3.2. Either (1) the background corrected EICP areas, or (2) the corrected relative intensities of the mass spectral peaks at the GC peak maximum shall agree within a factor of two for all masses stored in the spectral library.</P>
                        <P>13.3.3. The retention time difference between the pollutant and its labeled analog shall agree within ±6 scans or ±6 seconds (whichever is greater) of this difference in the shift standard (Section 12.1).</P>
                        <P>13.4 Masses present in the experimental mass spectrum that are not present in the reference mass spectrum shall be accounted for by contaminant or background ions. If the experimental mass spectrum is contaminated, an experienced spectrometrist (Section 1.4) is to determine the presence or absence of the cmmpound.</P>
                        <HD SOURCE="HD2">14. Quantitative Determination</HD>
                        <P>
                            14.1 Isotope dilution—by adding a known amount of a labeled compound to every sample prior to extraction, correction for recovery of the pollutant can be made because the pollutant and its labeled analog exhibit the same effects upon extraction, concentration, and gas chromatography. Relative response (RR) values for mixtures are used in conjunction with calibration curves described in 
                            <PRTPAGE P="372"/>
                            Section 7.4 to determine concentrations directly, so long as labeled compound spiking levels are constant. For the phenml example given in Figure 1 (Section 7.4.1), RR would be equal to 1.114. For this RR value, the phenol calibration curve given in Figure 1 indicates a concentration of 27 µg/mL in the sample extract (C
                            <E T="52">ex</E>
                            ).
                        </P>
                        <P>
                            14.2 Internal standard—compute the concentration in the extract using the response factor determined from calibration data (Section 7.5) and the following equation: C
                            <E T="52">ex</E>
                            (µg/mL) = (A
                            <E T="52">s</E>
                             × C
                            <E T="52">is</E>
                            /(A
                            <E T="52">is</E>
                             × RF) where C
                            <E T="52">ex</E>
                             is the concentration of the compound in the extract, and the other terms are as defined in Section 7.5.1.
                        </P>
                        <P>
                            14.3 The concentration of the pollutant in water is computed using the volumes of the original water sample (Section 10.1) and the final extract volume (Section 10.5), as follows: Concentration in water (µg/L) = (C
                            <E T="52">ex</E>
                             × V
                            <E T="52">ex</E>
                            )/V
                            <E T="52">s</E>
                             where V
                            <E T="52">ex</E>
                             is the extract volume in mL, and V
                            <E T="52">s</E>
                             is the sample volume in liters.
                        </P>
                        <P>14.4 If the EICP area at the quantitiation mass for any compound exceeds the calibration range of the system, the extract of the dilute aliquot (Section 10.1) is analyzed by isotope dilution; otherwise, the extract is diluted by a factor of 10, 9 µL of internal standard solution (Section 6.10) are added to a 1.0 mL aliquot, and this diluted extract is analyzed by the internal standard method (Section 14.2). Quantify each compound at the highest concentration level within the calibration range.</P>
                        <P>14.5 Report results for all pollutants and labeled compounds (Tables 1 and 2) found in all standards, blanks, and samples in µg/L, to three significant figures. Results for samples which have been diluted are reported at the least dilute level at which the area at the quantitation mass is within the calibration range (Section 14.4) and the labeled compound recovery is within the normal range for the method (Section 15.4).</P>
                        <HD SOURCE="HD2">15. Analysis of Complex Samples</HD>
                        <P>15.1 Untreated effluents and other samples frequently contain high levels (&gt;1000 µg/L) of the compounds of interest, interfering compounds, and/or polymeric materials. Some samples will not concentrate to one mL (Section 10.5); others will overload the GC column and/or mass spectrometer.</P>
                        <P>15.2 Analyze the dilute aliquot (Section 10.1) when the sample will not concentrate to 1.0 mL. If a dilute aliquot was not extracted, and the sample holding time (Section 9.3) has not been exceeded, dilute an aliquot of the sample with reagent water and re-extract (Section 10.1); otherwise, dilute the extract (Section 14.4) and analyze by the internal standard method (Section 14.2).</P>
                        <P>15.3 Recovery of internal standard—the EICP area of the internal standard should be within a factor of two of the area in the shift standard (Section 12.1). If the absolute areas of the labeled compounds are within a factor of two of the respective areas in the shift standard, and the internal standard area is less than one-half of its respective area, then internal standard loss in the extract has occurred. In this case, use one of the labeled compounds (perferably a polynuclear aromatic hydrocarbon) to compute the concentration of a pollutant with no labeled analog.</P>
                        <P>15.4 Recovery of labeled compounds—in most samples, labeled compound recoveries will be similar to those from reagent water (Section 12.7). If the labeled compound recovery is outside the limits given in Table 8, the dilute extract (Section 10.1) is analyzed as in Section 14.4. If the recoveries of all labeled compounds and the internal staldard are low (per the criteria above), then a loss in instrument sensitivity is the most likely cause. In this case, the 100 µg/mL calibration standard (Section 12.1) shall be analyzed and calibration verified (Section 12.5). If a loss in sensitivity has occurred, the instrument shall be repaired, the performance specifications in Section 12 shall be met, and the extract reanalyzed. If a loss in instrument sensitivity has not occurred, the method does not work on the sample being analyzed and the result may not be reported for regulatory compliance purposes.</P>
                        <HD SOURCE="HD2">16. Method Performance</HD>
                        <P>16.1 Interlaboratory performance for this method is detailed in references 9 and 10.</P>
                        <P>16.2 A chromatogram of the 100 µg/mL acid/base/neutral calibration standard (Section 6.13) is shown in Figure 6.</P>
                        <HD SOURCE="HD1">References</HD>
                        <P>1. “Performance Tests for the Evaluation of Computerized Gas Chromatography/Mass Spectrometry Equipment and Laboratories” USEPA, EMSL/Cincinnati, OH 45268, EPA-600/4-80-025 (April 1980).</P>
                        <P>2. “Working with Carcinogens,” DHEW, PHS, CDC, NIOSH, Publication 77-206, (August 1977).</P>
                        <P>3. “OSHA Safety and Health Standards, General Industry” OSHA 2206, 29 CFR part 1910 (January 1976).</P>
                        <P>4. “Safety in Academic Chemistry Laboratories, ” ACS Committee on Chemical Safety (1979).</P>
                        <P>
                            5. “Reference Compound to Calibrate Ion Abundance Measurement in Gas Chromatography-Mass Spectrometry Systems,” J.W. Eichelberger, L.E. Harris, and W.L. Budde, Anal. Chem., 
                            <E T="03">47,</E>
                             955 (1975).
                        </P>
                        <P>6. “Handbook of Analytical Quality Control in Water and Wastewater Laboratories,” USEPA, EMSL/Cincinnati, OH 45268, EPA-600/4-79-019 (March 1979).</P>
                        <P>
                            7. “Standard Practice for Sampling Water,” ASTM Annual Book of Standards, ASTM, Philadelphia, PA, 76 (1980).
                            <PRTPAGE P="373"/>
                        </P>
                        <P>8. “Methods 330.4 and 330.5 for Total Residual Chlorine,” USEPA, EMSL/ Cincinnati, OH 45268, EPA 600/4-70-020 (March 1979).</P>
                        <P>9. Colby, B.N., Beimer, R.G., Rushneck, D.R., and Telliard, W.A., “Isotope Dilution Gas Chromatography-Mass Spectrometry for the determination of Priority Pollutants in Industrial Effluents.” USEPA, Effluent Guidelines Division, Washington, DC 20460 (1980).</P>
                        <P>10. “Inter-laboratory Validation of US Environmental Protection Agency Method 1625,” USEPA, Effluent Guidelines Division, Washington, DC 20460 (June 15, 1984).</P>
                        <GPOTABLE COLS="5" OPTS="L2" CDEF="s50,7,10,7,7">
                            <TTITLE>Table 1—Base/Neutral Extractable Compounds</TTITLE>
                            <BOXHD>
                                <CHED H="1">Compound</CHED>
                                <CHED H="1">STORET</CHED>
                                <CHED H="1">CAS registry</CHED>
                                <CHED H="1">EPA-EGD</CHED>
                                <CHED H="1">NPDES</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">Acenaphthene</ENT>
                                <ENT>34205</ENT>
                                <ENT>83-32-9</ENT>
                                <ENT>001 B</ENT>
                                <ENT>001 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Acenaphthylene</ENT>
                                <ENT>34200</ENT>
                                <ENT>208-96-8</ENT>
                                <ENT>077 B</ENT>
                                <ENT>002 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Anthracene</ENT>
                                <ENT>34220</ENT>
                                <ENT>120-12-7</ENT>
                                <ENT>078 B</ENT>
                                <ENT>003 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzidine</ENT>
                                <ENT>39120</ENT>
                                <ENT>92-87-5</ENT>
                                <ENT>005 B</ENT>
                                <ENT>004 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzo(a)anthracene</ENT>
                                <ENT>34526</ENT>
                                <ENT>56-55-3</ENT>
                                <ENT>072 B</ENT>
                                <ENT>005 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzo(b)fluoranthene</ENT>
                                <ENT>34230</ENT>
                                <ENT>205-99-2</ENT>
                                <ENT>074 B</ENT>
                                <ENT>007 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzo(k)fluoranthene</ENT>
                                <ENT>34242</ENT>
                                <ENT>207-08-9</ENT>
                                <ENT>075 B</ENT>
                                <ENT>009 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzo(a)pyrene</ENT>
                                <ENT>34247</ENT>
                                <ENT>50-32-8</ENT>
                                <ENT>073 B</ENT>
                                <ENT>006 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzo(ghi)perylene</ENT>
                                <ENT>34521</ENT>
                                <ENT>191-24-2</ENT>
                                <ENT>079 B</ENT>
                                <ENT>008 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Biphenyl (Appendix C)</ENT>
                                <ENT>81513</ENT>
                                <ENT>92-52-4</ENT>
                                <ENT>512 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Bis(2-chloroethyl) ether</ENT>
                                <ENT>34273</ENT>
                                <ENT>111-44-4</ENT>
                                <ENT>018 B</ENT>
                                <ENT>011 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Bis(2-chloroethyoxy)methane</ENT>
                                <ENT>34278</ENT>
                                <ENT>111-91-1</ENT>
                                <ENT>043 B</ENT>
                                <ENT>010 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Bis(2-chloroisopropyl) ether</ENT>
                                <ENT>34283</ENT>
                                <ENT>108-60-1</ENT>
                                <ENT>042 B</ENT>
                                <ENT>012 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Bis(2-ethylhexyl) phthalate</ENT>
                                <ENT>39100</ENT>
                                <ENT>117-81-7</ENT>
                                <ENT>066 B</ENT>
                                <ENT>013 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4-bromophenyl phenyl ether</ENT>
                                <ENT>34636</ENT>
                                <ENT>101-55-3</ENT>
                                <ENT>041 B</ENT>
                                <ENT>014 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Butyl benzyl phthalate</ENT>
                                <ENT>34292</ENT>
                                <ENT>85-68-7</ENT>
                                <ENT>067 B</ENT>
                                <ENT>015 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">n-C10 (Appendix C)</ENT>
                                <ENT>77427</ENT>
                                <ENT>124-18-5</ENT>
                                <ENT>517 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">n-C12 (Appendix C)</ENT>
                                <ENT>77588</ENT>
                                <ENT>112-40-2</ENT>
                                <ENT>506 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">n-C14 (Appendix C)</ENT>
                                <ENT>77691</ENT>
                                <ENT>629-59-4</ENT>
                                <ENT>518 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">n-C16 (Appendix C)</ENT>
                                <ENT>77757</ENT>
                                <ENT>544-76-3</ENT>
                                <ENT>519 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">n-C18 (Appendix C)</ENT>
                                <ENT>77804</ENT>
                                <ENT>593-45-3</ENT>
                                <ENT>520 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">n-C20 (Appendix C)</ENT>
                                <ENT>77830</ENT>
                                <ENT>112-95-8</ENT>
                                <ENT>521 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">n-C22 (Appendix C)</ENT>
                                <ENT>77859</ENT>
                                <ENT>629-97-0</ENT>
                                <ENT>522 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">n-C24 (Appendix C)</ENT>
                                <ENT>77886</ENT>
                                <ENT>646-31-1</ENT>
                                <ENT>523 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">n-C26 (Appendix C)</ENT>
                                <ENT>77901</ENT>
                                <ENT>630-01-3</ENT>
                                <ENT>524 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">n-C28 (Appendix C)</ENT>
                                <ENT>78116</ENT>
                                <ENT>630-02-4</ENT>
                                <ENT>525 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">n-C30 (Appendix C)</ENT>
                                <ENT>78117</ENT>
                                <ENT>638-68-6</ENT>
                                <ENT>526 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Carbazole (4c)</ENT>
                                <ENT>77571</ENT>
                                <ENT>86-74-8</ENT>
                                <ENT>528 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-chloronaphthalene</ENT>
                                <ENT>34581</ENT>
                                <ENT>91-58-7</ENT>
                                <ENT>020 B</ENT>
                                <ENT>016 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4-chlorophenyl phenyl ether</ENT>
                                <ENT>34641</ENT>
                                <ENT>7005-72-3</ENT>
                                <ENT>040 B</ENT>
                                <ENT>017 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chrysene</ENT>
                                <ENT>34320</ENT>
                                <ENT>218-01-9</ENT>
                                <ENT>076 B</ENT>
                                <ENT>018 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">P-cymene (Appendix C)</ENT>
                                <ENT>77356</ENT>
                                <ENT>99-87-6</ENT>
                                <ENT>513 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dibenzo(a,h)anthracene</ENT>
                                <ENT>34556</ENT>
                                <ENT>53-70-3</ENT>
                                <ENT>082 B</ENT>
                                <ENT>019 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dibenzofuran (Appendix C and 4c)</ENT>
                                <ENT>81302</ENT>
                                <ENT>132-64-9</ENT>
                                <ENT>505 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dibenzothiophene (Synfuel)</ENT>
                                <ENT>77639</ENT>
                                <ENT>132-65-0</ENT>
                                <ENT>504 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Di-n-butyl phthalate</ENT>
                                <ENT>39110</ENT>
                                <ENT>84-74-2</ENT>
                                <ENT>068 B</ENT>
                                <ENT>026 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2-dichlorobenzene</ENT>
                                <ENT>34536</ENT>
                                <ENT>95-50-1</ENT>
                                <ENT>025 B</ENT>
                                <ENT>020 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,3-dichlorobenzene</ENT>
                                <ENT>34566</ENT>
                                <ENT>541-73-1</ENT>
                                <ENT>026 B</ENT>
                                <ENT>021 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,4-dichlorobenzene</ENT>
                                <ENT>34571</ENT>
                                <ENT>106-46-7</ENT>
                                <ENT>027 B</ENT>
                                <ENT>022 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">3,3′-dichlorobenzidine</ENT>
                                <ENT>34631</ENT>
                                <ENT>91-94-1</ENT>
                                <ENT>028 B</ENT>
                                <ENT>023 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Diethyl phthalate</ENT>
                                <ENT>34336</ENT>
                                <ENT>84-66-2</ENT>
                                <ENT>070 B</ENT>
                                <ENT>024 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4-dimethylphenol</ENT>
                                <ENT>34606</ENT>
                                <ENT>105-67-9</ENT>
                                <ENT>034 A</ENT>
                                <ENT>003 A</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dimethyl phthalate</ENT>
                                <ENT>34341</ENT>
                                <ENT>131-11-3</ENT>
                                <ENT>071 B</ENT>
                                <ENT>025 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4-dinitrotoluene</ENT>
                                <ENT>34611</ENT>
                                <ENT>121-14-2</ENT>
                                <ENT>035 B</ENT>
                                <ENT>027 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,6-dinitrotoluene</ENT>
                                <ENT>34626</ENT>
                                <ENT>606-20-2</ENT>
                                <ENT>036 B</ENT>
                                <ENT>028 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Di-n-octyl phthalate</ENT>
                                <ENT>34596</ENT>
                                <ENT>117-84-0</ENT>
                                <ENT>069 B</ENT>
                                <ENT>029 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Diphenylamine (Appendix C)</ENT>
                                <ENT>77579</ENT>
                                <ENT>122-39-4</ENT>
                                <ENT>507 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Diphenyl ether (Appendix C)</ENT>
                                <ENT>77587</ENT>
                                <ENT>101-84-8</ENT>
                                <ENT>508 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2-diphenylhydrazine</ENT>
                                <ENT>34346</ENT>
                                <ENT>122-66-7</ENT>
                                <ENT>037 B</ENT>
                                <ENT>030 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Fluoranthene</ENT>
                                <ENT>34376</ENT>
                                <ENT>206-44-0</ENT>
                                <ENT>039 B</ENT>
                                <ENT>031 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Fluorene</ENT>
                                <ENT>34381</ENT>
                                <ENT>86-73-7</ENT>
                                <ENT>080 B</ENT>
                                <ENT>032 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Hexachlorobenzene</ENT>
                                <ENT>39700</ENT>
                                <ENT>118-74-1</ENT>
                                <ENT>009 B</ENT>
                                <ENT>033 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Hexachlorobutadiene</ENT>
                                <ENT>34391</ENT>
                                <ENT>87-68-3</ENT>
                                <ENT>052 B</ENT>
                                <ENT>034 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Hexachloroethane</ENT>
                                <ENT>34396</ENT>
                                <ENT>67-72-1</ENT>
                                <ENT>012 B</ENT>
                                <ENT>036 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Hexachlorocyclopentadiene</ENT>
                                <ENT>34386</ENT>
                                <ENT>77-47-4</ENT>
                                <ENT>053 B</ENT>
                                <ENT>035 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Indeno(1,2,3-cd)pyrene</ENT>
                                <ENT>34403</ENT>
                                <ENT>193-39-5</ENT>
                                <ENT>083 B</ENT>
                                <ENT>037 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Isophorone</ENT>
                                <ENT>34408</ENT>
                                <ENT>78-59-1</ENT>
                                <ENT>054 B</ENT>
                                <ENT>038 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Naphthalene</ENT>
                                <ENT>34696</ENT>
                                <ENT>91-20-3</ENT>
                                <ENT>055 B</ENT>
                                <ENT>039 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">B-naphthylamine (Appendix C)</ENT>
                                <ENT>82553</ENT>
                                <ENT>91-59-8</ENT>
                                <ENT>502 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Nitrobenzene</ENT>
                                <ENT>34447</ENT>
                                <ENT>98-95-3</ENT>
                                <ENT>056 B</ENT>
                                <ENT>040 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">N-nitrosodimethylamine</ENT>
                                <ENT>34438</ENT>
                                <ENT>62-75-9</ENT>
                                <ENT>061 B</ENT>
                                <ENT>041 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">N-nitrosodi-n-propylamine</ENT>
                                <ENT>34428</ENT>
                                <ENT>621-64-7</ENT>
                                <ENT>063 B</ENT>
                                <ENT>042 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">N-nitrosodiphenylamine</ENT>
                                <ENT>34433</ENT>
                                <ENT>86-30-3</ENT>
                                <ENT>062 B</ENT>
                                <ENT>043 B</ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="374"/>
                                <ENT I="01">Phenanthrene</ENT>
                                <ENT>34461</ENT>
                                <ENT>85-01-8</ENT>
                                <ENT>081 B</ENT>
                                <ENT>044 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Phenol</ENT>
                                <ENT>34694</ENT>
                                <ENT>108-95-2</ENT>
                                <ENT>065 A</ENT>
                                <ENT>010 A</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    <E T="03">a</E>
                                    -Picoline (Synfuel)
                                </ENT>
                                <ENT>77088</ENT>
                                <ENT>109-06-89</ENT>
                                <ENT>503 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Pyrene</ENT>
                                <ENT>34469</ENT>
                                <ENT>129-00-0</ENT>
                                <ENT>084 B</ENT>
                                <ENT>045 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">styrene (Appendix C)</ENT>
                                <ENT>77128</ENT>
                                <ENT>100-42-5</ENT>
                                <ENT>510 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">a-terpineol (Appendix C)</ENT>
                                <ENT>77493</ENT>
                                <ENT>98-55-5</ENT>
                                <ENT>509 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3-trichlorobenzene (4c)</ENT>
                                <ENT>77613</ENT>
                                <ENT>87-61-6</ENT>
                                <ENT>529 B</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,4-trichlorobenzene</ENT>
                                <ENT>34551</ENT>
                                <ENT>120-82-1</ENT>
                                <ENT>008 B</ENT>
                                <ENT>046 B</ENT>
                            </ROW>
                        </GPOTABLE>
                        <GPOTABLE COLS="5" OPTS="L2" CDEF="s50,7,10,7,7">
                            <TTITLE>Table 2—Acid Extractable Compounds</TTITLE>
                            <BOXHD>
                                <CHED H="1">Compound</CHED>
                                <CHED H="1">STORET</CHED>
                                <CHED H="1">CAS registry</CHED>
                                <CHED H="1">EPA-EGD</CHED>
                                <CHED H="1">NPDES</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">4-chloro-3-methylphenol</ENT>
                                <ENT>34452</ENT>
                                <ENT>59-50-7</ENT>
                                <ENT>022 A</ENT>
                                <ENT>008 A</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-chlorophenol</ENT>
                                <ENT>34586</ENT>
                                <ENT>95-57-8</ENT>
                                <ENT>024 A</ENT>
                                <ENT>001 A</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4-dichlorophenol</ENT>
                                <ENT>34601</ENT>
                                <ENT>120-83-2</ENT>
                                <ENT>031 A</ENT>
                                <ENT>002 A</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4-dinitrophenol</ENT>
                                <ENT>34616</ENT>
                                <ENT>51-28-5</ENT>
                                <ENT>059 A</ENT>
                                <ENT>005 A</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-methyl-4,6-dinitrophenol</ENT>
                                <ENT>34657</ENT>
                                <ENT>534-52-1</ENT>
                                <ENT>060 A</ENT>
                                <ENT>004 A</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-nitrophenol</ENT>
                                <ENT>34591</ENT>
                                <ENT>88-75-5</ENT>
                                <ENT>057 A</ENT>
                                <ENT>006 A</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4-nitrophenol</ENT>
                                <ENT>34646</ENT>
                                <ENT>100-02-7</ENT>
                                <ENT>058 A</ENT>
                                <ENT>007 A</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Pentachlorophenol</ENT>
                                <ENT>39032</ENT>
                                <ENT>87-86-5</ENT>
                                <ENT>064 A</ENT>
                                <ENT>009 A</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,3,6-trichlorophenol (4c)</ENT>
                                <ENT>77688</ENT>
                                <ENT>93-37-55</ENT>
                                <ENT>530 A</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4,5-trichlorophenol (4c)</ENT>
                                <ENT/>
                                <ENT>95-95-4</ENT>
                                <ENT>531 A</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4,6-trichlorophenol</ENT>
                                <ENT>34621</ENT>
                                <ENT>88-06-2</ENT>
                                <ENT>021 A</ENT>
                                <ENT>011 A</ENT>
                            </ROW>
                        </GPOTABLE>
                        <GPOTABLE COLS="6" OPTS="L2" CDEF="5,r50,7,7,12,7">
                            <TTITLE>Table 3—Gas Chromatography of Base/Neutral Extractable Compounds</TTITLE>
                            <BOXHD>
                                <CHED H="1">
                                    EGD No. 
                                    <SU>1</SU>
                                </CHED>
                                <CHED H="1">Compound</CHED>
                                <CHED H="1">Retention time</CHED>
                                <CHED H="2">Mean (sec)</CHED>
                                <CHED H="2">EGD Ref</CHED>
                                <CHED H="2">Relative</CHED>
                                <CHED H="1">
                                    Detection limit 
                                    <SU>2</SU>
                                     (µg/L)
                                </CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">164</ENT>
                                <ENT>2,2′-difluorobiphenyl (int std)</ENT>
                                <ENT>1163</ENT>
                                <ENT>164</ENT>
                                <ENT>1.000-1.000</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">061</ENT>
                                <ENT>N-nitrosodimethylamine</ENT>
                                <ENT>385</ENT>
                                <ENT>164</ENT>
                                <ENT O="oi0">ns</ENT>
                                <ENT>50</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">603</ENT>
                                <ENT>alpha picoline-d7</ENT>
                                <ENT>417</ENT>
                                <ENT>164</ENT>
                                <ENT>0.326-0.393</ENT>
                                <ENT>50</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">703</ENT>
                                <ENT>alpha picoline</ENT>
                                <ENT>426</ENT>
                                <ENT>603</ENT>
                                <ENT>1.006-1.028</ENT>
                                <ENT>50</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">610</ENT>
                                <ENT>styrene-d5</ENT>
                                <ENT>546</ENT>
                                <ENT>164</ENT>
                                <ENT>0.450-0.488</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">710</ENT>
                                <ENT>styrene</ENT>
                                <ENT>549</ENT>
                                <ENT>610</ENT>
                                <ENT>1.002-1.009</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">613</ENT>
                                <ENT>p-cymene-d14</ENT>
                                <ENT>742</ENT>
                                <ENT>164</ENT>
                                <ENT>0.624-0.652</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">713</ENT>
                                <ENT>p-cymene</ENT>
                                <ENT>755</ENT>
                                <ENT>613</ENT>
                                <ENT>1.008-1.023</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">265</ENT>
                                <ENT>phenol-d5</ENT>
                                <ENT>696</ENT>
                                <ENT>164</ENT>
                                <ENT>0.584-0.613</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">365</ENT>
                                <ENT>phenol</ENT>
                                <ENT>700</ENT>
                                <ENT>265</ENT>
                                <ENT>0.995-1.010</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">218</ENT>
                                <ENT>bis(2-chloroethyl) ether-d8</ENT>
                                <ENT>696</ENT>
                                <ENT>164</ENT>
                                <ENT>0.584-0.607</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">318</ENT>
                                <ENT>bis(2-chloroethyl) ether</ENT>
                                <ENT>704</ENT>
                                <ENT>218</ENT>
                                <ENT>1.007-1.016</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">617</ENT>
                                <ENT>n-decane-d22</ENT>
                                <ENT>698</ENT>
                                <ENT>164</ENT>
                                <ENT>0.585-0.615</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">717</ENT>
                                <ENT>n-decane</ENT>
                                <ENT>720</ENT>
                                <ENT>617</ENT>
                                <ENT>1.022-1.038</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">226</ENT>
                                <ENT>1,3-dichlorobenzene-d4</ENT>
                                <ENT>722</ENT>
                                <ENT>164</ENT>
                                <ENT>0.605-0.636</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">326</ENT>
                                <ENT>1,3-dichlorobenzene</ENT>
                                <ENT>724</ENT>
                                <ENT>226</ENT>
                                <ENT>0.998-1.008</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">227</ENT>
                                <ENT>1,4-dichlorobenzene-d4</ENT>
                                <ENT>737</ENT>
                                <ENT>164</ENT>
                                <ENT>0.601-0.666</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">327</ENT>
                                <ENT>1,4-dichlorobenzene</ENT>
                                <ENT>740</ENT>
                                <ENT>227</ENT>
                                <ENT>0.997-1.009</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">225</ENT>
                                <ENT>1,2-dichlorobenzene-d4</ENT>
                                <ENT>758</ENT>
                                <ENT>164</ENT>
                                <ENT>0.632-0.667</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">325</ENT>
                                <ENT>1,2-dichlorobenzene</ENT>
                                <ENT>760</ENT>
                                <ENT>225</ENT>
                                <ENT>0.995-1.008</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">242</ENT>
                                <ENT>bis(2-chloroisopropyl) ether-d12</ENT>
                                <ENT>788</ENT>
                                <ENT>164</ENT>
                                <ENT>0.664-0.691</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">342</ENT>
                                <ENT>bis(2-chloroisopropyl) ether</ENT>
                                <ENT>799</ENT>
                                <ENT>242</ENT>
                                <ENT>1.010-1.016</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">212</ENT>
                                <ENT>hexachloroethane-13C</ENT>
                                <ENT>819</ENT>
                                <ENT>164</ENT>
                                <ENT>0.690-0.717</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">312</ENT>
                                <ENT>hexachloroethane</ENT>
                                <ENT>823</ENT>
                                <ENT>212</ENT>
                                <ENT>0.999-1.001</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">063</ENT>
                                <ENT>N-nitrosodi-n-propylamine</ENT>
                                <ENT>830</ENT>
                                <ENT>164</ENT>
                                <ENT O="oi0">ns</ENT>
                                <ENT>20</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">256</ENT>
                                <ENT>nitrobenzene-d5</ENT>
                                <ENT>845</ENT>
                                <ENT>164</ENT>
                                <ENT>0.706-0.727</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">356</ENT>
                                <ENT>nitrobenzene</ENT>
                                <ENT>849</ENT>
                                <ENT>256</ENT>
                                <ENT>1.002-1.007</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">254</ENT>
                                <ENT>isophorone-d8</ENT>
                                <ENT>881</ENT>
                                <ENT>164</ENT>
                                <ENT>0.747-0.767</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">354</ENT>
                                <ENT>isophorone</ENT>
                                <ENT>889</ENT>
                                <ENT>254</ENT>
                                <ENT>0.999-1.017</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">234</ENT>
                                <ENT>2,4-dimethyl phenol-d3</ENT>
                                <ENT>921</ENT>
                                <ENT>164</ENT>
                                <ENT>0.781-0.803</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">334</ENT>
                                <ENT>2,4-dimethylphenol</ENT>
                                <ENT>924</ENT>
                                <ENT>234</ENT>
                                <ENT>0.999-1.003</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">043</ENT>
                                <ENT>bis(2-chloroethoxy) methane</ENT>
                                <ENT>939</ENT>
                                <ENT>164</ENT>
                                <ENT O="oi0">ns</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">208</ENT>
                                <ENT>1,2,4-trichlorobenzene-d3</ENT>
                                <ENT>955</ENT>
                                <ENT>164</ENT>
                                <ENT>0.813-0.830</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">308</ENT>
                                <ENT>1,2,4-trichlorobenzene</ENT>
                                <ENT>958</ENT>
                                <ENT>208</ENT>
                                <ENT>1.000-1.005</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">255</ENT>
                                <ENT>naphthalene-d8</ENT>
                                <ENT>963</ENT>
                                <ENT>164</ENT>
                                <ENT>0.819-0.836</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">355</ENT>
                                <ENT>naphthalene</ENT>
                                <ENT>967</ENT>
                                <ENT>255</ENT>
                                <ENT>1.001-1.006</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">609</ENT>
                                <ENT>alpha-terpineol-d3</ENT>
                                <ENT>973</ENT>
                                <ENT>164</ENT>
                                <ENT>0.829-0.844</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="375"/>
                                <ENT I="01">709</ENT>
                                <ENT>alpha-terpineol</ENT>
                                <ENT>975</ENT>
                                <ENT>609</ENT>
                                <ENT>0.998-1.008</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">606</ENT>
                                <ENT>n-dodecane-d26</ENT>
                                <ENT>953</ENT>
                                <ENT>164</ENT>
                                <ENT>0.730-0.908</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">706</ENT>
                                <ENT>n-dodecane</ENT>
                                <ENT>981</ENT>
                                <ENT>606</ENT>
                                <ENT>0.986-1.051</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">529</ENT>
                                <ENT>1,2,3-trichlorobenzene</ENT>
                                <ENT>1003</ENT>
                                <ENT>164</ENT>
                                <ENT O="oi0">ns</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">252</ENT>
                                <ENT>hexachlorobutadiene-13C4</ENT>
                                <ENT>1005</ENT>
                                <ENT>164</ENT>
                                <ENT>0.856-0.871</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">352</ENT>
                                <ENT>hexachlorobutadiene</ENT>
                                <ENT>1006</ENT>
                                <ENT>252</ENT>
                                <ENT>0.999-1.002</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">253</ENT>
                                <ENT>hexachlorocyclopentadiene-13C4</ENT>
                                <ENT>1147</ENT>
                                <ENT>164</ENT>
                                <ENT>0.976-0.986</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">353</ENT>
                                <ENT>hexachlorocyclopentadiene</ENT>
                                <ENT>1142</ENT>
                                <ENT>253</ENT>
                                <ENT>0.999-1.001</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">220</ENT>
                                <ENT>2-chloronaphthalene-d7</ENT>
                                <ENT>1185</ENT>
                                <ENT>164</ENT>
                                <ENT>1.014-1.024</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">320</ENT>
                                <ENT>2-chloronaphthalene</ENT>
                                <ENT>1200</ENT>
                                <ENT>220</ENT>
                                <ENT>0.997-1.007</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">518</ENT>
                                <ENT>n-tetradecane</ENT>
                                <ENT>1203</ENT>
                                <ENT>164</ENT>
                                <ENT O="oi0">ns</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">612</ENT>
                                <ENT>Biphenyl-d10</ENT>
                                <ENT>1205</ENT>
                                <ENT>164</ENT>
                                <ENT>1.016-1.027</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">712</ENT>
                                <ENT>Biphenyl</ENT>
                                <ENT>1195</ENT>
                                <ENT>612</ENT>
                                <ENT>1.001-1.006</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">608</ENT>
                                <ENT>Diphenyl ether-d10</ENT>
                                <ENT>1211</ENT>
                                <ENT>164</ENT>
                                <ENT>1.036-1.047</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">708</ENT>
                                <ENT>Diphenyl ether</ENT>
                                <ENT>1216</ENT>
                                <ENT>608</ENT>
                                <ENT>0.997-1.009</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">277</ENT>
                                <ENT>Acenaphthylene-d8</ENT>
                                <ENT>1265</ENT>
                                <ENT>164</ENT>
                                <ENT>1.080-1.095</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">377</ENT>
                                <ENT>Acenaphthylene</ENT>
                                <ENT>1247</ENT>
                                <ENT>277</ENT>
                                <ENT>1.000-1.004</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">271</ENT>
                                <ENT>Dimethyl phthalate-d4</ENT>
                                <ENT>1269</ENT>
                                <ENT>164</ENT>
                                <ENT>1.083-1.102</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">371</ENT>
                                <ENT>Dimethyl phthalate</ENT>
                                <ENT>1273</ENT>
                                <ENT>271</ENT>
                                <ENT>0.998-1.005</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">236</ENT>
                                <ENT>2,6-dinitrotoluene-d3</ENT>
                                <ENT>1283</ENT>
                                <ENT>164</ENT>
                                <ENT>1.090-1.112</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">336</ENT>
                                <ENT>2,6-dinitrotoluene</ENT>
                                <ENT>1300</ENT>
                                <ENT>236</ENT>
                                <ENT>1.001-1.005</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">201</ENT>
                                <ENT>Acenaphthene-d10</ENT>
                                <ENT>1298</ENT>
                                <ENT>164</ENT>
                                <ENT>1.107-1.125</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">301</ENT>
                                <ENT>Acenaphthene</ENT>
                                <ENT>1304</ENT>
                                <ENT>201</ENT>
                                <ENT>0.999-1.009</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">605</ENT>
                                <ENT>Dibenzofuran-d8</ENT>
                                <ENT>1331</ENT>
                                <ENT>164</ENT>
                                <ENT>1.134-1.155</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">705</ENT>
                                <ENT>Dibenzofuran</ENT>
                                <ENT>1335</ENT>
                                <ENT>605</ENT>
                                <ENT>0.998-1.007</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">602</ENT>
                                <ENT>Beta-naphthylamine-d7</ENT>
                                <ENT>1368</ENT>
                                <ENT>164</ENT>
                                <ENT>1.163-1.189</ENT>
                                <ENT>50</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">702</ENT>
                                <ENT>Beta-naphthylamine</ENT>
                                <ENT>1371</ENT>
                                <ENT>602</ENT>
                                <ENT>0.996-1.007</ENT>
                                <ENT>50</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">280</ENT>
                                <ENT>Fluorene-d10</ENT>
                                <ENT>1395</ENT>
                                <ENT>164</ENT>
                                <ENT>1.185-1.214</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">380</ENT>
                                <ENT>Fluorene</ENT>
                                <ENT>1401</ENT>
                                <ENT>281</ENT>
                                <ENT>0.999-1.008</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">240</ENT>
                                <ENT>4-chlorophenyl phenyl ether-d5</ENT>
                                <ENT>1406</ENT>
                                <ENT>164</ENT>
                                <ENT>1.194-1.223</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">340</ENT>
                                <ENT>4-chlorophenyl phenyl ether</ENT>
                                <ENT>1409</ENT>
                                <ENT>240</ENT>
                                <ENT>0.990-1.015</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">270</ENT>
                                <ENT>Diethyl phthalate-d4</ENT>
                                <ENT>1409</ENT>
                                <ENT>164</ENT>
                                <ENT>1.197-1.229</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">370</ENT>
                                <ENT>Diethyl phthalate</ENT>
                                <ENT>1414</ENT>
                                <ENT>270</ENT>
                                <ENT>0.996-1.006</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">619</ENT>
                                <ENT>n-hexadecane-d34</ENT>
                                <ENT>1447</ENT>
                                <ENT>164</ENT>
                                <ENT>1.010-1.478</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">719</ENT>
                                <ENT>n-hexadecane</ENT>
                                <ENT>1469</ENT>
                                <ENT>619</ENT>
                                <ENT>1.013-1.020</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">235</ENT>
                                <ENT>2,4-dinitrotoluene-d3</ENT>
                                <ENT>1359</ENT>
                                <ENT>164</ENT>
                                <ENT>1.152-1.181</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">335</ENT>
                                <ENT>2,4-dinitrotoluene</ENT>
                                <ENT>1344</ENT>
                                <ENT>235</ENT>
                                <ENT>1.000-1.002</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">237</ENT>
                                <ENT>1,2-diphenylhydrazine-d8</ENT>
                                <ENT>1433</ENT>
                                <ENT>164</ENT>
                                <ENT>1.216-1.248</ENT>
                                <ENT>20</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">337</ENT>
                                <ENT>
                                    1,2-diphenylhydrazine (
                                    <SU>3</SU>
                                    )
                                </ENT>
                                <ENT>1439</ENT>
                                <ENT>237</ENT>
                                <ENT>0.999-1.009</ENT>
                                <ENT>20</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">607</ENT>
                                <ENT>Diphenylamine-d10</ENT>
                                <ENT>1437</ENT>
                                <ENT>164</ENT>
                                <ENT>1.213-1.249</ENT>
                                <ENT>20</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">707</ENT>
                                <ENT>Diphenylamine</ENT>
                                <ENT>1439</ENT>
                                <ENT>607</ENT>
                                <ENT>1.000-1.007</ENT>
                                <ENT>20</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">262</ENT>
                                <ENT>N-nitrosodiphenylamine-d6</ENT>
                                <ENT>1447</ENT>
                                <ENT>164</ENT>
                                <ENT>1.225-1.252</ENT>
                                <ENT>20</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">362</ENT>
                                <ENT>
                                    N-nitrosodiphenylamine (
                                    <SU>4</SU>
                                    )
                                </ENT>
                                <ENT>1464</ENT>
                                <ENT>262</ENT>
                                <ENT>1.000-1.002</ENT>
                                <ENT>20</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">041</ENT>
                                <ENT>4-bromophenyl phenyl ether</ENT>
                                <ENT>1498</ENT>
                                <ENT>164</ENT>
                                <ENT>1.271-1.307</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">209</ENT>
                                <ENT>Hexachlorobenzene-13C6</ENT>
                                <ENT>1521</ENT>
                                <ENT>164</ENT>
                                <ENT>1.288-1.327</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">309</ENT>
                                <ENT>Hexachlorobenzene</ENT>
                                <ENT>1522</ENT>
                                <ENT>209</ENT>
                                <ENT>0.999-1.001</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">281</ENT>
                                <ENT>Phenanthrene-d10</ENT>
                                <ENT>1578</ENT>
                                <ENT>164</ENT>
                                <ENT>1.334-1.380</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">520</ENT>
                                <ENT>n-octadecane</ENT>
                                <ENT>1580</ENT>
                                <ENT>164</ENT>
                                <ENT O="oi0">ns</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">381</ENT>
                                <ENT>Phenanthrene</ENT>
                                <ENT>1583</ENT>
                                <ENT>281</ENT>
                                <ENT>1.000-1.005</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">278</ENT>
                                <ENT>Anthracene-d10</ENT>
                                <ENT>1588</ENT>
                                <ENT>164</ENT>
                                <ENT>1.342-1.388</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">378</ENT>
                                <ENT>Anthracene</ENT>
                                <ENT>1592</ENT>
                                <ENT>278</ENT>
                                <ENT>0.998-1.006</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">604</ENT>
                                <ENT>Dibenzothiophene-d8</ENT>
                                <ENT>1559</ENT>
                                <ENT>164</ENT>
                                <ENT>1.314-1.361</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">704</ENT>
                                <ENT>Dibenzothiophene</ENT>
                                <ENT>1564</ENT>
                                <ENT>604</ENT>
                                <ENT>1.000-1.006</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">528</ENT>
                                <ENT>Carbazole</ENT>
                                <ENT>1650</ENT>
                                <ENT>164</ENT>
                                <ENT O="oi0">ns</ENT>
                                <ENT>20</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">621</ENT>
                                <ENT>n-eicosane-d42</ENT>
                                <ENT>1655</ENT>
                                <ENT>164</ENT>
                                <ENT>1.184-1.662</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">721</ENT>
                                <ENT>n-eicosane</ENT>
                                <ENT>1677</ENT>
                                <ENT>621</ENT>
                                <ENT>1.010-1.021</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">268</ENT>
                                <ENT>Di-n-butyl phthalate-d4</ENT>
                                <ENT>1719</ENT>
                                <ENT>164</ENT>
                                <ENT>1.446-1.510</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">368</ENT>
                                <ENT>Di-n-butyl phthalate</ENT>
                                <ENT>1723</ENT>
                                <ENT>268</ENT>
                                <ENT>1.000-1.003</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">239</ENT>
                                <ENT>Fluoranthene-d10</ENT>
                                <ENT>1813</ENT>
                                <ENT>164</ENT>
                                <ENT>1.522-1.596</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">339</ENT>
                                <ENT>Fluoranthene</ENT>
                                <ENT>1817</ENT>
                                <ENT>239</ENT>
                                <ENT>1.000-1.004</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">284</ENT>
                                <ENT>Pyrene-d10</ENT>
                                <ENT>1844</ENT>
                                <ENT>164</ENT>
                                <ENT>1.523-1.644</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">384</ENT>
                                <ENT>Pyrene</ENT>
                                <ENT>1852</ENT>
                                <ENT>284</ENT>
                                <ENT>1.001-1.003</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">205</ENT>
                                <ENT>Benzidine-d8</ENT>
                                <ENT>1854</ENT>
                                <ENT>164</ENT>
                                <ENT>1.549-1.632</ENT>
                                <ENT>50</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">305</ENT>
                                <ENT>Benzidine</ENT>
                                <ENT>1853</ENT>
                                <ENT>205</ENT>
                                <ENT>1.000-1.002</ENT>
                                <ENT>50</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">522</ENT>
                                <ENT>n-docosane</ENT>
                                <ENT>1889</ENT>
                                <ENT>164</ENT>
                                <ENT O="oi0">ns</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">623</ENT>
                                <ENT>n-tetracosane-d50</ENT>
                                <ENT>1997</ENT>
                                <ENT>164</ENT>
                                <ENT>1.671-1.764</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">723</ENT>
                                <ENT>n-tetracosane</ENT>
                                <ENT>2025</ENT>
                                <ENT>612</ENT>
                                <ENT>1.012-1.015</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">067</ENT>
                                <ENT>Butylbenzyl phthalate</ENT>
                                <ENT>2060</ENT>
                                <ENT>164</ENT>
                                <ENT O="oi0">ns</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">276</ENT>
                                <ENT>Chrysene-d12</ENT>
                                <ENT>2081</ENT>
                                <ENT>164</ENT>
                                <ENT>1.743-1.837</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">376</ENT>
                                <ENT>Chrysene</ENT>
                                <ENT>2083</ENT>
                                <ENT>276</ENT>
                                <ENT>1.000-1.004</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="376"/>
                                <ENT I="01">272</ENT>
                                <ENT>Benzo(a)anthracene-d12</ENT>
                                <ENT>2082</ENT>
                                <ENT>164</ENT>
                                <ENT>1.735-1.846</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">372</ENT>
                                <ENT>Benzo(a)anthracene</ENT>
                                <ENT>2090</ENT>
                                <ENT>272</ENT>
                                <ENT>0.999-1.007</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">228</ENT>
                                <ENT>3,3′-dichlorobenzidine-d6</ENT>
                                <ENT>2088</ENT>
                                <ENT>164</ENT>
                                <ENT>1.744-1.848</ENT>
                                <ENT>50</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">328</ENT>
                                <ENT>3,3′-dichlorobenzidine</ENT>
                                <ENT>2086</ENT>
                                <ENT>228</ENT>
                                <ENT>1.000-1.001</ENT>
                                <ENT>50</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">266</ENT>
                                <ENT>Bis(2-ethylhexyl) phthalate-d4</ENT>
                                <ENT>2123</ENT>
                                <ENT>164</ENT>
                                <ENT>1.771-1.880</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">366</ENT>
                                <ENT>Bis(2-ethylhexyl) phthalate</ENT>
                                <ENT>2124</ENT>
                                <ENT>266</ENT>
                                <ENT>1.000-1.002</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">524</ENT>
                                <ENT>n-hexacosane</ENT>
                                <ENT>2147</ENT>
                                <ENT>164</ENT>
                                <ENT O="oi0">ns</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">269</ENT>
                                <ENT>di-n-octyl phthalate-d4</ENT>
                                <ENT>2239</ENT>
                                <ENT>164</ENT>
                                <ENT>1.867-1.982</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">369</ENT>
                                <ENT>di-n-octyl phthalate</ENT>
                                <ENT>2240</ENT>
                                <ENT>269</ENT>
                                <ENT>1.000-1.002</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">525</ENT>
                                <ENT>n-octacosane</ENT>
                                <ENT>2272</ENT>
                                <ENT>164</ENT>
                                <ENT O="oi0">ns</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">274</ENT>
                                <ENT>Benzo(b)fluoranthene-d12</ENT>
                                <ENT>2281</ENT>
                                <ENT>164</ENT>
                                <ENT>1.902-2.025</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">354</ENT>
                                <ENT>Benzo(b)fluoranthene</ENT>
                                <ENT>2293</ENT>
                                <ENT>274</ENT>
                                <ENT>1.000-1.005</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">275</ENT>
                                <ENT>Benzo(k)fluoranthene-d12</ENT>
                                <ENT>2287</ENT>
                                <ENT>164</ENT>
                                <ENT>1.906-2.033</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">375</ENT>
                                <ENT>Benzo(k)fluoranthene</ENT>
                                <ENT>2293</ENT>
                                <ENT>275</ENT>
                                <ENT>1.000-1.005</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">273</ENT>
                                <ENT>Benzo(a)pyrene-d12</ENT>
                                <ENT>2351</ENT>
                                <ENT>164</ENT>
                                <ENT>1.954-2.088</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">373</ENT>
                                <ENT>Benzo(a)pyrene</ENT>
                                <ENT>2350</ENT>
                                <ENT>273</ENT>
                                <ENT>1.000-1.004</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">626</ENT>
                                <ENT>N-triacontane-d62</ENT>
                                <ENT>2384</ENT>
                                <ENT>164</ENT>
                                <ENT>1.972-2.127</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">726</ENT>
                                <ENT>N-triacontane</ENT>
                                <ENT>2429</ENT>
                                <ENT>626</ENT>
                                <ENT>1.011-1.028</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">083</ENT>
                                <ENT>Indeno(1,2,3-cd)pyrene</ENT>
                                <ENT>2650</ENT>
                                <ENT>164</ENT>
                                <ENT O="oi0">ns</ENT>
                                <ENT>20</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">082</ENT>
                                <ENT>Dibenzo(a,h)anthracene</ENT>
                                <ENT>2660</ENT>
                                <ENT>164</ENT>
                                <ENT O="oi0">ns</ENT>
                                <ENT>20</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">279</ENT>
                                <ENT>Benzo(ghi)perylene-d12</ENT>
                                <ENT>2741</ENT>
                                <ENT>164</ENT>
                                <ENT>2.187-2.524</ENT>
                                <ENT>20</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">379</ENT>
                                <ENT>Benzo(ghi)perylene</ENT>
                                <ENT>2750</ENT>
                                <ENT>279</ENT>
                                <ENT>1.001-1.006</ENT>
                                <ENT>20</ENT>
                            </ROW>
                            <TNOTE>
                                <SU>1</SU>
                                 Reference numbers beginning with 0, 1 or 5 indicate a pollutant quantified by the internal standard method; reference numbers beginning with 2 or 6 indicate a labeled compound quantified by the internal standard method; reference numbers beginning with 3 or 7 indicate a pollutant quantified by isotope dilution.
                            </TNOTE>
                            <TNOTE>
                                <SU>2</SU>
                                 This is a minimum level at which the entire GC/MS system must give recognizable mass spectra (background corrected) and acceptable calibration points.
                            </TNOTE>
                            <TNOTE>
                                <SU>3</SU>
                                 Detected as azobenzene.
                            </TNOTE>
                            <TNOTE>
                                <SU>4</SU>
                                 Detected as diphenylamine.
                            </TNOTE>
                            <TNOTE>ns = specification not available at time of release of method.</TNOTE>
                            <TNOTE>Column: 30 ±2 m × 0.25 ±0.02 mm i.d. 94% methyl, 4% phenyl, 1% vinyl bonded phase fused silica capillary.</TNOTE>
                            <TNOTE>Temperature program: 5 min at 30 °C; 30 - 280 °C at 8 °C per min; isothermal at 280 °C until benzo(ghi)perylene elutes.</TNOTE>
                            <TNOTE>Gas velocity: 30 ±5 cm/sec.</TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="6" OPTS="L2" CDEF="5,r50,7,7,12,7">
                            <TTITLE>Table 4—Gas Chromatography of Acid Extractable Compounds</TTITLE>
                            <BOXHD>
                                <CHED H="1">
                                    EGD No. 
                                    <SU>1</SU>
                                </CHED>
                                <CHED H="1">Compound</CHED>
                                <CHED H="1">Retention time</CHED>
                                <CHED H="2">Mean (sec)</CHED>
                                <CHED H="2">EGD Ref</CHED>
                                <CHED H="2">Relative</CHED>
                                <CHED H="1">
                                    Detection limit 
                                    <SU>2</SU>
                                     (µg/L)
                                </CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">164</ENT>
                                <ENT>2,2′-difluorobiphenyl (int std)</ENT>
                                <ENT>1163</ENT>
                                <ENT>164</ENT>
                                <ENT>1.000-1.000</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">224</ENT>
                                <ENT>2-chlorophenol-d4</ENT>
                                <ENT>701</ENT>
                                <ENT>164</ENT>
                                <ENT>0.587-0.618</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">324</ENT>
                                <ENT>2-chlorophenol</ENT>
                                <ENT>705</ENT>
                                <ENT>224</ENT>
                                <ENT>0.997-1.010</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">257</ENT>
                                <ENT>2-nitrophenol-d4</ENT>
                                <ENT>898</ENT>
                                <ENT>164</ENT>
                                <ENT>0.761-0.783</ENT>
                                <ENT>20</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">357</ENT>
                                <ENT>2-nitrophenol</ENT>
                                <ENT>900</ENT>
                                <ENT>257</ENT>
                                <ENT>0.994-1.009</ENT>
                                <ENT>20</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">231</ENT>
                                <ENT>2,4-dichlorophenol-d3</ENT>
                                <ENT>944</ENT>
                                <ENT>164</ENT>
                                <ENT>0.802-0.822</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">331</ENT>
                                <ENT>2,4-dichlorophenol</ENT>
                                <ENT>947</ENT>
                                <ENT>231</ENT>
                                <ENT>0.997-1.006</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">222</ENT>
                                <ENT>4-chloro-3-methylphenol-d2</ENT>
                                <ENT>1086</ENT>
                                <ENT>164</ENT>
                                <ENT>0.930-0.943</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">322</ENT>
                                <ENT>4-chloro-3-methylphenol</ENT>
                                <ENT>1091</ENT>
                                <ENT>222</ENT>
                                <ENT>0.998-1.003</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">221</ENT>
                                <ENT>2,4,6-trichlorophenol-d2</ENT>
                                <ENT>1162</ENT>
                                <ENT>164</ENT>
                                <ENT>0.994-1.005</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">321</ENT>
                                <ENT>2,4,6-trichlorophenol</ENT>
                                <ENT>1165</ENT>
                                <ENT>221</ENT>
                                <ENT>0.998-1.004</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">531</ENT>
                                <ENT>2,4,5-trichlorophenol</ENT>
                                <ENT>1170</ENT>
                                <ENT>164</ENT>
                                <ENT O="oi0">ns</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">530</ENT>
                                <ENT>2,3,6-trichlorophenol</ENT>
                                <ENT>1195</ENT>
                                <ENT>164</ENT>
                                <ENT O="oi0">ns</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">259</ENT>
                                <ENT>2,4-dinitrophenol-d3</ENT>
                                <ENT>1323</ENT>
                                <ENT>164</ENT>
                                <ENT>1.127-1.149</ENT>
                                <ENT>50</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">359</ENT>
                                <ENT>2,4-dinitrophenol</ENT>
                                <ENT>1325</ENT>
                                <ENT>259</ENT>
                                <ENT>1.000-1.005</ENT>
                                <ENT>50</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">258</ENT>
                                <ENT>4-nitrophenol-d4</ENT>
                                <ENT>1349</ENT>
                                <ENT>164</ENT>
                                <ENT>1.147-1.175</ENT>
                                <ENT>50</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">358</ENT>
                                <ENT>4-nitrophenol</ENT>
                                <ENT>1354</ENT>
                                <ENT>258</ENT>
                                <ENT>0.997-1.006</ENT>
                                <ENT>50</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">260</ENT>
                                <ENT>2-methyl-4,6-dinitrophenol-d2</ENT>
                                <ENT>1433</ENT>
                                <ENT>164</ENT>
                                <ENT>1.216-1.249</ENT>
                                <ENT>20</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">360</ENT>
                                <ENT>2-methyl-4,6-dinitrophenol</ENT>
                                <ENT>1435</ENT>
                                <ENT>260</ENT>
                                <ENT>1.000-1.002</ENT>
                                <ENT>20</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">264</ENT>
                                <ENT>Pentachlorophenol-13C6</ENT>
                                <ENT>1559</ENT>
                                <ENT>164</ENT>
                                <ENT>1.320-1.363</ENT>
                                <ENT>50</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">364</ENT>
                                <ENT>Pentachlorophenol</ENT>
                                <ENT>1561</ENT>
                                <ENT>264</ENT>
                                <ENT>0.998-1.002</ENT>
                                <ENT>50</ENT>
                            </ROW>
                            <TNOTE>
                                <SU>1</SU>
                                 Reference numbers beginning with 0, 1 or 5 indicate a pollutant quantified by the internal standard method; reference numbers beginning with 2 or 6 indicate a labeled compound quantified by the internal standard method; reference numbers beginning with 3 or 7 indicate a pollutant quantified by isotope dilution.
                            </TNOTE>
                            <TNOTE>
                                <SU>2</SU>
                                 This is a minimum level at which the entire GC/MS system must give recognizable mass spectra (background corrected) and acceptable calibration points.
                            </TNOTE>
                            <TNOTE>ns = specification not available at time of release of method.</TNOTE>
                            <TNOTE>Column: 30 ±2m × 0.25 ±0.02mm i.d. 94% methyl, 4% phenyl, 1% vinyl bonded phase fused silica capillary.</TNOTE>
                            <TNOTE>Temperature program: 5 min at 30 °C; 8 °C/min. to 250 °C or until pentachlorophenol elutes.</TNOTE>
                            <TNOTE>Gas velocity: 30 ±5 cm/sec.</TNOTE>
                        </GPOTABLE>
                        <PRTPAGE P="377"/>
                        <GPOTABLE COLS="2" OPTS="L2" CDEF="5,r10">
                            <TTITLE>Table 5—DFTPP Mass Intensity Specifications</TTITLE>
                            <BOXHD>
                                <CHED H="1">Mass</CHED>
                                <CHED H="1">Intensity required</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">51</ENT>
                                <ENT>30-60 percent of mass 198.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">68</ENT>
                                <ENT>Less than 2 percent of mass 69.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">70</ENT>
                                <ENT>Less than 2 percent of mass 69.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">127</ENT>
                                <ENT>40-60 percent of mass 198.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">197</ENT>
                                <ENT>Less than 1 percent of mass 198.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">199</ENT>
                                <ENT>5-9 percent of mass 198.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">275</ENT>
                                <ENT>10-30 percent of mass 198.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">365</ENT>
                                <ENT>greater than 1 percent of mass 198.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">441</ENT>
                                <ENT>present and less than mass 443.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">442</ENT>
                                <ENT>40-100 percent of mass 198.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">443</ENT>
                                <ENT>17-23 percent of mass 442.</ENT>
                            </ROW>
                        </GPOTABLE>
                        <GPOTABLE COLS="3" OPTS="L2" CDEF="s10,8,4/4">
                            <TTITLE>Table 6—Base/Neutral Extractable Compound Characteristic Masses</TTITLE>
                            <BOXHD>
                                <CHED H="1">Compound</CHED>
                                <CHED H="1">Labeled analog</CHED>
                                <CHED H="1">Primary m/z</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">Acenaphthene</ENT>
                                <ENT>d10</ENT>
                                <ENT>154/164</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Acenaphthylene</ENT>
                                <ENT>d8</ENT>
                                <ENT>152/160</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Anthracene</ENT>
                                <ENT>d10</ENT>
                                <ENT>178/188</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzidine</ENT>
                                <ENT>d8</ENT>
                                <ENT>184/192</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzo(a)anthracene</ENT>
                                <ENT>d12</ENT>
                                <ENT>228/240</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzo(b)fluoranthene</ENT>
                                <ENT>d12</ENT>
                                <ENT>252/264</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzo(k)fluoranthene</ENT>
                                <ENT>d12</ENT>
                                <ENT>252/264</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzo(a)pyrene</ENT>
                                <ENT>d12</ENT>
                                <ENT>252/264</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Benzo(ghi)perylene</ENT>
                                <ENT>d12</ENT>
                                <ENT>276/288</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Biphenyl</ENT>
                                <ENT>d10</ENT>
                                <ENT>154/164</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Bis(2-chloroethyl) ether</ENT>
                                <ENT>d8</ENT>
                                <ENT>93/101</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Bis(2-chloroethoxy)methane</ENT>
                                <ENT/>
                                <ENT>93</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Bis(2-chloroisopropyl) ether</ENT>
                                <ENT>d12</ENT>
                                <ENT>121/131</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Bis(2-ethylhexyl) phthalate</ENT>
                                <ENT>d4</ENT>
                                <ENT>149/153</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4-bromophenyl phenyl ether</ENT>
                                <ENT/>
                                <ENT>248</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Butyl benzyl phthalate</ENT>
                                <ENT/>
                                <ENT>149</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">n-C10</ENT>
                                <ENT>d22</ENT>
                                <ENT>55/66</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">n-C12</ENT>
                                <ENT>d26</ENT>
                                <ENT>55/66</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">n-C14</ENT>
                                <ENT/>
                                <ENT>55</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">n-C16</ENT>
                                <ENT>d34</ENT>
                                <ENT>55/66</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">n-C18</ENT>
                                <ENT/>
                                <ENT>55</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">n-C20</ENT>
                                <ENT>d42</ENT>
                                <ENT>55/66</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">n-C22</ENT>
                                <ENT/>
                                <ENT>55</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">n-C24</ENT>
                                <ENT>d50</ENT>
                                <ENT>55/66</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">n-C26</ENT>
                                <ENT/>
                                <ENT>55</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">n-C28</ENT>
                                <ENT/>
                                <ENT>55</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">n-C30</ENT>
                                <ENT>d62</ENT>
                                <ENT>55/66</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Carbazole</ENT>
                                <ENT>d8</ENT>
                                <ENT>167/175</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-chloronaphthalene</ENT>
                                <ENT>d7</ENT>
                                <ENT>162/169</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4-chlorophenyl phenyl ether</ENT>
                                <ENT>d5</ENT>
                                <ENT>204/209</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chrysene</ENT>
                                <ENT>d12</ENT>
                                <ENT>228/240</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">p-cymene</ENT>
                                <ENT>d14</ENT>
                                <ENT>114/130</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dibenzo(a,h)anthracene</ENT>
                                <ENT/>
                                <ENT>278</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dibenzofuran</ENT>
                                <ENT>d8</ENT>
                                <ENT>168/176</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dibenzothiophene</ENT>
                                <ENT>d8</ENT>
                                <ENT>184/192</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Di-n-butyl phthalate</ENT>
                                <ENT>d4</ENT>
                                <ENT>149/153</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2-dichlorobenzene</ENT>
                                <ENT>d4</ENT>
                                <ENT>146/152</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,3-dichlorobenzene</ENT>
                                <ENT>d4</ENT>
                                <ENT>146/152</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,4-dichlorobenzene</ENT>
                                <ENT>d4</ENT>
                                <ENT>146/152</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">3,3′-dichlorobenzidine</ENT>
                                <ENT>d6</ENT>
                                <ENT>252/258</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Diethyl phthalate</ENT>
                                <ENT>d4</ENT>
                                <ENT>149/153</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4-dimethylphenol</ENT>
                                <ENT>d3</ENT>
                                <ENT>122/125</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Dimethyl phthalate</ENT>
                                <ENT>d4</ENT>
                                <ENT>163/167</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4-dinitrotoluene</ENT>
                                <ENT>d3</ENT>
                                <ENT>164/168</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,6-dinitrotoluene</ENT>
                                <ENT>d3</ENT>
                                <ENT>165/167</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Di-n-octyl phthalate</ENT>
                                <ENT>d4</ENT>
                                <ENT>149/153</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Diphenylamine</ENT>
                                <ENT>d10</ENT>
                                <ENT>169/179</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Diphenyl ether</ENT>
                                <ENT>d10</ENT>
                                <ENT>170/180</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    1,2-diphenylhydrazine 
                                    <SU>1</SU>
                                </ENT>
                                <ENT>d10</ENT>
                                <ENT>77/82</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Fluoranthene</ENT>
                                <ENT>d10</ENT>
                                <ENT>202/212</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Fluorene</ENT>
                                <ENT>d10</ENT>
                                <ENT>166/176</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Hexachlorobenzene</ENT>
                                <ENT>13C6</ENT>
                                <ENT>284/292</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Hexachlorobutadiene</ENT>
                                <ENT>13C4</ENT>
                                <ENT>225/231</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Hexachloroethane</ENT>
                                <ENT>13C</ENT>
                                <ENT>201/204</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Hexachlorocyclopentadiene</ENT>
                                <ENT>13C4</ENT>
                                <ENT>237/241</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ideno(1,2,3-cd)pyrene</ENT>
                                <ENT/>
                                <ENT>276</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Isophorone</ENT>
                                <ENT>d8</ENT>
                                <ENT>82/88</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Naphthalene</ENT>
                                <ENT>d8</ENT>
                                <ENT>128/136</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">B-naphthylamine</ENT>
                                <ENT>d7</ENT>
                                <ENT>143/150</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Nitrobenzene</ENT>
                                <ENT>d5</ENT>
                                <ENT>123/128</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">N-nitrosodimethylamine</ENT>
                                <ENT/>
                                <ENT>74</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">N-nitrosodi-n-propylamine</ENT>
                                <ENT/>
                                <ENT>70</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    N-nitrosodiphenylamile 
                                    <SU>2</SU>
                                </ENT>
                                <ENT>d6</ENT>
                                <ENT>169/175</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Phenanthrene</ENT>
                                <ENT>d10</ENT>
                                <ENT>178/188</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Phenol</ENT>
                                <ENT>d5</ENT>
                                <ENT>94/71</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">a-picoline</ENT>
                                <ENT>d7</ENT>
                                <ENT>93/100</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Pyrene</ENT>
                                <ENT>d10</ENT>
                                <ENT>202/212</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Styrene</ENT>
                                <ENT>d5</ENT>
                                <ENT>104/109</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">a-terpineol</ENT>
                                <ENT>d3</ENT>
                                <ENT>59/62</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,3-trichlorobenzene</ENT>
                                <ENT>d3</ENT>
                                <ENT>180/183</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1,2,4-trichlorobenzene</ENT>
                                <ENT>d3</ENT>
                                <ENT>180/183</ENT>
                            </ROW>
                            <TNOTE>
                                <SU>1</SU>
                                 Detected as azobenzene.
                            </TNOTE>
                            <TNOTE>
                                <SU>2</SU>
                                 Detected as diphenylamine.
                            </TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="3" OPTS="L2" CDEF="s10,8,4/4">
                            <TTITLE>Table 7—Acid Extractable Compound Characteristic Masses</TTITLE>
                            <BOXHD>
                                <CHED H="1">Compound</CHED>
                                <CHED H="1">Labeled analog</CHED>
                                <CHED H="1">Primary m/z</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">4-chloro-3-methylphenol</ENT>
                                <ENT>d2</ENT>
                                <ENT>107/109</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-chlorophenol</ENT>
                                <ENT>d4</ENT>
                                <ENT>128/132</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4-dichlorophenol</ENT>
                                <ENT>d3</ENT>
                                <ENT>162/167</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4-dinitrophenol</ENT>
                                <ENT>d3</ENT>
                                <ENT>184/187</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-methyl-4,6-dinitrophenol</ENT>
                                <ENT>d2</ENT>
                                <ENT>198/200</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2-nitrophenol</ENT>
                                <ENT>d4</ENT>
                                <ENT>139/143</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">4-nitrophenol</ENT>
                                <ENT>d4</ENT>
                                <ENT>139/143</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Pentachlorophenol</ENT>
                                <ENT>13C6</ENT>
                                <ENT>266/272</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,3,6-trichlorophenol</ENT>
                                <ENT>d2</ENT>
                                <ENT>196/200</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4,5-trichlorophenol</ENT>
                                <ENT>d2</ENT>
                                <ENT>196/200</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">2,4,6-trichlorophenol</ENT>
                                <ENT>d2</ENT>
                                <ENT>196/200</ENT>
                            </ROW>
                        </GPOTABLE>
                        <GPOTABLE COLS="7" OPTS="L2" CDEF="5,r50,7,10,12,10,10">
                            <TTITLE>Table 8—Acceptance Criteria for Performance Tests</TTITLE>
                            <BOXHD>
                                <CHED H="1">
                                    EGD No. 
                                    <SU>1</SU>
                                </CHED>
                                <CHED H="1">Compound</CHED>
                                <CHED H="1">Acceptance criteria</CHED>
                                <CHED H="2">Initial precision and accuracy section 8.2.3 (µg/L)</CHED>
                                <CHED H="3">s</CHED>
                                <CHED H="3">X</CHED>
                                <CHED H="2">Labeled compound recovery sec. 8.3 and 14.2 P (percent)</CHED>
                                <CHED H="2">Calibration verification sec. 12.5 (µg/mL)</CHED>
                                <CHED H="2">On-going accuracy sec. 11.6 R (µg/L)</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">301</ENT>
                                <ENT>Acenaphthene</ENT>
                                <ENT>21</ENT>
                                <ENT>79-134</ENT>
                                <ENT/>
                                <ENT>80-125</ENT>
                                <ENT>72-144</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">201</ENT>
                                <ENT>Acenaphthene-d10</ENT>
                                <ENT>38</ENT>
                                <ENT>38-147</ENT>
                                <ENT>20-270</ENT>
                                <ENT>71-141</ENT>
                                <ENT>30-180</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">377</ENT>
                                <ENT>Acenaphtylene</ENT>
                                <ENT>38</ENT>
                                <ENT>69-186</ENT>
                                <ENT/>
                                <ENT>60-166</ENT>
                                <ENT>61-207</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">277</ENT>
                                <ENT>Acenaphthylene-d8</ENT>
                                <ENT>31</ENT>
                                <ENT>38-146</ENT>
                                <ENT>23-239</ENT>
                                <ENT>66-152</ENT>
                                <ENT>33-168</ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="378"/>
                                <ENT I="01">378</ENT>
                                <ENT>Anthracene</ENT>
                                <ENT>41</ENT>
                                <ENT>58-174</ENT>
                                <ENT/>
                                <ENT>60-168</ENT>
                                <ENT>50-199</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">278</ENT>
                                <ENT>Anthracene-d10</ENT>
                                <ENT>49</ENT>
                                <ENT>31-194</ENT>
                                <ENT>14-419</ENT>
                                <ENT>58-171</ENT>
                                <ENT>23-242</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">305</ENT>
                                <ENT>Benzidine</ENT>
                                <ENT>119</ENT>
                                <ENT>16-518</ENT>
                                <ENT/>
                                <ENT>34-296</ENT>
                                <ENT>11-672</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">205</ENT>
                                <ENT>Benzidine-d8</ENT>
                                <ENT>269</ENT>
                                <ENT>ns-ns</ENT>
                                <ENT>ns-ns</ENT>
                                <ENT>ns-ns</ENT>
                                <ENT>ns-ns</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">372</ENT>
                                <ENT>Benzo(a)anthracene</ENT>
                                <ENT>20</ENT>
                                <ENT>65-168</ENT>
                                <ENT/>
                                <ENT>70-142</ENT>
                                <ENT>62-176</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">272</ENT>
                                <ENT>Benzo(a)anthracene-d12</ENT>
                                <ENT>41</ENT>
                                <ENT>25-298</ENT>
                                <ENT>12-605</ENT>
                                <ENT>28-357</ENT>
                                <ENT>22-329</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">374</ENT>
                                <ENT>Benzo(b)fluoranthene</ENT>
                                <ENT>183</ENT>
                                <ENT>32-545</ENT>
                                <ENT/>
                                <ENT>61-164</ENT>
                                <ENT>20-ns</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">274</ENT>
                                <ENT>Benzo(b)fluoranthene-d12</ENT>
                                <ENT>168</ENT>
                                <ENT>11-577</ENT>
                                <ENT>ns-ns</ENT>
                                <ENT>14-ns</ENT>
                                <ENT>ns-ns</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">375</ENT>
                                <ENT>Benzo(k)fluoranthene</ENT>
                                <ENT>26</ENT>
                                <ENT>59-143</ENT>
                                <ENT/>
                                <ENT>13-ns</ENT>
                                <ENT>53-155</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">275</ENT>
                                <ENT>Benzo(k)fluoranthene-d12</ENT>
                                <ENT>114</ENT>
                                <ENT>15-514</ENT>
                                <ENT>ns-ns</ENT>
                                <ENT>13-ns</ENT>
                                <ENT>ns-685</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">373</ENT>
                                <ENT>Benzo(a)pyrene</ENT>
                                <ENT>26</ENT>
                                <ENT>62-195</ENT>
                                <ENT/>
                                <ENT>78-129</ENT>
                                <ENT>59-206</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">273</ENT>
                                <ENT>Benzo(a)pyrene-d12</ENT>
                                <ENT>24</ENT>
                                <ENT>35-181</ENT>
                                <ENT>21-290</ENT>
                                <ENT>12-ns</ENT>
                                <ENT>32-194</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">379</ENT>
                                <ENT>Benzo(ghi)perylene</ENT>
                                <ENT>21</ENT>
                                <ENT>72-160</ENT>
                                <ENT/>
                                <ENT>69-145</ENT>
                                <ENT>58-168</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">279</ENT>
                                <ENT>Benzo(ghi)perylene-d12</ENT>
                                <ENT>45</ENT>
                                <ENT>29-268</ENT>
                                <ENT>14-529</ENT>
                                <ENT>13-ns</ENT>
                                <ENT>25-303</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">712</ENT>
                                <ENT>Biphenyl (Appendix C)</ENT>
                                <ENT>41</ENT>
                                <ENT>75-148</ENT>
                                <ENT/>
                                <ENT>58-171</ENT>
                                <ENT>62-176</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">612</ENT>
                                <ENT>Biphenyl-d12</ENT>
                                <ENT>43</ENT>
                                <ENT>28-165</ENT>
                                <ENT>ns-ns</ENT>
                                <ENT>52-192</ENT>
                                <ENT>17-267</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">318</ENT>
                                <ENT>Bis(2-chloroethyl) ether</ENT>
                                <ENT>34</ENT>
                                <ENT>55-196</ENT>
                                <ENT/>
                                <ENT>61-164</ENT>
                                <ENT>50-213</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">218</ENT>
                                <ENT>Bis(2-chloroethyl) ether-d8</ENT>
                                <ENT>33</ENT>
                                <ENT>29-196</ENT>
                                <ENT>15-372</ENT>
                                <ENT>52-194</ENT>
                                <ENT>25-222</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">043</ENT>
                                <ENT>Bis(2-chloroethoxy)methane*</ENT>
                                <ENT>27</ENT>
                                <ENT>43-153</ENT>
                                <ENT/>
                                <ENT>44-228</ENT>
                                <ENT>39-166</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">342</ENT>
                                <ENT>Bis(2-chloroisopropyl) ether</ENT>
                                <ENT>17</ENT>
                                <ENT>81-138</ENT>
                                <ENT/>
                                <ENT>67-148</ENT>
                                <ENT>77-145</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">242</ENT>
                                <ENT>Bis(2-chloroisopropyl)ether-d12</ENT>
                                <ENT>27</ENT>
                                <ENT>35-149</ENT>
                                <ENT>20-260</ENT>
                                <ENT>44-229</ENT>
                                <ENT>30-169</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">366</ENT>
                                <ENT>Bis(2-ethylhexyl) phthalate</ENT>
                                <ENT>31</ENT>
                                <ENT>69-220</ENT>
                                <ENT/>
                                <ENT>76-131</ENT>
                                <ENT>64-232</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">266</ENT>
                                <ENT>Bis(2-ethylhexyl) phthalate-d4</ENT>
                                <ENT>29</ENT>
                                <ENT>32-205</ENT>
                                <ENT>18-364</ENT>
                                <ENT>43-232</ENT>
                                <ENT>28-224</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">041</ENT>
                                <ENT>4-bromophenyl phenyl ether*</ENT>
                                <ENT>44</ENT>
                                <ENT>44-140</ENT>
                                <ENT/>
                                <ENT>52-193</ENT>
                                <ENT>35-172</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">067</ENT>
                                <ENT>Butyl benzyl phthalate*</ENT>
                                <ENT>31</ENT>
                                <ENT>19-233</ENT>
                                <ENT/>
                                <ENT>22-450</ENT>
                                <ENT>35-170</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">717</ENT>
                                <ENT>n-C10 (Appendix C)</ENT>
                                <ENT>51</ENT>
                                <ENT>24-195</ENT>
                                <ENT/>
                                <ENT>42-235</ENT>
                                <ENT>19-237</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">617</ENT>
                                <ENT>n-C10-d22</ENT>
                                <ENT>70</ENT>
                                <ENT>ns-298</ENT>
                                <ENT>ns-ns</ENT>
                                <ENT>44-227</ENT>
                                <ENT>ns-504</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">706</ENT>
                                <ENT>n-C12 (Appendix C)</ENT>
                                <ENT>74</ENT>
                                <ENT>35-369</ENT>
                                <ENT/>
                                <ENT>60-166</ENT>
                                <ENT>29-424</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">606</ENT>
                                <ENT>n-C12-d26</ENT>
                                <ENT>53</ENT>
                                <ENT>ns-331</ENT>
                                <ENT>ns-ns</ENT>
                                <ENT>41-242</ENT>
                                <ENT>ns-408</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">518</ENT>
                                <ENT>n-C14 (Appendix C)*</ENT>
                                <ENT>109</ENT>
                                <ENT>ns-985</ENT>
                                <ENT/>
                                <ENT>37-268</ENT>
                                <ENT>ns-ns</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">719</ENT>
                                <ENT>n-C16 (Appendix C)</ENT>
                                <ENT>33</ENT>
                                <ENT>80-162</ENT>
                                <ENT/>
                                <ENT>72-138</ENT>
                                <ENT>71-181</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">619</ENT>
                                <ENT>n-C16-d34</ENT>
                                <ENT>46</ENT>
                                <ENT>37-162</ENT>
                                <ENT>18-308</ENT>
                                <ENT>54-186</ENT>
                                <ENT>28-202</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">520</ENT>
                                <ENT>n-C18 (Appendix C)*</ENT>
                                <ENT>39</ENT>
                                <ENT>42-131</ENT>
                                <ENT/>
                                <ENT>40-249</ENT>
                                <ENT>35-167</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">721</ENT>
                                <ENT>n-C20 (Appendix C)</ENT>
                                <ENT>59</ENT>
                                <ENT>53-263</ENT>
                                <ENT/>
                                <ENT>54-184</ENT>
                                <ENT>46-301</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">621</ENT>
                                <ENT>n-C20-d42</ENT>
                                <ENT>34</ENT>
                                <ENT>34-172</ENT>
                                <ENT>19-306</ENT>
                                <ENT>62-162</ENT>
                                <ENT>29-198</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">522</ENT>
                                <ENT>n-C22 (Appendix C)*</ENT>
                                <ENT>31</ENT>
                                <ENT>45-152</ENT>
                                <ENT/>
                                <ENT>40-249</ENT>
                                <ENT>39-195</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">723</ENT>
                                <ENT>n-C24 (Appendix C)</ENT>
                                <ENT>11</ENT>
                                <ENT>80-139</ENT>
                                <ENT/>
                                <ENT>65-154</ENT>
                                <ENT>78-142</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">623</ENT>
                                <ENT>n-C24-d50</ENT>
                                <ENT>28</ENT>
                                <ENT>27-211</ENT>
                                <ENT>15-376</ENT>
                                <ENT>50-199</ENT>
                                <ENT>25-229</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">524</ENT>
                                <ENT>n-C26 (Appendix C)*</ENT>
                                <ENT>35</ENT>
                                <ENT>35-193</ENT>
                                <ENT/>
                                <ENT>26-392</ENT>
                                <ENT>31-212</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">525</ENT>
                                <ENT>n-C28 (Appendix C)*</ENT>
                                <ENT>35</ENT>
                                <ENT>35-193</ENT>
                                <ENT/>
                                <ENT>26-392</ENT>
                                <ENT>31-212</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">726</ENT>
                                <ENT>n-C30 (Appendix C)</ENT>
                                <ENT>32</ENT>
                                <ENT>61-200</ENT>
                                <ENT/>
                                <ENT>66-152</ENT>
                                <ENT>56-215</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">626</ENT>
                                <ENT>n-C30-d62</ENT>
                                <ENT>41</ENT>
                                <ENT>27-242</ENT>
                                <ENT>13-479</ENT>
                                <ENT>24-423</ENT>
                                <ENT>23-274</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">528</ENT>
                                <ENT>Carbazole (4c)*</ENT>
                                <ENT>38</ENT>
                                <ENT>36-165</ENT>
                                <ENT/>
                                <ENT>44-227</ENT>
                                <ENT>31-188</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">320</ENT>
                                <ENT>2-chloronaphthalene</ENT>
                                <ENT>100</ENT>
                                <ENT>46-357</ENT>
                                <ENT/>
                                <ENT>58-171</ENT>
                                <ENT>35-442</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">220</ENT>
                                <ENT>2-chloronaphthalene-d7</ENT>
                                <ENT>41</ENT>
                                <ENT>30-168</ENT>
                                <ENT>15-324</ENT>
                                <ENT>72-139</ENT>
                                <ENT>24-204</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">322</ENT>
                                <ENT>4-chloro-3-methylphenol</ENT>
                                <ENT>37</ENT>
                                <ENT>76-131</ENT>
                                <ENT/>
                                <ENT>85-115</ENT>
                                <ENT>62-159</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">222</ENT>
                                <ENT>4-chloro-3-methylphenol-d2</ENT>
                                <ENT>111</ENT>
                                <ENT>30-174</ENT>
                                <ENT>ns-613</ENT>
                                <ENT>68-147</ENT>
                                <ENT>14-314</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">324</ENT>
                                <ENT>2-chlorophenol</ENT>
                                <ENT>13</ENT>
                                <ENT>79-135</ENT>
                                <ENT/>
                                <ENT>78-129</ENT>
                                <ENT>76-138</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">224</ENT>
                                <ENT>2-chlorophenol-d4</ENT>
                                <ENT>24</ENT>
                                <ENT>36-162</ENT>
                                <ENT>23-255</ENT>
                                <ENT>55-180</ENT>
                                <ENT>33-176</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">340</ENT>
                                <ENT>4-chlorophenyl phenyl ether</ENT>
                                <ENT>42</ENT>
                                <ENT>75-166</ENT>
                                <ENT/>
                                <ENT>71-142</ENT>
                                <ENT>63-194</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">240</ENT>
                                <ENT>4-chlorophenyl phenyl ether-d5</ENT>
                                <ENT>52</ENT>
                                <ENT>40-161</ENT>
                                <ENT>19-325</ENT>
                                <ENT>57-175</ENT>
                                <ENT>29-212</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">376</ENT>
                                <ENT>Chrysene</ENT>
                                <ENT>51</ENT>
                                <ENT>59-186</ENT>
                                <ENT/>
                                <ENT>70-142</ENT>
                                <ENT>48-221</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">276</ENT>
                                <ENT>Chrysene-d12</ENT>
                                <ENT>69</ENT>
                                <ENT>33-219</ENT>
                                <ENT>13-512</ENT>
                                <ENT>24-411</ENT>
                                <ENT>23-290</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">713</ENT>
                                <ENT>p-cymene (Appendix C)</ENT>
                                <ENT>18</ENT>
                                <ENT>76-140</ENT>
                                <ENT/>
                                <ENT>79-127</ENT>
                                <ENT>72-147</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">613</ENT>
                                <ENT>p-cymene-d14</ENT>
                                <ENT>67</ENT>
                                <ENT>ns-359</ENT>
                                <ENT>ns-ns</ENT>
                                <ENT>66-152</ENT>
                                <ENT>ns-468</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">082</ENT>
                                <ENT>Dibenzo(a,h)anthracene*</ENT>
                                <ENT>55</ENT>
                                <ENT>23-299</ENT>
                                <ENT/>
                                <ENT>13-761</ENT>
                                <ENT>19-340</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">705</ENT>
                                <ENT>Dibenzofuran (Appendix C)</ENT>
                                <ENT>20</ENT>
                                <ENT>85-136</ENT>
                                <ENT/>
                                <ENT>73-136</ENT>
                                <ENT>79-146</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">605</ENT>
                                <ENT>Dibenzofuran-d8</ENT>
                                <ENT>31</ENT>
                                <ENT>47-136</ENT>
                                <ENT>28-220</ENT>
                                <ENT>66-150</ENT>
                                <ENT>39-160</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">704</ENT>
                                <ENT>Dibenzothiophene (Synfuel)</ENT>
                                <ENT>31</ENT>
                                <ENT>79-150</ENT>
                                <ENT/>
                                <ENT>72-140</ENT>
                                <ENT>70-168</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">604</ENT>
                                <ENT>Dibenzothiophene-d8</ENT>
                                <ENT>31</ENT>
                                <ENT>48-130</ENT>
                                <ENT>29-215</ENT>
                                <ENT>69-145</ENT>
                                <ENT>40-156</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">368</ENT>
                                <ENT>Di-n-butyl phthalate</ENT>
                                <ENT>15</ENT>
                                <ENT>76-165</ENT>
                                <ENT/>
                                <ENT>71-142</ENT>
                                <ENT>74-169</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">268</ENT>
                                <ENT>Di-n-butyl phthalate-d4</ENT>
                                <ENT>23</ENT>
                                <ENT>23-195</ENT>
                                <ENT>13-346</ENT>
                                <ENT>52-192</ENT>
                                <ENT>22-209</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">325</ENT>
                                <ENT>1,2-dichlorobenzene</ENT>
                                <ENT>17</ENT>
                                <ENT>73-146</ENT>
                                <ENT/>
                                <ENT>74-135</ENT>
                                <ENT>70-152</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">225</ENT>
                                <ENT>1,2-dichlorobenzene-d4</ENT>
                                <ENT>35</ENT>
                                <ENT>14-212</ENT>
                                <ENT>ns-494</ENT>
                                <ENT>61-164</ENT>
                                <ENT>11-247</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">326</ENT>
                                <ENT>1,3-dichlorobenzene</ENT>
                                <ENT>43</ENT>
                                <ENT>63-201</ENT>
                                <ENT/>
                                <ENT>65-154</ENT>
                                <ENT>55-225</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">226</ENT>
                                <ENT>1,3-dichlorobenzene-d4</ENT>
                                <ENT>48</ENT>
                                <ENT>13-203</ENT>
                                <ENT>ns-550</ENT>
                                <ENT>52-192</ENT>
                                <ENT>ns-260</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">327</ENT>
                                <ENT>1,4-dichlorobenzene</ENT>
                                <ENT>42</ENT>
                                <ENT>61-194</ENT>
                                <ENT/>
                                <ENT>62-161</ENT>
                                <ENT>53-219</ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="379"/>
                                <ENT I="01">227</ENT>
                                <ENT>1,4-dichlorobenzene-d4</ENT>
                                <ENT>48</ENT>
                                <ENT>15-193</ENT>
                                <ENT>ns-474</ENT>
                                <ENT>65-153</ENT>
                                <ENT>11-245</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">328</ENT>
                                <ENT>3,3′-dichlorobenzidine</ENT>
                                <ENT>26</ENT>
                                <ENT>68-174</ENT>
                                <ENT/>
                                <ENT>77-130</ENT>
                                <ENT>64-185</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">228</ENT>
                                <ENT>3,3′-dichlorobenzidine-d6</ENT>
                                <ENT>80</ENT>
                                <ENT>ns-562</ENT>
                                <ENT>ns-ns</ENT>
                                <ENT>18-558</ENT>
                                <ENT>ns-ns</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">331</ENT>
                                <ENT>2,4-dichlorophenol</ENT>
                                <ENT>12</ENT>
                                <ENT>85-131</ENT>
                                <ENT/>
                                <ENT>67-149</ENT>
                                <ENT>83-135</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">231</ENT>
                                <ENT>2,4-dichlorophenol-d3</ENT>
                                <ENT>28</ENT>
                                <ENT>38-164</ENT>
                                <ENT>24-260</ENT>
                                <ENT>64-157</ENT>
                                <ENT>34-182</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">370</ENT>
                                <ENT>Diethyl phthalate</ENT>
                                <ENT>44</ENT>
                                <ENT>75-196</ENT>
                                <ENT/>
                                <ENT>74-135</ENT>
                                <ENT>65-222</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">270</ENT>
                                <ENT>Diethyl phthalate-d4</ENT>
                                <ENT>78</ENT>
                                <ENT>ns-260</ENT>
                                <ENT>ns-ns</ENT>
                                <ENT>47-211</ENT>
                                <ENT>ns-ns</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">334</ENT>
                                <ENT>2,4-dimethylphenol</ENT>
                                <ENT>13</ENT>
                                <ENT>62-153</ENT>
                                <ENT/>
                                <ENT>67-150</ENT>
                                <ENT>60-156</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">234</ENT>
                                <ENT>2,4-dimethylphenol-d3</ENT>
                                <ENT>22</ENT>
                                <ENT>15-228</ENT>
                                <ENT>ns-449</ENT>
                                <ENT>58-172</ENT>
                                <ENT>14-242</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">371</ENT>
                                <ENT>Dimethyl phthalate</ENT>
                                <ENT>36</ENT>
                                <ENT>74-188</ENT>
                                <ENT/>
                                <ENT>73-137</ENT>
                                <ENT>67-207</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">271</ENT>
                                <ENT>Dimethyl phthalate-d4</ENT>
                                <ENT>108</ENT>
                                <ENT>ns-640</ENT>
                                <ENT>ns-ns</ENT>
                                <ENT>50-201</ENT>
                                <ENT>ns-ns</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">359</ENT>
                                <ENT>2,4-dinitrophenol</ENT>
                                <ENT>18</ENT>
                                <ENT>72-134</ENT>
                                <ENT/>
                                <ENT>75-133</ENT>
                                <ENT>68-141</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">259</ENT>
                                <ENT>2,4-dinitrophenol-d3</ENT>
                                <ENT>66</ENT>
                                <ENT>22-308</ENT>
                                <ENT>ns-ns</ENT>
                                <ENT>39-256</ENT>
                                <ENT>17-378</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">335</ENT>
                                <ENT>2,4-dinitrotoluene</ENT>
                                <ENT>18</ENT>
                                <ENT>75-158</ENT>
                                <ENT/>
                                <ENT>79-127</ENT>
                                <ENT>72-164</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">235</ENT>
                                <ENT>2,4-dinitrotoluene-d3</ENT>
                                <ENT>37</ENT>
                                <ENT>22-245</ENT>
                                <ENT>10-514</ENT>
                                <ENT>53-187</ENT>
                                <ENT>19-275</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">336</ENT>
                                <ENT>2,6-dinitrotoluene</ENT>
                                <ENT>30</ENT>
                                <ENT>80-141</ENT>
                                <ENT/>
                                <ENT>55-183</ENT>
                                <ENT>70-159</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">236</ENT>
                                <ENT>2,6-dinitrotoluene-d3</ENT>
                                <ENT>59</ENT>
                                <ENT>44-184</ENT>
                                <ENT>17-442</ENT>
                                <ENT>36-278</ENT>
                                <ENT>31-250</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">369</ENT>
                                <ENT>Di-n-octyl phthalate</ENT>
                                <ENT>16</ENT>
                                <ENT>77-161</ENT>
                                <ENT/>
                                <ENT>71-140</ENT>
                                <ENT>74-166</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">269</ENT>
                                <ENT>Di-n-octyl phthalate-d4</ENT>
                                <ENT>46</ENT>
                                <ENT>12-383</ENT>
                                <ENT>ns-ns</ENT>
                                <ENT>21-467</ENT>
                                <ENT>10-433</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">707</ENT>
                                <ENT>Diphenylamine (Appendix C)</ENT>
                                <ENT>45</ENT>
                                <ENT>58-205</ENT>
                                <ENT/>
                                <ENT>57-176</ENT>
                                <ENT>51-231</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">607</ENT>
                                <ENT>Diphenylamine-d10</ENT>
                                <ENT>42</ENT>
                                <ENT>27-206</ENT>
                                <ENT>11-488</ENT>
                                <ENT>59-169</ENT>
                                <ENT>21-249</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">708</ENT>
                                <ENT>Diphenyl ether (Appendix C)</ENT>
                                <ENT>19</ENT>
                                <ENT>82-136</ENT>
                                <ENT/>
                                <ENT>83-120</ENT>
                                <ENT>77-144</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">608</ENT>
                                <ENT>Diphenyl ether-d10</ENT>
                                <ENT>37</ENT>
                                <ENT>36-155</ENT>
                                <ENT>19-281</ENT>
                                <ENT>77-129</ENT>
                                <ENT>29-186</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">337</ENT>
                                <ENT>1,2-diphenylhydrazine</ENT>
                                <ENT>73</ENT>
                                <ENT>49-308</ENT>
                                <ENT/>
                                <ENT>75-134</ENT>
                                <ENT>40-360</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">237</ENT>
                                <ENT>1,2-diphenylhydrazine-d10</ENT>
                                <ENT>35</ENT>
                                <ENT>31-173</ENT>
                                <ENT>17-316</ENT>
                                <ENT>58-174</ENT>
                                <ENT>26-200</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">339</ENT>
                                <ENT>Fluoranthene</ENT>
                                <ENT>33</ENT>
                                <ENT>71-177</ENT>
                                <ENT/>
                                <ENT>67-149</ENT>
                                <ENT>64-194</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">239</ENT>
                                <ENT>Fluoranthene-d10</ENT>
                                <ENT>35</ENT>
                                <ENT>36-161</ENT>
                                <ENT>20-278</ENT>
                                <ENT>47-215</ENT>
                                <ENT>30-187</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">380</ENT>
                                <ENT>Fluorene</ENT>
                                <ENT>29</ENT>
                                <ENT>81-132</ENT>
                                <ENT/>
                                <ENT>74-135</ENT>
                                <ENT>70-151</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">280</ENT>
                                <ENT>Fluorene-d10</ENT>
                                <ENT>43</ENT>
                                <ENT>51-131</ENT>
                                <ENT>27-238</ENT>
                                <ENT>61-164</ENT>
                                <ENT>38-172</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">309</ENT>
                                <ENT>Hexachlorobenzene</ENT>
                                <ENT>16</ENT>
                                <ENT>90-124</ENT>
                                <ENT/>
                                <ENT>78-128</ENT>
                                <ENT>85-132</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">209</ENT>
                                <ENT>Hexachlorobenzene-13C6</ENT>
                                <ENT>81</ENT>
                                <ENT>36-228</ENT>
                                <ENT>13-595</ENT>
                                <ENT>38-265</ENT>
                                <ENT>23-321</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">352</ENT>
                                <ENT>hexachlorobutadiene</ENT>
                                <ENT>56</ENT>
                                <ENT>51-251</ENT>
                                <ENT/>
                                <ENT>74-135</ENT>
                                <ENT>43-287</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">252</ENT>
                                <ENT>hexachlorobutadiene-13C4</ENT>
                                <ENT>63</ENT>
                                <ENT>ns-316</ENT>
                                <ENT>ns-ns</ENT>
                                <ENT>68-148</ENT>
                                <ENT>ns-413</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">312</ENT>
                                <ENT>hexachloroethane</ENT>
                                <ENT>227</ENT>
                                <ENT>21-ns</ENT>
                                <ENT/>
                                <ENT>71-141</ENT>
                                <ENT>13-ns</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">212</ENT>
                                <ENT>hexachloroethane-13C1</ENT>
                                <ENT>77</ENT>
                                <ENT>ns-400</ENT>
                                <ENT>ns-ns</ENT>
                                <ENT>47-212</ENT>
                                <ENT>ns-563</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">353</ENT>
                                <ENT>hexachlorocyclopentadiene</ENT>
                                <ENT>15</ENT>
                                <ENT>69-144</ENT>
                                <ENT/>
                                <ENT>77-129</ENT>
                                <ENT>67-148</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">253</ENT>
                                <ENT>hexachlorocyclopentadiene-13C4</ENT>
                                <ENT>60</ENT>
                                <ENT>ns-ns</ENT>
                                <ENT>ns-ns</ENT>
                                <ENT>47-211</ENT>
                                <ENT>ns-ns</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">083</ENT>
                                <ENT>ideno(1,2,3-cd)pyrene*</ENT>
                                <ENT>55</ENT>
                                <ENT>23-299</ENT>
                                <ENT/>
                                <ENT>13-761</ENT>
                                <ENT>19-340</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">354</ENT>
                                <ENT>isophorone</ENT>
                                <ENT>25</ENT>
                                <ENT>76-156</ENT>
                                <ENT/>
                                <ENT>70-142</ENT>
                                <ENT>70-168</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">254</ENT>
                                <ENT>isophorone-d8</ENT>
                                <ENT>23</ENT>
                                <ENT>49-133</ENT>
                                <ENT>33-193</ENT>
                                <ENT>52-194</ENT>
                                <ENT>44-147</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">360</ENT>
                                <ENT>2-methyl-4,6-dinitrophenol</ENT>
                                <ENT>19</ENT>
                                <ENT>77-133</ENT>
                                <ENT/>
                                <ENT>69-145</ENT>
                                <ENT>72-142</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">260</ENT>
                                <ENT>2-methyl-4,6-dinitrophenol-d2</ENT>
                                <ENT>64</ENT>
                                <ENT>36-247</ENT>
                                <ENT>16-527</ENT>
                                <ENT>56-177</ENT>
                                <ENT>28-307</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">355</ENT>
                                <ENT>naphthalene</ENT>
                                <ENT>20</ENT>
                                <ENT>80-139</ENT>
                                <ENT/>
                                <ENT>73-137</ENT>
                                <ENT>75-149</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">255</ENT>
                                <ENT>naphthalene-d8</ENT>
                                <ENT>39</ENT>
                                <ENT>28-157</ENT>
                                <ENT>14-305</ENT>
                                <ENT>71-141</ENT>
                                <ENT>22-192</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">702</ENT>
                                <ENT>B-naphthylamine (Appendix C)</ENT>
                                <ENT>49</ENT>
                                <ENT>10-ns</ENT>
                                <ENT/>
                                <ENT>39-256</ENT>
                                <ENT>ns-ns</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">602</ENT>
                                <ENT>B-naphthylamine-d7</ENT>
                                <ENT>33</ENT>
                                <ENT>ns-ns</ENT>
                                <ENT>ns-ns</ENT>
                                <ENT>44-230</ENT>
                                <ENT>ns-ns</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">356</ENT>
                                <ENT>nitrobenzene</ENT>
                                <ENT>25</ENT>
                                <ENT>69-161</ENT>
                                <ENT/>
                                <ENT>85-115</ENT>
                                <ENT>65-169</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">256</ENT>
                                <ENT>nitrobenzene-d5</ENT>
                                <ENT>28</ENT>
                                <ENT>18-265</ENT>
                                <ENT>ns-ns</ENT>
                                <ENT>46-219</ENT>
                                <ENT>15-314</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">357</ENT>
                                <ENT>2-nitrophenol</ENT>
                                <ENT>15</ENT>
                                <ENT>78-140</ENT>
                                <ENT/>
                                <ENT>77-129</ENT>
                                <ENT>75-145</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">257</ENT>
                                <ENT>2-nitrophenol-d4</ENT>
                                <ENT>23</ENT>
                                <ENT>41-145</ENT>
                                <ENT>27-217</ENT>
                                <ENT>61-163</ENT>
                                <ENT>37-158</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">358</ENT>
                                <ENT>4-nitrophenol</ENT>
                                <ENT>42</ENT>
                                <ENT>62-146</ENT>
                                <ENT/>
                                <ENT>55-183</ENT>
                                <ENT>51-175</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">258</ENT>
                                <ENT>4-nitrophenol-d4</ENT>
                                <ENT>188</ENT>
                                <ENT>14-398</ENT>
                                <ENT>ns-ns</ENT>
                                <ENT>35-287</ENT>
                                <ENT>ns-ns</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">061</ENT>
                                <ENT>N-nitrosodimethylamile*</ENT>
                                <ENT>198</ENT>
                                <ENT>21-472</ENT>
                                <ENT/>
                                <ENT>40-249</ENT>
                                <ENT>12-807</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">063</ENT>
                                <ENT>N-nitrosodi-n-proplyamine*</ENT>
                                <ENT>198</ENT>
                                <ENT>21-472</ENT>
                                <ENT/>
                                <ENT>40-249</ENT>
                                <ENT>12-807</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">362</ENT>
                                <ENT>N-nitrosodiphenylamine</ENT>
                                <ENT>45</ENT>
                                <ENT>65-142</ENT>
                                <ENT/>
                                <ENT>68-148</ENT>
                                <ENT>53-173</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">262</ENT>
                                <ENT>N-nitrosodiphenylamine-d6</ENT>
                                <ENT>37</ENT>
                                <ENT>54-126</ENT>
                                <ENT>26-256</ENT>
                                <ENT>59-170</ENT>
                                <ENT>40-166</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">364</ENT>
                                <ENT>pentachlorophenol</ENT>
                                <ENT>21</ENT>
                                <ENT>76-140</ENT>
                                <ENT/>
                                <ENT>77-130</ENT>
                                <ENT>71-150</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">264</ENT>
                                <ENT>pentachlorophenol-13C6</ENT>
                                <ENT>49</ENT>
                                <ENT>37-212</ENT>
                                <ENT>18-412</ENT>
                                <ENT>42-237</ENT>
                                <ENT>29-254</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">381</ENT>
                                <ENT>phenanthrene</ENT>
                                <ENT>13</ENT>
                                <ENT>93-119</ENT>
                                <ENT/>
                                <ENT>75-133</ENT>
                                <ENT>87-126</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">281</ENT>
                                <ENT>phenanthrene-d10</ENT>
                                <ENT>40</ENT>
                                <ENT>45-130</ENT>
                                <ENT>24-241</ENT>
                                <ENT>67-149</ENT>
                                <ENT>34-168</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">365</ENT>
                                <ENT>phenol</ENT>
                                <ENT>36</ENT>
                                <ENT>77-127</ENT>
                                <ENT/>
                                <ENT>65-155</ENT>
                                <ENT>62-154</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">265</ENT>
                                <ENT>phenol-d5</ENT>
                                <ENT>161</ENT>
                                <ENT>21-210</ENT>
                                <ENT>ns-ns</ENT>
                                <ENT>48-208</ENT>
                                <ENT>ns-ns</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">703</ENT>
                                <ENT>a-picoline (Synfuel)</ENT>
                                <ENT>38</ENT>
                                <ENT>59-149</ENT>
                                <ENT/>
                                <ENT>60-165</ENT>
                                <ENT>50-174</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">603</ENT>
                                <ENT>a-picoline-d7</ENT>
                                <ENT>138</ENT>
                                <ENT>11-380</ENT>
                                <ENT>ns-ns</ENT>
                                <ENT>31-324</ENT>
                                <ENT>ns-608</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">384</ENT>
                                <ENT>pyrene</ENT>
                                <ENT>19</ENT>
                                <ENT>76-152</ENT>
                                <ENT/>
                                <ENT>76-132</ENT>
                                <ENT>72-159</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">284</ENT>
                                <ENT>pyrene-d10</ENT>
                                <ENT>29</ENT>
                                <ENT>32-176</ENT>
                                <ENT>18-303</ENT>
                                <ENT>48-210</ENT>
                                <ENT>28-196</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">710</ENT>
                                <ENT>styrene (Appendix C)</ENT>
                                <ENT>42</ENT>
                                <ENT>53-221</ENT>
                                <ENT/>
                                <ENT>65-153</ENT>
                                <ENT>48-244</ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="380"/>
                                <ENT I="01">610</ENT>
                                <ENT>styrene-d5</ENT>
                                <ENT>49</ENT>
                                <ENT>ns-281</ENT>
                                <ENT>ns-ns</ENT>
                                <ENT>44-228</ENT>
                                <ENT>ns-348</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">709</ENT>
                                <ENT>a-terpineol (Appendix C)</ENT>
                                <ENT>44</ENT>
                                <ENT>42-234</ENT>
                                <ENT/>
                                <ENT>54-186</ENT>
                                <ENT>38-258</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">609</ENT>
                                <ENT>a-terpineol-d3</ENT>
                                <ENT>48</ENT>
                                <ENT>22-292</ENT>
                                <ENT>ns-672</ENT>
                                <ENT>20-502</ENT>
                                <ENT>18-339</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">529</ENT>
                                <ENT>1,2,3-trichlorobenzene (4c)*</ENT>
                                <ENT>69</ENT>
                                <ENT>15-229</ENT>
                                <ENT/>
                                <ENT>60-167</ENT>
                                <ENT>11-297</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">308</ENT>
                                <ENT>1,2,4-trichlorobenzene</ENT>
                                <ENT>19</ENT>
                                <ENT>82-136</ENT>
                                <ENT/>
                                <ENT>78-128</ENT>
                                <ENT>77-144</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">208</ENT>
                                <ENT>1,2,4-trichlorobenzene-d3</ENT>
                                <ENT>57</ENT>
                                <ENT>15-212</ENT>
                                <ENT>ns-592</ENT>
                                <ENT>61-163</ENT>
                                <ENT>10-282</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">530</ENT>
                                <ENT>2,3,6-trichlorophenol (4c)*</ENT>
                                <ENT>30</ENT>
                                <ENT>58-137</ENT>
                                <ENT/>
                                <ENT>56-180</ENT>
                                <ENT>51-153</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">531</ENT>
                                <ENT>2,4,5-trichlorophenol (4c)*</ENT>
                                <ENT>30</ENT>
                                <ENT>58-137</ENT>
                                <ENT/>
                                <ENT>56-180</ENT>
                                <ENT>51-153</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">321</ENT>
                                <ENT>2,4,6-trichlorophenol</ENT>
                                <ENT>57</ENT>
                                <ENT>59-205</ENT>
                                <ENT/>
                                <ENT>81-123</ENT>
                                <ENT>48-244</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">221</ENT>
                                <ENT>2,4,6-trichlorophenol-d2</ENT>
                                <ENT>47</ENT>
                                <ENT>43-183</ENT>
                                <ENT>21-363</ENT>
                                <ENT>69-144</ENT>
                                <ENT>34-226</ENT>
                            </ROW>
                            <TNOTE>
                                <SU>1</SU>
                                 Reference numbers beginning with 0, 1 or 5 indicate a pollutant quantified by the internal standard method; reference numbers beginning with 2 or 6 indicate a labeled compound quantified by the internal standard method; reference numbers beginning with 3 or 7 indicate a pollutant quantified by isotope dilution.
                            </TNOTE>
                            <TNOTE>* Measured by internal standard; specification derived from related compound.</TNOTE>
                            <TNOTE>ns = no specification; limit is outside the range that can be measured reliably.</TNOTE>
                        </GPOTABLE>
                        <GPH SPAN="2" DEEP="438">
                            <PRTPAGE P="381"/>
                            <GID>EC02JY92.057</GID>
                        </GPH>
                        <GPH SPAN="2" DEEP="470">
                            <PRTPAGE P="382"/>
                            <GID>EC02JY92.058</GID>
                        </GPH>
                        <GPH SPAN="2" DEEP="470">
                            <PRTPAGE P="383"/>
                            <GID>EC02JY92.059</GID>
                        </GPH>
                        <PRTPAGE P="384"/>
                        <HD SOURCE="HD1">Attachment 1 to Method 1625</HD>
                        <HD SOURCE="HD1">Introduction</HD>
                        <P>
                            To support measurement of several semivolatile pollutants, EPA has developed this attachment to EPA Method 1625B. 
                            <SU>1</SU>
                            <FTREF/>
                             The modifications listed in this attachment are approved only for monitoring wastestreams from the Centralized Waste Treatment Point Source Category (40 CFR part 437) and the Landfills Point Source Category (40 CFR part 445). EPA Method 1625B (the Method) employs sample extraction with methylene chloride followed by analysis of the extract using capillary column gas chromatography-mass spectrometry (GC/MS). This attachment addresses the addition of the semivolatile pollutants listed in Tables 1 and 2 to all applicable standard, stock, and spiking solutions utilized for the determination of semivolatile organic compounds by EPA Method 1625B.
                        </P>
                        <FTNT>
                            <P>
                                <SU>1</SU>
                                 EPA Method 1625 Revision B, Semivolatile Organic Compounds by Isotope Dilution GC/MS, 40 CFR part 136, appendix A.
                            </P>
                        </FTNT>
                        <HD SOURCE="HD1">1.0 EPA METHOD 1625 REVISION B MODIFICATION SUMMARY</HD>
                        <P>The additional semivolatile organic compounds listed in Tables 1 and 2 are added to all applicable calibration, spiking, and other solutions utilized in the determination of semivolatile compounds by EPA Method 1625. The instrument is to be calibrated with these compounds, and all procedures and quality control tests described in the Method must be performed.</P>
                        <HD SOURCE="HD1">2.0 SECTION MODIFICATIONS</HD>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>All section and figure numbers in this Attachment reference section and figure numbers in EPA Method 1625 Revision B unless noted otherwise. Sections not listed here remain unchanged.</P>
                        </NOTE>
                        <FP SOURCE="FP-2">Section 6.7 The stock standard solutions described in this section are modified such that the analytes in Tables 1 and 2 of this attachment are required in addition to those specified in the Method.</FP>
                        <FP SOURCE="FP-2">Section 6.8 The labeled compound spiking solution in this section is modified to include the labeled compounds listed in Tables 5 and 6 of this attachment.</FP>
                        <FP SOURCE="FP-2">Section 6.9 The secondary standard is modified to include the additional analytes listed in Tables 1 and 2 of this attachment.</FP>
                        <FP SOURCE="FP-2">Section 6.12 The solutions for obtaining authentic mass spectra are to include all additional analytes listed in Tables 1 and 2 of this attachment.</FP>
                        <FP SOURCE="FP-2">Section 6.13 The calibration solutions are modified to include the analytes listed in Tables 1 and 2 and the labeled compounds listed in Tables 5 and 6 of this attachment.</FP>
                        <FP SOURCE="FP-2">Section 6.14 The precision and recovery standard is modified to include the analytes listed in Tables 1 and 2 and the labeled compounds listed in Tables 5 and 6 of this attachment.</FP>
                        <FP SOURCE="FP-2">Section 6.15 The solutions containing the additional analytes listed in Tables 1 and 2 of this attachment are to be analyzed for stability.</FP>
                        <FP SOURCE="FP-2">Section 7.2.1 This section is modified to include the analytes listed in Tables 1 and 2 and the labeled compounds listed in Tables 5 and 6 of this attachment.</FP>
                        <FP SOURCE="FP-2">Section 7.4.5 This section is modified to include the analytes listed in Tables 1 and 2 and the labeled compounds listed in Tables 5 and 6 in the calibration.</FP>
                        <FP SOURCE="FP-2">Section 8.2 The initial precision and recovery (IPR) requirements are modified to include the analytes listed in Tables 1 and 2 and the labeled compounds listed in Tables 5 and 6 of this attachment. Additional IPR performance criteria are supplied in Table 7 of this attachment.</FP>
                        <FP SOURCE="FP-2">Section 8.3 The labeled compounds listed in Tables 3 and 4 of this attachment are to be included in the method performance tests. Additional method performance criteria are supplied in Table 7 of this attachment.</FP>
                        <FP SOURCE="FP-2">Section 8.5.2 The acceptance criteria for blanks includes the analytes listed in Tables 1 and 2 of this attachment.</FP>
                        <FP SOURCE="FP-2">Section 10.1.2 The labeled compound solution must include the labeled compounds listed in Tables 5 and 6 of this attachment.</FP>
                        <FP SOURCE="FP-2">Section 10.1.3 The precision and recovery standard must include the analytes listed in Tables 1 and 2 and the labeled compounds listed in Tables 5 and 6 of this attachment.</FP>
                        <FP SOURCE="FP-2">Section 12.5 Additional QC requirements for calibration verification are supplied in Table 7 of this attachment.</FP>
                        <FP SOURCE="FP-2">
                            Section 12.7 Additional QC requirements for ongoing precision and recovery are supplied in Table 7 of this attachment.
                            <PRTPAGE P="385"/>
                        </FP>
                        <GPOTABLE COLS="3" OPTS="L2" CDEF="s200,9,9">
                            <TTITLE>Table 1—Base/Neutral Extractable Compounds</TTITLE>
                            <BOXHD>
                                <CHED H="1">Compound</CHED>
                                <CHED H="1">Pollutant</CHED>
                                <CHED H="2">
                                    CAS
                                    <LI>Registry</LI>
                                </CHED>
                                <CHED H="2">EPA-EGD</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">
                                    acetophenone 
                                    <SU>1</SU>
                                </ENT>
                                <ENT>98-86-2</ENT>
                                <ENT>758</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    aniline 
                                    <SU>2</SU>
                                </ENT>
                                <ENT>62-53-3</ENT>
                                <ENT>757</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    -2,3-dichloroaniline 
                                    <SU>1</SU>
                                </ENT>
                                <ENT>608-27-5</ENT>
                                <ENT>578</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    -o-cresol 
                                    <SU>1</SU>
                                </ENT>
                                <ENT>95-48-7</ENT>
                                <ENT>771</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    pyridine 
                                    <SU>2</SU>
                                </ENT>
                                <ENT>110-86-1</ENT>
                                <ENT>1330</ENT>
                            </ROW>
                            <TNOTE>CAS = Chemical Abstracts Registry.</TNOTE>
                            <TNOTE>EGD = Effluent Guidelines Division.</TNOTE>
                            <TNOTE>
                                <SU>1</SU>
                                 Analysis of this pollutant is approved only for the Centralized Waste Treatment industry.
                            </TNOTE>
                            <TNOTE>
                                <SU>2</SU>
                                 Analysis of this pollutant is approved only for the Centralized Waste Treatment and Landfills industries.
                            </TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="3" OPTS="L2" CDEF="s200,9C,9C">
                            <TTITLE>Table 2—Acid Extractable Compounds</TTITLE>
                            <BOXHD>
                                <CHED H="1">Compound</CHED>
                                <CHED H="1">Pollutant</CHED>
                                <CHED H="2">
                                    CAS
                                    <LI>Registry</LI>
                                </CHED>
                                <CHED H="2">EPA-EGD</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">
                                    p-cresol 
                                    <SU>1</SU>
                                </ENT>
                                <ENT>106-44-5</ENT>
                                <ENT>1744</ENT>
                            </ROW>
                            <TNOTE>CAS = Chemical Abstracts Registry.</TNOTE>
                            <TNOTE>EGD = Effluent Guidelines Division.</TNOTE>
                            <TNOTE>
                                <SU>1</SU>
                                 Analysis of this pollutant is approved only for the Centralized Waste Treatment and Landfills industries.
                            </TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="6" OPTS="L2" CDEF="xs50,r50,12,12,12,12">
                            <TTITLE>
                                Table 3—Gas Chromatography 
                                <SU>1</SU>
                                 of Base/Neutral Extractable Compounds
                            </TTITLE>
                            <BOXHD>
                                <CHED H="1">EGD No.</CHED>
                                <CHED H="1">Compound</CHED>
                                <CHED H="1">
                                    Retention time 
                                    <SU>2</SU>
                                </CHED>
                                <CHED H="2">
                                    Mean
                                    <LI>(sec)</LI>
                                </CHED>
                                <CHED H="2">EGD Ref</CHED>
                                <CHED H="2">Relative</CHED>
                                <CHED H="1">
                                    Minimum
                                    <LI>
                                        level 
                                        <SU>3</SU>
                                    </LI>
                                    <LI>(µg/L)</LI>
                                </CHED>
                                <CHED H="1">EGD No.</CHED>
                                <CHED H="1">Compound</CHED>
                                <CHED H="1">
                                    Retention time 
                                    <SU>2</SU>
                                </CHED>
                                <CHED H="2">
                                    Mean
                                    <LI>(sec)</LI>
                                </CHED>
                                <CHED H="2">EGD Ref</CHED>
                                <CHED H="2">Relative</CHED>
                                <CHED H="1">
                                    Minimum level 
                                    <SU>3</SU>
                                    <LI>(µg/L)</LI>
                                </CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">758</ENT>
                                <ENT>
                                    acetophenone 
                                    <SU>4</SU>
                                </ENT>
                                <ENT>818</ENT>
                                <ENT>658</ENT>
                                <ENT>1.003-1.005</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">757</ENT>
                                <ENT>
                                    aniline 
                                    <SU>5</SU>
                                </ENT>
                                <ENT>694</ENT>
                                <ENT>657</ENT>
                                <ENT>0.994-1.023</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">578</ENT>
                                <ENT>
                                    2,3-dichloroaniline 
                                    <SU>4</SU>
                                </ENT>
                                <ENT>1160</ENT>
                                <ENT>164</ENT>
                                <ENT>1.003-1.007</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">771</ENT>
                                <ENT>
                                    o-cresol 
                                    <SU>4</SU>
                                </ENT>
                                <ENT>814</ENT>
                                <ENT>671</ENT>
                                <ENT>1.005-1.009</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1330</ENT>
                                <ENT>
                                    pyridine 
                                    <SU>5</SU>
                                </ENT>
                                <ENT>378</ENT>
                                <ENT>1230</ENT>
                                <ENT>1.005-1.011</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <TNOTE>EGD = Effluent Guidelines Division.</TNOTE>
                            <TNOTE>
                                <SU>1</SU>
                                 The data presented in this table were obtained under the chromatographic conditions given in the footnote to Table 3 of EPA Method 1625B.
                            </TNOTE>
                            <TNOTE>
                                <SU>2</SU>
                                 Retention times are approximate and are intended to be consistent with the retention times for the analytes in EPA Method 1625B.
                            </TNOTE>
                            <TNOTE>
                                <SU>3</SU>
                                 See the definition in footnote 2 to Table 3 of EPA Method 1625B.
                            </TNOTE>
                            <TNOTE>
                                <SU>4</SU>
                                 Analysis of this pollutant is approved only for the Centralized Waste Treatment industry.
                            </TNOTE>
                            <TNOTE>
                                <SU>5</SU>
                                 Analysis of this pollutant is approved only for the Centralized Waste Treatment and Landfills industries.
                            </TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="6" OPTS="L2" CDEF="xs50,r50,12,12,12,12">
                            <TTITLE>
                                Table 4—Gas Chromatography 
                                <SU>1</SU>
                                 of Acid Extractable Compounds
                            </TTITLE>
                            <BOXHD>
                                <CHED H="1">EGD No.</CHED>
                                <CHED H="1">Compound</CHED>
                                <CHED H="1">
                                    Retention time 
                                    <SU>2</SU>
                                </CHED>
                                <CHED H="2">
                                    Mean
                                    <LI>(sec)</LI>
                                </CHED>
                                <CHED H="2">EGD Ref</CHED>
                                <CHED H="2">Relative</CHED>
                                <CHED H="1">
                                    Minimum
                                    <LI>level</LI>
                                    <LI>
                                        (µ/L) 
                                        <SU>3</SU>
                                    </LI>
                                </CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">1744</ENT>
                                <ENT>
                                    p-cresol 
                                    <SU>4</SU>
                                </ENT>
                                <ENT>834</ENT>
                                <ENT>1644</ENT>
                                <ENT>1.004-1.008</ENT>
                                <ENT>20</ENT>
                            </ROW>
                            <TNOTE>EGD = Effluent Guidelines Division.</TNOTE>
                            <TNOTE>
                                <SU>1</SU>
                                 The data presented in this table were obtained under the chromatographic conditions given in the footnote to Table 4 of EPA Method 1625B.
                            </TNOTE>
                            <TNOTE>
                                <SU>2</SU>
                                 Retention times are approximate and are intended to be consistent with the retention times for the analytes in EPA Method 1625B.
                            </TNOTE>
                            <TNOTE>
                                <SU>3</SU>
                                 See the definition in footnote 2 to Table 4 of EPA Method 1625B.
                            </TNOTE>
                            <TNOTE>
                                <SU>4</SU>
                                 Analysis of this pollutant is approved only for the Centralized Waste Treatment and Landfills industries.
                            </TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="3" OPTS="L2" CDEF="s200,xls40,10">
                            <TTITLE>Table 5—Base/Neutral Extractable Compound Characteristic m/z's</TTITLE>
                            <BOXHD>
                                <CHED H="1">Compound</CHED>
                                <CHED H="1">Labeled Analog</CHED>
                                <CHED H="1">
                                    Primary
                                    <LI>
                                        m/z 
                                        <SU>1</SU>
                                    </LI>
                                </CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">
                                    acetophenone 
                                    <SU>2</SU>
                                </ENT>
                                <ENT>
                                    d
                                    <E T="52">5</E>
                                </ENT>
                                <ENT>105/110</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    aniline 
                                    <SU>3</SU>
                                </ENT>
                                <ENT>
                                    d
                                    <E T="52">7</E>
                                </ENT>
                                <ENT>93/100</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    o-cresol 
                                    <SU>2</SU>
                                </ENT>
                                <ENT>
                                    d
                                    <E T="52">7</E>
                                </ENT>
                                <ENT>108/116</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    2,3-dichloroaniline 
                                    <SU>2</SU>
                                </ENT>
                                <ENT>n/a</ENT>
                                <ENT>161</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    pyridine 
                                    <SU>3</SU>
                                </ENT>
                                <ENT>
                                    d
                                    <E T="52">5</E>
                                </ENT>
                                <ENT>79/84</ENT>
                            </ROW>
                            <TNOTE>
                                m/z = mass to charge ratio.
                                <PRTPAGE P="386"/>
                            </TNOTE>
                            <TNOTE>
                                <SU>1</SU>
                                 Native/labeled.
                            </TNOTE>
                            <TNOTE>
                                <SU>2</SU>
                                 Analysis of this pollutant is approved only for the Centralized Waste Treatment industry.
                            </TNOTE>
                            <TNOTE>
                                <SU>3</SU>
                                 Analysis of this pollutant is approved only for the Centralized Waste Treatment and Landfills industries.
                            </TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="3" OPTS="L2" CDEF="s200,xls40,10">
                            <TTITLE>Table 6—Acid Extractable Compound Characteristic m/z's</TTITLE>
                            <BOXHD>
                                <CHED H="1">Compound</CHED>
                                <CHED H="1">Labeled Analog</CHED>
                                <CHED H="1">
                                    Primary
                                    <LI>
                                        m/z 
                                        <SU>1</SU>
                                    </LI>
                                </CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">
                                    p-cresol 
                                    <SU>2</SU>
                                </ENT>
                                <ENT>
                                    d
                                    <E T="52">7</E>
                                </ENT>
                                <ENT>108/116</ENT>
                            </ROW>
                            <TNOTE>m/z = mass to charge ratio.</TNOTE>
                            <TNOTE>
                                <SU>1</SU>
                                 Native/labeled.
                            </TNOTE>
                            <TNOTE>
                                <SU>2</SU>
                                 Analysis of this pollutant is approved only for the Centralized Waste Treatment and Landfills industries.
                            </TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="7" OPTS="L2" CDEF="xs50,r50,10,10,10,10,10">
                            <TTITLE>Table 7—Acceptance Criteria for Performance Tests</TTITLE>
                            <BOXHD>
                                <CHED H="1">EGD No.</CHED>
                                <CHED H="1">Compound</CHED>
                                <CHED H="1">Acceptance criteria</CHED>
                                <CHED H="2">
                                    Initial precision and accuracy section 8.2
                                    <LI>(µg/L)</LI>
                                </CHED>
                                <CHED H="3">
                                    s
                                    <LI>(µg/L)</LI>
                                </CHED>
                                <CHED H="3">X</CHED>
                                <CHED H="2">
                                    Labeled compound recovery sec. 8.3 and 14.2 P
                                    <LI>(percent)</LI>
                                </CHED>
                                <CHED H="1">
                                    Calibration verification sec. 12.5
                                    <LI>µg/mL)</LI>
                                </CHED>
                                <CHED H="1">
                                    On-going accuracy sec. 12.7 R
                                    <LI>(µg/L)</LI>
                                </CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">758</ENT>
                                <ENT>
                                    acetophenone 
                                    <SU>1</SU>
                                </ENT>
                                <ENT>34</ENT>
                                <ENT>44-167</ENT>
                                <ENT/>
                                <ENT>85-115</ENT>
                                <ENT>45-162</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">658</ENT>
                                <ENT>
                                    acetophenone-d 
                                    <E T="52">5</E>
                                     
                                    <SU>1</SU>
                                </ENT>
                                <ENT>51</ENT>
                                <ENT>23-254</ENT>
                                <ENT>45-162</ENT>
                                <ENT>85-115</ENT>
                                <ENT>22-264</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">757</ENT>
                                <ENT>
                                    aniline 
                                    <SU>2</SU>
                                </ENT>
                                <ENT>32</ENT>
                                <ENT>30-171</ENT>
                                <ENT/>
                                <ENT>85-115</ENT>
                                <ENT>33-154</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">657</ENT>
                                <ENT>
                                    aniline-d 
                                    <E T="52">7</E>
                                     
                                    <SU>2</SU>
                                </ENT>
                                <ENT>71</ENT>
                                <ENT>15-278</ENT>
                                <ENT>33-154</ENT>
                                <ENT>85-115</ENT>
                                <ENT>12-344</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">771</ENT>
                                <ENT>
                                    o-cresol 
                                    <SU>1</SU>
                                </ENT>
                                <ENT>40</ENT>
                                <ENT>31-226</ENT>
                                <ENT/>
                                <ENT>85-115</ENT>
                                <ENT>35-196</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">671</ENT>
                                <ENT>
                                    o-cresol-d 
                                    <E T="52">7</E>
                                     
                                    <SU>1</SU>
                                </ENT>
                                <ENT>23</ENT>
                                <ENT>30-146</ENT>
                                <ENT>35-196</ENT>
                                <ENT>85-115</ENT>
                                <ENT>31-142</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1744</ENT>
                                <ENT>
                                    p-cresol 
                                    <SU>2</SU>
                                </ENT>
                                <ENT>59</ENT>
                                <ENT>54-140</ENT>
                                <ENT/>
                                <ENT>85-115</ENT>
                                <ENT>37-203</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1644</ENT>
                                <ENT>
                                    p-cresol-d
                                    <E T="52">7</E>
                                     
                                    <SU>2</SU>
                                </ENT>
                                <ENT>22</ENT>
                                <ENT>11-618</ENT>
                                <ENT>37-203</ENT>
                                <ENT>85-115</ENT>
                                <ENT>16-415</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">578</ENT>
                                <ENT>
                                    2,3-dichloroaniline 
                                    <SU>1</SU>
                                </ENT>
                                <ENT>13</ENT>
                                <ENT>40-160</ENT>
                                <ENT/>
                                <ENT>85-115</ENT>
                                <ENT>44-144</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1330</ENT>
                                <ENT>
                                    pyridine 
                                    <SU>2</SU>
                                </ENT>
                                <ENT>28</ENT>
                                <ENT>10-421</ENT>
                                <ENT/>
                                <ENT>83-117</ENT>
                                <ENT>18-238</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">1230</ENT>
                                <ENT>
                                    pyridine-d 
                                    <E T="52">5</E>
                                     
                                    <SU>2</SU>
                                </ENT>
                                <ENT>ns</ENT>
                                <ENT>7-392</ENT>
                                <ENT>19-238</ENT>
                                <ENT>85-115</ENT>
                                <ENT>4-621</ENT>
                            </ROW>
                            <TNOTE>s = Standard deviation of four recovery measurements.</TNOTE>
                            <TNOTE>X = Average recovery for four recovery measurements.</TNOTE>
                            <TNOTE>EGD = Effluent Guidelines Division.</TNOTE>
                            <TNOTE>ns = no specification; limit is outside the range that can be measured reliably.</TNOTE>
                            <TNOTE>
                                <SU>1</SU>
                                 Analysis of this pollutant is approved only for the Centralized Waste Treatment industry.
                            </TNOTE>
                            <TNOTE>
                                <SU>2</SU>
                                 Analysis of this pollutant is approved only for the Centralized Waste Treatment and Landfills industries.
                            </TNOTE>
                        </GPOTABLE>
                        <CITA>[49 FR 43261, Oct. 26, 1984; 50 FR 692, 695, Jan. 4, 1985, as amended at 51 FR 23702, June 30, 1986; 62 FR 48405, Sept. 15, 1997; 65 FR 3044, Jan. 19, 2000; 65 FR 81295, 81298, Dec. 22, 2000; 82 FR 40875, Aug. 28, 2017]</CITA>
                    </APPENDIX>
                    <APPENDIX>
                        <EAR>Pt. 136, App. B</EAR>
                        <HD SOURCE="HED">Appendix B to Part 136—Definition and Procedure for the Determination of the Method Detection Limit—Revision 2</HD>
                        <HD SOURCE="HD2">Definition</HD>
                        <P>The method detection limit (MDL) is defined as the minimum measured concentration of a substance that can be reported with 99% confidence that the measured concentration is distinguishable from method blank results.</P>
                        <HD SOURCE="HD3">I. Scope and Application</HD>
                        <P>(1) The MDL procedure is designed to be a straightforward technique for estimation of the detection limit for a broad variety of physical and chemical methods. The procedure requires a complete, specific, and well-defined analytical method. It is essential that all sample processing steps used by the laboratory be included in the determination of the method detection limit.</P>
                        <P>
                            (2) The MDL procedure is 
                            <E T="03">not</E>
                             applicable to methods that do not produce results with a continuous distribution, such as, but not limited to, methods for whole effluent toxicity, presence/absence methods, and microbiological methods that involve counting colonies. The MDL procedure also is 
                            <E T="03">not</E>
                             applicable to measurements such as, but not limited to, biochemical oxygen demand, color, pH, specific conductance, many titration methods, and any method where low-level spiked samples cannot be prepared. Except as described in the addendum, for the purposes of this procedure, “spiked samples” are prepared from a clean reference matrix, such as reagent water, spiked with a known and consistent quantity of the analyte. MDL determinations using spiked samples may not be appropriate for all gravimetric methods (e.g., residue or total suspended solids), but an MDL based on method blanks can be determined in such instances.
                            <PRTPAGE P="387"/>
                        </P>
                        <HD SOURCE="HD3">II. Procedure</HD>
                        <P>(1) Estimate the initial MDL using one or more of the following:</P>
                        <P>(a) The mean determined concentration plus three times the standard deviation of a set of method blanks.</P>
                        <P>(b) The concentration value that corresponds to an instrument signal-to-noise ratio in the range of 3 to 5.</P>
                        <P>(c) The concentration equivalent to three times the standard deviation of replicate instrumental measurements of spiked blanks.</P>
                        <P>
                            (d) That region of the calibration where there is a significant change in sensitivity, 
                            <E T="03">i.e.,</E>
                             a break in the slope of the calibration.
                        </P>
                        <P>(e) Instrumental limitations.</P>
                        <P>(f) Previously determined MDL.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>It is recognized that the experience of the analyst is important to this process. However, the analyst should include some or all of the above considerations in the initial estimate of the MDL.</P>
                        </NOTE>
                        <P>(2) Determine the initial MDL.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>The Initial MDL is used when the laboratory does not have adequate data to perform the Ongoing Annual Verification specified in Section (4), typically when a new method is implemented or if a method was rarely used in the last 24 months.</P>
                        </NOTE>
                        <P>(a) Select a spiking level, typically 2—10 times the estimated MDL in Section 1. Spiking levels in excess of 10 times the estimated detection limit may be required for analytes with very poor recovery (e.g., for an analyte with 10% recovery, spiked at 100 micrograms/L, with mean recovery of 10 micrograms/L; the calculated MDL may be around 3 micrograms/L. Therefore, in this example, the spiking level would be 33 times the MDL, but spiking lower may result in no recovery at all).</P>
                        <P>(b) Process a minimum of seven spiked samples and seven method blank samples through all steps of the method. The samples used for the MDL must be prepared in at least three batches on three separate calendar dates and analyzed on three separate calendar dates. (Preparation and analysis may be on the same day.) Existing data may be used, if compliant with the requirements for at least three batches, and generated within the last twenty four months. The most recent available data for method blanks and spiked samples must be used. Statistical outlier removal procedures should not be used to remove data for the initial MDL determination, since the total number of observations is small and the purpose of the MDL procedure is to capture routine method variability. However, documented instances of gross failures (e.g., instrument malfunctions, mislabeled samples, cracked vials) may be excluded from the calculations, provided that at least seven spiked samples and seven method blanks are available. (The rationale for removal of specific outliers must be documented and maintained on file with the results of the MDL determination.)</P>
                        <P>(i) If there are multiple instruments that will be assigned the same MDL, then the sample analyses must be distributed across all of the instruments.</P>
                        <P>(ii) A minimum of two spiked samples and two method blank samples prepared and analyzed on different calendar dates is required for each instrument. Each analytical batch may contain one spiked sample and one method blank sample run together. A spiked sample and a method blank sample may be analyzed in the same batch, but are not required to be.</P>
                        <P>(iii) The same prepared extract may be analyzed on multiple instruments so long as the minimum requirement of seven preparations in at least three separate batches is maintained.</P>
                        <P>(c) Evaluate the spiking level: If any result for any individual analyte from the spiked samples does not meet the method qualitative identification criteria or does not provide a numerical result greater than zero, then repeat the spiked samples at a higher concentration. (Qualitative identification criteria are a set of rules or guidelines for establishing the identification or presence of an analyte using a measurement system. Qualitative identification does not ensure that quantitative results for the analyte can be obtained.)</P>
                        <P>(d) Make all computations as specified in the analytical method and express the final results in the method-specified reporting units.</P>
                        <P>(i) Calculate the sample standard deviation (S) of the replicate spiked sample measurements and the sample standard deviation of the replicate method blank measurements from all instruments to which the MDL will be applied.</P>
                        <P>
                            (ii) Compute the MDL
                            <E T="52">s</E>
                             (the MDL based on spiked samples) as follows:
                        </P>
                        <FP SOURCE="FP-2">
                            <E T="03">MDL</E>
                            <E T="54">S</E>
                             = 
                            <E T="03">t</E>
                            <E T="52">(</E>
                            <E T="52">n −1, 1−</E>
                            <E T="7334">α</E>
                             
                            <E T="52">= 0.99)</E>
                            <E T="03">S</E>
                            <E T="54">s</E>
                        </FP>
                        <FP SOURCE="FP-2">Where:</FP>
                        <FP SOURCE="FP-2">
                            MDL
                            <E T="52">s</E>
                             = the method detection limit based on spiked samples
                        </FP>
                        <FP SOURCE="FP-2">
                            <E T="03">t</E>
                            <E T="52">(n-1, 1−</E>
                            <E T="7334">α</E>
                             
                            <E T="52">= 0.99)</E>
                             = the Student's t-value appropriate for a single-tailed 99th percentile t statistic and a standard deviation estimate with n-1 degrees of freedom. See Addendum Table 1.
                        </FP>
                        <FP SOURCE="FP-2">
                            S
                            <E T="52">s</E>
                             = sample standard deviation of the replicate spiked sample analyses.
                        </FP>
                        <P>
                            (iii) Compute the MDL
                            <E T="52">b</E>
                             (the MDL based on method blanks) as follows:
                        </P>
                        <P>
                            (A) If none of the method blanks give numerical results for an individual analyte, the MDL
                            <E T="52">b</E>
                             does not apply. A numerical result includes both positive and negative results, including results below the current MDL, but not results of “ND” (not detected) commonly 
                            <PRTPAGE P="388"/>
                            observed when a peak is not present in chromatographic analysis.
                        </P>
                        <P>
                            (B) If some (but not all) of the method blanks for an individual analyte give numerical results, set the MDL
                            <E T="52">b</E>
                             equal to the highest method blank result. If more than 100 method blanks are available, set MDL
                            <E T="52">b</E>
                             to the level that is no less than the 99th percentile of the method blank results. For “n” method blanks where n ≥ 100, sort the method blanks in rank order. The (n * 0.99) ranked method blank result (round to the nearest whole number) is the MDL
                            <E T="52">b</E>
                            . For example, to find MDL
                            <E T="52">b</E>
                             from a set of 164 method blanks where the highest ranked method blank results are . . . 1.5, 1.7, 1.9, 5.0, and 10, then 164 × 0.99 = 162.36 which rounds to the 162nd method blank result. Therefore, MDL
                            <E T="52">b</E>
                             is 1.9 for n = 164 (10 is the 164th result, 5.0 is the 163rd result, and 1.9 is the 162nd result). Alternatively, you may use spreadsheet algorithms to calculate the 99th percentile to interpolate between the ranks more precisely.
                        </P>
                        <P>
                            (C) If all of the method blanks for an individual analyte give numerical results, then calculate the MDL
                            <E T="52">b</E>
                             as:
                        </P>
                        <FP SOURCE="FP-2">
                            <E T="03">MDL</E>
                            <E T="52">b</E>
                             = 
                            <E T="7503">X</E>
                             + 
                            <E T="03">t</E>
                            <E T="54">n</E>
                            <E T="52">−1,1−</E>
                            <E T="7334">α</E>
                             
                            <E T="52">= (0.99)</E>
                            <E T="03">S</E>
                            <E T="54">b</E>
                        </FP>
                        <FP SOURCE="FP-2">Where:</FP>
                        <FP SOURCE="FP-2">
                            MDL
                            <E T="52">b</E>
                             = the MDL based on method blanks
                        </FP>
                        <FP SOURCE="FP-2">
                            <E T="7503">X</E>
                             = mean of the method blank results (use zero in place of the mean if the mean is negative)
                        </FP>
                        <FP SOURCE="FP-2">
                            <E T="03">t</E>
                            <E T="52">(n−1, 1</E>
                            <E T="7334">α</E>
                             
                            <E T="52">= 0.99)</E>
                             = the Student's t-value appropriate for the single-tailed 99th percentile t statistic and a standard deviation estimate with n−1 degrees of freedom. See Addendum Table 1.
                        </FP>
                        <FP SOURCE="FP-1">
                            S
                            <E T="52">b</E>
                             = sample standard deviation of the replicate method blank sample analyses.
                        </FP>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>
                                If 100 or more method blanks are available, as an option, MDL
                                <E T="52">b</E>
                                 may be set to the concentration that is greater than or equal to the 99th percentile of the method blank results, as described in Section (2)(d)(iii)(B).
                            </P>
                        </NOTE>
                        <P>
                            (e) Select the greater of MDL
                            <E T="52">s</E>
                             or MDL
                            <E T="52">b</E>
                             as the initial MDL.
                        </P>
                        <P>(3) Ongoing Data Collection.</P>
                        <P>(a) During any quarter in which samples are being analyzed, prepare and analyze a minimum of two spiked samples on each instrument, in separate batches, using the same spiking concentration used in Section 2. If any analytes are repeatedly not detected in the quarterly spiked sample analyses, or do not meet the qualitative identification criteria of the method (see section 2(c) of this procedure), then this is an indication that the spiking level is not high enough and should be adjusted upward. Note that it is not necessary to analyze additional method blanks together with the spiked samples, the method blank population should include all of the routine method blanks analyzed with each batch during the course of sample analysis.</P>
                        <P>(b) Ensure that at least seven spiked samples and seven method blanks are completed for the annual verification. If only one instrument is in use, a minimum of seven spikes are still required, but they may be drawn from the last two years of data collection.</P>
                        <P>(c) At least once per year, re-evaluate the spiking level.</P>
                        <P>(i) If more than 5% of the spiked samples do not return positive numerical results that meet all method qualitative identification criteria, then the spiking level must be increased and the initial MDL re-determined following the procedure in section 2.</P>
                        <P>(ii) [Reserved]</P>
                        <P>(d) If the method is altered in a way that can be reasonably expected to change its sensitivity, then re-determine the initial MDL according to section 2, and the restart the ongoing data collection.</P>
                        <P>
                            (e) If a new instrument is added to a group of instruments whose data are being pooled to create a single MDL, analyze a minimum of two spiked replicates and two method blank replicates on the new instrument. If both method blank results are below the existing MDL, then the existing MDL
                            <E T="52">b</E>
                             is validated. Combine the new spiked sample results to the existing spiked sample results and recalculate the MDL
                            <E T="52">s</E>
                             as in Section 4. If the recalculated MDL
                            <E T="52">s</E>
                             does not vary by more than the factor specified in section 4(f) of this procedure, then the existing MDL
                            <E T="52">s</E>
                             is validated. If either of these two conditions is not met, then calculate a new MDL following the instructions in section 2.
                        </P>
                        <P>(4) Ongoing Annual Verification.</P>
                        <P>
                            (a) At least once every thirteen months, re-calculate MDL
                            <E T="52">s</E>
                             and MDL
                            <E T="52">b</E>
                             from the collected spiked samples and method blank results using the equations in section 2.
                        </P>
                        <P>(b) Include data generated within the last twenty four months, but only data with the same spiking level. Only documented instances of gross failures (e.g., instrument malfunctions, mislabeled samples, cracked vials) may be excluded from the calculations. (The rationale for removal of specific outliers must be documented and maintained on file with the results of the MDL determination.) If the laboratory believes the sensitivity of the method has changed significantly, then the most recent data available may be used, maintaining compliance with the requirement for at least seven replicates in three separate batches on three separate days (see section 2b).</P>
                        <P>(c) Include the initial MDL spiked samples, if the data were generated within twenty four months.</P>
                        <P>
                            (d) Only use data associated with acceptable calibrations and batch QC. Include all routine data, with the exception of batches that are rejected and the associated samples reanalyzed. If the method has been altered in a way that can be reasonably expected to 
                            <PRTPAGE P="389"/>
                            change its sensitivity, then use only data collected after the change.
                        </P>
                        <P>
                            (e) Ideally, use all method blank results from the last 24 months for the MDL
                            <E T="52">b</E>
                             calculation. The laboratory has the option to use only the last six months of method blank data or the fifty most recent method blanks, whichever criteria yields the greater number of method blanks.
                        </P>
                        <P>
                            (f) The verified MDL is the greater of the MDL
                            <E T="52">s</E>
                             or MDL
                            <E T="52">b</E>
                            . If the verified MDL is within 0.5 to 2.0 times the existing MDL, and fewer than 3% of the method blank results (for the individual analyte) have numerical results above the existing MDL, then the existing MDL may optionally be left unchanged. Otherwise, adjust the MDL to the new verification MDL. (The range of 0.5 to 2.0 approximates the 95th percentile confidence interval for the initial MDL determination with six degrees of freedom.)
                        </P>
                        <HD SOURCE="HD1">Addendum to Section II: Determination of the MDL for a Specific Matrix</HD>
                        <P>The MDL may be determined in a specific sample matrix as well as in reagent water.</P>
                        <P>(1) Analyze the sample matrix to determine the native (background) concentration of the analyte(s) of interest.</P>
                        <P>(2) If the response for the native concentration is at a signal-to-noise ratio of approximately 5-20, determine the matrix-specific MDL according to Section 2 but without spiking additional analyte.</P>
                        <P>
                            (3) Calculate MDL
                            <E T="52">b</E>
                             using the method blanks, not the sample matrix.
                        </P>
                        <P>(4) If the signal-to-noise ratio is less than 5, then the analyte(s) should be spiked into the sample matrix to obtain a concentration that will give results with a signal-to-noise ratio of approximately 10-20.</P>
                        <P>(5) If the analytes(s) of interest have signal-to-noise ratio(s) greater than approximately 20, then the resulting MDL is likely to be biased high.</P>
                        <GPOTABLE COLS="3" OPTS="L2" CDEF="s100,12,12">
                            <TTITLE>
                                Table 1—Single-Tailed 99
                                <E T="01">th</E>
                                 Percentile 
                                <E T="01">t</E>
                                 Statistic
                            </TTITLE>
                            <BOXHD>
                                <CHED H="1">Number of replicates</CHED>
                                <CHED H="1">
                                    Degrees of freedom
                                    <LI>(n−1)</LI>
                                </CHED>
                                <CHED H="1">
                                    t 
                                    <E T="52">(n−1, 0.99)</E>
                                </CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">7</ENT>
                                <ENT>6</ENT>
                                <ENT>3.143</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">8</ENT>
                                <ENT>7</ENT>
                                <ENT>2.998</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">9</ENT>
                                <ENT>8</ENT>
                                <ENT>2.896</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">10</ENT>
                                <ENT>9</ENT>
                                <ENT>2.821</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">11</ENT>
                                <ENT>10</ENT>
                                <ENT>2.764</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">16</ENT>
                                <ENT>15</ENT>
                                <ENT>2.602</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">21</ENT>
                                <ENT>20</ENT>
                                <ENT>2.528</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">26</ENT>
                                <ENT>25</ENT>
                                <ENT>2.485</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">31</ENT>
                                <ENT>30</ENT>
                                <ENT>2.457</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">32</ENT>
                                <ENT>31</ENT>
                                <ENT>2.453</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">48</ENT>
                                <ENT>47</ENT>
                                <ENT>2.408</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">50</ENT>
                                <ENT>49</ENT>
                                <ENT>2.405</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">61</ENT>
                                <ENT>60</ENT>
                                <ENT>2.390</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">64</ENT>
                                <ENT>63</ENT>
                                <ENT>2.387</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">80</ENT>
                                <ENT>79</ENT>
                                <ENT>2.374</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">96</ENT>
                                <ENT>95</ENT>
                                <ENT>2.366</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">100</ENT>
                                <ENT>99</ENT>
                                <ENT>2.365</ENT>
                            </ROW>
                        </GPOTABLE>
                        <HD SOURCE="HD3">III. Documentation</HD>
                        <P>The analytical method used must be specifically identified by number or title and the MDL for each analyte expressed in the appropriate method reporting units. Data and calculations used to establish the MDL must be able to be reconstructed upon request. The sample matrix used to determine the MDL must also be identified with MDL value. Document the mean spiked and recovered analyte levels with the MDL. The rationale for removal of outlier results, if any, must be documented and maintained on file with the results of the MDL determination.</P>
                        <CITA>[82 FR 40939, Aug. 28, 2017]</CITA>
                    </APPENDIX>
                    <APPENDIX>
                        <EAR>Pt. 136, App. C</EAR>
                        <HD SOURCE="HED">Appendix C to Part 136—Determination of Metals and Trace Elements in Water and Wastes by Inductively Coupled Plasma-Atomic Emission Spectrometry Method 200.7</HD>
                        <HD SOURCE="HD2">1.0 Scope and Application</HD>
                        <P>
                            1.1 Inductively coupled plasma-atomic emission spectrometry (ICP-AES) is used to determine metals and some nonmetals in solution. This method is a consolidation of existing methods for water, wastewater, and solid wastes.
                            <E T="51">1-4</E>
                             (For analysis of petroleum products see References 5 and 6, Section 16.0). This method is applicable to the following analytes:
                            <PRTPAGE P="390"/>
                        </P>
                        <GPOTABLE COLS="2" OPTS="L2" CDEF="s30,18">
                            <BOXHD>
                                <CHED H="1">Analyte</CHED>
                                <CHED H="1">
                                    Chemical abstract services registry
                                    <LI>number (CASRN)</LI>
                                </CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">Aluminum (Al)</ENT>
                                <ENT>7429-90-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Antimony (Sb)</ENT>
                                <ENT>7440-36-0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Arsenic (As)</ENT>
                                <ENT>7440-38-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Barium (Ba)</ENT>
                                <ENT>7440-39-3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Beryllium (Be)</ENT>
                                <ENT>7440-41-7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Boron (B)</ENT>
                                <ENT>7440-42-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Cadmium (Cd)</ENT>
                                <ENT>7440-43-9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Calcium (Ca)</ENT>
                                <ENT>7440-70-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Cerium 
                                    <SU>a</SU>
                                     (Cr)
                                </ENT>
                                <ENT>7440-45-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chromium (Cr)</ENT>
                                <ENT>7440-47-3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Cobalt (Co)</ENT>
                                <ENT>7440-48-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Copper (Cu)</ENT>
                                <ENT>7440-50-8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Iron (Fe)</ENT>
                                <ENT>7439-89-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Lead (Pb)</ENT>
                                <ENT>7439-92-1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Lithium (Li)</ENT>
                                <ENT>7439-93-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Magnesium (Mg)</ENT>
                                <ENT>7439-95-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Manganese (Mn)</ENT>
                                <ENT>7439-96-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Mercury (Hg)</ENT>
                                <ENT>7439-97-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Molybdenum (Mo)</ENT>
                                <ENT>7439-98-7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Nickel (Ni)</ENT>
                                <ENT>7440-02-0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Phosphorus (P)</ENT>
                                <ENT>7723-14-0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Potassium (K)</ENT>
                                <ENT>7440-09-7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Selenium (Se)</ENT>
                                <ENT>7782-49-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Silica 
                                    <SU>b</SU>
                                     (Si0
                                    <E T="52">2</E>
                                    )
                                </ENT>
                                <ENT>7631-86-9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Silver (Ag)</ENT>
                                <ENT>7440-22-4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Sodium (Na)</ENT>
                                <ENT>7440-23-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Strontium (Sr)</ENT>
                                <ENT>7440-24-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Thallium (Tl)</ENT>
                                <ENT>7440-28-0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Tin (Sn)</ENT>
                                <ENT>7440-31-5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Titanium (Ti)</ENT>
                                <ENT>7440-32-6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Vanadium (V)</ENT>
                                <ENT>7440-62-2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Zinc (Zn)</ENT>
                                <ENT>7440-66-6</ENT>
                            </ROW>
                            <TNOTE>
                                <SU>a</SU>
                                 Cerium has been included as method analyte for correction of potential interelement spectral interference.
                            </TNOTE>
                            <TNOTE>
                                <SU>b</SU>
                                 This method is 
                                <E T="03">not</E>
                                 suitable for the determination of silica in solids.
                            </TNOTE>
                        </GPOTABLE>
                        <P>
                            1.2 For reference where this method is approved for use in compliance monitoring programs [e.g., Clean Water Act (NPDES) or Safe Drinking Water Act (SDWA)] consult both the appropriate sections of the Code of Federal Regulation (40 CFR Part 136 Table 1B for NPDES, and Part 141 § 141.23 for drinking water), and the latest 
                            <E T="04">Federal Register</E>
                             announcements.
                        </P>
                        <P>1.3 ICP-AES can be used to determine dissolved analytes in aqueous samples after suitable filtration and acid preservation. To reduce potential interferences, dissolved solids should be &lt;0.2% (w/v) (Section 4.2).</P>
                        <P>1.4 With the exception of silver, where this method is approved for the determination of certain metal and metalloid contaminants in drinking water, samples may be analyzed directly by pneumatic nebulization without acid digestion if the sample has been properly preserved with acid and has turbidity of &lt;1 NTU at the time of analysis. This total recoverable determination procedure is referred to as “direct analysis”. However, in the determination of some primary drinking water metal contaminants, preconcentration of the sample may be required prior to analysis in order to meet drinking water acceptance performance criteria (Sections 11.2.2 through 11.2.7).</P>
                        <P>1.5 For the determination of total recoverable analytes in aqueous and solid samples a digestion/extraction is required prior to analysis when the elements are not in solution (e.g., soils, sludges, sediments and aqueous samples that may contain particulate and suspended solids). Aqueous samples containing suspended or particulate material 1% (w/v) should be extracted as a solid type sample.</P>
                        <P>1.6 When determining boron and silica in aqueous samples, only plastic, PTFE or quartz labware should be used from time of sample collection to completion of analysis. For accurate determination of boron in solid samples only quartz or PTFE beakers should be used during acid extraction with immediate transfer of an extract aliquot to a plastic centrifuge tube following dilution of the extract to volume. When possible, borosilicate glass should be avoided to prevent contamination of these analytes.</P>
                        <P>1.7 Silver is only slightly soluble in the presence of chloride unless there is a sufficient chloride concentration to form the soluble chloride complex. Therefore, low recoveries of silver may occur in samples, fortified sample matrices and even fortified blanks if determined as a dissolved analyte or by “direct analysis” where the sample has not been processed using the total recoverable mixed acid digestion. For this reason it is recommended that samples be digested prior to the determination of silver. The total recoverable sample digestion procedure given in this method is suitable for the determination of silver in aqueous samples containing concentrations up to 0.1 mg/L. For the analysis of wastewater samples containing higher concentrations of silver, succeeding smaller volume, well mixed aliquots should be prepared until the analysis solution contains &lt;0.1 mg/L silver. The extraction of solid samples containing concentrations of silver &gt;50 mg/kg should be treated in a similar manner. Also, the extraction of tin from solid samples should be prepared again using aliquots &lt;1 g when determined sample concentrations exceed 1%.</P>
                        <P>1.8 The total recoverable sample digestion procedure given in this method will solubilize and hold in solution only minimal concentrations of barium in the presence of free sulfate. For the analysis of barium in samples having varying and unknown concentrations of sulfate, analysis should be completed as soon as possible after sample preparation.</P>
                        <P>
                            1.9 The total recoverable sample digestion procedure given in this method is not suitable for the determination of volatile organo-mercury compounds. However, if digestion is not required (turbidity &lt;1 NTU), the combined concentrations of inorganic and organo-mercury in solution can be determined by “direct analysis” pneumatic nebulization provided the sample solution is adjusted to contain the same mixed acid 
                            <PRTPAGE P="391"/>
                            (HNO
                            <E T="52">3</E>
                             + HCl) matrix as the total recoverable calibration standards and blank solutions.
                        </P>
                        <P>
                            1.10 Detection limits and linear ranges for the elements will vary with the wavelength selected, the spectrometer, and the matrices. Table 1 provides estimated instrument detection limits for the listed wavelengths.
                            <SU>7</SU>
                             However, actual method detection limits and linear working ranges will be dependent on the sample matrix, instrumentation, and selected operating conditions.
                        </P>
                        <P>1.11 Users of the method data should state the data-quality objectives prior to analysis. Users of the method must document and have on file the required initial demonstration performance data described in Section 9.2 prior to using the method for analysis.</P>
                        <HD SOURCE="HD2">2.0 Summary of Method</HD>
                        <P>2.1 An aliquot of a well mixed, homogeneous aqueous or solid sample is accurately weighed or measured for sample processing. For total recoverable analysis of a solid or an aqueous sample containing undissolved material, analytes are first solubilized by gentle refluxing with nitric and hydrochloric acids. After cooling, the sample is made up to volume, is mixed and centrifuged or allowed to settle overnight prior to analysis. For the determination of dissolved analytes in a filtered aqueous sample aliquot, or for the “direct analysis” total recoverable determination of analytes in drinking water where sample turbidity is &lt;1 NTU, the sample is made ready for analysis by the appropriate addition of nitric acid, and then diluted to a predetermined volume and mixed before analysis.</P>
                        <P>2.2 The analysis described in this method involves multielemental determinations by ICP-AES using sequential or simultaneous instruments. The instruments measure characteristic atomic-line emission spectra by optical spectrometry. Samples are nebulized and the resulting aerosol is transported to the plasma torch. Element specific emission spectra are produced by a radio-frequency inductively coupled plasma. The spectra are dispersed by a grating spectrometer, and the intensities of the line spectra are monitored at specific wavelengths by a photosensitive device. Photocurrents from the photosensitive device are processed and controlled by a computer system. A background correction technique is required to compensate for variable background contribution to the determination of the analytes. Background must be measured adjacent to the analyte wavelength during analysis. Various interferences must be considered and addressed appropriately as discussed in Sections 4.0, 7.0, 9.0, 10.0, and 11.0.</P>
                        <HD SOURCE="HD2">3.0 Definitions</HD>
                        <P>3.1 Calibration Blank—A volume of reagent water acidified with the same acid matrix as in the calibration standards. The calibration blank is a zero standard and is used to calibrate the ICP instrument (Section 7.10.1).</P>
                        <P>3.2 Calibration Standard (CAL)—A solution prepared from the dilution of stock standard solutions. The CAL solutions are used to calibrate the instrument response with respect to analyte concentration (Section 7.9).</P>
                        <P>3.3 Dissolved Analyte—The concentration of analyte in an aqueous sample that will pass through a 0.45 µm membrane filter assembly prior to sample acidification (Section 11.1).</P>
                        <P>3.4 Field Reagent Blank (FRB)—An aliquot of reagent water or other blank matrix that is placed in a sample container in the laboratory and treated as a sample in all respects, including shipment to the sampling site, exposure to the sampling site conditions, storage, preservation, and all analytical procedures. The purpose of the FRB is to determine if method analytes or other interferences are present in the field environment (Section 8.5).</P>
                        <P>3.5 Instrument Detection Limit (IDL)—The concentration equivalent to the analyte signal which is equal to three times the standard deviation of a series of 10 replicate measurements of the calibration blank signal at the same wavelength (Table 1.).</P>
                        <P>3.6 Instrument Performance Check (IPC) Solution—A solution of method analytes, used to evaluate the performance of the instrument system with respect to a defined set of method criteria (Sections 7.11 and 9.3.4).</P>
                        <P>3.7 Internal Standard—Pure analyte(s) added to a sample, extract, or standard solution in known amount(s) and used to measure the relative responses of other method analytes that are components of the same sample or solution. The internal standard must be an analyte that is not a sample component (Section 11.5).</P>
                        <P>3.8 Laboratory Duplicates (LD1 and LD2)—Two aliquots of the same sample taken in the laboratory and analyzed separately with identical procedures. Analyses of LD1 and LD2 indicate precision associated with laboratory procedures, but not with sample collection, preservation, or storage procedures.</P>
                        <P>3.9 Laboratory Fortified Blank (LFB)—An aliquot of LRB to which known quantities of the method analytes are added in the laboratory. The LFB is analyzed exactly like a sample, and its purpose is to determine whether the methodology is in control and whether the laboratory is capable of making accurate and precise measurements (Sections 7.10.3 and 9.3.2).</P>
                        <P>
                            3.10 Laboratory Fortified Sample Matrix (LFM)—An aliquot of an environmental sample to which known quantities of the method analytes are added in the laboratory. The 
                            <PRTPAGE P="392"/>
                            LFM is analyzed exactly like a sample, and its purpose is to determine whether the sample matrix contributes bias to the analytical results. The background concentrations of the analytes in the sample matrix must be determined in a separate aliquot and the measured values in the LFM corrected for background concentrations (Section 9.4).
                        </P>
                        <P>3.11 Laboratory Reagent Blank (LRB)—An aliquot of reagent water or other blank matrices that are treated exactly as a sample including exposure to all glassware, equipment, solvents, reagents, and internal standards that are used with other samples. The LRB is used to determine if method analytes or other interferences are present in the laboratory environment, reagents, or apparatus (Sections 7.10.2 and 9.3.1).</P>
                        <P>3.12 Linear Dynamic Range (LDR)—The concentration range over which the instrument response to an analyte is linear (Section 9.2.2).</P>
                        <P>3.13 Method Detection Limit (MDL)—The minimum concentration of an analyte that can be identified, measured, and reported with 99% confidence that the analyte concentration is greater than zero (Section 9.2.4 and Table 4.).</P>
                        <P>3.14 Plasma Solution—A solution that is used to determine the optimum height above the work coil for viewing the plasma (Sections 7.15 and 10.2.3).</P>
                        <P>3.15 Quality Control Sample (QCS)—A solution of method analytes of known concentrations which is used to fortify an aliquot of LRB or sample matrix. The QCS is obtained from a source external to the laboratory and different from the source of calibration standards. It is used to check either laboratory or instrument performance (Sections 7.12 and 9.2.3).</P>
                        <P>3.16 Solid Sample—For the purpose of this method, a sample taken from material classified as soil, sediment or sludge.</P>
                        <P>3.17 Spectral Interference Check (SIC) Solution—A solution of selected method analytes of higher concentrations which is used to evaluate the procedural routine for correcting known interelement spectral interferences with respect to a defined set of method criteria (Sections 7.13, 7.14 and 9.3.5).</P>
                        <P>3.18 Standard Addition—The addition of a known amount of analyte to the sample in order to determine the relative response of the detector to an analyte within the sample matrix. The relative response is then used to assess either an operative matrix effect or the sample analyte concentration (Sections 9.5.1 and 11.5).</P>
                        <P>3.19 Stock Standard Solution—A concentrated solution containing one or more method analytes prepared in the laboratory using assayed reference materials or purchased from a reputable commercial source (Section 7.8).</P>
                        <P>3.20 Total Recoverable Analyte—The concentration of analyte determined either by “direct analysis” of an unfiltered acid preserved drinking water sample with turbidity of &lt;1 NTU (Section 11.2.1), or by analysis of the solution extract of a solid sample or an unfiltered aqueous sample following digestion by refluxing with hot dilute mineral acid(s) as specified in the method (Sections 11.2 and 11.3).</P>
                        <P>3.21 Water Sample—For the purpose of this method, a sample taken from one of the following sources: drinking, surface, ground, storm runoff, industrial or domestic wastewater.</P>
                        <HD SOURCE="HD2">4.0 Interferences</HD>
                        <P>4.1 Spectral interferences are caused by background emission from continuous or recombination phenomena, stray light from the line emission of high concentration elements, overlap of a spectral line from another element, or unresolved overlap of molecular band spectra.</P>
                        <P>4.1.1 Background emission and stray light can usually be compensated for by subtracting the background emission determined by measurement(s) adjacent to the analyte wavelength peak. Spectral scans of samples or single element solutions in the analyte regions may indicate not only when alternate wavelengths are desirable because of severe spectral interference, but also will show whether the most appropriate estimate of the background emission is provided by an interpolation from measurements on both sides of the wavelength peak or by the measured emission on one side or the other. The location(s) selected for the measurement of background intensity will be determined by the complexity of the spectrum adjacent to the wavelength peak. The location(s) used for routine measurement must be free of off-line spectral interference (interelement or molecular) or adequately corrected to reflect the same change in background intensity as occurs at the wavelength peak.</P>
                        <P>
                            4.1.2 Spectral overlaps may be avoided by using an alternate wavelength or can be compensated for by equations that correct for interelement contributions, which involves measuring the interfering elements. Some potential on-line spectral interferences observed for the recommended wavelengths are given in Table 2. When operative and uncorrected, these interferences will produce false-positive determinations and be reported as analyte concentrations. The interferences listed are only those that occur between method analytes. Only interferences of a direct overlap nature that were observed with a single instrument having a working resolution of 0.035 nm are listed. More extensive information on interferant effects at various wavelengths and resolutions is available in Boumans' Tables.
                            <SU>8</SU>
                             Users may apply interelement correction factors determined on their instruments within tested concentration ranges to compensate (off-line or 
                            <PRTPAGE P="393"/>
                            on-line) for the effects of interfering elements.
                        </P>
                        <P>
                            4.1.3 When interelement corrections are applied, there is a need to verify their accuracy by analyzing spectral interference check solutions as described in Section 7.13. Interelement corrections will vary for the same emission line among instruments because of differences in resolution, as determined by the grating plus the entrance and exit slit widths, and by the order of dispersion. Interelement corrections will also vary depending upon the choice of background correction points. Selecting a background correction point where an interfering emission line may appear should be avoided when practical. Interelement corrections that constitute a major portion of an emission signal may not yield accurate data. Users should not forget that some samples may contain uncommon elements that could contribute spectral interferences.
                            <SU>7 8</SU>
                        </P>
                        <P>4.1.4 The interference effects must be evaluated for each individual instrument whether configured as a sequential or simultaneous instrument. For each instrument, intensities will vary not only with optical resolution but also with operating conditions (such as power, viewing height and argon flow rate). When using the recommended wavelengths given in Table 1, the analyst is required to determine and document for each wavelength the effect from the known interferences given in Table 2, and to utilize a computer routine for their automatic correction on all analyses. To determine the appropriate location for off-line background correction, the user must scan the area on either side adjacent to the wavelength and record the apparent emission intensity from all other method analytes. This spectral information must be documented and kept on file. The location selected for background correction must be either free of off-line interelement spectral interference or a computer routine must be used for their automatic correction on all determinations. If a wavelength other than the recommended wavelength is used, the user must determine and document both the on-line and off-line spectral interference effect from all method analytes and provide for their automatic correction on all analyses. Tests to determine the spectral interference must be done using analyte concentrations that will adequately describe the interference. Normally, 100 mg/L single element solutions are sufficient, however, for analytes such as iron that may be found at high concentration a more appropriate test would be to use a concentration near the upper LDR limit. See Section 10.4 for required spectral interference test criteria.</P>
                        <P>4.1.5 When interelement corrections are not used, either on-going SIC solutions (Section 7.14) must be analyzed to verify the absence of interelement spectral interference or a computer software routine must be employed for comparing the determinative data to limits files for notifying the analyst when an interfering element is detected in the sample at a concentration that will produce either an apparent false positive concentration, greater than the analyte IDL, or false negative analyte concentration, less than the 99% lower control limit of the calibration blank. When the interference accounts for 10% or more of the analyte concentration, either an alternate wavelength free of interference or another approved test procedure must be used to complete the analysis. For example, the copper peak at 213.853 nm could be mistaken for the zinc peak at 213.856 nm in solutions with high copper and low zinc concentrations. For this example, a spectral scan in the 213.8 nm region would not reveal the misidentification because a single peak near the zinc location would be observed. The possibility of this misidentification of copper for the zinc peak at 213.856 nm can be identified by measuring the copper at another emission line, e.g., 324.754 nm. Users should be aware that, depending upon the instrumental resolution, alternate wavelengths with adequate sensitivity and freedom from interference may not be available for all matrices. In these circumstances the analyte must be determined using another approved test procedure.</P>
                        <P>4.2 Physical interferences are effects associated with the sample nebulization and transport processes. Changes in viscosity and surface tension can cause significant inaccuracies, especially in samples containing high dissolved solids or high acid concentrations. If physical interferences are present, they must be reduced by such means as a high-solids nebulizer, diluting the sample, using a peristaltic pump, or using an appropriate internal standard element. Another problem that can occur with high dissolved solids is salt buildup at the tip of the nebulizer, which affects aerosol flow rate and causes instrumental drift. This problem can be controlled by a high-solids nebulizer, wetting the argon prior to nebulization, using a tip washer, or diluting the sample. Also, it has been reported that better control of the argon flow rates, especially for the nebulizer, improves instrument stability and precision; this is accomplished with the use of mass flow controllers.</P>
                        <P>
                            4.3 Chemical interferences include molecular-compound formation, ionization effects, and solute-vaporization effects. Normally, these effects are not significant with the ICP-AES technique. If observed, they can be minimized by careful selection of operating conditions (such as incident power and observation height), by buffering of the sample, by matrix matching, and by standard-addition 
                            <PRTPAGE P="394"/>
                            procedures. Chemical interferences are highly dependent on matrix type and the specific analyte element.
                        </P>
                        <P>4.4 Memory interferences result when analytes in a previous sample contribute to the signals measured in a new sample. Memory effects can result from sample deposition on the uptake tubing to the nebulizer, and from the buildup of sample material in the plasma torch and spray chamber. The site where these effects occur is dependent on the element and can be minimized by flushing the system with a rinse blank between samples (Section 7.10.4). The possibility of memory interferences should be recognized within an analytical run and suitable rinse times should be used to reduce them. The rinse times necessary for a particular element must be estimated prior to analysis. This may be achieved by aspirating a standard containing elements corresponding to either their LDR or a concentration ten times those usually encountered. The aspiration time should be the same as a normal sample analysis period, followed by analysis of the rinse blank at designated intervals. The length of time required to reduce analyte signals to within a factor of two of the method detection limit, should be noted. Until the required rinse time is established, this method requires a rinse period of at least 60 seconds between samples and standards. If a memory interference is suspected, the sample must be re-analyzed after a long rinse period.</P>
                        <HD SOURCE="HD2">5.0 Safety</HD>
                        <P>
                            5.1 The toxicity or carcinogenicity of each reagent used in this method have not been fully established. Each chemical should be regarded as a potential health hazard and exposure to these compounds should be as low as reasonably achievable. Each laboratory is responsible for maintaining a current awareness file of OSHA regulations regarding the safe handling of the chemicals specified in this method.
                            <E T="51">9-12</E>
                             A reference file of material data handling sheets should also be made available to all personnel involved in the chemical analysis. Specifically, concentrated nitric and hydrochloric acids present various hazards and are moderately toxic and extremely irritating to skin and mucus membranes. Use these reagents in a fume hood whenever possible and if eye or skin contact occurs, flush with large volumes of water. Always wear safety glasses or a shield for eye protection, protective clothing and observe proper mixing when working with these reagents.
                        </P>
                        <P>5.2 The acidification of samples containing reactive materials may result in the release of toxic gases, such as cyanides or sulfides. Acidification of samples should be done in a fume hood.</P>
                        <P>5.3 All personnel handling environmental samples known to contain or to have been in contact with human waste should be immunized against known disease causative agents.</P>
                        <P>5.4 The inductively coupled plasma should only be viewed with proper eye protection from the ultraviolet emissions.</P>
                        <P>5.5 It is the responsibility of the user of this method to comply with relevant disposal and waste regulations. For guidance see Sections 14.0 and 15.0.</P>
                        <HD SOURCE="HD2">6.0 Equipment and Supplies</HD>
                        <P>6.1 Inductively coupled plasma emission spectrometer:</P>
                        <P>6.1.1 Computer-controlled emission spectrometer with background-correction capability.</P>
                        <FP>The spectrometer must be capable of meeting and complying with the requirements described and referenced in Section 2.2.</FP>
                        <P>6.1.2 Radio-frequency generator compliant with FCC regulations.</P>
                        <P>6.1.3 Argon gas supply—High purity grade (99.99%). When analyses are conducted frequently, liquid argon is more economical and requires less frequent replacement of tanks than compressed argon in conventional cylinders.</P>
                        <P>6.1.4 A variable speed peristaltic pump is required to deliver both standard and sample solutions to the nebulizer.</P>
                        <P>6.1.5 (Optional) Mass flow controllers to regulate the argon flow rates, especially the aerosol transport gas, are highly recommended. Their use will provide more exacting control of reproducible plasma conditions.</P>
                        <P>6.2 Analytical balance, with capability to measure to 0.1 mg, for use in weighing solids, for preparing standards, and for determining dissolved solids in digests or extracts.</P>
                        <P>6.3 A temperature adjustable hot plate capable of maintaining a temperature of 95 °C.</P>
                        <P>6.4 (Optional) A temperature adjustable block digester capable of maintaining a temperature of 95 °C and equipped with 250 mL constricted digestion tubes.</P>
                        <P>6.5 (Optional) A steel cabinet centrifuge with guard bowl, electric timer and brake.</P>
                        <P>6.6 A gravity convection drying oven with thermostatic control capable of maintaining 180 °C ±5 °C.</P>
                        <P>6.7 (Optional) An air displacement pipetter capable of delivering volumes ranging from 0.1-2500 µL with an assortment of high quality disposable pipet tips.</P>
                        <P>6.8 Mortar and pestle, ceramic or nonmetallic material.</P>
                        <P>6.9 Polypropylene sieve, 5-mesh (4 mm opening).</P>
                        <P>
                            6.10 Labware—For determination of trace levels of elements, contamination and loss are of prime consideration. Potential contamination sources include improperly cleaned laboratory apparatus and general 
                            <PRTPAGE P="395"/>
                            contamination within the laboratory environment from dust, etc. A clean laboratory work area designated for trace element sample handling must be used. Sample containers can introduce positive and negative errors in the determination of trace elements by contributing contaminants through surface desorption or leaching, or depleting element concentrations through adsorption processes. All reusable labware (glass, quartz, polyethylene, PTFE, FEP, etc.) should be sufficiently clean for the task objectives. Several procedures found to provide clean labware include washing with a detergent solution, rinsing with tap water, soaking for four hours or more in 20% (v/v) nitric acid or a mixture of HNO
                            <E T="52">3</E>
                             and HCl (1 + 2 + 9), rinsing with reagent water and storing clean. 
                            <SU>2 3</SU>
                             Chromic acid cleaning solutions must be avoided because chromium is an analyte.
                        </P>
                        <P>6.10.1 Glassware—Volumetric flasks, graduated cylinders, funnels and centrifuge tubes (glass and/or metal-free plastic).</P>
                        <P>6.10.2 Assorted calibrated pipettes.</P>
                        <P>6.10.3 Conical Phillips beakers (Corning 1080-250 or equivalent), 250 mL with 50 mm watch glasses.</P>
                        <P>6.10.4 Griffin beakers, 250 mL with 75 mm watch glasses and (optional) 75 mm ribbed watch glasses.</P>
                        <P>6.10.5 (Optional) PTFE and/or quartz Griffin beakers, 250 mL with PTFE covers.</P>
                        <P>6.10.6 Evaporating dishes or high-form crucibles, porcelain, 100 mL capacity.</P>
                        <P>6.10.7 Narrow-mouth storage bottles, FEP (fluorinated ethylene propylene) with screw closure, 125 mL to 1 L capacities.</P>
                        <P>6.10.8 One-piece stem FEP wash bottle with screw closure, 125 mL capacity.</P>
                        <HD SOURCE="HD2">7.0 Reagents and Standards</HD>
                        <P>
                            7.1 Reagents may contain elemental impurities which might affect analytical data. Only high-purity reagents that conform to the American Chemical Society specifications 
                            <SU>13</SU>
                             should be used whenever possible. If the purity of a reagent is in question, analyze for contamination. All acids used for this method must be of ultra high-purity grade or equivalent. Suitable acids are available from a number of manufacturers. Redistilled acids prepared by sub-boiling distillation are acceptable.
                        </P>
                        <P>7.2 Hydrochloric acid, concentrated (sp.gr. 1.19)—HCl.</P>
                        <P>7.2.1 Hydrochloric acid (1 + 1)—Add 500 mL concentrated HCl to 400 mL reagent water and dilute to 1 L.</P>
                        <P>7.2.2 Hydrochloric acid (1 + 4)—Add 200 mL concentrated HCl to 400 mL reagent water and dilute to 1 L.</P>
                        <P>7.2.3 Hydrochloric acid (1 + 20)—Add 10 mL concentrated HCl to 200 mL reagent water.</P>
                        <P>
                            7.3 Nitric acid, concentrated (sp.gr. 1.41)—HNO
                            <E T="52">3</E>
                            .
                        </P>
                        <P>
                            7.3.1 Nitric acid (1 + 1)—Add 500 mL concentrated HNO
                            <E T="52">3</E>
                             to 400 mL reagent water and dilute to 1 L.
                        </P>
                        <P>
                            7.3.2 Nitric acid (1 + 2)—Add 100 mL concentrated HNO
                            <E T="52">3</E>
                             to 200 mL reagent water.
                        </P>
                        <P>
                            7.3.3 Nitric acid (1 + 5)—Add 50 mL concentrated HNO
                            <E T="52">3</E>
                             to 250 mL reagent water.
                        </P>
                        <P>
                            7.3.4 Nitric acid (1 + 9)—Add 10 mL concentrated HNO
                            <E T="52">3</E>
                             to 90 mL reagent water.
                        </P>
                        <P>
                            7.4 Reagent water. All references to water in this method refer to ASTM Type I grade water.
                            <SU>14</SU>
                        </P>
                        <P>7.5 Ammonium hydroxide, concentrated (sp.gr. 0.902).</P>
                        <P>7.6 Tartaric acid, ACS reagent grade.</P>
                        <P>7.7 Hydrogen peroxide, 50%, stabilized certified reagent grade.</P>
                        <P>7.8 Standard Stock Solutions—Stock standards may be purchased or prepared from ultra-high purity grade chemicals (99.99-99.999% pure). All compounds must be dried for one hour at 105 °C, unless otherwise specified. It is recommended that stock solutions be stored in FEP bottles. Replace stock standards when succeeding dilutions for preparation of calibration standards cannot be verified.</P>
                        <P>CAUTION: Many of these chemicals are extremely toxic if inhaled or swallowed (Section 5.1). Wash hands thoroughly after handling.</P>
                        <P>Typical stock solution preparation procedures follow for 1 L quantities, but for the purpose of pollution prevention, the analyst is encouraged to prepare smaller quantities when possible. Concentrations are calculated based upon the weight of the pure element or upon the weight of the compound multiplied by the fraction of the analyte in the compound</P>
                        <P>From pure element,</P>
                        <GPH SPAN="2" DEEP="88">
                            <PRTPAGE P="396"/>
                            <GID>ER18MY12.001</GID>
                        </GPH>
                        <FP>where: gravimetric factor = the weight fraction of the analyte in the compound</FP>
                        <P>
                            7.8.1 Aluminum solution, stock, 1 mL = 1000 µg Al: Dissolve 1.000 g of aluminum metal, weighed accurately to at least four significant figures, in an acid mixture of 4.0 mL of (1 + 1) HCl and 1 mL of concentrated HNO
                            <E T="52">3</E>
                             in a beaker. Warm beaker slowly to effect solution. When dissolution is complete, transfer solution quantitatively to a 1 L flask, add an additional 10.0 mL of (1 + 1) HCl and dilute to volume with reagent water.
                        </P>
                        <P>
                            7.8.2 Antimony solution, stock, 1 mL = 1000 µg Sb: Dissolve 1.000 g of antimony powder, weighed accurately to at least four significant figures, in 20.0 mL (1 + 1) HNO
                            <E T="52">3</E>
                             and 10.0 mL concentrated HCl. Add 100 mL reagent water and 1.50 g tartaric acid. Warm solution slightly to effect complete dissolution. Cool solution and add reagent water to volume in a 1 L volumetric flask.
                        </P>
                        <P>
                            7.8.3 Arsenic solution, stock, 1 mL = 1000 µg As: Dissolve 1.320 g of As
                            <E T="52">2</E>
                            O
                            <E T="52">3</E>
                             (As fraction = 0.7574), weighed accurately to at least four significant figures, in 100 mL of reagent water containing 10.0 mL concentrated NH
                            <E T="52">4</E>
                            OH. Warm the solution gently to effect dissolution. Acidify the solution with 20.0 mL concentrated HNO
                            <E T="52">3</E>
                             and dilute to volume in a 1 L volumetric flask with reagent water.
                        </P>
                        <P>
                            7.8.4 Barium solution, stock, 1 mL = 1000 µg Ba: Dissolve 1.437 g BaCO
                            <E T="52">3</E>
                             (Ba fraction = 0.6960), weighed accurately to at least four significant figures, in 150 mL (1 + 2) HNO
                            <E T="52">3</E>
                             with heating and stirring to degas and dissolve compound. Let solution cool and dilute with reagent water in 1 L volumetric flask.
                        </P>
                        <P>
                            7.8.5 Beryllium solution, stock, 1 mL = 1000 µg Be: 
                            <E T="03">DO NOT DRY.</E>
                             Dissolve 19.66 g BeSO
                            <E T="52">4</E>
                            •4H
                            <E T="52">2</E>
                            O (Be fraction = 0.0509), weighed accurately to at least four significant figures, in reagent water, add 10.0 mL concentrated HNO
                            <E T="52">3</E>
                            , and dilute to volume in a 1 L volumetric flask with reagent water.
                        </P>
                        <P>
                            7.8.6 Boron solution, stock, 1 mL = 1000 µg B: 
                            <E T="03">DO NOT DRY.</E>
                             Dissolve 5.716 g anhydrous H
                            <E T="52">3</E>
                            BO
                            <E T="52">3</E>
                             (B fraction = 0.1749), weighed accurately to at least four significant figures, in reagent water and dilute in a 1 L volumetric flask with reagent water. Transfer immediately after mixing to a clean FEP bottle to minimize any leaching of boron from the glass volumetric container. Use of a nonglass volumetric flask is recommended to avoid boron contamination from glassware.
                        </P>
                        <P>
                            7.8.7 Cadmium solution, stock, 1 mL = 1000 µg Cd: Dissolve 1.000 g Cd metal, acid cleaned with (1 + 9) HNO
                            <E T="52">3</E>
                            , weighed accurately to at least four significant figures, in 50 mL (1 + 1) HNO
                            <E T="52">3</E>
                             with heating to effect dissolution. Let solution cool and dilute with reagent water in a 1 L volumetric flask.
                        </P>
                        <P>
                            7.8.8 Calcium solution, stock, 1 mL = 1000 µg Ca: Suspend 2.498 g CaCO
                            <E T="52">3</E>
                             (Ca fraction = 0.4005), dried at 180 °C for one hour before weighing, weighed accurately to at least four significant figures, in reagent water and dissolve cautiously with a minimum amount of (1 + 1) HNO
                            <E T="52">3</E>
                            . Add 10.0 mL concentrated HNO
                            <E T="52">3</E>
                             and dilute to volume in a 1 L volumetric flask with reagent water.
                        </P>
                        <P>
                            7.8.9 Cerium solution, stock, 1 mL = 1000 µg Ce: Slurry 1.228 g CeO
                            <E T="52">2</E>
                             (Ce fraction = 0.8141), weighed accurately to at least four significant figures, in 100 mL concentrated HNO
                            <E T="52">3</E>
                             and evaporate to dryness. Slurry the residue in 20 mL H
                            <E T="52">2</E>
                            O, add 50 mL concentrated HNO
                            <E T="52">3</E>
                            , with heat and stirring add 60 mL 50% H
                            <E T="52">2</E>
                            O
                            <E T="52">2</E>
                             dropwise in 1 mL increments allowing periods of stirring between the 1 mL additions. Boil off excess H
                            <E T="52">2</E>
                            O
                            <E T="52">2</E>
                             before diluting to volume in a 1 L volumetric flask with reagent water.
                        </P>
                        <P>
                            7.8.10 Chromium solution, stock, 1 mL = 1000 µg Cr: Dissolve 1.923 g CrO
                            <E T="52">3</E>
                             (Cr fraction = 0.5200), weighed accurately to at least four significant figures, in 120 mL (1 + 5) HNO
                            <E T="52">3</E>
                            . When solution is complete, dilute to volume in a 1 L volumetric flask with reagent water.
                        </P>
                        <P>
                            7.8.11 Cobalt solution, stock, 1 mL = 1000 µg Co: Dissolve 1.000 g Co metal, acid cleaned with (1 + 9) HNO
                            <E T="52">3</E>
                            , weighed accurately to at least four significant figures, in 50.0 mL (1 + 1) HNO
                            <E T="52">3</E>
                            . Let solution cool and dilute to volume in a 1 L volumetric flask with reagent water.
                        </P>
                        <P>
                            7.8.12 Copper solution, stock, 1 mL = 1000 µg Cu: Dissolve 1.000 g Cu metal, acid cleaned with (1 + 9) HNO
                            <E T="52">3</E>
                            , weighed accurately to at least four significant figures, in 50.0 mL (1 + 1) HNO
                            <E T="52">3</E>
                             with heating to effect dissolution. Let solution cool and dilute in a 1 L volumetric flask with reagent water.
                        </P>
                        <P>
                            7.8.13 Iron solution, stock, 1 mL = 1000 µg Fe: Dissolve 1.000 g Fe metal, acid cleaned 
                            <PRTPAGE P="397"/>
                            with (1 + 1) HCl, weighed accurately to four significant figures, in 100 mL (1 + 1) HCl with heating to effect dissolution. Let solution cool and dilute with reagent water in a 1 L volumetric flask.
                        </P>
                        <P>
                            7.8.14 Lead solution, stock, 1 mL = 1000 µg Pb: Dissolve 1.599 g Pb(NO
                            <E T="52">3</E>
                            )
                            <E T="52">2</E>
                             (Pb fraction = 0.6256), weighed accurately to at least four significant figures, in a minimum amount of (1 + 1) HNO
                            <E T="52">3</E>
                            . Add 20.0 mL (1 + 1) HNO
                            <E T="52">3</E>
                             and dilute to volume in a 1 L volumetric flask with reagent water.
                        </P>
                        <P>
                            7.8.15 Lithium solution, stock, 1 mL = 1000 µg Li: Dissolve 5.324 g Li
                            <E T="52">2</E>
                            CO
                            <E T="52">3</E>
                             (Li fraction = 0.1878), weighed accurately to at least four significant figures, in a minimum amount of (1 + 1) HCl and dilute to volume in a 1 L volumetric flask with reagent water.
                        </P>
                        <P>
                            7.8.16 Magnesium solution, stock, 1 mL = 1000 µg Mg: Dissolve 1.000 g cleanly polished Mg ribbon, accurately weighed to at least four significant figures, in slowly added 5.0 mL (1 + 1) HCl (CAUTION: reaction is vigorous). Add 20.0 mL (1 + 1) HNO
                            <E T="52">3</E>
                             and dilute to volume in a 1 L volumetric flask with reagent water.
                        </P>
                        <P>
                            7.8.17 Manganese solution, stock, 1 mL = 1000 µg Mn: Dissolve 1.000 g of manganese metal, weighed accurately to at least four significant figures, in 50 mL (1 + 1) HNO
                            <E T="52">3</E>
                             and dilute to volume in a 1 L volumetric flask with reagent water.
                        </P>
                        <P>
                            7.8.18 Mercury solution, stock, 1 mL = 1000 µg Hg: 
                            <E T="03">DO NOT DRY.</E>
                             CAUTION: highly toxic element. Dissolve 1.354 g HgCl
                            <E T="52">2</E>
                             (Hg fraction = 0.7388) in reagent water. Add 50.0 mL concentrated HNO
                            <E T="52">3</E>
                             and dilute to volume in 1 L volumetric flask with reagent water.
                        </P>
                        <P>
                            7.8.19 Molybdenum solution, stock, 1 mL = 1000 µg Mo: Dissolve 1.500 g MoO
                            <E T="52">3</E>
                             (Mo fraction = 0.6666), weighed accurately to at least four significant figures, in a mixture of 100 mL reagent water and 10.0 mL concentrated NH
                            <E T="52">4</E>
                            OH, heating to effect dissolution. Let solution cool and dilute with reagent water in a 1 L volumetric flask.
                        </P>
                        <P>
                            7.8.20 Nickel solution, stock, 1 mL = 1000 µg Ni: Dissolve 1.000 g of nickel metal, weighed accurately to at least four significant figures, in 20.0 mL hot concentrated HNO
                            <E T="52">3</E>
                            , cool, and dilute to volume in a 1 L volumetric flask with reagent water.
                        </P>
                        <P>
                            7.8.21 Phosphorus solution, stock, 1 mL = 1000 µg P: Dissolve 3.745 g NH
                            <E T="52">4</E>
                            H
                            <E T="52">2</E>
                            PO
                            <E T="52">4</E>
                             (P fraction = 0.2696), weighed accurately to at least four significant figures, in 200 mL reagent water and dilute to volume in a 1 L volumetric flask with reagent water.
                        </P>
                        <P>7.8.22 Potassium solution, stock, 1 mL = 1000 µg K: Dissolve 1.907 g KCl (K fraction = 0.5244) dried at 110 °C, weighed accurately to at least four significant figures, in reagent water, add 20 mL (1 + 1) HCl and dilute to volume in a 1 L volumetric flask with reagent water.</P>
                        <P>
                            7.8.23 Selenium solution, stock, 1 mL = 1000 µg Se: Dissolve 1.405 g SeO
                            <E T="52">2</E>
                             (Se fraction = 0.7116), weighed accurately to at least four significant figures, in 200 mL reagent water and dilute to volume in a 1 L volumetric flask with reagent water.
                        </P>
                        <P>
                            7.8.24 Silica solution, stock, 1 mL = 1000 µg SiO
                            <E T="52">2</E>
                            : 
                            <E T="03">DO NOT DRY.</E>
                             Dissolve 2.964 g (NH
                            <E T="52">4</E>
                            )
                            <E T="52">2</E>
                            SiF
                            <E T="52">6</E>
                            , weighed accurately to at least four significant figures, in 200 mL (1 + 20) HCl with heating at 85 °C to effect dissolution. Let solution cool and dilute to volume in a 1 L volumetric flask with reagent water.
                        </P>
                        <P>
                            7.8.25 Silver solution, stock, 1 mL = 1000 µg Ag: Dissolve 1.000 g Ag metal, weighed accurately to at least four significant figures, in 80 mL (1 + 1) HNO
                            <E T="52">3</E>
                             with heating to effect dissolution. Let solution cool and dilute with reagent water in a 1 L volumetric flask. Store solution in amber bottle or wrap bottle completely with aluminum foil to protect solution from light.
                        </P>
                        <P>
                            7.8.26 Sodium solution, stock, 1 mL = 1000 µg Na: Dissolve 2.542 g NaCl (Na fraction = 0.3934), weighed accurately to at least four significant figures, in reagent water. Add 10.0 mL concentrated HNO
                            <E T="52">3</E>
                             and dilute to volume in a 1 L volumetric flask with reagent water.
                        </P>
                        <P>
                            7.8.27 Strontium solution, stock, 1 mL = 1000 µg Sr: Dissolve 1.685 g SrCO
                            <E T="52">3</E>
                             (Sr fraction = 0.5935), weighed accurately to at least four significant figures, in 200 mL reagent water with dropwise addition of 100 mL (1 + 1) HCl. Dilute to volume in a 1 L volumetric flask with reagent water.
                        </P>
                        <P>
                            7.8.28 Thallium solution, stock, 1 mL = 1000 µg Tl: Dissolve 1.303 g TlNO
                            <E T="52">3</E>
                             (Tl fraction = 0.7672), weighed accurately to at least four significant figures, in reagent water. Add 10.0 mL concentrated HNO
                            <E T="52">3</E>
                             and dilute to volume in a 1 L volumetric flask with reagent water.
                        </P>
                        <P>
                            7.8.29 Tin solution, stock, 1 mL = 1000 µg Sn: Dissolve 1.000 g Sn shot, weighed accurately to at least four significant figures, in an acid mixture of 10.0 mL concentrated HCl and 2.0 mL (1 + 1) HNO
                            <E T="52">3</E>
                             with heating to effect dissolution. Let solution cool, add 200 mL concentrated HCl, and dilute to volume in a 1 L volumetric flask with reagent water.
                        </P>
                        <P>
                            7.8.30 Titanium solution, stock, 1 mL = 1000 µg Ti: 
                            <E T="03">DO NOT DRY.</E>
                             Dissolve 6.138 g (NH
                            <E T="52">4</E>
                            )
                            <E T="52">2</E>
                            TiO(C
                            <E T="52">2</E>
                            O
                            <E T="52">4</E>
                            )
                            <E T="52">2</E>
                            •H
                            <E T="52">2</E>
                            O (Ti fraction = 0.1629), weighed accurately to at least four significant figures, in 100 mL reagent water. Dilute to volume in a 1 L volumetric flask with reagent water.
                        </P>
                        <P>
                            7.8.31 Vanadium solution, stock, 1 mL = 1000 µg V: Dissolve 1.000 g V metal, acid cleaned with (1 + 9) HNO
                            <E T="52">3</E>
                            , weighed accurately to at least four significant figures, in 50 mL (1 + 1) HNO
                            <E T="52">3</E>
                             with heating to effect dissolution. Let solution cool and dilute with reagent water to volume in a 1 L volumetric flask.
                        </P>
                        <P>
                            7.8.32 Yttrium solution, stock 1 mL = 1000 µg Y: Dissolve 1.270 g Y
                            <E T="52">2</E>
                            O
                            <E T="52">3</E>
                             (Y fraction = 0.7875), weighed accurately to at least four significant figures, in 50 mL (1 + 1) HNO
                            <E T="52">3</E>
                            , heating to effect dissolution. Cool and dilute 
                            <PRTPAGE P="398"/>
                            to volume in a 1 L volumetric flask with reagent water.
                        </P>
                        <P>
                            7.8.33 Zinc solution, stock, 1 mL = 1000 µg Zn: Dissolve 1.000 g Zn metal, acid cleaned with (1 + 9) HNO
                            <E T="52">3</E>
                            , weighed accurately to at least four significant figures, in 50 mL (1 + 1) HNO
                            <E T="52">3</E>
                             with heating to effect dissolution. Let solution cool and dilute with reagent water to volume in a 1 L volumetric flask.
                        </P>
                        <P>
                            7.9 Mixed Calibration Standard Solutions—For the analysis of total recoverable digested samples prepare mixed calibration standard solutions (see Table 3) by combining appropriate volumes of the stock solutions in 500 mL volumetric flasks containing 20 mL (1 + 1) HNO
                            <E T="52">3</E>
                             and 20 mL (1 + 1) HCl and dilute to volume with reagent water. Prior to preparing the mixed standards, each stock solution should be analyzed separately to determine possible spectral interferences or the presence of impurities. Care should be taken when preparing the mixed standards to ensure that the elements are compatible and stable together. To minimize the opportunity for contamination by the containers, it is recommended to transfer the mixed-standard solutions to acid-cleaned, never-used FEP fluorocarbon (FEP) bottles for storage. Fresh mixed standards should be prepared, as needed, with the realization that concentrations can change on aging. Calibration standards not prepared from primary standards must be initially verified using a certified reference solution. For the recommended wavelengths listed in Table 1 some typical calibration standard combinations are given in Table 3.
                        </P>
                        <P>Note: If the addition of silver to the recommended mixed-acid calibration standard results in an initial precipitation, add 15 mL of reagent water and warm the flask until the solution clears. For this acid combination, the silver concentration should be limited to 0.5 mg/L.</P>
                        <P>7.10 Blanks—Four types of blanks are required for the analysis. The calibration blank is used in establishing the analytical curve, the laboratory reagent blank is used to assess possible contamination from the sample preparation procedure, the laboratory fortified blank is used to assess routine laboratory performance and a rinse blank is used to flush the instrument uptake system and nebulizer between standards, check solutions, and samples to reduce memory interferences.</P>
                        <P>7.10.1 The calibration blank for aqueous samples and extracts is prepared by acidifying reagent water to the same concentrations of the acids as used for the standards. The calibration blank should be stored in a FEP bottle.</P>
                        <P>7.10.2 The laboratory reagent blank (LRB) must contain all the reagents in the same volumes as used in the processing of the samples. The LRB must be carried through the same entire preparation scheme as the samples including sample digestion, when applicable.</P>
                        <P>7.10.3 The laboratory fortified blank (LFB) is prepared by fortifying an aliquot of the laboratory reagent blank with all analytes to a suitable concentration using the following recommended criteria: Ag 0.1 mg/L, K 5.0 mg/L and all other analytes 0.2 mg/L or a concentration approximately 100 times their respective MDL, whichever is greater. The LFB must be carried through the same entire preparation scheme as the samples including sample digestion, when applicable.</P>
                        <P>7.10.4 The rinse blank is prepared by acidifying reagent water to the same concentrations of acids as used in the calibration blank and stored in a convenient manner.</P>
                        <P>7.11 Instrument Performance Check (IPC) Solution—The IPC solution is used to periodically verify instrument performance during analysis. It should be prepared in the same acid mixture as the calibration standards by combining method analytes at appropriate concentrations. Silver must be limited to &lt;0.5 mg/L; while potassium and phosphorus because of higher MDLs and silica because of potential contamination should be at concentrations of 10 mg/L. For other analytes a concentration of 2 mg/L is recommended. The IPC solution should be prepared from the same standard stock solutions used to prepare the calibration standards and stored in an FEP bottle. Agency programs may specify or request that additional instrument performance check solutions be prepared at specified concentrations in order to meet particular program needs.</P>
                        <P>7.12 Quality Control Sample (QCS)—Analysis of a QCS is required for initial and periodic verification of calibration standards or stock standard solutions in order to verify instrument performance. The QCS must be obtained from an outside source different from the standard stock solutions and prepared in the same acid mixture as the calibration standards. The concentration of the analytes in the QCS solution should be 1 mg/L, except silver, which must be limited to a concentration of 0.5 mg/L for solution stability. The QCS solution should be stored in a FEP bottle and analyzed as needed to meet data-quality needs. A fresh solution should be prepared quarterly or more frequently as needed.</P>
                        <P>7.13 Spectral Interference Check (SIC) Solutions—When interelement corrections are applied, SIC solutions are needed containing concentrations of the interfering elements at levels that will provide an adequate test of the correction factors.</P>
                        <P>
                            7.13.1 SIC solutions containing (a) 300 mg/L Fe; (b) 200 mg/L AL; (c) 50 mg/L Ba; (d) 50 mg/L Be; (e) 50 mg/L Cd; (f) 50 mg/L Ce; (g) 50 mg/L Co; (h) 50 mg/L Cr; (i) 50 mg/L Cu; (j) 50 
                            <PRTPAGE P="399"/>
                            mg/L Mn; (k) 50 mg/L Mo; (l) 50 mg/L Ni; (m) 50 mg/L Sn; (n) 50 mg/L SiO
                            <E T="52">2</E>
                            ; (o) 50 mg/L Ti; (p) 50 mg/L Tl and (q) 50 mg/L V should be prepared in the same acid mixture as the calibration standards and stored in FEP bottles. These solutions can be used to periodically verify a partial list of the on-line (and possible off-line) interelement spectral correction factors for the recommended wavelengths given in Table 1. Other solutions could achieve the same objective as well. (Multielement SIC solutions
                            <SU>3</SU>
                             may be prepared and substituted for the single element solutions provided an analyte is not subject to interference from more than one interferant in the solution.)
                        </P>
                        <P>Note: If wavelengths other than those recommended in Table 1 are used, other solutions different from those above (a through q) may be required.</P>
                        <P>7.13.2 For interferences from iron and aluminum, only those correction factors (positive or negative) when multiplied by 100 to calculate apparent analyte concentrations that exceed the determined analyte IDL or fall below the lower 3-sigma control limit of the calibration blank need be tested on a daily basis.</P>
                        <P>7.13.3 For the other interfering elements, only those correction factors (positive or negative) when multiplied by 10 to calculate apparent analyte concentrations that exceed the determined analyte IDL or fall below the lower 3-sigma control limit of the calibration blank need be tested on a daily basis.</P>
                        <P>7.13.4 If the correction routine is operating properly, the determined apparent analyte(s) concentration from analysis of each interference solution (a through q) should fall within a specific concentration range bracketing the calibration blank. This concentration range is calculated by multiplying the concentration of the interfering element by the value of the correction factor being tested and dividing by 10. If after subtraction of the calibration blank the apparent analyte concentration is outside (above or below) this range, a change in the correction factor of more than 10% should be suspected. The cause of the change should be determined and corrected and the correction factor should be updated.</P>
                        <P>Note: The SIC solution should be analyzed more than once to confirm a change has occurred with adequate rinse time between solutions and before subsequent analysis of the calibration blank.</P>
                        <P>7.13.5 If the correction factors tested on a daily basis are found to be within the 10% criteria for five consecutive days, the required verification frequency of those factors in compliance may be extended to a weekly basis. Also, if the nature of the samples analyzed is such (e.g., finished drinking water) that they do not contain concentrations of the interfering elements at the 10 mg/L level, daily verification is not required; however, all interelement spectral correction factors must be verified annually and updated, if necessary.</P>
                        <P>7.13.6 If the instrument does not display negative concentration values, fortify the SIC solutions with the elements of interest at 1 mg/L and test for analyte recoveries that are below 95%. In the absence of measurable analyte, over-correction could go undetected because a negative value could be reported as zero.</P>
                        <P>7.14 For instruments without interelement correction capability or when interelement corrections are not used, SIC solutions (containing similar concentrations of the major components in the samples, e.g., 10 mg/L) can serve to verify the absence of effects at the wavelengths selected. These data must be kept on file with the sample analysis data. If the SIC solution confirms an operative interference that is 10% of the analyte concentration, the analyte must be determined using a wavelength and background correction location free of the interference or by another approved test procedure. Users are advised that high salt concentrations can cause analyte signal suppressions and confuse interference tests.</P>
                        <P>7.15 Plasma Solution—The plasma solution is used for determining the optimum viewing height of the plasma above the work coil prior to using the method (Section 10.2). The solution is prepared by adding a 5 mL aliquot from each of the stock standard solutions of arsenic, lead, selenium, and thallium to a mixture of 20 mL (1 + 1) nitric acid and 20 mL (1 + 1) hydrochloric acid and diluting to 500 mL with reagent water. Store in a FEP bottle.</P>
                        <HD SOURCE="HD2">8.0 Sample Collection, Preservation, and Storage</HD>
                        <P>
                            8.1 Prior to the collection of an aqueous sample, consideration should be given to the type of data required, (
                            <E T="03">i.e.,</E>
                             dissolved or total recoverable), so that appropriate preservation and pretreatment steps can be taken. The pH of all aqueous samples must be tested immediately prior to aliquoting for processing or “direct analysis” to ensure the sample has been properly preserved. If properly acid preserved, the sample can be held up to six months before analysis.
                        </P>
                        <P>
                            8.2 For the determination of the dissolved elements, the sample must be filtered through a 0.45 µm pore diameter membrane filter at the time of collection or as soon thereafter as practically possible. (Glass or plastic filtering apparatus are recommended to avoid possible contamination. Only plastic apparatus should be used when the determinations of boron and silica are critical.) Use a portion of the filtered sample to rinse the filter flask, discard this portion and collect the required volume of filtrate. Acidify 
                            <PRTPAGE P="400"/>
                            the filtrate with (1 + 1) nitric acid immediately following filtration to pH &lt;2.
                        </P>
                        <P>8.3 For the determination of total recoverable elements in aqueous samples, samples are not filtered, but acidified with (1 + 1) nitric acid to pH &lt;2 (normally, 3 mL of (1 + 1) acid per liter of sample is sufficient for most ambient and drinking water samples). Preservation may be done at the time of collection, however, to avoid the hazards of strong acids in the field, transport restrictions, and possible contamination it is recommended that the samples be returned to the laboratory within two weeks of collection and acid preserved upon receipt in the laboratory. Following acidification, the sample should be mixed, held for 16 hours, and then verified to be pH &lt;2 just prior withdrawing an aliquot for processing or “direct analysis”. If for some reason such as high alkalinity the sample pH is verified to be &gt;2, more acid must be added and the sample held for 16 hours until verified to be pH &lt;2. See Section 8.1.</P>
                        <P>Note: When the nature of the sample is either unknown or is known to be hazardous, acidification should be done in a fume hood. See Section 5.2.</P>
                        <P>8.4 Solid samples require no preservation prior to analysis other than storage at 4 °C. There is no established holding time limitation for solid samples.</P>
                        <P>8.5 For aqueous samples, a field blank should be prepared and analyzed as required by the data user. Use the same container and acid as used in sample collection.</P>
                        <HD SOURCE="HD2">9.0 Quality Control</HD>
                        <P>9.1 Each laboratory using this method is required to operate a formal quality control (QC) program. The minimum requirements of this program consist of an initial demonstration of laboratory capability, and the periodic analysis of laboratory reagent blanks, fortified blanks and other laboratory solutions as a continuing check on performance. The laboratory is required to maintain performance records that define the quality of the data thus generated.</P>
                        <P>9.2 Initial Demonstration of Performance (mandatory).</P>
                        <P>9.2.1 The initial demonstration of performance is used to characterize instrument performance (determination of linear dynamic ranges and analysis of quality control samples) and laboratory performance (determination of method detection limits) prior to analyses conducted by this method.</P>
                        <P>9.2.2 Linear dynamic range (LDR)—The upper limit of the LDR must be established for each wavelength utilized. It must be determined from a linear calibration prepared in the normal manner using the established analytical operating procedure for the instrument. The LDR should be determined by analyzing succeedingly higher standard concentrations of the analyte until the observed analyte concentration is no more than 10% below the stated concentration of the standard. Determined LDRs must be documented and kept on file. The LDR which may be used for the analysis of samples should be judged by the analyst from the resulting data. Determined sample analyte concentrations that are greater than 90% of the determined upper LDR limit must be diluted and reanalyzed. The LDRs should be verified annually or whenever, in the judgment of the analyst, a change in analytical performance caused by either a change in instrument hardware or operating conditions would dictate they be redetermined.</P>
                        <P>9.2.3 Quality control sample (QCS)—When beginning the use of this method, on a quarterly basis, after the preparation of stock or calibration standard solutions or as required to meet data-quality needs, verify the calibration standards and acceptable instrument performance with the preparation and analyses of a QCS (Section 7.12). To verify the calibration standards the determined mean concentrations from three analyses of the QCS must be within 5% of the stated values. If the calibration standard cannot be verified, performance of the determinative step of the method is unacceptable. The source of the problem must be identified and corrected before either proceeding on with the initial determination of method detection limits or continuing with on-going analyses.</P>
                        <P>
                            9.2.4 Method detection limit (MDL)—MDLs must be established for all wavelengths utilized, using reagent water (blank) fortified at a concentration of two to three times the estimated instrument detection limit.
                            <SU>15</SU>
                             To determine MDL values, take seven replicate aliquots of the fortified reagent water and process through the entire analytical method. Perform all calculations defined in the method and report the concentration values in the appropriate units. Calculate the MDL as follows:
                        </P>
                        <FP SOURCE="FP-2">MDL = (t) × (S)</FP>
                        <FP>where:</FP>
                        <FP SOURCE="FP-2">t = students' t value for a 99% confidence level and a standard deviation estimate with n-1 degrees of freedom [t = 3.14 for seven replicates]</FP>
                        <FP SOURCE="FP-2">S = standard deviation of the replicate analyses</FP>
                        <P>
                            Note: If additional confirmation is desired, reanalyze the seven replicate aliquots on two more nonconsecutive days and again calculate the MDL values for each day. An average of the three MDL values for each analyte may provide for a more appropriate MDL estimate. If the relative standard deviation (RSD) from the analyses of the seven aliquots is &lt;10%, the concentration used to determine the analyte MDL may have been inappropriately high for the determination. If so, this could result in the calculation of 
                            <PRTPAGE P="401"/>
                            an unrealistically low MDL. Concurrently, determination of MDL in reagent water represents a best case situation and does not reflect possible matrix effects of real world samples. However, successful analyses of LFMs (Section 9.4) and the analyte addition test described in Section 9.5.1 can give confidence to the MDL value determined in reagent water. Typical single laboratory MDL values using this method are given in Table 4.
                        </P>
                        <P>The MDLs must be sufficient to detect analytes at the required levels according to compliance monitoring regulation (Section 1.2). MDLs should be determined annually, when a new operator begins work or whenever, in the judgment of the analyst, a change in analytical performance caused by either a change in instrument hardware or operating conditions would dictate they be redetermined.</P>
                        <P>9.3 Assessing Laboratory Performance (mandatory)</P>
                        <P>9.3.1 Laboratory reagent blank (LRB)—The laboratory must analyze at least one LRB (Section 7.10.2) with each batch of 20 or fewer samples of the same matrix. LRB data are used to assess contamination from the laboratory environment. LRB values that exceed the MDL indicate laboratory or reagent contamination should be suspected. When LRB values constitute 10% or more of the analyte level determined for a sample or is 2.2 times the analyte MDL whichever is greater, fresh aliquots of the samples must be prepared and analyzed again for the affected analytes after the source of contamination has been corrected and acceptable LRB values have been obtained.</P>
                        <P>9.3.2 Laboratory fortified blank (LFB)—The laboratory must analyze at least one LFB (Section 7.10.3) with each batch of samples. Calculate accuracy as percent recovery using the following equation:</P>
                        <GPH SPAN="2" DEEP="23">
                            <GID>ER18MY12.002</GID>
                        </GPH>
                        <FP>where:</FP>
                        <FP SOURCE="FP-2">R = percent recovery</FP>
                        <FP SOURCE="FP-2">LFB = laboratory fortified blank</FP>
                        <FP SOURCE="FP-2">LRB = laboratory reagent blank</FP>
                        <FP SOURCE="FP-2">s = concentration equivalent of analyte added to fortify the LBR solution</FP>
                        <P>If the recovery of any analyte falls outside the required control limits of 85-115%, that analyte is judged out of control, and the source of the problem should be identified and resolved before continuing analyses.</P>
                        <P>9.3.3 The laboratory must use LFB analyses data to assess laboratory performance against the required control limits of 85-115% (Section 9.3.2). When sufficient internal performance data become available (usually a minimum of 20-30 analyses), optional control limits can be developed from the mean percent recovery (x) and the standard deviation (S) of the mean percent recovery. These data can be used to establish the upper and lower control limits as follows:</P>
                        <FP SOURCE="FP-2">UPPER CONTROL LIMIT = x + 3S</FP>
                        <FP SOURCE="FP-2">LOWER CONTROL LIMIT = x − 3S</FP>
                        <P>The optional control limits must be equal to or better than the required control limits of 85-115%. After each five to 10 new recovery measurements, new control limits can be calculated using only the most recent 20-30 data points. Also, the standard deviation (S) data should be used to establish an on-going precision statement for the level of concentrations included in the LFB. These data must be kept on file and be available for review.</P>
                        <P>
                            9.3.4 Instrument performance check (IPC) solution—For all determinations the laboratory must analyze the IPC solution (Section 7.11) and a calibration blank immediately following daily calibration, after every 10th sample (or more frequently, if required) and at the end of the sample run. Analysis of the calibration blank should always be &lt;the analyte IDL, but greater than the lower 3-sigma control limit of the calibration blank. Analysis of the IPC solution immediately following calibration must verify that the instrument is within 5% of calibration with a relative standard deviation &lt;3% from replicate integrations 4. Subsequent analyses of the IPC solution must be within 10% of calibration. If the calibration cannot be verified within the specified limits, reanalyze either or both the IPC solution and the calibration blank. If the second analysis of the IPC solution or the calibration blank confirm calibration to be outside the limits, sample analysis must be discontinued, the cause determined, corrected and/or the instrument recalibrated. All samples following the last acceptable IPC solution must be reanalyzed. The analysis data of the calibration blank and IPC solution must be kept on file with the sample analyses data.
                            <PRTPAGE P="402"/>
                        </P>
                        <P>9.3.5 Spectral interference check (SIC) solution—For all determinations the laboratory must periodically verify the interelement spectral interference correction routine by analyzing SIC solutions. The preparation and required periodic analysis of SIC solutions and test criteria for verifying the interelement interference correction routine are given in Section 7.13. Special cases where on-going verification is required are described in Section 7.14.</P>
                        <P>9.4 Assessing Analyte Recovery and Data Quality.</P>
                        <P>9.4.1 Sample homogeneity and the chemical nature of the sample matrix can affect analyte recovery and the quality of the data. Taking separate aliquots from the sample for replicate and fortified analyses can in some cases assess the effect. Unless otherwise specified by the data user, laboratory or program, the following laboratory fortified matrix (LFM) procedure (Section 9.4.2) is required. Also, other tests such as the analyte addition test (Section 9.5.1) and sample dilution test (Section 9.5.2) can indicate if matrix effects are operative.</P>
                        <P>9.4.2 The laboratory must add a known amount of each analyte to a minimum of 10% of the routine samples. In each case the LFM aliquot must be a duplicate of the aliquot used for sample analysis and for total recoverable determinations added prior to sample preparation. For water samples, the added analyte concentration must be the same as that used in the laboratory fortified blank (Section 7.10.3). For solid samples, however, the concentration added should be expressed as mg/kg and is calculated for a one gram aliquot by multiplying the added analyte concentration (mg/L) in solution by the conversion factor 100 (mg/L × 0.1L/0.001kg = 100, Section 12.5). (For notes on Ag, Ba, and Sn see Sections 1.7 and 1.8.) Over time, samples from all routine sample sources should be fortified.</P>
                        <P>Note: The concentration of calcium, magnesium, sodium and strontium in environmental waters, along with iron and aluminum in solids can vary greatly and are not necessarily predictable. Fortifying these analytes in routine samples at the same concentration used for the LFB may prove to be of little use in assessing data quality for these analytes. For these analytes sample dilution and reanalysis using the criteria given in Section 9.5.2 is recommended. Also, if specified by the data user, laboratory or program, samples can be fortified at higher concentrations, but even major constituents should be limited to &lt;25 mg/L so as not to alter the sample matrix and affect the analysis.</P>
                        <P>
                            9.4.3 Calculate the percent recovery for each analyte, corrected for background concentrations measured in the unfortified sample, and compare these values to the designated LFM recovery range of 70-130% or a 3-sigma recovery range calculated from the regression equations given in Table 9.
                            <SU>16</SU>
                             Recovery calculations are not required if the concentration added is less than 30% of the sample background concentration. Percent recovery may be calculated in units appropriate to the matrix, using the following equation:
                        </P>
                        <GPH SPAN="2" DEEP="23">
                            <GID>ER18MY12.003</GID>
                        </GPH>
                        <FP>where:</FP>
                        <FP SOURCE="FP-2">R = percent recovery</FP>
                        <FP SOURCE="FP-2">
                            C
                            <E T="52">s</E>
                             = fortified sample concentration
                        </FP>
                        <FP SOURCE="FP-2">C = sample background concentration</FP>
                        <FP SOURCE="FP-2">s = concentration equivalent of analyte added to fortify the sample</FP>
                        <P>9.4.4 If the recovery of any analyte falls outside the designated LFM recovery range, and the laboratory performance for that analyte is shown to be in control (Section 9.3), the recovery problem encountered with the fortified sample is judged to be matrix related, not system related. The data user should be informed that the result for that analyte in the unfortified sample is suspect due to either the heterogeneous nature of the sample or matrix effects and analysis by method of standard addition or the use of an internal standard(s) (Section 11.5) should be considered.</P>
                        <P>9.4.5 Where reference materials are available, they should be analyzed to provide additional performance data. The analysis of reference samples is a valuable tool for demonstrating the ability to perform the method acceptably. Reference materials containing high concentrations of analytes can provide additional information on the performance of the spectral interference correction routine.</P>
                        <P>9.5 Assess the possible need for the method of standard additions (MSA) or internal standard elements by the following tests. Directions for using MSA or internal standard(s) are given in Section 11.5.</P>
                        <P>
                            9.5.1 Analyte addition test: An analyte(s) standard added to a portion of a prepared sample, or its dilution, should be recovered to within 85% to 115% of the known value. The analyte(s) addition should produce a 
                            <PRTPAGE P="403"/>
                            minimum level of 20 times and a maximum of 100 times the method detection limit. If the analyte addition is &lt;20% of the sample analyte concentration, the following dilution test should be used. If recovery of the analyte(s) is not within the specified limits, a matrix effect should be suspected, and the associated data flagged accordingly. The method of additions or the use of an appropriate internal standard element may provide more accurate data.
                        </P>
                        <P>9.5.2 Dilution test: If the analyte concentration is sufficiently high (minimally, a factor of 50 above the instrument detection limit in the original solution but &lt;90% of the linear limit), an analysis of a 1 + 4 dilution should agree (after correction for the fivefold dilution) within 10% of the original determination. If not, a chemical or physical interference effect should be suspected and the associated data flagged accordingly. The method of standard additions or the use of an internal-standard element may provide more accurate data for samples failing this test.</P>
                        <HD SOURCE="HD2">10.0 Calibration and Standardization</HD>
                        <P>
                            10.1 Specific wavelengths are listed in Table 1. Other wavelengths may be substituted if they can provide the needed sensitivity and are corrected for spectral interference. However, because of the difference among various makes and models of spectrometers, specific instrument operating conditions cannot be given. The instrument and operating conditions utilized for determination must be capable of providing data of acceptable quality to the program and data user. The analyst should follow the instructions provided by the instrument manufacturer unless other conditions provide similar or better performance for a task. Operating conditions for aqueous solutions usually vary from 1100-1200 watts forward power, 15-16 mm viewing height, 15-19 L/min. argon coolant flow, 0.6-1 L/min. argon aerosol flow, 1-1.8 mL/min. sample pumping rate with a one minute preflush time and measurement time near 1 s per wavelength peak (for sequential instruments) and near 10 s per sample (for simultaneous instruments). Use of the Cu/Mn intensity ratio at 324.754 nm and 257.610 nm (by adjusting the argon aerosol flow) has been recommended as a way to achieve repeatable interference correction factors.
                            <SU>17</SU>
                        </P>
                        <P>10.2 Prior to using this method optimize the plasma operating conditions. The following procedure is recommended for vertically configured plasmas. The purpose of plasma optimization is to provide a maximum signal-to-background ratio for the least sensitive element in the analytical array. The use of a mass flow controller to regulate the nebulizer gas flow rate greatly facilitates the procedure.</P>
                        <P>
                            10.2.1 Ignite the plasma and select an appropriate incident rf power with minimum reflected power. Allow the instrument to become thermally stable before beginning. This usually requires at least 30 to 60 minutes of operation. While aspirating the 1000 µg/mL solution of yttrium (Section 7.8.32), follow the instrument manufacturer's instructions and adjust the aerosol carrier gas flow rate through the nebulizer so a definitive blue emission region of the plasma extends approximately from 5-20 mm above the top of the work coil.
                            <SU>18</SU>
                             Record the nebulizer gas flow rate or pressure setting for future reference.
                        </P>
                        <P>10.2.2 After establishing the nebulizer gas flow rate, determine the solution uptake rate of the nebulizer in mL/min. by aspirating a known volume calibration blank for a period of at least three minutes. Divide the spent volume by the aspiration time (in minutes) and record the uptake rate. Set the peristaltic pump to deliver the uptake rate in a steady even flow.</P>
                        <P>
                            10.2.3 After horizontally aligning the plasma and/or optically profiling the spectrometer, use the selected instrument conditions from Sections 10.2.1 and 10.2.2, and aspirate the plasma solution (Section 7.15), containing 10 µg/mL each of As, Pb, Se and Tl. Collect intensity data at the wavelength peak for each analyte at 1 mm intervals from 14-18 mm above the top of the work coil. (This region of the plasma is commonly referred to as the analytical zone.)
                            <SU>19</SU>
                             Repeat the process using the calibration blank. Determine the net signal to blank intensity ratio for each analyte for each viewing height setting. Choose the height for viewing the plasma that provides the largest intensity ratio for the least sensitive element of the four analytes. If more than one position provides the same ratio, select the position that provides the highest net intensity counts for the least sensitive element or accept a compromise position of the intensity ratios of all four analytes.
                        </P>
                        <P>10.2.4 The instrument operating condition finally selected as being optimum should provide the lowest reliable instrument detection limits and method detection limits. Refer to Tables 1 and 4 for comparison of IDLs and MDLs, respectively.</P>
                        <P>10.2.5 If either the instrument operating conditions, such as incident power and/or nebulizer gas flow rate are changed, or a new torch injector tube having a different orifice i.d. is installed, the plasma and plasma viewing height should be reoptimized.</P>
                        <P>
                            10.2.6 Before daily calibration and after the instrument warmup period, the nebulizer gas flow must be reset to the determined optimized flow. If a mass flow controller is being used, it should be reset to the recorded optimized flow rate. In order to maintain valid spectral interelement correction routines the nebulizer gas flow rate should be 
                            <PRTPAGE P="404"/>
                            the same from day-to-day (&lt;2% change). The change in signal intensity with a change in nebulizer gas flow rate for both “hard” (Pb 220.353 nm) and “soft” (Cu 324.754) lines is illustrated in Figure 1.
                        </P>
                        <P>10.3 Before using the procedure (Section 11.0) to analyze samples, there must be data available documenting initial demonstration of performance. The required data and procedure is described in Section 9.2. This data must be generated using the same instrument operating conditions and calibration routine (Section 11.4) to be used for sample analysis. These documented data must be kept on file and be available for review by the data user.</P>
                        <P>10.4 After completing the initial demonstration of performance, but before analyzing samples, the laboratory must establish and initially verify an interelement spectral interference correction routine to be used during sample analysis. A general description concerning spectral interference and the analytical requirements for background correction and for correction of interelement spectral interference in particular are given in Section 4.1. To determine the appropriate location for background correction and to establish the interelement interference correction routine, repeated spectral scan about the analyte wavelength and repeated analyses of the single element solutions may be required. Criteria for determining an interelement spectral interference is an apparent positive or negative concentration on the analyte that is outside the 3-sigma control limits of the calibration blank for the analyte. (The upper-control limit is the analyte IDL.) Once established, the entire routine must be initially and periodically verified annually, or whenever there is a change in instrument operating conditions (Section 10.2.5). Only a portion of the correction routine must be verified more frequently or on a daily basis. Test criteria and required solutions are described in Section 7.13. Initial and periodic verification data of the routine should be kept on file. Special cases where on-going verification are required is described in Section 7.14.</P>
                        <HD SOURCE="HD2">11.0 Procedure</HD>
                        <HD SOURCE="HD3">11.1 Aqueous Sample Preparation—Dissolved Analytes</HD>
                        <P>
                            11.1.1 For the determination of dissolved analytes in ground and surface waters, pipet an aliquot (20 mL) of the filtered, acid preserved sample into a 50 mL polypropylene centrifuge tube. Add an appropriate volume of (1 + 1) nitric acid to adjust the acid concentration of the aliquot to approximate a 1% (v/v) nitric acid solution (e.g., add 0.4 mL (1 + 1) HNO
                            <E T="52">3</E>
                             to a 20 mL aliquot of sample). Cap the tube and mix. The sample is now ready for analysis (Section 1.3). Allowance for sample dilution should be made in the calculations. (If mercury is to be determined, a separate aliquot must be additionally acidified to contain 1% (v/v) HCl to match the signal response of mercury in the calibration standard and reduce memory interference effects. Section 1.9).
                        </P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>If a precipitate is formed during acidification, transport, or storage, the sample aliquot must be treated using the procedure described in Sections 11.2.2 through 11.2.7 prior to analysis.</P>
                        </NOTE>
                        <HD SOURCE="HD3">11.2 Aqueous Sample Preparation—Total Recoverable Analytes</HD>
                        <P>11.2.1 For the “direct analysis” of total recoverable analytes in drinking water samples containing turbidity &lt;1 NTU, treat an unfiltered acid preserved sample aliquot using the sample preparation procedure described in Section 11.1.1 while making allowance for sample dilution in the data calculation (Section 1.2). For the determination of total recoverable analytes in all other aqueous samples or for preconcentrating drinking water samples prior to analysis follow the procedure given in Sections 11.2.2 through 11.2.7.</P>
                        <P>11.2.2 For the determination of total recoverable analytes in aqueous samples (other than drinking water with &lt;1 NTU turbidity), transfer a 100 mL (1 mL) aliquot from a well mixed, acid preserved sample to a 250 mL Griffin beaker (Sections 1.2, 1.3, 1.6, 1.7, 1.8, and 1.9). (When necessary, smaller sample aliquot volumes may be used.)</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>
                                If the sample contains 
                                <E T="03">undissolved</E>
                                 solids &gt;1%, a well mixed, acid preserved aliquot containing no more than 1 g particulate material should be cautiously evaporated to near 10 mL and extracted using the acid-mixture procedure described in Sections 11.3.3 through 11.3.6.
                            </P>
                        </NOTE>
                        <P>11.2.3 Add 2 mL (1 + 1) nitric acid and 1.0 mL of (1 + 1) hydrochloric acid to the beaker containing the measured volume of sample. Place the beaker on the hot plate for solution evaporation. The hot plate should be located in a fume hood and previously adjusted to provide evaporation at a temperature of approximately but no higher than 85 °C. (See the following note.) The beaker should be covered with an elevated watch glass or other necessary steps should be taken to prevent sample contamination from the fume hood environment.</P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>For proper heating adjust the temperature control of the hot plate such that an uncovered Griffin beaker containing 50 mL of water placed in the center of the hot plate can be maintained at a temperature approximately but no higher than 85 °C. (Once the beaker is covered with a watch glass the temperature of the water will rise to approximately 95 °C.)</P>
                        </NOTE>
                        <PRTPAGE P="405"/>
                        <P>
                            11.2.4 Reduce the volume of the sample aliquot to about 20 mL by gentle heating at 85 °C. 
                            <E T="03">DO NOT BOIL.</E>
                             This step takes about two hours for a 100 mL aliquot with the rate of evaporation rapidly increasing as the sample volume approaches 20 mL. (A spare beaker containing 20 mL of water can be used as a gauge.)
                        </P>
                        <P>
                            11.2.5 Cover the lip of the beaker with a watch glass to reduce additional evaporation and gently reflux the sample for 30 minutes. (Slight boiling may occur, but vigorous boiling must be avoided to prevent loss of the HCl-H
                            <E T="52">2</E>
                            O azeotrope.)
                        </P>
                        <P>11.2.6 Allow the beaker to cool. Quantitatively transfer the sample solution to a 50 mL volumetric flask, make to volume with reagent water, stopper and mix.</P>
                        <P>11.2.7 Allow any undissolved material to settle overnight, or centrifuge a portion of the prepared sample until clear. (If after centrifuging or standing overnight the sample contains suspended solids that would clog the nebulizer, a portion of the sample may be filtered for their removal prior to analysis. However, care should be exercised to avoid potential contamination from filtration.) The sample is now ready for analysis. Because the effects of various matrices on the stability of diluted samples cannot be characterized, all analyses should be performed as soon as possible after the completed preparation.</P>
                        <HD SOURCE="HD3">11.3 Solid Sample Preparation—Total Recoverable Analytes</HD>
                        <P>11.3.1 For the determination of total recoverable analytes in solid samples, mix the sample thoroughly and transfer a portion (&gt;20 g) to tared weighing dish, weigh the sample and record the wet weight (WW). (For samples with &lt;35% moisture a 20 g portion is sufficient. For samples with moisture &gt;35% a larger aliquot 50-100 g is required.) Dry the sample to a constant weight at 60 °C and record the dry weight (DW) for calculation of percent solids (Section 12.6). (The sample is dried at 60 °C to prevent the loss of mercury and other possible volatile metallic compounds, to facilitate sieving, and to ready the sample for grinding.)</P>
                        <P>11.3.2 To achieve homogeneity, sieve the dried sample using a 5-mesh polypropylene sieve and grind in a mortar and pestle. (The sieve, mortar and pestle should be cleaned between samples.) From the dried, ground material weigh accurately a representative 1.0 ±0.01 g aliquot (W) of the sample and transfer to a 250 mL Phillips beaker for acid extraction (Sections 1.6, 1.7, 1.8, and 1.9).</P>
                        <P>
                            11.3.3 To the beaker add 4 mL of (1 + 1) HNO
                            <E T="52">3</E>
                             and 10 mL of (1 + 4) HCl. Cover the lip of the beaker with a watch glass. Place the beaker on a hot plate for reflux extraction of the analytes. The hot plate should be located in a fume hood and previously adjusted to provide a reflux temperature of approximately 95 °C. (See the following note.)
                        </P>
                        <NOTE>
                            <HD SOURCE="HED">Note:</HD>
                            <P>For proper heating adjust the temperature control of the hot plate such that an uncovered Griffin beaker containing 50 mL of water placed in the center of the hot plate can be maintained at a temperature approximately but no higher than 85 °C. (Once the beaker is covered with a watch glass the temperature of the water will rise to approximately 95 °C.) Also, a block digester capable of maintaining a temperature of 95 °C and equipped with 250 mL constricted volumetric digestion tubes may be substituted for the hot plate and conical beakers in the extraction step.</P>
                        </NOTE>
                        <P>
                            11.3.4 Heat the sample and gently reflux for 30 minutes. Very slight boiling may occur, however vigorous boiling must be avoided to prevent loss of the HCl-H
                            <E T="52">2</E>
                            O azeotrope. Some solution evaporation will occur (3-4 mL).
                        </P>
                        <P>11.3.5 Allow the sample to cool and quantitatively transfer the extract to a 100 mL volumetric flask. Dilute to volume with reagent water, stopper and mix.</P>
                        <P>11.3.6 Allow the sample extract solution to stand overnight to separate insoluble material or centrifuge a portion of the sample solution until clear. (If after centrifuging or standing overnight the extract solution contains suspended solids that would clog the nebulizer, a portion of the extract solution may be filtered for their removal prior to analysis. However, care should be exercised to avoid potential contamination from filtration.) The sample extract is now ready for analysis. Because the effects of various matrices on the stability of diluted samples cannot be characterized, all analyses should be performed as soon as possible after the completed preparation.</P>
                        <HD SOURCE="HD3">11.4 Sample Analysis</HD>
                        <P>11.4.1 Prior to daily calibration of the instrument inspect the sample introduction system including the nebulizer, torch, injector tube and uptake tubing for salt deposits, dirt and debris that would restrict solution flow and affect instrument performance. Clean the system when needed or on a daily basis.</P>
                        <P>11.4.2 Configure the instrument system to the selected power and operating conditions as determined in Sections 10.1 and 10.2.</P>
                        <P>
                            11.4.3 The instrument must be allowed to become thermally stable before calibration and analyses. This usually requires at least 30 to 60 minutes of operation. After instrument warmup, complete any required optical profiling or alignment particular to the instrument.
                            <PRTPAGE P="406"/>
                        </P>
                        <P>
                            11.4.4 For initial and daily operation calibrate the instrument according to the instrument manufacturer's recommended procedures, using mixed calibration standard solutions (Section 7.9) and the calibration blank (Section 7.10.1). A peristaltic pump must be used to introduce all solutions to the nebulizer. To allow equilibrium to be reached in the plasma, aspirate all solutions for 30 seconds after reaching the plasma before beginning integration of the background corrected signal to accumulate data. When possible, use the average value of replicate integration periods of the signal to be correlated to the analyte concentration. Flush the system with the rinse blank (Section 7.10.4) for a minimum of 60 seconds (Section 4.4) between each standard. The calibration line should consist of a minimum of a calibration blank and a high standard. Replicates of the blank and highest standard provide an optimal distribution of calibration standards to minimize the confidence band for a straight-line calibration in a response region with uniform variance.
                            <SU>20</SU>
                        </P>
                        <P>11.4.5 After completion of the initial requirements of this method (Sections 10.3 and 10.4), samples should be analyzed in the same operational manner used in the calibration routine with the rinse blank also being used between all sample solutions, LFBs, LFMs, and check solutions (Section 7.10.4).</P>
                        <P>11.4.6 During the analysis of samples, the laboratory must comply with the required quality control described in Sections 9.3 and 9.4. Only for the determination of dissolved analytes or the “direct analysis” of drinking water with turbidity of &lt;1 NTU is the sample digestion step of the LRB, LFB, and LFM not required.</P>
                        <P>11.4.7 Determined sample analyte concentrations that are 90% or more of the upper limit of the analyte LDR must be diluted with reagent water that has been acidified in the same manner as calibration blank and reanalyzed (see Section 11.4.8). Also, for the interelement spectral interference correction routines to remain valid during sample analysis, the interferant concentration must not exceed its LDR. If the interferant LDR is exceeded, sample dilution with acidified reagent water and reanalysis is required. In these circumstances analyte detection limits are raised and determination by another approved test procedure that is either more sensitive and/or interference free is recommended.</P>
                        <P>11.4.8 When it is necessary to assess an operative matrix interference (e.g., signal reduction due to high dissolved solids), the tests described in Section 9.5 are recommended.</P>
                        <P>11.4.9 Report data as directed in Section 12.0.</P>
                        <P>
                            11.5 If the method of standard additions (MSA) is used, standards are added at one or more levels to portions of a prepared sample. This technique 
                            <SU>21</SU>
                             compensates for enhancement or depression of an analyte signal by a matrix. It will not correct for additive interferences such as contamination, interelement interferences, or baseline shifts. This technique is valid in the linear range when the interference effect is constant over the range, the added analyte responds the same as the endogenous analyte, and the signal is corrected for additive interferences. The simplest version of this technique is the single-addition method. This procedure calls for two identical aliquots of the sample solution to be taken. To the first aliquot, a small volume of standard is added; while to the second aliquot, a volume of acid blank is added equal to the standard addition. The sample concentration is calculated by the following:
                        </P>
                        <GPH SPAN="2" DEEP="26">
                            <GID>ER18MY12.004</GID>
                        </GPH>
                        <FP>where:</FP>
                        <FP SOURCE="FP-2">C = Concentration of the standard solution (mg/L)</FP>
                        <FP SOURCE="FP-2">
                            S
                            <E T="52">1</E>
                             = Signal for fortified aliquot
                        </FP>
                        <FP SOURCE="FP-2">
                            S
                            <E T="52">2</E>
                             = Signal for unfortified aliquot
                        </FP>
                        <FP SOURCE="FP-2">
                            V
                            <E T="52">1</E>
                             = Volume of the standard addition (L)
                        </FP>
                        <FP SOURCE="FP-2">
                            V
                            <E T="52">2</E>
                             = Volume of the sample aliquot (L) used for MSA
                        </FP>
                        <P>For more than one fortified portion of the prepared sample, linear regression analysis can be applied using a computer or calculator program to obtain the concentration of the sample solution. An alternative to using the method of standard additions is use of the internal standard technique by adding one or more elements (not in the samples and verified not to cause an uncorrected interelement spectral interference) at the same concentration (which is sufficient for optimum precision) to the prepared samples (blanks and standards) that are affected the same as the analytes by the sample matrix. Use the ratio of analyte signal to the internal standard signal for calibration and quantitation.</P>
                        <HD SOURCE="HD2">12.0 Data Analysis and Calculations</HD>
                        <P>
                            12.1 Sample data should be reported in units of mg/L for aqueous samples and mg/kg dry weight for solid samples.
                            <PRTPAGE P="407"/>
                        </P>
                        <P>12.2 For dissolved aqueous analytes (Section 11.1) report the data generated directly from the instrument with allowance for sample dilution. Do not report analyte concentrations below the IDL.</P>
                        <P>12.3 For total recoverable aqueous analytes (Section 11.2), multiply solution analyte concentrations by the dilution factor 0.5, when 100 mL aliquot is used to produce the 50 mL final solution, and report data as instructed in Section 12.4. If a different aliquot volume other than 100 mL is used for sample preparation, adjust the dilution factor accordingly. Also, account for any additional dilution of the prepared sample solution needed to complete the determination of analytes exceeding 90% or more of the LDR upper limit. Do not report data below the determined analyte MDL concentration or below an adjusted detection limit reflecting smaller sample aliquots used in processing or additional dilutions required to complete the analysis.</P>
                        <P>12.4 For analytes with MDLs &lt;0.01 mg/L, round the data values to the thousandth place and report analyte concentrations up to three significant figures. For analytes with MDLs &lt;0.01 mg/L round the data values to the 100th place and report analyte concentrations up to three significant figures. Extract concentrations for solids data should be rounded in a similar manner before calculations in Section 12.5 are performed.</P>
                        <P>12.5 For total recoverable analytes in solid samples (Section 11.3), round the solution analyte concentrations (mg/L) as instructed in Section 12.4. Report the data up to three significant figures as mg/kg dry-weight basis unless specified otherwise by the program or data user. Calculate the concentration using the equation below:</P>
                        <GPH SPAN="2" DEEP="23">
                            <GID>ER18MY12.005</GID>
                        </GPH>
                        <FP>where:</FP>
                        <FP SOURCE="FP-2">C = Concentration in extract (mg/L)</FP>
                        <FP SOURCE="FP-2">V = Volume of extract (L, 100 mL = 0.1L)</FP>
                        <FP SOURCE="FP-2">D = Dilution factor (undiluted = 1)</FP>
                        <FP SOURCE="FP-2">W = Weight of sample aliquot extracted (g × 0.001 = kg)</FP>
                        <P>Do not report analyte data below the estimated solids MDL or an adjusted MDL because of additional dilutions required to complete the analysis.</P>
                        <P>12.6 To report percent solids in solid samples (Section 11.3) calculate as follows:</P>
                        <GPH SPAN="2" DEEP="23">
                            <GID>ER18MY12.006</GID>
                        </GPH>
                        <FP>where:</FP>
                        <FP SOURCE="FP-2">DW = Sample weight (g) dried at 60 ºC</FP>
                        <FP SOURCE="FP-2">WW = Sample weight (g) before drying</FP>
                        <P>Note: If the data user, program or laboratory requires that the reported percent solids be determined by drying at 105 °C, repeat the procedure given in Section 11.3 using a separate portion (&gt;20 g) of the sample and dry to constant weight at 103-105 °C.</P>
                        <P>12.7 The QC data obtained during the analyses provide an indication of the quality of the sample data and should be provided with the sample results.</P>
                        <HD SOURCE="HD2">13.0 Method Performance</HD>
                        <P>13.1 Listed in Table 4 are typical single laboratory total recoverable MDLs determined for the recommended wavelengths using simultaneous ICP-AES and the operating conditions given in Table 5. The MDLs were determined in reagent blank matrix (best case situation). PTFE beakers were used to avoid boron and silica contamination from glassware with the final dilution to 50 mL completed in polypropylene centrifuged tubes. The listed MDLs for solids are estimates and were calculated from the aqueous MDL determinations.</P>
                        <P>
                            13.2 Data obtained from single laboratory method testing are summarized in Table 6 for five types of water samples consisting of drinking water, surface water, ground water, and two wastewater effluents. The data presented cover all analytes except cerium and titanium. Samples were prepared using the procedure described in Section 11.2. For each matrix, five replicate aliquots were prepared, analyzed and the average of the five determinations used to define the sample background concentration of each analyte. In addition, two pairs of duplicates were fortified at different concentration levels. For each method analyte, the sample background concentration, mean percent recovery, standard 
                            <PRTPAGE P="408"/>
                            deviation of the percent recovery, and relative percent difference between the duplicate fortified samples are listed in Table 6. The variance of the five replicate sample background determinations is included in the calculated standard deviation of the percent recovery when the analyte concentration in the sample was greater than the MDL. The tap and well waters were processed in Teflon and quartz beakers and diluted in polypropylene centrifuged tubes. The nonuse of borosilicate glassware is reflected in the precision and recovery data for boron and silica in those two sample types.
                        </P>
                        <P>13.3 Data obtained from single laboratory method testing are summarized in Table 7 for three solid samples consisting of EPA 884 Hazardous Soil, SRM 1645 River Sediment, and EPA 286 Electroplating Sludge. Samples were prepared using the procedure described in Section 11.3. For each method analyte, the sample background concentration, mean percent recovery of the fortified additions, the standard deviation of the percent recovery, and relative percent difference between duplicate additions were determined as described in Section 13.2. Data presented are for all analytes except cerium, silica, and titanium. Limited comparative data to other methods and SRM materials are presented in Reference 23 of Section 16.0.</P>
                        <P>
                            13.4 Performance data for aqueous solutions independent of sample preparation from a multilaboratory study are provided in Table 8.
                            <SU>22</SU>
                        </P>
                        <P>
                            13.5 Listed in Table 9 are regression equations for precision and bias for 25 analytes abstracted from EPA Method Study 27, a multilaboratory validation study of Method 200.7.
                            <SU>1</SU>
                             These equations were developed from data received from 12 laboratories using the total recoverable sample preparation procedure on reagent water, drinking water, surface water and three industrial effluents. For a complete review and description of the study, see Reference 16 of Section 16.0.
                        </P>
                        <HD SOURCE="HD2">14.0 Pollution Prevention</HD>
                        <P>14.1 Pollution prevention encompasses any technique that reduces or eliminates the quantity or toxicity of waste at the point of generation. Numerous opportunities for pollution prevention exist in laboratory operation. The EPA has established a preferred hierarchy of environmental management techniques that places pollution prevention as the management option of first choice. Whenever feasible, laboratory personnel should use pollution prevention techniques to address their waste generation (e.g., Section 7.8). When wastes cannot be feasibly reduced at the source, the Agency recommends recycling as the next best option.</P>
                        <P>14.2 For information about pollution prevention that may be applicable to laboratories and research institutions, consult “Less is Better: Laboratory Chemical Management for Waste Reduction”, available from the American Chemical Society's Department of Government Relations and Science Policy, 1155 16th Street NW., Washington, DC 20036, (202) 872-4477.</P>
                        <HD SOURCE="HD2">15.0 Waste Management</HD>
                        <P>15.1 The Environmental Protection Agency requires that laboratory waste management practices be conducted consistent with all applicable rules and regulations. The Agency urges laboratories to protect the air, water, and land by minimizing and controlling all releases from hoods and bench operations, complying with the letter and spirit of any sewer discharge permits and regulations, and by complying with all solid and hazardous waste regulations, particularly the hazardous waste identification rules and land disposal restrictions. For further information on waste management consult “The Waste Management Manual for Laboratory Personnel”, available from the American Chemical Society at the address listed in the Section 14.2.</P>
                        <HD SOURCE="HD2">16.0 References</HD>
                        <FP SOURCE="FP-2">1. U.S. Environmental Protection Agency. Inductively Coupled Plasma—Atomic Emission Spectrometric Method for Trace Element Analysis of Water and Wastes—Method 200.7, Dec. 1982. EPA-600/4-79-020, revised March 1983.</FP>
                        <FP SOURCE="FP-2">2. U.S. Environmental Protection Agency. Inductively Coupled Plasma Atomic Emission Spectroscopy Method 6010, SW-846 Test Methods for Evaluating Solid Waste, 3rd Edition, 1986.</FP>
                        <FP SOURCE="FP-2">3. U.S. Environmental Protection Agency. Method 200.7: Determination of Metals and Trace Elements in Water and Wastes by Inductively Coupled Plasma—Atomic Emission Spectrometry, revision 3.3, EPA 600 4-91/010, June 1991.</FP>
                        <FP SOURCE="FP-2">4. U.S. Environmental Protection Agency. Inductively Coupled Plasma—Atomic Emission Spectrometry Method for the Analysis of Waters and Solids, EMMC, July 1992.</FP>
                        <FP SOURCE="FP-2">
                            5. Fassel, V.A. et al. Simultaneous Determination of Wear Metals in Lubricating Oils by Inductively-Coupled Plasma Atomic Emission Spectrometry. Anal. Chem. 
                            <E T="03">48:</E>
                            516-519, 1976.
                        </FP>
                        <FP SOURCE="FP-2">
                            6. Merryfield, R.N. and R.C. Loyd. Simultaneous Determination of Metals in Oil by Inductively Coupled Plasma Emission Spectrometry. Anal. Chem. 
                            <E T="03">51:</E>
                            1965-1968, 1979.
                        </FP>
                        <FP SOURCE="FP-2">7. Winge, R.K. et al. Inductively Coupled Plasma—Atomic Emission Spectroscopy: An Atlas of Spectral Information, Physical Science Data 20. Elsevier Science Publishing, New York, New York, 1985.</FP>
                        <FP SOURCE="FP-2">
                            8. Boumans, P.W.J.M. Line Coincidence Tables for Inductively Coupled Plasma 
                            <PRTPAGE P="409"/>
                            Atomic Emission Spectrometry, 2nd edition. Pergamon Press, Oxford, United Kingdom, 1984.
                        </FP>
                        <FP SOURCE="FP-2">9. Carcinogens—Working With Carcinogens, Department of Health, Education, and Welfare, Public Health Service, Center for Disease Control, National Institute for Occupational Safety and Health, Publication No. 77-206, Aug. 1977. Available from the National Technical Information Service (NTIS) as PB-277256.</FP>
                        <FP SOURCE="FP-2">10. OSHA Safety and Health Standards, General Industry, (29 CFR 1910), Occupational Safety and Health Administration, OSHA 2206, (Revised, January 1976).</FP>
                        <FP SOURCE="FP-2">11. Safety in Academic Chemistry Laboratories, American Chemical Society Publication, Committee on Chemical Safety, 3rd Edition, 1979.</FP>
                        <FP SOURCE="FP-2">
                            12. Proposed OSHA Safety and Health Standards, Laboratories, Occupational Safety and Health Administration, 
                            <E T="04">Federal Register,</E>
                             July 24, 1986.
                        </FP>
                        <FP SOURCE="FP-2">13. Rohrbough, W.G. et al. Reagent Chemicals, American Chemical Society Specifications, 7th edition. American Chemical Society, Washington, DC, 1986.</FP>
                        <FP SOURCE="FP-2">14. American Society for Testing and Materials. Standard Specification for Reagent Water, D1193-77. Annual Book of ASTM Standards, Vol. 11.01. Philadelphia, PA, 1991.</FP>
                        <FP SOURCE="FP-2">
                            15. Code of Federal Regulations 
                            <E T="03">40,</E>
                             Ch. 1, Pt. 136 Appendix B.
                        </FP>
                        <FP SOURCE="FP-2">16. Maxfield, R. and B. Mindak. EPA Method Study 27, Method 200.7 Trace Metals by ICP, Nov. 1983. Available from National Technical Information Service (NTIS) as PB 85-248-656.</FP>
                        <FP SOURCE="FP-2">17. Botto, R.I. Quality Assurance in Operating a Multielement ICP Emission Spectrometer. Spectrochim. Acta, 39B(1):95-113, 1984.</FP>
                        <FP SOURCE="FP-2">18. Wallace, G.F., Some Factors Affecting the Performance of an ICP Sample Introduction System. Atomic Spectroscopy, Vol. 4, p. 188-192, 1983.</FP>
                        <FP SOURCE="FP-2">
                            19. Koirtyohann, S.R. et al. Nomenclature System for the Low-Power Argon Inductively Coupled Plasma, Anal. Chem. 
                            <E T="03">52:</E>
                            1965, 1980.
                        </FP>
                        <FP SOURCE="FP-2">20. Deming, S.N. and S.L. Morgan. Experimental Design for Quality and Productivity in Research, Development, and Manufacturing, Part III, pp. 119-123. Short course publication by Statistical Designs, 9941 Rowlett, Suite 6, Houston, TX 77075, 1989.</FP>
                        <FP SOURCE="FP-2">21. Winefordner, J.D., Trace Analysis: Spectroscopic Methods for Elements, Chemical Analysis, Vol. 46, pp. 41-42.</FP>
                        <FP SOURCE="FP-2">22. Jones, C.L. et al. An Interlaboratory Study of Inductively Coupled Plasma Atomic Emission Spectroscopy Method 6010 and Digestion Method 3050. EPA-600/4-87-032, U.S. Environmental Protection Agency, Las Vegas, Nevada, 1987.</FP>
                        <FP SOURCE="FP-2">
                            23. Martin, T.D., E.R. Martin and SE. Long. 
                            <E T="03">Method 200.2: Sample Preparation Procedure for Spectrochemical Analyses of Total Recoverable Elements,</E>
                             EMSL ORD, USEPA, 1989.
                        </FP>
                        <HD SOURCE="HD2">17.0 Tables, Diagrams, Flowcharts, and Validation Data</HD>
                        <GPOTABLE COLS="4" OPTS="L2" CDEF="s30,r30,xs28,xs34">
                            <TTITLE>Table 1—Wavelengths, Estimated Instrument Detection Limits, and Recommended Calibration</TTITLE>
                            <BOXHD>
                                <CHED H="1">Analyte</CHED>
                                <CHED H="1">
                                    Wavelength
                                    <SU>a</SU>
                                    <LI>(nm)</LI>
                                </CHED>
                                <CHED H="1">
                                    Estimated
                                    <LI>detection</LI>
                                    <LI>
                                        limit
                                        <SU>b</SU>
                                         (µg/L)
                                    </LI>
                                </CHED>
                                <CHED H="1">
                                    Calibrate
                                    <SU>c</SU>
                                    <LI>to (mg/L)</LI>
                                </CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">Aluminum</ENT>
                                <ENT>308.215</ENT>
                                <ENT>45</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Antimony</ENT>
                                <ENT>206.833</ENT>
                                <ENT>32</ENT>
                                <ENT>5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Arsenic</ENT>
                                <ENT>193.759</ENT>
                                <ENT>53</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Barium</ENT>
                                <ENT>493.409</ENT>
                                <ENT>2.3</ENT>
                                <ENT>1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Beryllium</ENT>
                                <ENT>313.042</ENT>
                                <ENT>0.27</ENT>
                                <ENT>1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Boron</ENT>
                                <ENT>249.678</ENT>
                                <ENT>5.7</ENT>
                                <ENT>1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Cadmium</ENT>
                                <ENT>226.502</ENT>
                                <ENT>3.4</ENT>
                                <ENT>2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Calcium</ENT>
                                <ENT>315.887</ENT>
                                <ENT>30</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Cerium</ENT>
                                <ENT>413.765</ENT>
                                <ENT>48</ENT>
                                <ENT>2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chromium</ENT>
                                <ENT>205.552</ENT>
                                <ENT>6.1</ENT>
                                <ENT>5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Cobalt</ENT>
                                <ENT>228.616</ENT>
                                <ENT>7.0</ENT>
                                <ENT>2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Copper</ENT>
                                <ENT>324.754</ENT>
                                <ENT>5.4</ENT>
                                <ENT>2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Iron</ENT>
                                <ENT>259.940</ENT>
                                <ENT>6.2</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Lead</ENT>
                                <ENT>220.353</ENT>
                                <ENT>42</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Lithium</ENT>
                                <ENT>670.784</ENT>
                                <ENT>
                                    <SU>d</SU>
                                     3.7
                                </ENT>
                                <ENT>5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Magnesium</ENT>
                                <ENT>279.079</ENT>
                                <ENT>30</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Manganese</ENT>
                                <ENT>257.610</ENT>
                                <ENT>1.4</ENT>
                                <ENT>2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Mercury</ENT>
                                <ENT>194.227</ENT>
                                <ENT>2.5</ENT>
                                <ENT>2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Molybdenum</ENT>
                                <ENT>203.844</ENT>
                                <ENT>12</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Nickel</ENT>
                                <ENT>231.604</ENT>
                                <ENT>15</ENT>
                                <ENT>2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Phosphorus</ENT>
                                <ENT>214.914</ENT>
                                <ENT>76</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Potassium</ENT>
                                <ENT>766.491</ENT>
                                <ENT>
                                    <SU>e</SU>
                                     700
                                </ENT>
                                <ENT>20</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Selenium</ENT>
                                <ENT>196.090</ENT>
                                <ENT>75</ENT>
                                <ENT>5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    Silica (SiO
                                    <E T="52">2</E>
                                    )
                                </ENT>
                                <ENT>251.611</ENT>
                                <ENT>
                                    <SU>d</SU>
                                     26 (SiO
                                    <E T="52">2</E>
                                    )
                                </ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Silver</ENT>
                                <ENT>328.068</ENT>
                                <ENT>7.0</ENT>
                                <ENT>0.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Sodium</ENT>
                                <ENT>588.995</ENT>
                                <ENT>29</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Strontium</ENT>
                                <ENT>421.552</ENT>
                                <ENT>0.77</ENT>
                                <ENT>1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Thallium</ENT>
                                <ENT>190.864</ENT>
                                <ENT>40</ENT>
                                <ENT>5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Tin</ENT>
                                <ENT>189.980</ENT>
                                <ENT>25</ENT>
                                <ENT>4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Titanium</ENT>
                                <ENT>334.941</ENT>
                                <ENT>3.8</ENT>
                                <ENT>10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Vanadium</ENT>
                                <ENT>292.402</ENT>
                                <ENT>7.5</ENT>
                                <ENT>2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Zinc</ENT>
                                <ENT>213.856</ENT>
                                <ENT>1.8</ENT>
                                <ENT>5</ENT>
                            </ROW>
                            <TNOTE>
                                <SU>a</SU>
                                 The wavelengths listed are recommended because of their sensitivity and overall acceptability. Other wavelengths may be substituted if they can provide the needed sensitivity and are treated with the same corrective techniques for spectral interference (see Section 4.1).
                            </TNOTE>
                            <TNOTE>
                                <SU>b</SU>
                                 These estimated 3-sigma instrumental detection limits 
                                <SU>16</SU>
                                 are provided only as a guide to instrumental limits. The method detection limits are sample dependent and may vary as the sample matrix varies. 
                                <E T="03">Detection limits for solids</E>
                                 can be estimated by dividing these values by the grams extracted per liter, which depends upon the extraction procedure. Divide solution detection limits by 10 for 1 g extracted to 100 mL for solid detection limits.
                            </TNOTE>
                            <TNOTE>
                                <SU>c</SU>
                                 Suggested concentration for instrument calibration.
                                <SU>2</SU>
                                 Other calibration limits in the linear ranges may be used.
                            </TNOTE>
                            <TNOTE>
                                <SU>d</SU>
                                 Calculated from 2-sigma data.
                                <SU>5</SU>
                            </TNOTE>
                            <TNOTE>
                                <SU>e</SU>
                                 Highly dependent on operating conditions and plasma position.
                            </TNOTE>
                        </GPOTABLE>
                        <PRTPAGE P="410"/>
                        <GPOTABLE COLS="3" OPTS="L2" CDEF="s5,8,xs90">
                            <TTITLE>TABLE 2—On-Line Method Interelement Spectral Interferances Arising From Interferants at the 100 mg/L Level</TTITLE>
                            <BOXHD>
                                <CHED H="1">Analyte</CHED>
                                <CHED H="1">Wavelength (nm)</CHED>
                                <CHED H="1">Interferant*</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">
                                    Ag
                                    <LI>Al</LI>
                                    <LI>As</LI>
                                    <LI>B</LI>
                                    <LI>Ba</LI>
                                    <LI>Be</LI>
                                    <LI>Ca</LI>
                                    <LI>Cd</LI>
                                    <LI>Ce</LI>
                                    <LI>Co</LI>
                                    <LI>Cr</LI>
                                    <LI>Cu</LI>
                                    <LI>Fe</LI>
                                    <LI>Hg</LI>
                                    <LI>K</LI>
                                    <LI>Li</LI>
                                    <LI>Mg</LI>
                                    <LI>Mn</LI>
                                    <LI>Mo</LI>
                                    <LI>Na</LI>
                                    <LI>Ni</LI>
                                    <LI>P</LI>
                                    <LI>Pb</LI>
                                    <LI>Sb</LI>
                                    <LI>Se</LI>
                                    <LI>
                                        SiO
                                        <E T="52">2</E>
                                    </LI>
                                    <LI>Sn</LI>
                                    <LI>Sr</LI>
                                    <LI>Tl</LI>
                                    <LI>Ti</LI>
                                    <LI>V</LI>
                                    <LI>Zn</LI>
                                </ENT>
                                <ENT>
                                    328.068
                                    <LI>308.215</LI>
                                    <LI>193.759</LI>
                                    <LI>249.678</LI>
                                    <LI>493.409</LI>
                                    <LI>313.042</LI>
                                    <LI>315.887</LI>
                                    <LI>226.502</LI>
                                    <LI>413.765</LI>
                                    <LI>228.616</LI>
                                    <LI>205.552</LI>
                                    <LI>324.754</LI>
                                    <LI>259.940</LI>
                                    <LI>194.227</LI>
                                    <LI>766.491</LI>
                                    <LI>670.784</LI>
                                    <LI>279.079</LI>
                                    <LI>257.610</LI>
                                    <LI>203.844</LI>
                                    <LI>588.995</LI>
                                    <LI>231.604</LI>
                                    <LI>214.914</LI>
                                    <LI>220.353</LI>
                                    <LI>206.833</LI>
                                    <LI>196.099</LI>
                                    <LI>251.611</LI>
                                    <LI>189.980</LI>
                                    <LI>421.552</LI>
                                    <LI>190.864</LI>
                                    <LI>334.941</LI>
                                    <LI>292.402</LI>
                                    <LI>213.856</LI>
                                </ENT>
                                <ENT>
                                    Ce, Ti, Mn
                                    <LI>V, Mo, Ce, Mn</LI>
                                    <LI>V, Al, Co, Fe, Ni</LI>
                                    <LI>None</LI>
                                    <LI>None</LI>
                                    <LI>V, Ce</LI>
                                    <LI>Co, Mo, Ce</LI>
                                    <LI>Ni, Ti, Fe, Ce</LI>
                                    <LI>None</LI>
                                    <LI>Ti, Ba, Cd, Ni, Cr, Mo, Ce</LI>
                                    <LI>Be, Mo, Ni</LI>
                                    <LI>Mo, Ti</LI>
                                    <LI>None</LI>
                                    <LI>V, Mo</LI>
                                    <LI>None</LI>
                                    <LI>None</LI>
                                    <LI>Ce</LI>
                                    <LI>Ce</LI>
                                    <LI>Ce</LI>
                                    <LI>None</LI>
                                    <LI>Co, Tl</LI>
                                    <LI>Cu, Mo</LI>
                                    <LI>Co, Al, Ce, Cu, Ni, Ti, Fe</LI>
                                    <LI>Cr, Mo, Sn, Ti, Ce, Fe</LI>
                                    <LI>Fe</LI>
                                    <LI>None</LI>
                                    <LI>Mo, Ti, Fe, Mn, Si</LI>
                                    <LI>None</LI>
                                    <LI>Ti, Mo, Co, Ce, Al, V, Mn</LI>
                                    <LI>None</LI>
                                    <LI>Mo, Ti, Cr, Fe, Ce</LI>
                                    <LI>Ni, Cu, Fe</LI>
                                </ENT>
                            </ROW>
                            <TNOTE>* These on-line interferences from method analytes and titanium only were observed using an instrument with 0.035 nm resolution (see Section 4.1.2). Interferant ranked by magnitude of intensity with the most severe interferant listed first in the row.</TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="2" OPTS="L2" CDEF="s8,xs145">
                            <TTITLE>TABLE 3—Mixed Standard Solutions</TTITLE>
                            <BOXHD>
                                <CHED H="1">Solution</CHED>
                                <CHED H="1">Analytes</CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">
                                    I
                                    <LI>II</LI>
                                    <LI>III</LI>
                                    <LI>IV</LI>
                                    <LI>V</LI>
                                </ENT>
                                <ENT>
                                    Ag, As, B, Ba, Ca, Cd, Cu, Mn, Sb, and Se
                                    <LI>K, Li, Mo, Na, Sr, and Ti</LI>
                                    <LI>Co, P, V, and Ce</LI>
                                    <LI>
                                        Al, Cr, Hg, SiO
                                        <E T="52">2</E>
                                        , Sn, and Zn
                                    </LI>
                                    <LI>Be, Fe, Mg, Ni, Pb, and Tl</LI>
                                </ENT>
                            </ROW>
                        </GPOTABLE>
                        <GPOTABLE COLS="3" OPTS="L2" CDEF="s16,16,16">
                            <TTITLE>TABLE 4—Total Recoverable Method Detection Limits (MDL)</TTITLE>
                            <BOXHD>
                                <CHED H="1">Analyte</CHED>
                                <CHED H="1">
                                    MDLs
                                    <LI>
                                        Aqueous, mg/L
                                        <SU>(1)</SU>
                                    </LI>
                                </CHED>
                                <CHED H="1">
                                    Solids, mg/kg
                                    <SU>(2)</SU>
                                </CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">Ag</ENT>
                                <ENT>0.002</ENT>
                                <ENT>0.3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Al</ENT>
                                <ENT>0.02</ENT>
                                <ENT>3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">As</ENT>
                                <ENT>0.008</ENT>
                                <ENT>2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">B</ENT>
                                <ENT>0.003</ENT>
                                <ENT>—</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ba</ENT>
                                <ENT>0.001</ENT>
                                <ENT>0.2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Be</ENT>
                                <ENT>0.0003</ENT>
                                <ENT>0.1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ca</ENT>
                                <ENT>0.01</ENT>
                                <ENT>2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Cd</ENT>
                                <ENT>0.001</ENT>
                                <ENT>0.2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ce</ENT>
                                <ENT>0.02</ENT>
                                <ENT>3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Co</ENT>
                                <ENT>0.002</ENT>
                                <ENT>0.4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Cr</ENT>
                                <ENT>0.004</ENT>
                                <ENT>0.8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Cu</ENT>
                                <ENT>0.003</ENT>
                                <ENT>0.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Fe</ENT>
                                <ENT>*0.03</ENT>
                                <ENT>6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Hg</ENT>
                                <ENT>0.007</ENT>
                                <ENT>2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">K</ENT>
                                <ENT>0.3</ENT>
                                <ENT>60</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Li</ENT>
                                <ENT>0.001</ENT>
                                <ENT>0.2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Mg</ENT>
                                <ENT>0.02</ENT>
                                <ENT>3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Mn</ENT>
                                <ENT>0.001</ENT>
                                <ENT>0.2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Mo</ENT>
                                <ENT>0.004</ENT>
                                <ENT>1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Na</ENT>
                                <ENT>0.03</ENT>
                                <ENT>6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ni</ENT>
                                <ENT>0.005</ENT>
                                <ENT>1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">P</ENT>
                                <ENT>0.06</ENT>
                                <ENT>12</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Pb</ENT>
                                <ENT>0.01</ENT>
                                <ENT>2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Sb</ENT>
                                <ENT>0.008</ENT>
                                <ENT>2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Se</ENT>
                                <ENT>0.02</ENT>
                                <ENT>5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    SiO
                                    <E T="52">2</E>
                                </ENT>
                                <ENT>0.02</ENT>
                                <ENT>—</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Sn</ENT>
                                <ENT>0.007</ENT>
                                <ENT>2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Sr</ENT>
                                <ENT>0.0003</ENT>
                                <ENT>0.1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Tl</ENT>
                                <ENT>0.001</ENT>
                                <ENT>0.2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ti</ENT>
                                <ENT>0.02</ENT>
                                <ENT>3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">V</ENT>
                                <ENT>0.003</ENT>
                                <ENT>1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Zn</ENT>
                                <ENT>0.002</ENT>
                                <ENT>0.3</ENT>
                            </ROW>
                            <TNOTE>
                                <SU>(1)</SU>
                                 MDL concentrations are computed for original matrix with allowance for 2x sample preconcentration during preparation. Samples were processed in PTFE and diluted in 50-mL plastic centrifuge tubes.
                            </TNOTE>
                            <TNOTE>
                                <SU>(2)</SU>
                                 Estimated, calculated from aqueous MDL determinations.
                            </TNOTE>
                            <TNOTE>— Boron not reported because of glassware contamination. Silica not determined in solid samples.</TNOTE>
                            <TNOTE>* Elevated value due to fume-hood contamination.</TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="2" OPTS="L2,p1,7/8" CDEF="s75,xs48">
                            <TTITLE>TABLE 5—Inductively Coupled Plasma Instrument Operating Conditions</TTITLE>
                            <ROW>
                                <ENT I="01">Incident rf power</ENT>
                                <ENT>1100 watts</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Reflected rf power</ENT>
                                <ENT>&lt;5 watts</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Viewing height above work coil</ENT>
                                <ENT>15 mm</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Injector tube orifice i.d.</ENT>
                                <ENT>1 mm</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Argon supply</ENT>
                                <ENT>liquid argon</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Argon pressure</ENT>
                                <ENT>40 psi</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Coolant argon flow rate</ENT>
                                <ENT>19 L/min.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Aerosol carrier argon flow rate</ENT>
                                <ENT>620 mL/min.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Auxiliary (plasma) argon flow rate</ENT>
                                <ENT>300 mL/min.</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Sample uptake rate controlled to</ENT>
                                <ENT>1.2 mL/min.</ENT>
                            </ROW>
                        </GPOTABLE>
                        <PRTPAGE P="411"/>
                        <GPOTABLE COLS="10" OPTS="L2" CDEF="s30,10,10,10,10,10,10,10,10,10">
                            <TTITLE>Table 6—Precision and Recovery Data in Aqueous Matrices</TTITLE>
                            <BOXHD>
                                <CHED H="1">Analyte</CHED>
                                <CHED H="1">
                                    Sample conc.
                                    <LI>mg/L</LI>
                                </CHED>
                                <CHED H="1">
                                    Low spike
                                    <LI>mg/L</LI>
                                </CHED>
                                <CHED H="1">
                                    Average
                                    <LI>recovery</LI>
                                    <LI>R (%)</LI>
                                </CHED>
                                <CHED H="1">S (R)</CHED>
                                <CHED H="1">RPD</CHED>
                                <CHED H="1">
                                    High spike
                                    <LI>mg/L</LI>
                                </CHED>
                                <CHED H="1">
                                    Average
                                    <LI>recovery</LI>
                                    <LI>R (%)</LI>
                                </CHED>
                                <CHED H="1">S (R)</CHED>
                                <CHED H="1">RPD</CHED>
                            </BOXHD>
                            <ROW EXPSTB="09" RUL="s">
                                <ENT I="21">
                                    <E T="02">Tap Water</E>
                                </ENT>
                            </ROW>
                            <ROW EXPSTB="00">
                                <ENT I="01">Ag</ENT>
                                <ENT>&lt;0.002</ENT>
                                <ENT>0.05</ENT>
                                <ENT>95</ENT>
                                <ENT>0.7</ENT>
                                <ENT>2.1</ENT>
                                <ENT>0.2</ENT>
                                <ENT>96</ENT>
                                <ENT>0.0</ENT>
                                <ENT>0.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Al</ENT>
                                <ENT>0.185</ENT>
                                <ENT>0.05</ENT>
                                <ENT>98</ENT>
                                <ENT>8.8</ENT>
                                <ENT>1.7</ENT>
                                <ENT>0.2</ENT>
                                <ENT>105</ENT>
                                <ENT>3.0</ENT>
                                <ENT>3.1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">As</ENT>
                                <ENT>&lt;0.008</ENT>
                                <ENT>0.05</ENT>
                                <ENT>108</ENT>
                                <ENT>1.4</ENT>
                                <ENT>3.7</ENT>
                                <ENT>0.2</ENT>
                                <ENT>101</ENT>
                                <ENT>0.7</ENT>
                                <ENT>2.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">B</ENT>
                                <ENT>0.023</ENT>
                                <ENT>0.1</ENT>
                                <ENT>98</ENT>
                                <ENT>0.2</ENT>
                                <ENT>0.0</ENT>
                                <ENT>0.4</ENT>
                                <ENT>98</ENT>
                                <ENT>0.2</ENT>
                                <ENT>0.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ba</ENT>
                                <ENT>0.042</ENT>
                                <ENT>0.05</ENT>
                                <ENT>102</ENT>
                                <ENT>1.6</ENT>
                                <ENT>2.2</ENT>
                                <ENT>0.2</ENT>
                                <ENT>98</ENT>
                                <ENT>0.4</ENT>
                                <ENT>0.8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Be</ENT>
                                <ENT>&lt;0.0003</ENT>
                                <ENT>0.01</ENT>
                                <ENT>100</ENT>
                                <ENT>0.0</ENT>
                                <ENT>0.0</ENT>
                                <ENT>0.1</ENT>
                                <ENT>99</ENT>
                                <ENT>0.0</ENT>
                                <ENT>0.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ca</ENT>
                                <ENT>35.2</ENT>
                                <ENT>5.0</ENT>
                                <ENT>101</ENT>
                                <ENT>8.8</ENT>
                                <ENT>1.7</ENT>
                                <ENT>20.0</ENT>
                                <ENT>103</ENT>
                                <ENT>2.0</ENT>
                                <ENT>0.9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Cd</ENT>
                                <ENT>&lt;0.001</ENT>
                                <ENT>0.01</ENT>
                                <ENT>105</ENT>
                                <ENT>3.5</ENT>
                                <ENT>9.5</ENT>
                                <ENT>0.1</ENT>
                                <ENT>98</ENT>
                                <ENT>0.0</ENT>
                                <ENT>0.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Co</ENT>
                                <ENT>&lt;0.002</ENT>
                                <ENT>0.02</ENT>
                                <ENT>100</ENT>
                                <ENT>0.0</ENT>
                                <ENT>0.0</ENT>
                                <ENT>0.2</ENT>
                                <ENT>99</ENT>
                                <ENT>0.5</ENT>
                                <ENT>1.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Cr</ENT>
                                <ENT>&lt;0.004</ENT>
                                <ENT>0.01</ENT>
                                <ENT>110</ENT>
                                <ENT>0.0</ENT>
                                <ENT>0.0</ENT>
                                <ENT>0.1</ENT>
                                <ENT>102</ENT>
                                <ENT>0.0</ENT>
                                <ENT>0.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Cu</ENT>
                                <ENT>&lt;0.003</ENT>
                                <ENT>0.02</ENT>
                                <ENT>103</ENT>
                                <ENT>1.8</ENT>
                                <ENT>4.9</ENT>
                                <ENT>0.2</ENT>
                                <ENT>101</ENT>
                                <ENT>1.2</ENT>
                                <ENT>3.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Fe</ENT>
                                <ENT>0.008</ENT>
                                <ENT>0.1</ENT>
                                <ENT>106</ENT>
                                <ENT>1.0</ENT>
                                <ENT>1.8</ENT>
                                <ENT>0.4</ENT>
                                <ENT>105</ENT>
                                <ENT>0.3</ENT>
                                <ENT>0.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Hg</ENT>
                                <ENT>&lt;0.007</ENT>
                                <ENT>0.05</ENT>
                                <ENT>103</ENT>
                                <ENT>0.7</ENT>
                                <ENT>1.9</ENT>
                                <ENT>0.2</ENT>
                                <ENT>100</ENT>
                                <ENT>0.4</ENT>
                                <ENT>1.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">K</ENT>
                                <ENT>1.98</ENT>
                                <ENT>5.0</ENT>
                                <ENT>109</ENT>
                                <ENT>1.4</ENT>
                                <ENT>2.3</ENT>
                                <ENT>20.</ENT>
                                <ENT>107</ENT>
                                <ENT>0.7</ENT>
                                <ENT>1.7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Li</ENT>
                                <ENT>0.006</ENT>
                                <ENT>0.02</ENT>
                                <ENT>103</ENT>
                                <ENT>6.9</ENT>
                                <ENT>3.8</ENT>
                                <ENT>0.2</ENT>
                                <ENT>110</ENT>
                                <ENT>1.9</ENT>
                                <ENT>4.4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Mg</ENT>
                                <ENT>8.08</ENT>
                                <ENT>5.0</ENT>
                                <ENT>104</ENT>
                                <ENT>2.2</ENT>
                                <ENT>1.5</ENT>
                                <ENT>20.0</ENT>
                                <ENT>100</ENT>
                                <ENT>0.7</ENT>
                                <ENT>1.1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Mn</ENT>
                                <ENT>&lt;0.001</ENT>
                                <ENT>0.01</ENT>
                                <ENT>100</ENT>
                                <ENT>0.0</ENT>
                                <ENT>0.0</ENT>
                                <ENT>0.1</ENT>
                                <ENT>99</ENT>
                                <ENT>0.0</ENT>
                                <ENT>0.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Mo</ENT>
                                <ENT>&lt;0.004</ENT>
                                <ENT>0.02</ENT>
                                <ENT>95</ENT>
                                <ENT>3.5</ENT>
                                <ENT>10.5</ENT>
                                <ENT>0.2</ENT>
                                <ENT>108</ENT>
                                <ENT>0.5</ENT>
                                <ENT>1.4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Na</ENT>
                                <ENT>10.3</ENT>
                                <ENT>5.0</ENT>
                                <ENT>99</ENT>
                                <ENT>3.0</ENT>
                                <ENT>2.0</ENT>
                                <ENT>20.0</ENT>
                                <ENT>106</ENT>
                                <ENT>1.0</ENT>
                                <ENT>1.6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ni</ENT>
                                <ENT>&lt;0.005</ENT>
                                <ENT>0.02</ENT>
                                <ENT>108</ENT>
                                <ENT>1.8</ENT>
                                <ENT>4.7</ENT>
                                <ENT>0.2</ENT>
                                <ENT>104</ENT>
                                <ENT>1.1</ENT>
                                <ENT>2.9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">P</ENT>
                                <ENT>0.045</ENT>
                                <ENT>0.1</ENT>
                                <ENT>102</ENT>
                                <ENT>13.1</ENT>
                                <ENT>9.4</ENT>
                                <ENT>0.4</ENT>
                                <ENT>104</ENT>
                                <ENT>3.2</ENT>
                                <ENT>1.3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Pb</ENT>
                                <ENT>&lt;0.01</ENT>
                                <ENT>0.05</ENT>
                                <ENT>95</ENT>
                                <ENT>0.7</ENT>
                                <ENT>2.1</ENT>
                                <ENT>0.2</ENT>
                                <ENT>100</ENT>
                                <ENT>0.2</ENT>
                                <ENT>0.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Sb</ENT>
                                <ENT>&lt;0.008</ENT>
                                <ENT>0.05</ENT>
                                <ENT>99</ENT>
                                <ENT>0.7</ENT>
                                <ENT>2.0</ENT>
                                <ENT>0.2</ENT>
                                <ENT>102</ENT>
                                <ENT>0.7</ENT>
                                <ENT>2.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Se</ENT>
                                <ENT>&lt;0.02</ENT>
                                <ENT>0.1</ENT>
                                <ENT>87</ENT>
                                <ENT>1.1</ENT>
                                <ENT>3.5</ENT>
                                <ENT>0.4</ENT>
                                <ENT>99</ENT>
                                <ENT>0.8</ENT>
                                <ENT>2.3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    SiO
                                    <E T="52">2</E>
                                </ENT>
                                <ENT>6.5</ENT>
                                <ENT>5.0</ENT>
                                <ENT>104</ENT>
                                <ENT>3.3</ENT>
                                <ENT>3.4</ENT>
                                <ENT>20.0</ENT>
                                <ENT>96</ENT>
                                <ENT>1.1</ENT>
                                <ENT>2.3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Sn</ENT>
                                <ENT>&lt;0.007</ENT>
                                <ENT>0.05</ENT>
                                <ENT>103</ENT>
                                <ENT>2.1</ENT>
                                <ENT>5.8</ENT>
                                <ENT>0.2</ENT>
                                <ENT>101</ENT>
                                <ENT>1.8</ENT>
                                <ENT>5.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Sr</ENT>
                                <ENT>0.181</ENT>
                                <ENT>0.1</ENT>
                                <ENT>102</ENT>
                                <ENT>3.3</ENT>
                                <ENT>2.1</ENT>
                                <ENT>0.4</ENT>
                                <ENT>105</ENT>
                                <ENT>0.8</ENT>
                                <ENT>1.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Tl</ENT>
                                <ENT>&lt;0.02</ENT>
                                <ENT>0.1</ENT>
                                <ENT>101</ENT>
                                <ENT>3.9</ENT>
                                <ENT>10.9</ENT>
                                <ENT>0.4</ENT>
                                <ENT>101</ENT>
                                <ENT>0.1</ENT>
                                <ENT>0.3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">V</ENT>
                                <ENT>&lt;0.003</ENT>
                                <ENT>0.05</ENT>
                                <ENT>101</ENT>
                                <ENT>0.7</ENT>
                                <ENT>2.0</ENT>
                                <ENT>0.2</ENT>
                                <ENT>99</ENT>
                                <ENT>0.2</ENT>
                                <ENT>0.5</ENT>
                            </ROW>
                            <ROW RUL="s">
                                <ENT I="01">Zn</ENT>
                                <ENT>0.005</ENT>
                                <ENT>0.05</ENT>
                                <ENT>101</ENT>
                                <ENT>3.7</ENT>
                                <ENT>9.0</ENT>
                                <ENT>0.2</ENT>
                                <ENT>98</ENT>
                                <ENT>0.9</ENT>
                                <ENT>2.5</ENT>
                            </ROW>
                            <ROW EXPSTB="09" RUL="s">
                                <ENT I="21">
                                    <E T="02">Pond Water</E>
                                </ENT>
                            </ROW>
                            <ROW EXPSTB="00">
                                <ENT I="01">Ag </ENT>
                                <ENT>&lt;0.002</ENT>
                                <ENT>0.05</ENT>
                                <ENT>92</ENT>
                                <ENT>0.0</ENT>
                                <ENT>0.0</ENT>
                                <ENT>0.2</ENT>
                                <ENT>94</ENT>
                                <ENT>0.0</ENT>
                                <ENT>0.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Al</ENT>
                                <ENT>0.819</ENT>
                                <ENT>0.2</ENT>
                                <ENT>88</ENT>
                                <ENT>10.0</ENT>
                                <ENT>5.0</ENT>
                                <ENT>0.8</ENT>
                                <ENT>100</ENT>
                                <ENT>2.9</ENT>
                                <ENT>3.7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">As</ENT>
                                <ENT>&lt;0.008</ENT>
                                <ENT>0.05</ENT>
                                <ENT>102</ENT>
                                <ENT>0.0</ENT>
                                <ENT>0.0</ENT>
                                <ENT>0.2</ENT>
                                <ENT>98</ENT>
                                <ENT>1.4</ENT>
                                <ENT>4.1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">B</ENT>
                                <ENT>0.034</ENT>
                                <ENT>0.1</ENT>
                                <ENT>111</ENT>
                                <ENT>8.9</ENT>
                                <ENT>6.9</ENT>
                                <ENT>0.4</ENT>
                                <ENT>103</ENT>
                                <ENT>2.0</ENT>
                                <ENT>0.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ba</ENT>
                                <ENT>0.029</ENT>
                                <ENT>0.05</ENT>
                                <ENT>96</ENT>
                                <ENT>0.9</ENT>
                                <ENT>0.0</ENT>
                                <ENT>0.2</ENT>
                                <ENT>97</ENT>
                                <ENT>0.3</ENT>
                                <ENT>0.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Be</ENT>
                                <ENT>&lt;0.0003</ENT>
                                <ENT>0.01</ENT>
                                <ENT>95</ENT>
                                <ENT>0.4</ENT>
                                <ENT>1.1</ENT>
                                <ENT>0.2</ENT>
                                <ENT>95</ENT>
                                <ENT>0.0</ENT>
                                <ENT>0.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ca</ENT>
                                <ENT>53.9</ENT>
                                <ENT>5.0</ENT>
                                <ENT>*</ENT>
                                <ENT>*</ENT>
                                <ENT>0.7</ENT>
                                <ENT>20.0</ENT>
                                <ENT>100</ENT>
                                <ENT>2.0</ENT>
                                <ENT>1.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Cd</ENT>
                                <ENT>&lt;0.001</ENT>
                                <ENT>0.01</ENT>
                                <ENT>107</ENT>
                                <ENT>0.0</ENT>
                                <ENT>0.0</ENT>
                                <ENT>0.1</ENT>
                                <ENT>97</ENT>
                                <ENT>0.0</ENT>
                                <ENT>0.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Co</ENT>
                                <ENT>&lt;0.002</ENT>
                                <ENT>0.02</ENT>
                                <ENT>100</ENT>
                                <ENT>2.7</ENT>
                                <ENT>7.5</ENT>
                                <ENT>0.2</ENT>
                                <ENT>97</ENT>
                                <ENT>0.7</ENT>
                                <ENT>2.1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Cr</ENT>
                                <ENT>&lt;0.004</ENT>
                                <ENT>0.01</ENT>
                                <ENT>105</ENT>
                                <ENT>3.5</ENT>
                                <ENT>9.5</ENT>
                                <ENT>0.1</ENT>
                                <ENT>103</ENT>
                                <ENT>1.1</ENT>
                                <ENT>2.9</ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="412"/>
                                <ENT I="01">Cu</ENT>
                                <ENT>&lt;0.003</ENT>
                                <ENT>0.02</ENT>
                                <ENT>98</ENT>
                                <ENT>2.1</ENT>
                                <ENT>4.4</ENT>
                                <ENT>0.2</ENT>
                                <ENT>100</ENT>
                                <ENT>0.5</ENT>
                                <ENT>1.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Fe</ENT>
                                <ENT>0.875</ENT>
                                <ENT>0.2</ENT>
                                <ENT>95</ENT>
                                <ENT>8.9</ENT>
                                <ENT>2.8</ENT>
                                <ENT>0.8</ENT>
                                <ENT>97</ENT>
                                <ENT>3.2</ENT>
                                <ENT>3.6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Hg</ENT>
                                <ENT>&lt;0.007</ENT>
                                <ENT>0.05</ENT>
                                <ENT>97</ENT>
                                <ENT>3.5</ENT>
                                <ENT>10.3</ENT>
                                <ENT>0.2</ENT>
                                <ENT>98</ENT>
                                <ENT>0.0</ENT>
                                <ENT>0.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">K</ENT>
                                <ENT>2.48</ENT>
                                <ENT>5.0</ENT>
                                <ENT>106</ENT>
                                <ENT>0.3</ENT>
                                <ENT>0.1</ENT>
                                <ENT>20.0</ENT>
                                <ENT>103</ENT>
                                <ENT>0.2</ENT>
                                <ENT>0.4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Li</ENT>
                                <ENT>&lt;0.001</ENT>
                                <ENT>0.02</ENT>
                                <ENT>110</ENT>
                                <ENT>0.0</ENT>
                                <ENT>0.0</ENT>
                                <ENT>0.2</ENT>
                                <ENT>106</ENT>
                                <ENT>0.2</ENT>
                                <ENT>0.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Mg</ENT>
                                <ENT>10.8</ENT>
                                <ENT>5.0</ENT>
                                <ENT>102</ENT>
                                <ENT>0.5</ENT>
                                <ENT>0.0</ENT>
                                <ENT>20.0</ENT>
                                <ENT>96</ENT>
                                <ENT>0.7</ENT>
                                <ENT>1.3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Mn</ENT>
                                <ENT>0.632</ENT>
                                <ENT>0.01</ENT>
                                <ENT>*</ENT>
                                <ENT>*</ENT>
                                <ENT>0.2</ENT>
                                <ENT>0.1</ENT>
                                <ENT>97</ENT>
                                <ENT>2.3</ENT>
                                <ENT>0.3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Mo</ENT>
                                <ENT>&lt;0.004</ENT>
                                <ENT>0.02</ENT>
                                <ENT>105</ENT>
                                <ENT>3.5</ENT>
                                <ENT>9.5</ENT>
                                <ENT>0.2</ENT>
                                <ENT>103</ENT>
                                <ENT>0.4</ENT>
                                <ENT>1.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Na</ENT>
                                <ENT>17.8</ENT>
                                <ENT>5.0</ENT>
                                <ENT>103</ENT>
                                <ENT>1.3</ENT>
                                <ENT>0.4</ENT>
                                <ENT>20.0</ENT>
                                <ENT>94</ENT>
                                <ENT>0.3</ENT>
                                <ENT>0.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ni</ENT>
                                <ENT>&lt;0.005</ENT>
                                <ENT>0.02</ENT>
                                <ENT>96</ENT>
                                <ENT>5.6</ENT>
                                <ENT>9.1</ENT>
                                <ENT>0.2</ENT>
                                <ENT>100</ENT>
                                <ENT>0.7</ENT>
                                <ENT>1.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">P</ENT>
                                <ENT>0.196</ENT>
                                <ENT>0.1</ENT>
                                <ENT>91</ENT>
                                <ENT>14.7</ENT>
                                <ENT>0.3</ENT>
                                <ENT>0.4</ENT>
                                <ENT>108</ENT>
                                <ENT>3.9</ENT>
                                <ENT>1.3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Pb</ENT>
                                <ENT>&lt;0.01</ENT>
                                <ENT>0.05</ENT>
                                <ENT>96</ENT>
                                <ENT>2.6</ENT>
                                <ENT>7.8</ENT>
                                <ENT>0.2</ENT>
                                <ENT>100</ENT>
                                <ENT>0.7</ENT>
                                <ENT>2.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Sb</ENT>
                                <ENT>&lt;0.008</ENT>
                                <ENT>0.05</ENT>
                                <ENT>102</ENT>
                                <ENT>2.8</ENT>
                                <ENT>7.8</ENT>
                                <ENT>0.2</ENT>
                                <ENT>104</ENT>
                                <ENT>0.4</ENT>
                                <ENT>1.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Se</ENT>
                                <ENT>&lt;0.02</ENT>
                                <ENT>0.1</ENT>
                                <ENT>104</ENT>
                                <ENT>2.1</ENT>
                                <ENT>5.8</ENT>
                                <ENT>0.4</ENT>
                                <ENT>103</ENT>
                                <ENT>1.6</ENT>
                                <ENT>4.4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    SiO
                                    <E T="52">2</E>
                                </ENT>
                                <ENT>7.83</ENT>
                                <ENT>5.0</ENT>
                                <ENT>151</ENT>
                                <ENT>1.6</ENT>
                                <ENT>1.3</ENT>
                                <ENT>20.0</ENT>
                                <ENT>117</ENT>
                                <ENT>0.4</ENT>
                                <ENT>0.6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Sn</ENT>
                                <ENT>&lt;0.007</ENT>
                                <ENT>0.05</ENT>
                                <ENT>98</ENT>
                                <ENT>0.0</ENT>
                                <ENT>0.0</ENT>
                                <ENT>0.2</ENT>
                                <ENT>99</ENT>
                                <ENT>1.1</ENT>
                                <ENT>3.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Sr</ENT>
                                <ENT>0.129</ENT>
                                <ENT>0.1</ENT>
                                <ENT>105</ENT>
                                <ENT>0.4</ENT>
                                <ENT>0.0</ENT>
                                <ENT>0.4</ENT>
                                <ENT>99</ENT>
                                <ENT>0.1</ENT>
                                <ENT>0.2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Tl</ENT>
                                <ENT>&lt;0.02</ENT>
                                <ENT>0.1</ENT>
                                <ENT>103</ENT>
                                <ENT>1.1</ENT>
                                <ENT>2.9</ENT>
                                <ENT>0.4</ENT>
                                <ENT>97</ENT>
                                <ENT>1.3</ENT>
                                <ENT>3.9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">V</ENT>
                                <ENT>0.003</ENT>
                                <ENT>0.05</ENT>
                                <ENT>94</ENT>
                                <ENT>0.4</ENT>
                                <ENT>0.0</ENT>
                                <ENT>0.2</ENT>
                                <ENT>98</ENT>
                                <ENT>0.1</ENT>
                                <ENT>0.0</ENT>
                            </ROW>
                            <ROW RUL="s">
                                <ENT I="01">Zn</ENT>
                                <ENT>0.006</ENT>
                                <ENT>0.05</ENT>
                                <ENT>97</ENT>
                                <ENT>1.6</ENT>
                                <ENT>1.8</ENT>
                                <ENT>0.2</ENT>
                                <ENT>94</ENT>
                                <ENT>0.4</ENT>
                                <ENT>0.0</ENT>
                            </ROW>
                            <ROW EXPSTB="09" RUL="s">
                                <ENT I="21">
                                    <E T="02">Well Water</E>
                                </ENT>
                            </ROW>
                            <ROW EXPSTB="00">
                                <ENT I="01">Ag</ENT>
                                <ENT>&lt;0.002</ENT>
                                <ENT>0.05</ENT>
                                <ENT>97</ENT>
                                <ENT>0.7</ENT>
                                <ENT>2.1</ENT>
                                <ENT>0.2</ENT>
                                <ENT>96</ENT>
                                <ENT>0.2</ENT>
                                <ENT>0.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Al</ENT>
                                <ENT>0.036</ENT>
                                <ENT>0.05</ENT>
                                <ENT>107</ENT>
                                <ENT>7.6</ENT>
                                <ENT>10.1</ENT>
                                <ENT>0.2</ENT>
                                <ENT>101</ENT>
                                <ENT>1.1</ENT>
                                <ENT>0.8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">As</ENT>
                                <ENT>&lt;0.008</ENT>
                                <ENT>0.05</ENT>
                                <ENT>107</ENT>
                                <ENT>0.7</ENT>
                                <ENT>1.9</ENT>
                                <ENT>0.2</ENT>
                                <ENT>104</ENT>
                                <ENT>0.4</ENT>
                                <ENT>1.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">B</ENT>
                                <ENT>0.063</ENT>
                                <ENT>0.1</ENT>
                                <ENT>97</ENT>
                                <ENT>0.6</ENT>
                                <ENT>0.7</ENT>
                                <ENT>0.4</ENT>
                                <ENT>98</ENT>
                                <ENT>0.8</ENT>
                                <ENT>2.1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ba</ENT>
                                <ENT>0.102</ENT>
                                <ENT>0.05</ENT>
                                <ENT>102</ENT>
                                <ENT>3.0</ENT>
                                <ENT>0.0</ENT>
                                <ENT>0.2</ENT>
                                <ENT>99</ENT>
                                <ENT>0.9</ENT>
                                <ENT>1.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Be</ENT>
                                <ENT>&lt;0.0003</ENT>
                                <ENT>0.01</ENT>
                                <ENT>100</ENT>
                                <ENT>0.0</ENT>
                                <ENT>0.0</ENT>
                                <ENT>0.1</ENT>
                                <ENT>100</ENT>
                                <ENT>0.0</ENT>
                                <ENT>0.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ca</ENT>
                                <ENT>93.8</ENT>
                                <ENT>5.0</ENT>
                                <ENT>*</ENT>
                                <ENT>*</ENT>
                                <ENT>2.1</ENT>
                                <ENT>20.0</ENT>
                                <ENT>100</ENT>
                                <ENT>4.1</ENT>
                                <ENT>0.1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Cd</ENT>
                                <ENT>0.002</ENT>
                                <ENT>0.01</ENT>
                                <ENT>90</ENT>
                                <ENT>0.0</ENT>
                                <ENT>0.0</ENT>
                                <ENT>0.1</ENT>
                                <ENT>96</ENT>
                                <ENT>0.0</ENT>
                                <ENT>0.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Co</ENT>
                                <ENT>&lt;0.002</ENT>
                                <ENT>0.02</ENT>
                                <ENT>94</ENT>
                                <ENT>0.4</ENT>
                                <ENT>1.1</ENT>
                                <ENT>0.2</ENT>
                                <ENT>94</ENT>
                                <ENT>0.4</ENT>
                                <ENT>1.1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Cr</ENT>
                                <ENT>&lt;0.004</ENT>
                                <ENT>0.01</ENT>
                                <ENT>100</ENT>
                                <ENT>7.1</ENT>
                                <ENT>20.0</ENT>
                                <ENT>0.1</ENT>
                                <ENT>100</ENT>
                                <ENT>0.4</ENT>
                                <ENT>1.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Cu</ENT>
                                <ENT>&lt;0.005</ENT>
                                <ENT>0.02</ENT>
                                <ENT>100</ENT>
                                <ENT>1.1</ENT>
                                <ENT>0.4</ENT>
                                <ENT>0.2</ENT>
                                <ENT>96</ENT>
                                <ENT>0.5</ENT>
                                <ENT>1.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Fe</ENT>
                                <ENT>0.042</ENT>
                                <ENT>0.1</ENT>
                                <ENT>99</ENT>
                                <ENT>2.3</ENT>
                                <ENT>1.4</ENT>
                                <ENT>0.4</ENT>
                                <ENT>97</ENT>
                                <ENT>1.4</ENT>
                                <ENT>3.3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Hg</ENT>
                                <ENT>&lt;0.007</ENT>
                                <ENT>0.05</ENT>
                                <ENT>94</ENT>
                                <ENT>2.8</ENT>
                                <ENT>8.5</ENT>
                                <ENT>0.2</ENT>
                                <ENT>93</ENT>
                                <ENT>1.2</ENT>
                                <ENT>3.8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">K</ENT>
                                <ENT>6.21</ENT>
                                <ENT>5.0</ENT>
                                <ENT>96</ENT>
                                <ENT>3.4</ENT>
                                <ENT>3.6</ENT>
                                <ENT>20.0</ENT>
                                <ENT>101</ENT>
                                <ENT>1.2</ENT>
                                <ENT>2.3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Li</ENT>
                                <ENT>0.001</ENT>
                                <ENT>0.02</ENT>
                                <ENT>100</ENT>
                                <ENT>7.6</ENT>
                                <ENT>9.5</ENT>
                                <ENT>0.2</ENT>
                                <ENT>104</ENT>
                                <ENT>1.0</ENT>
                                <ENT>1.9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Mg</ENT>
                                <ENT>24.5</ENT>
                                <ENT>5.0</ENT>
                                <ENT>95</ENT>
                                <ENT>5.6</ENT>
                                <ENT>0.3</ENT>
                                <ENT>20.0</ENT>
                                <ENT>93</ENT>
                                <ENT>1.6</ENT>
                                <ENT>1.2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Mn</ENT>
                                <ENT>2.76</ENT>
                                <ENT>0.01</ENT>
                                <ENT>*</ENT>
                                <ENT>*</ENT>
                                <ENT>0.4</ENT>
                                <ENT>0.1</ENT>
                                <ENT>*</ENT>
                                <ENT>*</ENT>
                                <ENT>0.7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Mo</ENT>
                                <ENT>&lt;0.004</ENT>
                                <ENT>0.02</ENT>
                                <ENT>108</ENT>
                                <ENT>1.8</ENT>
                                <ENT>4.7</ENT>
                                <ENT>0.2</ENT>
                                <ENT>101</ENT>
                                <ENT>0.2</ENT>
                                <ENT>0.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Na</ENT>
                                <ENT>35.0</ENT>
                                <ENT>5.0</ENT>
                                <ENT>101</ENT>
                                <ENT>11.4</ENT>
                                <ENT>0.8</ENT>
                                <ENT>20.0</ENT>
                                <ENT>100</ENT>
                                <ENT>3.1</ENT>
                                <ENT>1.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ni</ENT>
                                <ENT>&lt;0.005</ENT>
                                <ENT>0.02</ENT>
                                <ENT>112</ENT>
                                <ENT>1.8</ENT>
                                <ENT>4.4</ENT>
                                <ENT>0.2</ENT>
                                <ENT>96</ENT>
                                <ENT>0.2</ENT>
                                <ENT>0.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">P</ENT>
                                <ENT>0.197</ENT>
                                <ENT>0.1</ENT>
                                <ENT>95</ENT>
                                <ENT>12.7</ENT>
                                <ENT>1.9</ENT>
                                <ENT>0.4</ENT>
                                <ENT>98</ENT>
                                <ENT>3.4</ENT>
                                <ENT>0.9</ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="413"/>
                                <ENT I="01">Pb</ENT>
                                <ENT>&lt;0.01</ENT>
                                <ENT>0.05</ENT>
                                <ENT>87</ENT>
                                <ENT>4.9</ENT>
                                <ENT>16.1</ENT>
                                <ENT>0.2</ENT>
                                <ENT>95</ENT>
                                <ENT>0.2</ENT>
                                <ENT>0.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Sb</ENT>
                                <ENT>&lt;0.008</ENT>
                                <ENT>0.05</ENT>
                                <ENT>98</ENT>
                                <ENT>2.8</ENT>
                                <ENT>8.2</ENT>
                                <ENT>0.2</ENT>
                                <ENT>99</ENT>
                                <ENT>1.4</ENT>
                                <ENT>4.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Se</ENT>
                                <ENT>&lt;0.02</ENT>
                                <ENT>0.1</ENT>
                                <ENT>102</ENT>
                                <ENT>0.4</ENT>
                                <ENT>1.0</ENT>
                                <ENT>0.4</ENT>
                                <ENT>94</ENT>
                                <ENT>1.1</ENT>
                                <ENT>3.4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    SiO
                                    <E T="52">2</E>
                                </ENT>
                                <ENT>13.1</ENT>
                                <ENT>5.0</ENT>
                                <ENT>93</ENT>
                                <ENT>4.8</ENT>
                                <ENT>2.8</ENT>
                                <ENT>20.0</ENT>
                                <ENT>99</ENT>
                                <ENT>0.8</ENT>
                                <ENT>0.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Sn</ENT>
                                <ENT>&lt;0.007</ENT>
                                <ENT>0.05</ENT>
                                <ENT>98</ENT>
                                <ENT>2.8</ENT>
                                <ENT>8.2</ENT>
                                <ENT>0.2</ENT>
                                <ENT>94</ENT>
                                <ENT>0.2</ENT>
                                <ENT>0.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Sr</ENT>
                                <ENT>0.274</ENT>
                                <ENT>0.1</ENT>
                                <ENT>94</ENT>
                                <ENT>5.7</ENT>
                                <ENT>2.7</ENT>
                                <ENT>0.4</ENT>
                                <ENT>95</ENT>
                                <ENT>1.7</ENT>
                                <ENT>2.2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Tl</ENT>
                                <ENT>&lt;0.02</ENT>
                                <ENT>0.1</ENT>
                                <ENT>92</ENT>
                                <ENT>0.4</ENT>
                                <ENT>1.1</ENT>
                                <ENT>0.4</ENT>
                                <ENT>95</ENT>
                                <ENT>1.1</ENT>
                                <ENT>3.2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">V</ENT>
                                <ENT>&lt;0.003</ENT>
                                <ENT>0.05</ENT>
                                <ENT>98</ENT>
                                <ENT>0.0</ENT>
                                <ENT>0.0</ENT>
                                <ENT>0.2</ENT>
                                <ENT>99</ENT>
                                <ENT>0.4</ENT>
                                <ENT>1.0</ENT>
                            </ROW>
                            <ROW RUL="s">
                                <ENT I="01">Zn</ENT>
                                <ENT>0.538</ENT>
                                <ENT>0.05</ENT>
                                <ENT>*</ENT>
                                <ENT>*</ENT>
                                <ENT>0.7</ENT>
                                <ENT>0.2</ENT>
                                <ENT>99</ENT>
                                <ENT>2.5</ENT>
                                <ENT>1.1</ENT>
                            </ROW>
                            <ROW EXPSTB="09" RUL="s">
                                <ENT I="21">
                                    <E T="02">Sewage Treatment Effluent</E>
                                </ENT>
                            </ROW>
                            <ROW EXPSTB="00">
                                <ENT I="01">Ag</ENT>
                                <ENT>0.009</ENT>
                                <ENT>0.05</ENT>
                                <ENT>92</ENT>
                                <ENT>1.5</ENT>
                                <ENT>3.6</ENT>
                                <ENT>0.2</ENT>
                                <ENT>95</ENT>
                                <ENT>0.1</ENT>
                                <ENT>0.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Al</ENT>
                                <ENT>1.19</ENT>
                                <ENT>0.05</ENT>
                                <ENT>*</ENT>
                                <ENT>*</ENT>
                                <ENT>0.9</ENT>
                                <ENT>0.2</ENT>
                                <ENT>113</ENT>
                                <ENT>12.4</ENT>
                                <ENT>2.1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">As</ENT>
                                <ENT>&lt;0.008</ENT>
                                <ENT>0.05</ENT>
                                <ENT>99</ENT>
                                <ENT>2.1</ENT>
                                <ENT>6.1</ENT>
                                <ENT>0.2</ENT>
                                <ENT>93</ENT>
                                <ENT>2.1</ENT>
                                <ENT>6.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">B</ENT>
                                <ENT>0.226</ENT>
                                <ENT>0.1</ENT>
                                <ENT>217</ENT>
                                <ENT>16.3</ENT>
                                <ENT>9.5</ENT>
                                <ENT>0.4</ENT>
                                <ENT>119</ENT>
                                <ENT>13.1</ENT>
                                <ENT>20.9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ba</ENT>
                                <ENT>0.189</ENT>
                                <ENT>0.05</ENT>
                                <ENT>90</ENT>
                                <ENT>6.8</ENT>
                                <ENT>1.7</ENT>
                                <ENT>0.2</ENT>
                                <ENT>99</ENT>
                                <ENT>1.6</ENT>
                                <ENT>0.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Be</ENT>
                                <ENT>&lt;0.0003</ENT>
                                <ENT>0.01</ENT>
                                <ENT>94</ENT>
                                <ENT>0.4</ENT>
                                <ENT>1.1</ENT>
                                <ENT>0.1</ENT>
                                <ENT>100</ENT>
                                <ENT>0.4</ENT>
                                <ENT>1.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ca</ENT>
                                <ENT>87.9</ENT>
                                <ENT>5.0</ENT>
                                <ENT>*</ENT>
                                <ENT>*</ENT>
                                <ENT>0.6</ENT>
                                <ENT>20.0</ENT>
                                <ENT>101</ENT>
                                <ENT>3.7</ENT>
                                <ENT>0.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Cd</ENT>
                                <ENT>0.009</ENT>
                                <ENT>0.01</ENT>
                                <ENT>89</ENT>
                                <ENT>2.6</ENT>
                                <ENT>2.3</ENT>
                                <ENT>0.1</ENT>
                                <ENT>97</ENT>
                                <ENT>0.4</ENT>
                                <ENT>1.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Co</ENT>
                                <ENT>0.016</ENT>
                                <ENT>0.02</ENT>
                                <ENT>95</ENT>
                                <ENT>3.1</ENT>
                                <ENT>0.0</ENT>
                                <ENT>0.2</ENT>
                                <ENT>93</ENT>
                                <ENT>0.4</ENT>
                                <ENT>0.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Cr</ENT>
                                <ENT>0.128</ENT>
                                <ENT>0.01</ENT>
                                <ENT>*</ENT>
                                <ENT>*</ENT>
                                <ENT>1.5</ENT>
                                <ENT>0.1</ENT>
                                <ENT>97</ENT>
                                <ENT>2.4</ENT>
                                <ENT>2.7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Cu</ENT>
                                <ENT>0.174</ENT>
                                <ENT>0.02</ENT>
                                <ENT>98</ENT>
                                <ENT>33.1</ENT>
                                <ENT>4.7</ENT>
                                <ENT>0.2</ENT>
                                <ENT>98</ENT>
                                <ENT>3.0</ENT>
                                <ENT>1.4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Fe</ENT>
                                <ENT>1.28</ENT>
                                <ENT>0.1</ENT>
                                <ENT>*</ENT>
                                <ENT>*</ENT>
                                <ENT>2.8</ENT>
                                <ENT>0.4</ENT>
                                <ENT>111</ENT>
                                <ENT>7.0</ENT>
                                <ENT>0.6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Hg</ENT>
                                <ENT>&lt;0.007</ENT>
                                <ENT>0.05</ENT>
                                <ENT>102</ENT>
                                <ENT>1.4</ENT>
                                <ENT>3.9</ENT>
                                <ENT>0.2</ENT>
                                <ENT>98</ENT>
                                <ENT>0.5</ENT>
                                <ENT>1.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">K</ENT>
                                <ENT>10.6</ENT>
                                <ENT>5.0</ENT>
                                <ENT>104</ENT>
                                <ENT>2.8</ENT>
                                <ENT>1.3</ENT>
                                <ENT>20.0</ENT>
                                <ENT>101</ENT>
                                <ENT>0.6</ENT>
                                <ENT>0.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Li</ENT>
                                <ENT>0.011</ENT>
                                <ENT>0.02</ENT>
                                <ENT>103</ENT>
                                <ENT>8.5</ENT>
                                <ENT>3.2</ENT>
                                <ENT>0.2</ENT>
                                <ENT>105</ENT>
                                <ENT>0.8</ENT>
                                <ENT>0.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Mg</ENT>
                                <ENT>22.7</ENT>
                                <ENT>5.0</ENT>
                                <ENT>100</ENT>
                                <ENT>4.4</ENT>
                                <ENT>0.0</ENT>
                                <ENT>20.0</ENT>
                                <ENT>92</ENT>
                                <ENT>1.1</ENT>
                                <ENT>0.2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Mn</ENT>
                                <ENT>0.199</ENT>
                                <ENT>0.01</ENT>
                                <ENT>*</ENT>
                                <ENT>*</ENT>
                                <ENT>2.0</ENT>
                                <ENT>0.1</ENT>
                                <ENT>104</ENT>
                                <ENT>1.9</ENT>
                                <ENT>0.3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Mo</ENT>
                                <ENT>0.125</ENT>
                                <ENT>0.02</ENT>
                                <ENT>110</ENT>
                                <ENT>21.2</ENT>
                                <ENT>6.8</ENT>
                                <ENT>0.2</ENT>
                                <ENT>102</ENT>
                                <ENT>1.3</ENT>
                                <ENT>0.9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Na</ENT>
                                <ENT>0.236</ENT>
                                <ENT>5.0</ENT>
                                <ENT>*</ENT>
                                <ENT>*</ENT>
                                <ENT>0.0</ENT>
                                <ENT>20.0</ENT>
                                <ENT>*</ENT>
                                <ENT>*</ENT>
                                <ENT>0.4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ni</ENT>
                                <ENT>0.087</ENT>
                                <ENT>0.02</ENT>
                                <ENT>122</ENT>
                                <ENT>10.7</ENT>
                                <ENT>4.5</ENT>
                                <ENT>0.2</ENT>
                                <ENT>98</ENT>
                                <ENT>0.8</ENT>
                                <ENT>1.1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">P</ENT>
                                <ENT>4.71</ENT>
                                <ENT>0.1</ENT>
                                <ENT>*</ENT>
                                <ENT>*</ENT>
                                <ENT>2.6</ENT>
                                <ENT>0.4</ENT>
                                <ENT>*</ENT>
                                <ENT>*</ENT>
                                <ENT>1.4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Pb</ENT>
                                <ENT>0.015</ENT>
                                <ENT>0.05</ENT>
                                <ENT>91</ENT>
                                <ENT>3.5</ENT>
                                <ENT>5.0</ENT>
                                <ENT>0.2</ENT>
                                <ENT>96</ENT>
                                <ENT>1.3</ENT>
                                <ENT>2.9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Sb</ENT>
                                <ENT>&lt;0.008</ENT>
                                <ENT>0.05</ENT>
                                <ENT>97</ENT>
                                <ENT>0.7</ENT>
                                <ENT>2.1</ENT>
                                <ENT>0.2</ENT>
                                <ENT>103</ENT>
                                <ENT>1.1</ENT>
                                <ENT>2.9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Se</ENT>
                                <ENT>&lt;0.02</ENT>
                                <ENT>0.1</ENT>
                                <ENT>108</ENT>
                                <ENT>3.9</ENT>
                                <ENT>10.0</ENT>
                                <ENT>0.4</ENT>
                                <ENT>101</ENT>
                                <ENT>2.6</ENT>
                                <ENT>7.2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    SiO
                                    <E T="52">2</E>
                                </ENT>
                                <ENT>16.7</ENT>
                                <ENT>5.0</ENT>
                                <ENT>124</ENT>
                                <ENT>4.0</ENT>
                                <ENT>0.9</ENT>
                                <ENT>20.0</ENT>
                                <ENT>108</ENT>
                                <ENT>1.1</ENT>
                                <ENT>0.8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Sn</ENT>
                                <ENT>0.016</ENT>
                                <ENT>0.05</ENT>
                                <ENT>90</ENT>
                                <ENT>3.8</ENT>
                                <ENT>0.0</ENT>
                                <ENT>0.2</ENT>
                                <ENT>95</ENT>
                                <ENT>1.0</ENT>
                                <ENT>0.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Sr</ENT>
                                <ENT>0.515</ENT>
                                <ENT>0.1</ENT>
                                <ENT>103</ENT>
                                <ENT>6.4</ENT>
                                <ENT>0.5</ENT>
                                <ENT>0.4</ENT>
                                <ENT>96</ENT>
                                <ENT>1.6</ENT>
                                <ENT>0.2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Tl</ENT>
                                <ENT>&lt;0.02</ENT>
                                <ENT>0.1</ENT>
                                <ENT>105</ENT>
                                <ENT>0.4</ENT>
                                <ENT>1.0</ENT>
                                <ENT>0.4</ENT>
                                <ENT>95</ENT>
                                <ENT>0.0</ENT>
                                <ENT>0.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">V</ENT>
                                <ENT>0.003</ENT>
                                <ENT>0.05</ENT>
                                <ENT>93</ENT>
                                <ENT>0.9</ENT>
                                <ENT>2.0</ENT>
                                <ENT>0.2</ENT>
                                <ENT>97</ENT>
                                <ENT>0.2</ENT>
                                <ENT>0.5</ENT>
                            </ROW>
                            <ROW RUL="s">
                                <ENT I="01">Zn</ENT>
                                <ENT>0.160</ENT>
                                <ENT>0.05</ENT>
                                <ENT>98</ENT>
                                <ENT>3.3</ENT>
                                <ENT>1.9</ENT>
                                <ENT>0.2</ENT>
                                <ENT>101</ENT>
                                <ENT>1.0</ENT>
                                <ENT>1.4</ENT>
                            </ROW>
                            <ROW EXPSTB="09" RUL="s">
                                <ENT I="21">
                                    <E T="02">Industrial Effluent</E>
                                </ENT>
                            </ROW>
                            <ROW EXPSTB="00">
                                <ENT I="01">Ag</ENT>
                                <ENT>&lt;0.0003</ENT>
                                <ENT>0.05</ENT>
                                <ENT>88</ENT>
                                <ENT>0.0</ENT>
                                <ENT>0.0</ENT>
                                <ENT>0.2</ENT>
                                <ENT>84</ENT>
                                <ENT>0.9</ENT>
                                <ENT>3.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Al</ENT>
                                <ENT>0.054</ENT>
                                <ENT>0.05</ENT>
                                <ENT>88</ENT>
                                <ENT>11.7</ENT>
                                <ENT>12.2</ENT>
                                <ENT>0.2</ENT>
                                <ENT>90</ENT>
                                <ENT>3.9</ENT>
                                <ENT>8.1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">As</ENT>
                                <ENT>&lt;0.02</ENT>
                                <ENT>0.05</ENT>
                                <ENT>82</ENT>
                                <ENT>2.8</ENT>
                                <ENT>9.8</ENT>
                                <ENT>0.2</ENT>
                                <ENT>88</ENT>
                                <ENT>0.5</ENT>
                                <ENT>1.7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">B</ENT>
                                <ENT>0.17</ENT>
                                <ENT>0.1</ENT>
                                <ENT>162</ENT>
                                <ENT>17.6</ENT>
                                <ENT>13.9</ENT>
                                <ENT>0.4</ENT>
                                <ENT>92</ENT>
                                <ENT>4.7</ENT>
                                <ENT>9.3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ba</ENT>
                                <ENT>0.083</ENT>
                                <ENT>0.05</ENT>
                                <ENT>86</ENT>
                                <ENT>8.2</ENT>
                                <ENT>1.6</ENT>
                                <ENT>0.2</ENT>
                                <ENT>85</ENT>
                                <ENT>2.3</ENT>
                                <ENT>2.4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Be</ENT>
                                <ENT>&lt;0.0006</ENT>
                                <ENT>0.01</ENT>
                                <ENT>94</ENT>
                                <ENT>0.4</ENT>
                                <ENT>1.1</ENT>
                                <ENT>0.1</ENT>
                                <ENT>82</ENT>
                                <ENT>1.4</ENT>
                                <ENT>4.9</ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="414"/>
                                <ENT I="01">Ca</ENT>
                                <ENT>500</ENT>
                                <ENT>5.0</ENT>
                                <ENT>*</ENT>
                                <ENT>*</ENT>
                                <ENT>2.8</ENT>
                                <ENT>20.0</ENT>
                                <ENT>*</ENT>
                                <ENT>*</ENT>
                                <ENT>2.3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Cd</ENT>
                                <ENT>0.008</ENT>
                                <ENT>0.01</ENT>
                                <ENT>85</ENT>
                                <ENT>4.7</ENT>
                                <ENT>6.1</ENT>
                                <ENT>0.1</ENT>
                                <ENT>82</ENT>
                                <ENT>1.4</ENT>
                                <ENT>4.4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Co</ENT>
                                <ENT>&lt;0.004</ENT>
                                <ENT>0.02</ENT>
                                <ENT>93</ENT>
                                <ENT>1.8</ENT>
                                <ENT>5.4</ENT>
                                <ENT>0.2</ENT>
                                <ENT>83</ENT>
                                <ENT>0.4</ENT>
                                <ENT>1.2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Cr</ENT>
                                <ENT>0.165</ENT>
                                <ENT>0.01</ENT>
                                <ENT>*</ENT>
                                <ENT>*</ENT>
                                <ENT>4.5</ENT>
                                <ENT>0.1</ENT>
                                <ENT>106</ENT>
                                <ENT>6.6</ENT>
                                <ENT>5.6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Cu</ENT>
                                <ENT>0.095</ENT>
                                <ENT>0.02</ENT>
                                <ENT>93</ENT>
                                <ENT>23.3</ENT>
                                <ENT>0.9</ENT>
                                <ENT>0.2</ENT>
                                <ENT>95</ENT>
                                <ENT>2.7</ENT>
                                <ENT>2.8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Fe</ENT>
                                <ENT>0.315</ENT>
                                <ENT>0.1</ENT>
                                <ENT>88</ENT>
                                <ENT>16.4</ENT>
                                <ENT>1.0</ENT>
                                <ENT>0.4</ENT>
                                <ENT>99</ENT>
                                <ENT>6.5</ENT>
                                <ENT>8.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Hg</ENT>
                                <ENT>&lt;0.01</ENT>
                                <ENT>0.05</ENT>
                                <ENT>87</ENT>
                                <ENT>0.7</ENT>
                                <ENT>2.3</ENT>
                                <ENT>0.2</ENT>
                                <ENT>86</ENT>
                                <ENT>0.4</ENT>
                                <ENT>1.2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">K</ENT>
                                <ENT>2.87</ENT>
                                <ENT>5.0</ENT>
                                <ENT>101</ENT>
                                <ENT>3.4</ENT>
                                <ENT>2.4</ENT>
                                <ENT>20.0</ENT>
                                <ENT>100</ENT>
                                <ENT>0.8</ENT>
                                <ENT>0.4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Li</ENT>
                                <ENT>0.069</ENT>
                                <ENT>0.02</ENT>
                                <ENT>103</ENT>
                                <ENT>24.7</ENT>
                                <ENT>5.6</ENT>
                                <ENT>0.2</ENT>
                                <ENT>104</ENT>
                                <ENT>2.5</ENT>
                                <ENT>2.2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Mg</ENT>
                                <ENT>6.84</ENT>
                                <ENT>5.0</ENT>
                                <ENT>87</ENT>
                                <ENT>3.1</ENT>
                                <ENT>0.0</ENT>
                                <ENT>20.0</ENT>
                                <ENT>87</ENT>
                                <ENT>0.9</ENT>
                                <ENT>1.2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Mn</ENT>
                                <ENT>0.141</ENT>
                                <ENT>0.01</ENT>
                                <ENT>*</ENT>
                                <ENT>*</ENT>
                                <ENT>1.2</ENT>
                                <ENT>0.1</ENT>
                                <ENT>89</ENT>
                                <ENT>6.6</ENT>
                                <ENT>4.8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Mo</ENT>
                                <ENT>1.27</ENT>
                                <ENT>0.02</ENT>
                                <ENT>*</ENT>
                                <ENT>*</ENT>
                                <ENT>0.0</ENT>
                                <ENT>0.2</ENT>
                                <ENT>100</ENT>
                                <ENT>15.0</ENT>
                                <ENT>2.7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Na</ENT>
                                <ENT>1500</ENT>
                                <ENT>5.0</ENT>
                                <ENT>*</ENT>
                                <ENT>*</ENT>
                                <ENT>2.7</ENT>
                                <ENT>20.0</ENT>
                                <ENT>*</ENT>
                                <ENT>*</ENT>
                                <ENT>2.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ni</ENT>
                                <ENT>0.014</ENT>
                                <ENT>0.02</ENT>
                                <ENT>98</ENT>
                                <ENT>4.4</ENT>
                                <ENT>3.0</ENT>
                                <ENT>0.2</ENT>
                                <ENT>87</ENT>
                                <ENT>0.5</ENT>
                                <ENT>1.1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">P</ENT>
                                <ENT>0.326</ENT>
                                <ENT>0.1</ENT>
                                <ENT>105</ENT>
                                <ENT>16.0</ENT>
                                <ENT>4.7</ENT>
                                <ENT>0.4</ENT>
                                <ENT>97</ENT>
                                <ENT>3.9</ENT>
                                <ENT>1.4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Pb</ENT>
                                <ENT>0.251</ENT>
                                <ENT>0.05</ENT>
                                <ENT>80</ENT>
                                <ENT>19.9</ENT>
                                <ENT>1.4</ENT>
                                <ENT>0.2</ENT>
                                <ENT>88</ENT>
                                <ENT>5.0</ENT>
                                <ENT>0.9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Sb</ENT>
                                <ENT>2.81</ENT>
                                <ENT>0.05</ENT>
                                <ENT>*</ENT>
                                <ENT>*</ENT>
                                <ENT>0.4</ENT>
                                <ENT>0.2</ENT>
                                <ENT>*</ENT>
                                <ENT>*</ENT>
                                <ENT>2.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Se</ENT>
                                <ENT>0.021</ENT>
                                <ENT>0.1</ENT>
                                <ENT>106</ENT>
                                <ENT>2.6</ENT>
                                <ENT>3.2</ENT>
                                <ENT>0.4</ENT>
                                <ENT>105</ENT>
                                <ENT>1.9</ENT>
                                <ENT>4.6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">
                                    SiO
                                    <E T="52">2</E>
                                </ENT>
                                <ENT>6.83</ENT>
                                <ENT>5.0</ENT>
                                <ENT>99</ENT>
                                <ENT>6.8</ENT>
                                <ENT>1.7</ENT>
                                <ENT>20.0</ENT>
                                <ENT>100</ENT>
                                <ENT>2.2</ENT>
                                <ENT>3.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Sn</ENT>
                                <ENT>&lt;0.01</ENT>
                                <ENT>0.05</ENT>
                                <ENT>87</ENT>
                                <ENT>0.7</ENT>
                                <ENT>2.3</ENT>
                                <ENT>0.2</ENT>
                                <ENT>86</ENT>
                                <ENT>0.4</ENT>
                                <ENT>1.2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Sr</ENT>
                                <ENT>6.54</ENT>
                                <ENT>0.1</ENT>
                                <ENT>*</ENT>
                                <ENT>*</ENT>
                                <ENT>2.0</ENT>
                                <ENT>0.4</ENT>
                                <ENT>*</ENT>
                                <ENT>*</ENT>
                                <ENT>2.7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Tl</ENT>
                                <ENT>&lt;0.03</ENT>
                                <ENT>0.1</ENT>
                                <ENT>87</ENT>
                                <ENT>1.8</ENT>
                                <ENT>5.8</ENT>
                                <ENT>0.4</ENT>
                                <ENT>84</ENT>
                                <ENT>1.1</ENT>
                                <ENT>3.6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">V</ENT>
                                <ENT>&lt;0.005</ENT>
                                <ENT>0.05</ENT>
                                <ENT>90</ENT>
                                <ENT>1.4</ENT>
                                <ENT>4.4</ENT>
                                <ENT>0.2</ENT>
                                <ENT>84</ENT>
                                <ENT>1.1</ENT>
                                <ENT>3.6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Zn</ENT>
                                <ENT>0.024</ENT>
                                <ENT>0.05</ENT>
                                <ENT>89</ENT>
                                <ENT>6.0</ENT>
                                <ENT>4.4</ENT>
                                <ENT>0.2</ENT>
                                <ENT>91</ENT>
                                <ENT>3.5</ENT>
                                <ENT>8.9</ENT>
                            </ROW>
                            <TNOTE>S (R) Standard deviation of percent recovery.</TNOTE>
                            <TNOTE>RPD Relative percent difference between duplicate spike determinations.</TNOTE>
                            <TNOTE>&lt;Sample concentration below established method detection limit.</TNOTE>
                            <TNOTE>* Spike concentration &lt;10% of sample background concentration.</TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="10" OPTS="L2" CDEF="s20,10,10,10,10,10,10,10,10,10">
                            <TTITLE>Table 7—Precision and Recovery Data in Solid Matrices</TTITLE>
                            <BOXHD>
                                <CHED H="1">Analyte</CHED>
                                <CHED H="1">
                                    Sample conc.
                                    <LI>mg/kg</LI>
                                </CHED>
                                <CHED H="1">
                                    Low + spike
                                    <LI>mg/kg</LI>
                                </CHED>
                                <CHED H="1">
                                    Average
                                    <LI>recovery R (%)</LI>
                                </CHED>
                                <CHED H="1">S (R)</CHED>
                                <CHED H="1">RPD</CHED>
                                <CHED H="1">
                                    High + spike
                                    <LI>mg/kg</LI>
                                </CHED>
                                <CHED H="1">
                                    Average
                                    <LI>recovery R (%)</LI>
                                </CHED>
                                <CHED H="1">S (R)</CHED>
                                <CHED H="1">RPD</CHED>
                            </BOXHD>
                            <ROW EXPSTB="09" RUL="s">
                                <ENT I="21">
                                    <E T="02"> EPA Hazardous Soil #884</E>
                                </ENT>
                            </ROW>
                            <ROW EXPSTB="00">
                                <ENT I="01">Ag</ENT>
                                <ENT>1.1</ENT>
                                <ENT>20</ENT>
                                <ENT>98</ENT>
                                <ENT>0.7</ENT>
                                <ENT>1.0</ENT>
                                <ENT>100</ENT>
                                <ENT>96</ENT>
                                <ENT>0.2</ENT>
                                <ENT>0.6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Al</ENT>
                                <ENT>5080</ENT>
                                <ENT>20</ENT>
                                <ENT>*</ENT>
                                <ENT>*</ENT>
                                <ENT>7.2</ENT>
                                <ENT>100</ENT>
                                <ENT>*</ENT>
                                <ENT>*</ENT>
                                <ENT>5.4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">As</ENT>
                                <ENT>5.7</ENT>
                                <ENT>20</ENT>
                                <ENT>95</ENT>
                                <ENT>5.4</ENT>
                                <ENT>10.6</ENT>
                                <ENT>100</ENT>
                                <ENT>96</ENT>
                                <ENT>1.4</ENT>
                                <ENT>3.6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">B</ENT>
                                <ENT>20.4</ENT>
                                <ENT>100</ENT>
                                <ENT>93</ENT>
                                <ENT>2.7</ENT>
                                <ENT>5.3</ENT>
                                <ENT>400</ENT>
                                <ENT>100</ENT>
                                <ENT>2.1</ENT>
                                <ENT>5.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ba</ENT>
                                <ENT>111</ENT>
                                <ENT>20</ENT>
                                <ENT>98</ENT>
                                <ENT>71.4</ENT>
                                <ENT>22.2</ENT>
                                <ENT>100</ENT>
                                <ENT>97</ENT>
                                <ENT>10.0</ENT>
                                <ENT>1.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Be</ENT>
                                <ENT>0.66</ENT>
                                <ENT>20</ENT>
                                <ENT>97</ENT>
                                <ENT>0.7</ENT>
                                <ENT>2.3</ENT>
                                <ENT>100</ENT>
                                <ENT>99</ENT>
                                <ENT>0.1</ENT>
                                <ENT>0.2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ca</ENT>
                                <ENT>85200</ENT>
                                <ENT>−</ENT>
                                <ENT>−</ENT>
                                <ENT>−</ENT>
                                <ENT>−</ENT>
                                <ENT>−</ENT>
                                <ENT>−</ENT>
                                <ENT>−</ENT>
                                <ENT>−</ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="415"/>
                                <ENT I="01">Cd</ENT>
                                <ENT>2</ENT>
                                <ENT>20</ENT>
                                <ENT>93</ENT>
                                <ENT>0.7</ENT>
                                <ENT>1.0</ENT>
                                <ENT>100</ENT>
                                <ENT>94</ENT>
                                <ENT>0.2</ENT>
                                <ENT>0.4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Co</ENT>
                                <ENT>5.5</ENT>
                                <ENT>20</ENT>
                                <ENT>96</ENT>
                                <ENT>3.5</ENT>
                                <ENT>7.7</ENT>
                                <ENT>100</ENT>
                                <ENT>93</ENT>
                                <ENT>0.8</ENT>
                                <ENT>2.1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Cr</ENT>
                                <ENT>79.7</ENT>
                                <ENT>20</ENT>
                                <ENT>87</ENT>
                                <ENT>28.8</ENT>
                                <ENT>16.5</ENT>
                                <ENT>100</ENT>
                                <ENT>104</ENT>
                                <ENT>1.3</ENT>
                                <ENT>1.1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Cu</ENT>
                                <ENT>113</ENT>
                                <ENT>20</ENT>
                                <ENT>110</ENT>
                                <ENT>16.2</ENT>
                                <ENT>4.4</ENT>
                                <ENT>100</ENT>
                                <ENT>104</ENT>
                                <ENT>4.0</ENT>
                                <ENT>4.2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Fe</ENT>
                                <ENT>16500</ENT>
                                <ENT>−</ENT>
                                <ENT>−</ENT>
                                <ENT>−</ENT>
                                <ENT>−</ENT>
                                <ENT>−</ENT>
                                <ENT>−</ENT>
                                <ENT>−</ENT>
                                <ENT>−</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Hg</ENT>
                                <ENT>&lt;1.4</ENT>
                                <ENT>10</ENT>
                                <ENT>92</ENT>
                                <ENT>2.5</ENT>
                                <ENT>7.7</ENT>
                                <ENT>40</ENT>
                                <ENT>98</ENT>
                                <ENT>0.0</ENT>
                                <ENT>0.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">K</ENT>
                                <ENT>621</ENT>
                                <ENT>500</ENT>
                                <ENT>121</ENT>
                                <ENT>1.3</ENT>
                                <ENT>0.0</ENT>
                                <ENT>2000</ENT>
                                <ENT>107</ENT>
                                <ENT>0.9</ENT>
                                <ENT>1.8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Li</ENT>
                                <ENT>6.7</ENT>
                                <ENT>10</ENT>
                                <ENT>113</ENT>
                                <ENT>3.5</ENT>
                                <ENT>4.4</ENT>
                                <ENT>40</ENT>
                                <ENT>106</ENT>
                                <ENT>0.6</ENT>
                                <ENT>0.6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Mg</ENT>
                                <ENT>24400</ENT>
                                <ENT>500</ENT>
                                <ENT>*</ENT>
                                <ENT>*</ENT>
                                <ENT>8.4</ENT>
                                <ENT>2000</ENT>
                                <ENT>*</ENT>
                                <ENT>*</ENT>
                                <ENT>10.1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Mn</ENT>
                                <ENT>343</ENT>
                                <ENT>20</ENT>
                                <ENT>*</ENT>
                                <ENT>*</ENT>
                                <ENT>8.5</ENT>
                                <ENT>100</ENT>
                                <ENT>95</ENT>
                                <ENT>11.0</ENT>
                                <ENT>1.6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Mo</ENT>
                                <ENT>5.3</ENT>
                                <ENT>20</ENT>
                                <ENT>88</ENT>
                                <ENT>5.3</ENT>
                                <ENT>13.2</ENT>
                                <ENT>100</ENT>
                                <ENT>91</ENT>
                                <ENT>1.4</ENT>
                                <ENT>4.1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Na</ENT>
                                <ENT>195</ENT>
                                <ENT>500</ENT>
                                <ENT>102</ENT>
                                <ENT>2.2</ENT>
                                <ENT>2.4</ENT>
                                <ENT>2000</ENT>
                                <ENT>100</ENT>
                                <ENT>1.5</ENT>
                                <ENT>3.7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ni</ENT>
                                <ENT>15.6</ENT>
                                <ENT>20</ENT>
                                <ENT>100</ENT>
                                <ENT>1.8</ENT>
                                <ENT>0.0</ENT>
                                <ENT>100</ENT>
                                <ENT>94</ENT>
                                <ENT>1.5</ENT>
                                <ENT>3.6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">P</ENT>
                                <ENT>595</ENT>
                                <ENT>500</ENT>
                                <ENT>106</ENT>
                                <ENT>13.4</ENT>
                                <ENT>8.0</ENT>
                                <ENT>2000</ENT>
                                <ENT>103</ENT>
                                <ENT>3.2</ENT>
                                <ENT>2.7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Pb</ENT>
                                <ENT>145</ENT>
                                <ENT>20</ENT>
                                <ENT>88</ENT>
                                <ENT>51.8</ENT>
                                <ENT>17.9</ENT>
                                <ENT>100</ENT>
                                <ENT>108</ENT>
                                <ENT>15.6</ENT>
                                <ENT>17.4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Sb</ENT>
                                <ENT>6.1</ENT>
                                <ENT>20</ENT>
                                <ENT>83</ENT>
                                <ENT>3.9</ENT>
                                <ENT>7.5</ENT>
                                <ENT>100</ENT>
                                <ENT>81</ENT>
                                <ENT>1.9</ENT>
                                <ENT>5.9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Se</ENT>
                                <ENT>&lt;5</ENT>
                                <ENT>20</ENT>
                                <ENT>79</ENT>
                                <ENT>14.7</ENT>
                                <ENT>52.4</ENT>
                                <ENT>100</ENT>
                                <ENT>99</ENT>
                                <ENT>0.7</ENT>
                                <ENT>2.1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Sn</ENT>
                                <ENT>16.6</ENT>
                                <ENT>20</ENT>
                                <ENT>91</ENT>
                                <ENT>34.6</ENT>
                                <ENT>5.8</ENT>
                                <ENT>80</ENT>
                                <ENT>112</ENT>
                                <ENT>8.7</ENT>
                                <ENT>2.8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Sr</ENT>
                                <ENT>102</ENT>
                                <ENT>100</ENT>
                                <ENT>84</ENT>
                                <ENT>9.6</ENT>
                                <ENT>10.8</ENT>
                                <ENT>400</ENT>
                                <ENT>94</ENT>
                                <ENT>2.5</ENT>
                                <ENT>4.6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Tl</ENT>
                                <ENT>&lt;4</ENT>
                                <ENT>20</ENT>
                                <ENT>92</ENT>
                                <ENT>4.8</ENT>
                                <ENT>14.6</ENT>
                                <ENT>100</ENT>
                                <ENT>91</ENT>
                                <ENT>1.5</ENT>
                                <ENT>4.6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">V</ENT>
                                <ENT>16.7</ENT>
                                <ENT>20</ENT>
                                <ENT>104</ENT>
                                <ENT>4.2</ENT>
                                <ENT>5.4</ENT>
                                <ENT>100</ENT>
                                <ENT>99</ENT>
                                <ENT>0.8</ENT>
                                <ENT>1.7</ENT>
                            </ROW>
                            <ROW RUL="s">
                                <ENT I="01">Zn</ENT>
                                <ENT>131</ENT>
                                <ENT>20</ENT>
                                <ENT>103</ENT>
                                <ENT>31.2</ENT>
                                <ENT>7.3</ENT>
                                <ENT>100</ENT>
                                <ENT>104</ENT>
                                <ENT>7.2</ENT>
                                <ENT>6.4</ENT>
                            </ROW>
                            <ROW EXPSTB="09" RUL="s">
                                <ENT I="21">
                                    <E T="02">EPA Electroplating Sludge #286</E>
                                </ENT>
                            </ROW>
                            <ROW EXPSTB="00">
                                <ENT I="01">Ag</ENT>
                                <ENT>6</ENT>
                                <ENT>20</ENT>
                                <ENT>96</ENT>
                                <ENT>0.2</ENT>
                                <ENT>0.4</ENT>
                                <ENT>100</ENT>
                                <ENT>93</ENT>
                                <ENT>0.1</ENT>
                                <ENT>0.4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Al</ENT>
                                <ENT>4980</ENT>
                                <ENT>20</ENT>
                                <ENT>*</ENT>
                                <ENT>*</ENT>
                                <ENT>4.4</ENT>
                                <ENT>100</ENT>
                                <ENT>*</ENT>
                                <ENT>*</ENT>
                                <ENT>5.6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">As</ENT>
                                <ENT>32</ENT>
                                <ENT>20</ENT>
                                <ENT>94</ENT>
                                <ENT>1.3</ENT>
                                <ENT>0.8</ENT>
                                <ENT>100</ENT>
                                <ENT>97</ENT>
                                <ENT>0.7</ENT>
                                <ENT>1.6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">B</ENT>
                                <ENT>210</ENT>
                                <ENT>100</ENT>
                                <ENT>113</ENT>
                                <ENT>2.0</ENT>
                                <ENT>1.6</ENT>
                                <ENT>400</ENT>
                                <ENT>98</ENT>
                                <ENT>1.9</ENT>
                                <ENT>3.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ba</ENT>
                                <ENT>39.8</ENT>
                                <ENT>20</ENT>
                                <ENT>0</ENT>
                                <ENT>6.8</ENT>
                                <ENT>0.3</ENT>
                                <ENT>100</ENT>
                                <ENT>0</ENT>
                                <ENT>1.6</ENT>
                                <ENT>5.7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Be</ENT>
                                <ENT>0.32</ENT>
                                <ENT>20</ENT>
                                <ENT>96</ENT>
                                <ENT>0.2</ENT>
                                <ENT>0.5</ENT>
                                <ENT>100</ENT>
                                <ENT>101</ENT>
                                <ENT>0.7</ENT>
                                <ENT>2.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ca</ENT>
                                <ENT>48500</ENT>
                                <ENT>−</ENT>
                                <ENT>−</ENT>
                                <ENT>−</ENT>
                                <ENT>−</ENT>
                                <ENT>−</ENT>
                                <ENT>−</ENT>
                                <ENT>−</ENT>
                                <ENT>−</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Cd</ENT>
                                <ENT>108</ENT>
                                <ENT>20</ENT>
                                <ENT>98</ENT>
                                <ENT>2.5</ENT>
                                <ENT>0.8</ENT>
                                <ENT>100</ENT>
                                <ENT>96</ENT>
                                <ENT>0.5</ENT>
                                <ENT>0.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Co</ENT>
                                <ENT>5.9</ENT>
                                <ENT>20</ENT>
                                <ENT>93</ENT>
                                <ENT>2.9</ENT>
                                <ENT>5.7</ENT>
                                <ENT>100</ENT>
                                <ENT>93</ENT>
                                <ENT>0.6</ENT>
                                <ENT>1.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Cr</ENT>
                                <ENT>7580</ENT>
                                <ENT>20</ENT>
                                <ENT>*</ENT>
                                <ENT>*</ENT>
                                <ENT>0.7</ENT>
                                <ENT>100</ENT>
                                <ENT>*</ENT>
                                <ENT>*</ENT>
                                <ENT>1.3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Cu</ENT>
                                <ENT>806</ENT>
                                <ENT>20</ENT>
                                <ENT>*</ENT>
                                <ENT>*</ENT>
                                <ENT>1.5</ENT>
                                <ENT>100</ENT>
                                <ENT>94</ENT>
                                <ENT>8.3</ENT>
                                <ENT>0.7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Fe</ENT>
                                <ENT>31100</ENT>
                                <ENT>−</ENT>
                                <ENT>−</ENT>
                                <ENT>−</ENT>
                                <ENT>−</ENT>
                                <ENT>−</ENT>
                                <ENT>−</ENT>
                                <ENT>−</ENT>
                                <ENT>−</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Hg</ENT>
                                <ENT>6.1</ENT>
                                <ENT>10</ENT>
                                <ENT>90</ENT>
                                <ENT>2.5</ENT>
                                <ENT>4.0</ENT>
                                <ENT>40</ENT>
                                <ENT>97</ENT>
                                <ENT>1.7</ENT>
                                <ENT>4.3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">K</ENT>
                                <ENT>2390</ENT>
                                <ENT>500</ENT>
                                <ENT>75</ENT>
                                <ENT>8.3</ENT>
                                <ENT>4.0</ENT>
                                <ENT>2000</ENT>
                                <ENT>94</ENT>
                                <ENT>2.9</ENT>
                                <ENT>3.8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Li</ENT>
                                <ENT>9.1</ENT>
                                <ENT>10</ENT>
                                <ENT>101</ENT>
                                <ENT>2.8</ENT>
                                <ENT>0.5</ENT>
                                <ENT>40</ENT>
                                <ENT>106</ENT>
                                <ENT>1.6</ENT>
                                <ENT>3.1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Mg</ENT>
                                <ENT>1950</ENT>
                                <ENT>500</ENT>
                                <ENT>110</ENT>
                                <ENT>2.0</ENT>
                                <ENT>0.8</ENT>
                                <ENT>2000</ENT>
                                <ENT>108</ENT>
                                <ENT>2.3</ENT>
                                <ENT>3.2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Mn</ENT>
                                <ENT>262</ENT>
                                <ENT>20</ENT>
                                <ENT>*</ENT>
                                <ENT>*</ENT>
                                <ENT>1.8</ENT>
                                <ENT>100</ENT>
                                <ENT>91</ENT>
                                <ENT>1.2</ENT>
                                <ENT>0.9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Mo</ENT>
                                <ENT>13.2</ENT>
                                <ENT>20</ENT>
                                <ENT>92</ENT>
                                <ENT>2.1</ENT>
                                <ENT>2.9</ENT>
                                <ENT>100</ENT>
                                <ENT>92</ENT>
                                <ENT>0.3</ENT>
                                <ENT>0.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Na</ENT>
                                <ENT>73400</ENT>
                                <ENT>500</ENT>
                                <ENT>*</ENT>
                                <ENT>*</ENT>
                                <ENT>1.7</ENT>
                                <ENT>2000</ENT>
                                <ENT>*</ENT>
                                <ENT>*</ENT>
                                <ENT>1.4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ni</ENT>
                                <ENT>456</ENT>
                                <ENT>20</ENT>
                                <ENT>*</ENT>
                                <ENT>*</ENT>
                                <ENT>0.4</ENT>
                                <ENT>100</ENT>
                                <ENT>88</ENT>
                                <ENT>2.7</ENT>
                                <ENT>0.9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">P</ENT>
                                <ENT>9610</ENT>
                                <ENT>500</ENT>
                                <ENT>*</ENT>
                                <ENT>*</ENT>
                                <ENT>2.9</ENT>
                                <ENT>2000</ENT>
                                <ENT>114</ENT>
                                <ENT>7.4</ENT>
                                <ENT>3.4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Pb</ENT>
                                <ENT>1420</ENT>
                                <ENT>20</ENT>
                                <ENT>*</ENT>
                                <ENT>*</ENT>
                                <ENT>2.1</ENT>
                                <ENT>100</ENT>
                                <ENT>*</ENT>
                                <ENT>*</ENT>
                                <ENT>1.3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Sb</ENT>
                                <ENT>&lt;2</ENT>
                                <ENT>20</ENT>
                                <ENT>76</ENT>
                                <ENT>0.9</ENT>
                                <ENT>3.3</ENT>
                                <ENT>100</ENT>
                                <ENT>75</ENT>
                                <ENT>2.8</ENT>
                                <ENT>10.7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Se</ENT>
                                <ENT>6.3</ENT>
                                <ENT>20</ENT>
                                <ENT>86</ENT>
                                <ENT>9.0</ENT>
                                <ENT>16.6</ENT>
                                <ENT>100</ENT>
                                <ENT>103</ENT>
                                <ENT>1.6</ENT>
                                <ENT>2.7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Sn</ENT>
                                <ENT>24.0</ENT>
                                <ENT>20</ENT>
                                <ENT>87</ENT>
                                <ENT>4.0</ENT>
                                <ENT>2.7</ENT>
                                <ENT>80</ENT>
                                <ENT>92</ENT>
                                <ENT>0.7</ENT>
                                <ENT>0.0</ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="416"/>
                                <ENT I="01">Sr</ENT>
                                <ENT>145</ENT>
                                <ENT>100</ENT>
                                <ENT>90</ENT>
                                <ENT>8.1</ENT>
                                <ENT>8.1</ENT>
                                <ENT>400</ENT>
                                <ENT>93</ENT>
                                <ENT>2.4</ENT>
                                <ENT>4.6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Tl</ENT>
                                <ENT>16</ENT>
                                <ENT>20</ENT>
                                <ENT>89</ENT>
                                <ENT>4.6</ENT>
                                <ENT>5.3</ENT>
                                <ENT>100</ENT>
                                <ENT>92</ENT>
                                <ENT>0.8</ENT>
                                <ENT>0.9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">V</ENT>
                                <ENT>21.7</ENT>
                                <ENT>20</ENT>
                                <ENT>95</ENT>
                                <ENT>1.2</ENT>
                                <ENT>1.0</ENT>
                                <ENT>100</ENT>
                                <ENT>96</ENT>
                                <ENT>0.4</ENT>
                                <ENT>0.9</ENT>
                            </ROW>
                            <ROW RUL="s">
                                <ENT I="01">Zn</ENT>
                                <ENT>12500</ENT>
                                <ENT>20</ENT>
                                <ENT>*</ENT>
                                <ENT>*</ENT>
                                <ENT>0.8</ENT>
                                <ENT>100</ENT>
                                <ENT>*</ENT>
                                <ENT>*</ENT>
                                <ENT>0.8</ENT>
                            </ROW>
                            <ROW EXPSTB="09" RUL="s">
                                <ENT I="21">
                                    <E T="02">NBS 1645 River Sediment</E>
                                </ENT>
                            </ROW>
                            <ROW EXPSTB="00">
                                <ENT I="01">Ag</ENT>
                                <ENT>1.6</ENT>
                                <ENT>20</ENT>
                                <ENT>92</ENT>
                                <ENT>0.4</ENT>
                                <ENT>1.0</ENT>
                                <ENT>100</ENT>
                                <ENT>96</ENT>
                                <ENT>0.3</ENT>
                                <ENT>0.9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Al</ENT>
                                <ENT>5160</ENT>
                                <ENT>20</ENT>
                                <ENT>*</ENT>
                                <ENT>*</ENT>
                                <ENT>8.4</ENT>
                                <ENT>100</ENT>
                                <ENT>*</ENT>
                                <ENT>*</ENT>
                                <ENT>2.4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">As</ENT>
                                <ENT>62.8</ENT>
                                <ENT>20</ENT>
                                <ENT>89</ENT>
                                <ENT>14.4</ENT>
                                <ENT>9.7</ENT>
                                <ENT>100</ENT>
                                <ENT>97</ENT>
                                <ENT>2.9</ENT>
                                <ENT>5.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">B</ENT>
                                <ENT>31.9</ENT>
                                <ENT>100</ENT>
                                <ENT>116</ENT>
                                <ENT>7.1</ENT>
                                <ENT>13.5</ENT>
                                <ENT>400</ENT>
                                <ENT>95</ENT>
                                <ENT>0.6</ENT>
                                <ENT>1.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ba</ENT>
                                <ENT>54.8</ENT>
                                <ENT>20</ENT>
                                <ENT>95</ENT>
                                <ENT>6.1</ENT>
                                <ENT>2.8</ENT>
                                <ENT>100</ENT>
                                <ENT>98</ENT>
                                <ENT>1.2</ENT>
                                <ENT>1.3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Be</ENT>
                                <ENT>0.72</ENT>
                                <ENT>20</ENT>
                                <ENT>101</ENT>
                                <ENT>0.4</ENT>
                                <ENT>1.0</ENT>
                                <ENT>100</ENT>
                                <ENT>103</ENT>
                                <ENT>1.4</ENT>
                                <ENT>3.9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ca</ENT>
                                <ENT>28000</ENT>
                                <ENT>−</ENT>
                                <ENT>−</ENT>
                                <ENT>−</ENT>
                                <ENT>−</ENT>
                                <ENT>−</ENT>
                                <ENT>−</ENT>
                                <ENT>−</ENT>
                                <ENT>−</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Cd</ENT>
                                <ENT>9.7</ENT>
                                <ENT>20</ENT>
                                <ENT>100</ENT>
                                <ENT>1.1</ENT>
                                <ENT>0.0</ENT>
                                <ENT>100</ENT>
                                <ENT>101</ENT>
                                <ENT>0.7</ENT>
                                <ENT>1.8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Co</ENT>
                                <ENT>9.4</ENT>
                                <ENT>20</ENT>
                                <ENT>98</ENT>
                                <ENT>3.8</ENT>
                                <ENT>4.8</ENT>
                                <ENT>100</ENT>
                                <ENT>98</ENT>
                                <ENT>0.9</ENT>
                                <ENT>1.8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Cr</ENT>
                                <ENT>28500</ENT>
                                <ENT>20</ENT>
                                <ENT>*</ENT>
                                <ENT>*</ENT>
                                <ENT>0.4</ENT>
                                <ENT>100</ENT>
                                <ENT>*</ENT>
                                <ENT>*</ENT>
                                <ENT>0.7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Cu</ENT>
                                <ENT>109</ENT>
                                <ENT>20</ENT>
                                <ENT>115</ENT>
                                <ENT>8.5</ENT>
                                <ENT>0.0</ENT>
                                <ENT>100</ENT>
                                <ENT>102</ENT>
                                <ENT>1.8</ENT>
                                <ENT>1.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Fe</ENT>
                                <ENT>84800</ENT>
                                <ENT>−</ENT>
                                <ENT>−</ENT>
                                <ENT>−</ENT>
                                <ENT>−</ENT>
                                <ENT>−</ENT>
                                <ENT>−</ENT>
                                <ENT>−</ENT>
                                <ENT>−</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Hg</ENT>
                                <ENT>3.1</ENT>
                                <ENT>10</ENT>
                                <ENT>99</ENT>
                                <ENT>4.3</ENT>
                                <ENT>7.7</ENT>
                                <ENT>40</ENT>
                                <ENT>96</ENT>
                                <ENT>0.7</ENT>
                                <ENT>1.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">K</ENT>
                                <ENT>452</ENT>
                                <ENT>500</ENT>
                                <ENT>98</ENT>
                                <ENT>4.1</ENT>
                                <ENT>2.0</ENT>
                                <ENT>2000</ENT>
                                <ENT>106</ENT>
                                <ENT>1.4</ENT>
                                <ENT>2.3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Li</ENT>
                                <ENT>3.7</ENT>
                                <ENT>10</ENT>
                                <ENT>101</ENT>
                                <ENT>2.0</ENT>
                                <ENT>0.7</ENT>
                                <ENT>40</ENT>
                                <ENT>108</ENT>
                                <ENT>1.3</ENT>
                                <ENT>3.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Mg</ENT>
                                <ENT>6360</ENT>
                                <ENT>500</ENT>
                                <ENT>*</ENT>
                                <ENT>*</ENT>
                                <ENT>1.8</ENT>
                                <ENT>2000</ENT>
                                <ENT>93</ENT>
                                <ENT>2.7</ENT>
                                <ENT>1.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Mn</ENT>
                                <ENT>728</ENT>
                                <ENT>20</ENT>
                                <ENT>*</ENT>
                                <ENT>*</ENT>
                                <ENT>3.5</ENT>
                                <ENT>100</ENT>
                                <ENT>97</ENT>
                                <ENT>12.4</ENT>
                                <ENT>2.2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Mo</ENT>
                                <ENT>17.9</ENT>
                                <ENT>20</ENT>
                                <ENT>97</ENT>
                                <ENT>12.5</ENT>
                                <ENT>18.5</ENT>
                                <ENT>100</ENT>
                                <ENT>98</ENT>
                                <ENT>0.6</ENT>
                                <ENT>0.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Na</ENT>
                                <ENT>1020</ENT>
                                <ENT>500</ENT>
                                <ENT>92</ENT>
                                <ENT>2.6</ENT>
                                <ENT>0.0</ENT>
                                <ENT>2000</ENT>
                                <ENT>97</ENT>
                                <ENT>1.1</ENT>
                                <ENT>1.7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ni</ENT>
                                <ENT>36.2</ENT>
                                <ENT>20</ENT>
                                <ENT>94</ENT>
                                <ENT>5.9</ENT>
                                <ENT>4.0</ENT>
                                <ENT>100</ENT>
                                <ENT>100</ENT>
                                <ENT>1.1</ENT>
                                <ENT>1.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">P</ENT>
                                <ENT>553</ENT>
                                <ENT>500</ENT>
                                <ENT>102</ENT>
                                <ENT>1.4</ENT>
                                <ENT>0.9</ENT>
                                <ENT>2000</ENT>
                                <ENT>100</ENT>
                                <ENT>0.8</ENT>
                                <ENT>1.6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Pb</ENT>
                                <ENT>707</ENT>
                                <ENT>20</ENT>
                                <ENT>*</ENT>
                                <ENT>*</ENT>
                                <ENT>0.8</ENT>
                                <ENT>100</ENT>
                                <ENT>103</ENT>
                                <ENT>5.9</ENT>
                                <ENT>0.4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Sb</ENT>
                                <ENT>22.8</ENT>
                                <ENT>20</ENT>
                                <ENT>86</ENT>
                                <ENT>2.3</ENT>
                                <ENT>0.0</ENT>
                                <ENT>100</ENT>
                                <ENT>88</ENT>
                                <ENT>0.6</ENT>
                                <ENT>0.9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Se</ENT>
                                <ENT>6.7</ENT>
                                <ENT>20</ENT>
                                <ENT>103</ENT>
                                <ENT>14.3</ENT>
                                <ENT>27.1</ENT>
                                <ENT>100</ENT>
                                <ENT>98</ENT>
                                <ENT>3.1</ENT>
                                <ENT>7.6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Sn</ENT>
                                <ENT>309</ENT>
                                <ENT>20</ENT>
                                <ENT>*</ENT>
                                <ENT>*</ENT>
                                <ENT>1.0</ENT>
                                <ENT>80</ENT>
                                <ENT>101</ENT>
                                <ENT>7.9</ENT>
                                <ENT>2.7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Sr</ENT>
                                <ENT>782</ENT>
                                <ENT>100</ENT>
                                <ENT>91</ENT>
                                <ENT>12.3</ENT>
                                <ENT>3.0</ENT>
                                <ENT>400</ENT>
                                <ENT>96</ENT>
                                <ENT>3.3</ENT>
                                <ENT>2.6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Tl</ENT>
                                <ENT>&lt;4</ENT>
                                <ENT>20</ENT>
                                <ENT>90</ENT>
                                <ENT>0.0</ENT>
                                <ENT>0.0</ENT>
                                <ENT>100</ENT>
                                <ENT>95</ENT>
                                <ENT>1.3</ENT>
                                <ENT>4.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">V</ENT>
                                <ENT>20.1</ENT>
                                <ENT>20</ENT>
                                <ENT>89</ENT>
                                <ENT>5.4</ENT>
                                <ENT>5.8</ENT>
                                <ENT>100</ENT>
                                <ENT>98</ENT>
                                <ENT>0.7</ENT>
                                <ENT>0.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Zn</ENT>
                                <ENT>1640</ENT>
                                <ENT>20</ENT>
                                <ENT>*</ENT>
                                <ENT>*</ENT>
                                <ENT>1.8</ENT>
                                <ENT>100</ENT>
                                <ENT>*</ENT>
                                <ENT>*</ENT>
                                <ENT>1.1</ENT>
                            </ROW>
                            <TNOTE>S (R) Standard deviation of percent recovery.</TNOTE>
                            <TNOTE>RPD Relative percent difference between duplicate spike determinations.</TNOTE>
                            <TNOTE>&lt;Sample concentration below established method detection limit.</TNOTE>
                            <TNOTE>* Spike concentration &lt;10% of sample background concentration.</TNOTE>
                            <TNOTE>− Not spiked.</TNOTE>
                            <TNOTE> + Equivalent.</TNOTE>
                        </GPOTABLE>
                        <PRTPAGE P="417"/>
                        <GPOTABLE COLS="5" OPTS="L2" CDEF="s30,14,14,14,14">
                            <TTITLE>
                                Table 8—ICP-AES Instrumental Precision and Accuracy for Aqueous Solutions 
                                <E T="01">
                                    <SU>a</SU>
                                </E>
                            </TTITLE>
                            <BOXHD>
                                <CHED H="1">Element</CHED>
                                <CHED H="1">
                                    Mean conc.
                                    <LI>(mg/L)</LI>
                                </CHED>
                                <CHED H="1">
                                    N 
                                    <SU>b</SU>
                                </CHED>
                                <CHED H="1">RSD (%)</CHED>
                                <CHED H="1">
                                    Accurace 
                                    <SU>c</SU>
                                    <LI>(% of Nominal)</LI>
                                </CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">Al</ENT>
                                <ENT>14.8</ENT>
                                <ENT>8</ENT>
                                <ENT>6.3</ENT>
                                <ENT>100</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Sb</ENT>
                                <ENT>15.1</ENT>
                                <ENT>8</ENT>
                                <ENT>7.7</ENT>
                                <ENT>102</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">As</ENT>
                                <ENT>14.7</ENT>
                                <ENT>7</ENT>
                                <ENT>6.4</ENT>
                                <ENT>99</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ba</ENT>
                                <ENT>3.66</ENT>
                                <ENT>7</ENT>
                                <ENT>3.1</ENT>
                                <ENT>99</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Be</ENT>
                                <ENT>3.78</ENT>
                                <ENT>8</ENT>
                                <ENT>5.8</ENT>
                                <ENT>102</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Cd</ENT>
                                <ENT>3.61</ENT>
                                <ENT>8</ENT>
                                <ENT>7.0</ENT>
                                <ENT>97</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ca</ENT>
                                <ENT>15.0</ENT>
                                <ENT>8</ENT>
                                <ENT>7.4</ENT>
                                <ENT>101</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Cr</ENT>
                                <ENT>3.75</ENT>
                                <ENT>8</ENT>
                                <ENT>8.2</ENT>
                                <ENT>101</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Co</ENT>
                                <ENT>3.52</ENT>
                                <ENT>8</ENT>
                                <ENT>5.9</ENT>
                                <ENT>95</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Cu</ENT>
                                <ENT>3.58</ENT>
                                <ENT>8</ENT>
                                <ENT>5.6</ENT>
                                <ENT>97</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Fe</ENT>
                                <ENT>14.8</ENT>
                                <ENT>8</ENT>
                                <ENT>5.9</ENT>
                                <ENT>100</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Pb</ENT>
                                <ENT>14.4</ENT>
                                <ENT>7</ENT>
                                <ENT>5.9</ENT>
                                <ENT>97</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Mg</ENT>
                                <ENT>14.1</ENT>
                                <ENT>8</ENT>
                                <ENT>6.5</ENT>
                                <ENT>96</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Mn</ENT>
                                <ENT>3.70</ENT>
                                <ENT>8</ENT>
                                <ENT>4.3</ENT>
                                <ENT>100</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Mo</ENT>
                                <ENT>3.70</ENT>
                                <ENT>8</ENT>
                                <ENT>6.9</ENT>
                                <ENT>100</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Ni</ENT>
                                <ENT>3.70</ENT>
                                <ENT>7</ENT>
                                <ENT>5.7</ENT>
                                <ENT>100</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">K</ENT>
                                <ENT>14.1</ENT>
                                <ENT>8</ENT>
                                <ENT>6.6</ENT>
                                <ENT>95</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Se</ENT>
                                <ENT>15.3</ENT>
                                <ENT>8</ENT>
                                <ENT>7.5</ENT>
                                <ENT>104</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Na</ENT>
                                <ENT>14.0</ENT>
                                <ENT>8</ENT>
                                <ENT>4.2</ENT>
                                <ENT>95</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Tl</ENT>
                                <ENT>15.1</ENT>
                                <ENT>7</ENT>
                                <ENT>8.5</ENT>
                                <ENT>102</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">V</ENT>
                                <ENT>3.51</ENT>
                                <ENT>8</ENT>
                                <ENT>6.6</ENT>
                                <ENT>95</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Zn</ENT>
                                <ENT>3.57</ENT>
                                <ENT>8</ENT>
                                <ENT>8.3</ENT>
                                <ENT>96</ENT>
                            </ROW>
                            <TNOTE>
                                <SU>a</SU>
                                 These performance values are independent of sample preparation because the labs analyzed portions of the same solutions using sequential or simultaneous instruments.
                            </TNOTE>
                            <TNOTE>
                                <SU>b</SU>
                                 N = Number of measurements for mean and relative standard deviation (RSD).
                            </TNOTE>
                            <TNOTE>
                                <SU>c</SU>
                                 Accuracy is expressed as a percentage of the nominal value for each analyte in the acidified, multi-element solutions.
                            </TNOTE>
                        </GPOTABLE>
                        <GPOTABLE COLS="3" OPTS="L2" CDEF="s40,13,xs110">
                            <TTITLE>Table 9—Multilaboratory ICP Precision and Accuracy Data*</TTITLE>
                            <BOXHD>
                                <CHED H="1">Analyte</CHED>
                                <CHED H="1">
                                    Concentration
                                    <LI>µg/L</LI>
                                </CHED>
                                <CHED H="1">
                                    Total recoverable digestion
                                    <LI>µ/L</LI>
                                </CHED>
                            </BOXHD>
                            <ROW>
                                <ENT I="01">Aluminum</ENT>
                                <ENT>69-4792</ENT>
                                <ENT>X = 0.9380 (C) + 22.1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT> </ENT>
                                <ENT>SR = 0.0481 (X) + 18.8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Antimony</ENT>
                                <ENT>77-1406</ENT>
                                <ENT>0.8908 (C) + 0.9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT> </ENT>
                                <ENT>SR = 0.0682 (X) + 2.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Arsenic</ENT>
                                <ENT>69-1887</ENT>
                                <ENT>X = 1.0175 (C) + 3.9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT> </ENT>
                                <ENT>SR = 0.0643 (X) + 10.3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Barium</ENT>
                                <ENT>9-377</ENT>
                                <ENT>X = 0.8.80 (C) + 1.68</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT> </ENT>
                                <ENT>SR = 0.0826 (X) + 3.54</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Beryllium</ENT>
                                <ENT>3-1906</ENT>
                                <ENT>X = 1.0177 (C) − 0.55</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT> </ENT>
                                <ENT>SR = 0.0445 (X) − 0.10</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Boron</ENT>
                                <ENT>19-5189</ENT>
                                <ENT>X = 0.9676 (C) + 18.7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT> </ENT>
                                <ENT>SR = 0.0743 (X) + 21.1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Cadmium</ENT>
                                <ENT>9-1943</ENT>
                                <ENT>X = 1.0137 (C) − 0.65</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT> </ENT>
                                <ENT>SR = 0.0332 (X) + 0.90</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Calcium</ENT>
                                <ENT>17-47170</ENT>
                                <ENT>X = 0.9658 (C) + 0.8</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT> </ENT>
                                <ENT>SR = 0.0327 (X) + 10.1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Chromium</ENT>
                                <ENT>13-1406</ENT>
                                <ENT>X = 1.0049 (C) − 1.2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT> </ENT>
                                <ENT>SR = 0.0571 (X) + 1.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Cobalt</ENT>
                                <ENT>17-2340</ENT>
                                <ENT>X = 0.9278 (C) + 1.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT> </ENT>
                                <ENT>SR = 0.0407 (X) + 0.4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Copper</ENT>
                                <ENT>8-1887</ENT>
                                <ENT>X = 0.9647 (C) − 3.64</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT> </ENT>
                                <ENT>SR = 0.0406 (X) + 0.96</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Iron</ENT>
                                <ENT>13-9359</ENT>
                                <ENT>X = 0.9830 (C) + 5.7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT> </ENT>
                                <ENT>SR = 0.0790 (X) + 11.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Lead</ENT>
                                <ENT>42-4717</ENT>
                                <ENT>X = 1.0056 (C) + 4.1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT> </ENT>
                                <ENT>SR = 0.0448 (X) + 3.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Magnesium</ENT>
                                <ENT>34-13868</ENT>
                                <ENT>X = 0.9879 (C) + 2.2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT> </ENT>
                                <ENT>SR = 0.0268 (X) + 8.1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Manganese</ENT>
                                <ENT>4-1887</ENT>
                                <ENT>X = 0.9725 (C) + 0.07</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT> </ENT>
                                <ENT>SR = 0.0400 (X) + 0.82</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Molybdenum</ENT>
                                <ENT>17-1830</ENT>
                                <ENT>X = 0.9707 (C) − 2.3</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT> </ENT>
                                <ENT>SR = 0.0529 (X) + 2.1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Nickel</ENT>
                                <ENT>17-47170</ENT>
                                <ENT>X = 0.9869 (C) + 1.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT> </ENT>
                                <ENT>SR = 0.0393 (X) + 2.2</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Potassium</ENT>
                                <ENT>347-14151</ENT>
                                <ENT>X = 0.9355 (C) − 183.1</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT> </ENT>
                                <ENT>SR = 0.0329 (X) + 60.9</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Selenium</ENT>
                                <ENT>69-1415</ENT>
                                <ENT>X = 0.9737 (C) − 1.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT> </ENT>
                                <ENT>SR = 0.0443 (X) + 6.6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Silicon</ENT>
                                <ENT>189-9434</ENT>
                                <ENT>X = 0.9737 (C) − 22.6</ENT>
                            </ROW>
                            <ROW>
                                <PRTPAGE P="418"/>
                                <ENT I="22"> </ENT>
                                <ENT> </ENT>
                                <ENT>SR = 0.2133 (X) + 22.6</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Silver</ENT>
                                <ENT>8-189</ENT>
                                <ENT>X = 0.3987 (C) + 8.25</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT> </ENT>
                                <ENT>SR = 0.1836 (X) − 0.27</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Sodium</ENT>
                                <ENT>35-47170</ENT>
                                <ENT>X = 1.0526 (C) + 26.7</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT> </ENT>
                                <ENT>SR = 0.0884 (X) + 50.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Thallium</ENT>
                                <ENT>79-1434</ENT>
                                <ENT>X = 0.9238 (C) + 5.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT> </ENT>
                                <ENT>SR = 0.0106 (X) + 48.0</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Vanadium</ENT>
                                <ENT>13-4698</ENT>
                                <ENT>X = 0.9551 (C) + 0.4</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT> </ENT>
                                <ENT>SR = 0.0472 (X) + 0.5</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="01">Zinc</ENT>
                                <ENT>7-7076</ENT>
                                <ENT>X = 0.9500 (C) + 1.82</ENT>
                            </ROW>
                            <ROW>
                                <ENT I="22"> </ENT>
                                <ENT> </ENT>
                                <ENT>SR = 0.0153 (X) + 7.78</ENT>
                            </ROW>
                            <TNOTE>*—Regression equations abstracted from Reference 16.</TNOTE>
                            <TNOTE>X = Mean Recovery, µg/L.</TNOTE>
                            <TNOTE>C = True Value for the Concentration, µg/L.</TNOTE>
                            <TNOTE>SR = Single-analyst Standard Deviation, µg/L.</TNOTE>
                        </GPOTABLE>
                        <GPH SPAN="2" DEEP="460">
                            <PRTPAGE P="419"/>
                            <GID>ER18MY12.007</GID>
                        </GPH>
                        <PRTPAGE P="420"/>
                        <CITA>[77 FR 29813, May 18, 2012]</CITA>
                    </APPENDIX>
                    <APPENDIX>
                        <EAR>Pt. 136, App. D</EAR>
                        <HD SOURCE="HED">Appendix D to Part 136—Precision and Recovery Statements for Methods for Measuring Metals</HD>
                        <P>Two selected methods from “Methods for Chemical Analysis of Water and Wastes,” EPA-600/4-79-020 (1979) have been subjected to interlaboratory method validation studies. The two selected methods are for Thallium and Zinc. The following precision and recovery statements are presented in this appendix and incorporated into Part 136:</P>
                        <HD SOURCE="HD2">Method 279.2</HD>
                        <P>For Thallium, Method 279.2 (Atomic Absorption, Furnace Technique) replace the Precision and Accuracy Section statement with the following:</P>
                        <HD SOURCE="HD2">Precision and Accuracy</HD>
                        <P>An interlaboratory study on metal analyses by this method was conducted by the Quality Assurance Branch (QAB) of the Environmental Monitoring Systems Laboratory—Cincinnati (EMSL-CI). Synthetic concentrates containing various levels of this element were added to reagent water, surface water, drinking water and three effluents. These samples were digested by the total digestion procedure, 4.1.3 in this manual. Results for the reagent water are given below. Results for other water types and study details are found in “EPA Method Study 31, Trace Metals by Atomic Absorption (Furnace Techniques),” National Technical Information Service, 5285 Port Royal Road, Springfield, VA 22161 Order No. PB 86-121 704/AS, by Copeland, F.R. and Maney, J.P., January 1986.</P>
                        <P>For a concentration range of 10.00-252 µg/L</P>
                        <FP SOURCE="FP-2">X = 0.8781(C) − 0.715</FP>
                        <FP SOURCE="FP-2">S = 0.1112(X) + 0.669</FP>
                        <FP SOURCE="FP-2">SR = 0.1005(X) + 0.241</FP>
                        <FP>Where:</FP>
                        <FP SOURCE="FP-2">C = True Value for the Concentration, µg/L</FP>
                        <FP SOURCE="FP-2">X = Mean Recovery, µg/L</FP>
                        <FP SOURCE="FP-2">S = Multi-laboratory Standard Deviation, µg/L</FP>
                        <FP SOURCE="FP-2">SR = Single-analyst Standard Deviation, µg/L</FP>
                        <HD SOURCE="HD2">Method 289.2</HD>
                        <P>For Zinc, Method 289.2 (Atomic Absorption, Furnace Technique) replace the Precision and Accuracy Section statement with the following:</P>
                        <HD SOURCE="HD2">Precision and Accuracy</HD>
                        <P>An interlaboratory study on metal analyses by this method was conducted by the Quality Assurance Branch (QAB) of the Environmental Monitoring Systems Laboratory—Cincinnati (EMSL-CI). Synthetic concentrates containing various levels of this element were added to reagent water, surface water, drinking water and three effluents. These samples were digested by the total digestion procedure, 4.1.3 in this manual. Results for the reagent water are given below. Results for other water types and study details are found in “EPA Method Study 31, Trace Metals by Atomic Absorption (Furnace Techniques),” National Technical Information Service, 5285 Port Royal Road, Springfield, VA 22161 Order No. PB 86-121 704/AS, by Copeland, F.R. and Maney, J.P., January 1986.</P>
                        <P>For a concentration range of 0.51-189 µg/L</P>
                        <FP SOURCE="FP-2">X = 1.6710(C) + 1.485</FP>
                        <FP SOURCE="FP-2">S = 0.6740(X) − 0.342</FP>
                        <FP SOURCE="FP-2">SR = 0.3895(X)− 0.384</FP>
                        <FP>Where:</FP>
                        <FP SOURCE="FP-2">C = True Value for the Concentration, µg/L</FP>
                        <FP SOURCE="FP-2">X = Mean Recovery, µg/L</FP>
                        <FP SOURCE="FP-2">S = Multi-laboratory Standard Deviation, µg/L</FP>
                        <FP SOURCE="FP-2">SR = Single-analyst Standard Deviation, µg/L</FP>
                        <CITA>[77 FR 29833, May 18, 2012]</CITA>
                    </APPENDIX>
                </PART>
                <PART>
                    <EAR>Pt. 139</EAR>
                    <HD SOURCE="HED">PART 139—DISCHARGES INCIDENTAL TO THE NORMAL OPERATION OF VESSELS</HD>
                    <CONTENTS>
                        <SUBPART>
                            <HD SOURCE="HED">Subpart A—Scope</HD>
                            <SECHD>Sec.</SECHD>
                            <SECTNO>139.1</SECTNO>
                            <SUBJECT>Coverage.</SUBJECT>
                            <SECTNO>139.2</SECTNO>
                            <SUBJECT>Definitions.</SUBJECT>
                            <SECTNO>139.3</SECTNO>
                            <SUBJECT>Other Federal laws.</SUBJECT>
                        </SUBPART>
                        <SUBPART>
                            <HD SOURCE="HED">Subpart B—General Standards for Discharges Incidental to the Normal Operation of a Vessel</HD>
                            <SECTNO>139.4</SECTNO>
                            <SUBJECT>General operation and maintenance.</SUBJECT>
                            <SECTNO>139.5</SECTNO>
                            <SUBJECT>Biofouling management.</SUBJECT>
                            <SECTNO>139.6</SECTNO>
                            <SUBJECT>Oil management.</SUBJECT>
                        </SUBPART>
                        <SUBPART>
                            <HD SOURCE="HED">Subpart C—Standards for Specific Discharges Incidental to the Normal Operation of a Vessel</HD>
                            <SECTNO>139.10</SECTNO>
                            <SUBJECT>Ballast tanks.</SUBJECT>
                            <SECTNO>139.11</SECTNO>
                            <SUBJECT>Bilges.</SUBJECT>
                            <SECTNO>139.12</SECTNO>
                            <SUBJECT>Boilers.</SUBJECT>
                            <SECTNO>139.13</SECTNO>
                            <SUBJECT>Cathodic protection.</SUBJECT>
                            <SECTNO>139.14</SECTNO>
                            <SUBJECT>Chain lockers.</SUBJECT>
                            <SECTNO>139.15</SECTNO>
                            <SUBJECT>Decks.</SUBJECT>
                            <SECTNO>139.16</SECTNO>
                            <SUBJECT>Desalination and purification systems.</SUBJECT>
                            <SECTNO>139.17</SECTNO>
                            <SUBJECT>Elevator pits.</SUBJECT>
                            <SECTNO>139.18</SECTNO>
                            <SUBJECT>Exhaust gas emission control systems.</SUBJECT>
                            <SECTNO>139.19</SECTNO>
                            <SUBJECT>Fire protection equipment.</SUBJECT>
                            <SECTNO>139.20</SECTNO>
                            <SUBJECT>Gas turbines.</SUBJECT>
                            <SECTNO>139.21</SECTNO>
                            <SUBJECT>Graywater systems.</SUBJECT>
                            <SECTNO>139.22</SECTNO>
                            <SUBJECT>
                                Hulls and associated niche areas.
                                <PRTPAGE P="421"/>
                            </SUBJECT>
                            <SECTNO>139.23</SECTNO>
                            <SUBJECT>Inert gas systems.</SUBJECT>
                            <SECTNO>139.24</SECTNO>
                            <SUBJECT>Motor gasoline and compensating systems.</SUBJECT>
                            <SECTNO>139.25</SECTNO>
                            <SUBJECT>Non-oily machinery.</SUBJECT>
                            <SECTNO>139.26</SECTNO>
                            <SUBJECT>Pools and spas.</SUBJECT>
                            <SECTNO>139.27</SECTNO>
                            <SUBJECT>Refrigeration and air conditioning.</SUBJECT>
                            <SECTNO>139.28</SECTNO>
                            <SUBJECT>Seawater piping.</SUBJECT>
                            <SECTNO>139.29</SECTNO>
                            <SUBJECT>Sonar domes.</SUBJECT>
                        </SUBPART>
                        <SUBPART>
                            <HD SOURCE="HED">Subpart D—Special Area Requirements</HD>
                            <SECTNO>139.40</SECTNO>
                            <SUBJECT>Federally-protected waters.</SUBJECT>
                        </SUBPART>
                        <SUBPART>
                            <HD SOURCE="HED">Subpart E—Procedures for States to Request Changes to Standards, Regulations, or Policy Promulgated by the Administrator</HD>
                            <SECTNO>139.50</SECTNO>
                            <SUBJECT>Petition by a Governor for the Administrator to establish an emergency order or review a standard, regulation, or policy.</SUBJECT>
                            <SECTNO>139.51</SECTNO>
                            <SUBJECT>Petition by a Governor for the Administrator to establish enhanced Great Lakes System requirements.</SUBJECT>
                            <SECTNO>139.52</SECTNO>
                            <SUBJECT>Application by a State for the Administrator to establish a State no-discharge zone.</SUBJECT>
                            <APP>Appendix A to Part 139—Federally-Protected Waters</APP>
                        </SUBPART>
                    </CONTENTS>
                    <AUTH>
                        <HD SOURCE="HED">Authority:</HD>
                        <P>
                            33 U.S.C. 1251 
                            <E T="03">et seq.</E>
                        </P>
                    </AUTH>
                    <SOURCE>
                        <HD SOURCE="HED">Source:</HD>
                        <P>89 FR 82131, Oct. 9, 2024, unless otherwise noted.</P>
                    </SOURCE>
                    <SUBPART>
                        <HD SOURCE="HED">Subpart A—Scope</HD>
                        <SECTION>
                            <SECTNO>§ 139.1</SECTNO>
                            <SUBJECT>Coverage.</SUBJECT>
                            <P>
                                (a) 
                                <E T="03">Vessel discharges.</E>
                                 Except as provided in paragraph (b) of this section, this part applies to:
                            </P>
                            <P>(1) Any discharge incidental to the normal operation of a vessel; and</P>
                            <P>(2) Any discharge incidental to the normal operation of a vessel (such as most graywater) that is commingled with sewage, subject to the conditions that:</P>
                            <P>(i) Nothing in this part prevents a State from regulating sewage discharges; and</P>
                            <P>(ii) Any such commingled discharge must comply with all applicable requirements of:</P>
                            <P>(A) This part; and</P>
                            <P>(B) Any law applicable to the discharge of sewage.</P>
                            <P>
                                (b) 
                                <E T="03">Exclusions.</E>
                                 This part does not apply to any discharge:
                            </P>
                            <P>(1) Incidental to the normal operation of:</P>
                            <P>(i) A vessel of the Armed Forces subject to 33 U.S.C. 1322(n);</P>
                            <P>(ii) A recreational vessel subject to 33 U.S.C. 1322(o);</P>
                            <P>(iii) A small vessel or fishing vessel, except that this part applies to any discharge of ballast water from a small vessel or fishing vessel; or</P>
                            <P>(iv) A floating craft that is permanently moored to a pier, including, but not limited to, a floating casino, hotel, restaurant, or bar; or</P>
                            <P>(2) That results from, or contains material derived from, an activity other than the normal operation of the vessel, such as material resulting from an industrial or manufacturing process onboard the vessel; or</P>
                            <P>(3) If compliance with this part would compromise the safety of life at sea.</P>
                            <P>
                                (c) 
                                <E T="03">Area of coverage.</E>
                                 The standards in this part apply to any vessel identified in paragraph (a) of this section, not otherwise excluded in paragraph (b) of this section, while operating in the waters of the United States or the waters of the contiguous zone.
                            </P>
                            <P>
                                (d) 
                                <E T="03">Effective date.</E>
                                 (1) The standards in this part are effective beginning on the date upon which regulations promulgated by the Secretary governing the design, construction, testing, approval, installation, and use of marine pollution control devices as necessary to ensure compliance with the standards are final, effective, and enforceable.
                            </P>
                            <P>(2) As of the effective date identified in paragraph (d)(1) of this section, the requirements of the Vessel General Permit and all regulations promulgated by the Secretary pursuant to section 1101 of the Nonindigenous Aquatic Nuisance Prevention and Control Act of 1990 (16 U.S.C. 4711), including the regulations contained in 46 CFR 162.060 and 33 CFR part 151 subparts C and D, as in effect on December 3, 2018, shall be deemed repealed and have no force or effect.</P>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 139.2</SECTNO>
                            <SUBJECT>Definitions.</SUBJECT>
                            <P>The following definitions apply for the purposes of this part. Terms not defined in this section have the meaning as defined under the Clean Water Act (CWA) and applicable regulations.</P>
                            <P>
                                <E T="03">Active discharge of biofouling</E>
                                 means the discharge of biofouling from a vessel resulting from in-water cleaning activities.
                                <PRTPAGE P="422"/>
                            </P>
                            <P>
                                <E T="03">Administrator</E>
                                 means the Administrator of the Environmental Protection Agency.
                            </P>
                            <P>
                                <E T="03">Anti-fouling coating</E>
                                 means a coating or paint designed to prevent, repel, or facilitate the detachment of biofouling from hull and niche areas that are typically or occasionally submerged.
                            </P>
                            <P>
                                <E T="03">Anti-fouling system</E>
                                 means a coating, paint, surface treatment, surface, or device that is used on a vessel to control or prevent attachment of organisms.
                            </P>
                            <P>
                                <E T="03">Aquatic nuisance species (ANS)</E>
                                 means a nonindigenous species that threatens the diversity or abundance of a native species; the ecological stability of waters of the United States or the waters of the contiguous zone; or a commercial, agricultural, aquacultural, or recreational activity that is dependent on waters of the United States or the waters of the contiguous zone.
                            </P>
                            <P>
                                <E T="03">Ballast tank</E>
                                 means any tank or hold on a vessel used for carrying ballast water, whether or not the tank or hold was designed for that purpose.
                            </P>
                            <P>
                                <E T="03">Ballast water</E>
                                 means any water, to include suspended matter and other materials taken onboard a vessel, to control or maintain trim, draft, stability, or stresses of the vessel, regardless of the means by which any such water or suspended matter is carried; or taken onboard a vessel during the cleaning, maintenance, or other operation of a ballast tank or ballast water management system of the vessel. The term does not include any substance that is added to that water that is directly related to the operation of a properly functioning ballast water management system.
                            </P>
                            <P>
                                <E T="03">Ballast water exchange</E>
                                 means the replacement of ballast water in a ballast tank using one of the following methods:
                            </P>
                            <P>(1) Flow-through exchange, in which ballast water is flushed out by pumping in midocean water at the bottom of the tank if practicable, and continuously overflowing the tank from the top, until three full volumes of tank water have been changed.</P>
                            <P>(2) Empty and refill exchange, in which ballast water is pumped out until the pump loses suction, after which the ballast tank is refilled with water from the midocean.</P>
                            <P>
                                <E T="03">Ballast water management system (BWMS)</E>
                                 means any marine pollution control device (including all ballast water treatment equipment, ballast tanks, pipes, pumps, and all associated control and monitoring equipment) that processes ballast water to kill, render nonviable, or remove organisms; or to avoid the uptake or discharge of organisms.
                            </P>
                            <P>
                                <E T="03">Bioaccumulative</E>
                                 means the failure to meet one or more of the criteria established in the definition of 
                                <E T="03">not bioaccumulative.</E>
                            </P>
                            <P>
                                <E T="03">Biodegradable</E>
                                 for the following classes of substances, means (all percentages are on a weight/weight concentration basis):
                            </P>
                            <P>(1) For oils: At least 90% of the formulation (for any substances present above 0.1%) demonstrates, within 28 days, either the removal of at least 70% of dissolved organic carbon (DOC), production of at least 60% of the theoretical carbon dioxide, or consumption of at least 60% of the theoretical oxygen demand). Up to 5% of the formulation may be non-biodegradable but may not be bioaccumulative. The remaining 5% must be inherently biodegradable.</P>
                            <P>(2) For greases: At least 75% of the formulation (for any substances present above 0.1%) demonstrates, within 28 days, either the removal of at least 70% of DOC, production of at least 60% of the theoretical carbon dioxide, or consumption of at least 60% of the theoretical oxygen demand). Up to 25% of the formulation may be non-biodegradable or inherently biodegradable but may not be bioaccumulative.</P>
                            <P>(3) For soaps, cleaners, and detergents: A product that demonstrates, within 28 days, either the removal of at least 70% of DOC, production of at least 60% of the theoretical carbon dioxide, or consumption of at least 60% of the theoretical oxygen demand.</P>
                            <P>(4) For biocides: A compound or mixture that, within 28 days, demonstrates removal of at least 70% of DOC and production of at least 60% of the theoretical carbon dioxide.</P>
                            <P>
                                <E T="03">Biofouling</E>
                                 means the accumulation of aquatic organisms, such as microorganisms, plants, and animals, on surfaces 
                                <PRTPAGE P="423"/>
                                and structures immersed in or exposed to the aquatic environment.
                            </P>
                            <P>
                                <E T="03">Broom clean</E>
                                 means a condition in which care has been taken to prevent or eliminate any visible concentration of tank or cargo residues, so that any remaining tank or cargo residues consist only of dust, powder, or isolated and random pieces, none of which exceeds one inch in diameter.
                            </P>
                            <P>
                                <E T="03">Captain of the Port (COTP) Zone</E>
                                 means such zone as established by the Secretary or Commandant of the Coast Guard pursuant to sections 501, 503, and 504 of title 14, United States Code, as reorganized in Title I of the Frank LoBiondo Coast Guard Authorization Act of 2018).
                            </P>
                            <P>
                                <E T="03">Commercial vessel</E>
                                 means, except as the term is used in § 139.10(g), any vessel used in the business of transporting property for compensation or hire, or in transporting property in the business of the owner, lessee, or operator of the vessel. As used in § 139.10(g), the term 
                                <E T="03">commercial vessel</E>
                                 means a vessel operating between:
                            </P>
                            <P>(1) Two ports or places of destination within the Pacific Region; or</P>
                            <P>(2) A port or place of destination within the Pacific Region and a port or place of destination on the Pacific Coast of Canada or Mexico north of parallel 20 degrees north latitude, inclusive of the Gulf of California.</P>
                            <P>
                                <E T="03">Constructed</E>
                                 with respect to a vessel means a stage of construction when one of the following occurs:
                            </P>
                            <P>(1) The keel of a vessel is laid;</P>
                            <P>(2) Construction identifiable with the specific vessel begins;</P>
                            <P>(3) Assembly of the vessel has commenced and comprises at least 50 tons or 1 percent of the estimated mass of all structural material, whichever is less; or</P>
                            <P>(4) The vessel undergoes a major conversion.</P>
                            <P>
                                <E T="03">Contiguous zone</E>
                                 means the entire zone established by the United States under Article 24 of the Convention on the Territorial Sea and the Contiguous Zone.
                            </P>
                            <P>
                                <E T="03">Discharge</E>
                                 means 
                                <E T="03">discharge incidental to the normal operation of a vessel</E>
                                 as defined in this section.
                            </P>
                            <P>
                                <E T="03">Discharge incidental to the normal operation of a vessel</E>
                                 means a discharge, including:
                            </P>
                            <P>(1) Graywater, bilgewater, cooling water, weather deck runoff, ballast water, oil water separator effluent, and any other pollutant discharge from the operation of a marine propulsion system, shipboard maneuvering system, crew habitability system, or installed major equipment, such as an aircraft carrier elevator or a catapult, or from a protective, preservative, or absorptive application to the hull of the vessel; and</P>
                            <P>(2) A discharge in connection with the testing, maintenance, and repair of a system described in clause (1):</P>
                            <P>(i) Whenever the vessel is waterborne; and does not include:</P>
                            <P>(A) A discharge of rubbish, trash, garbage, or other such material discharged overboard;</P>
                            <P>(B) An air emission resulting from the operation of a vessel propulsion system, motor driven equipment, or incinerator; or</P>
                            <P>(ii) [Reserved]</P>
                            <P>(3) A discharge that is not covered by § 122.3 of this chapter (as in effect on February 10, 1996).</P>
                            <P>
                                <E T="03">Discharge of oil in such quantities as may be harmful</E>
                                 means any discharge of oil, including an oily mixture, in such quantities identified in 40 CFR 110.3 and excluding those discharges specified in 40 CFR 110.5.
                            </P>
                            <P>
                                <E T="03">Empty ballast tank</E>
                                 means a tank that has previously held ballast water that has been drained to the limit of the functional or operational capabilities of the tank (such as loss of pump suction); is recorded as empty on a vessel log; and may contain unpumpable residual ballast water and sediment.
                            </P>
                            <P>
                                <E T="03">Environmentally acceptable lubricant (EAL)</E>
                                 means a lubricant or hydraulic fluid, including any oil or grease, that is “biodegradable,” “minimally-toxic,” and “not bioaccumulative,” as these terms are defined in this section.
                            </P>
                            <P>
                                <E T="03">Exclusive Economic Zone (</E>
                                EEZ
                                <E T="03">)</E>
                                 means the area established by Presidential Proclamation Number 5030, dated March 10, 1983, that extends from the base line of the territorial sea of the United States seaward 200 nautical miles, and the equivalent zone of Canada.
                            </P>
                            <P>
                                <E T="03">Existing vessel</E>
                                 means a vessel constructed, or where construction has begun, prior to the date identified in 
                                <PRTPAGE P="424"/>
                                regulations promulgated by the Secretary as described in § 139.1(e).
                            </P>
                            <P>
                                <E T="03">Federally-protected waters</E>
                                 means any waters of the United States or the waters of the contiguous zone subject to Federal protection, in whole or in part, for conservation purposes, located within any area listed in appendix A, as designated under:
                            </P>
                            <P>
                                (1) National Marine Sanctuaries designated under the National Marine Sanctuaries Act (16 U.S.C. 1431 
                                <E T="03">et seq.</E>
                                );
                            </P>
                            <P>(2) Marine National Monuments designated under the Antiquities Act of 1906;</P>
                            <P>(3) A unit of the National Park System, including but not limited to National Preserves and National Monuments, designated by the National Park Service within the U.S. Department of the Interior;</P>
                            <P>(4) A unit of the National Wildlife Refuge System, including Wetland Management Districts, Waterfowl Production Areas, National Game Preserves, Wildlife Management Areas, and National Fish and Wildlife Refuges designated under the National Wildlife Refuge System Administration Act of 1966 as amended by the National Wildlife Refuge System Improvement Act of 1997;</P>
                            <P>(5) National Wilderness Areas designated under the Wilderness Act of 1964 (16 U.S.C. 1131-1136); and</P>
                            <P>(6) Any component designated under the National Wild and Scenic Rivers Act of 1968, 16 U.S.C. 1273.</P>
                            <P>
                                <E T="03">Ferry</E>
                                 means a vessel that is used on a regular schedule to:
                            </P>
                            <P>(1) Provide transportation only between places than are not more than 300 miles apart; and</P>
                            <P>(2) Transport only:</P>
                            <P>(i) Passengers; or</P>
                            <P>(ii) Vehicles or railroad cars that are being used, or have been used, in transporting passengers or goods.</P>
                            <P>
                                <E T="03">Fire protection equipment</E>
                                 includes all components used for fire protection including but not limited to firemain systems, sprinkler systems, extinguishers, and firefighting agents such as foam.
                            </P>
                            <P>
                                <E T="03">Graywater</E>
                                 means drainage from galley, shower, laundry, bath, water fountain, and sink drains, and other similar sources.
                            </P>
                            <P>
                                <E T="03">Great Lakes</E>
                                 means Lake Ontario, Lake Erie, Lake Huron (including Lake Saint Clair), Lake Michigan, Lake Superior, and the connecting channels (Saint Mary's River, Saint Clair River, Detroit River, Niagara River, and Saint Lawrence River to the Canadian border), and includes all other bodies of water within the drainage basin of such lakes and connecting channels.
                            </P>
                            <P>
                                <E T="03">Great Lakes State</E>
                                 means any of the states of Illinois, Indiana, Michigan, Minnesota, New York, Ohio, Pennsylvania, and Wisconsin.
                            </P>
                            <P>
                                <E T="03">Gross register tonnage (GRT)</E>
                                 means the gross tonnage measurement of the vessel under the Regulatory Measurement System.
                            </P>
                            <P>
                                <E T="03">Gross tonnage (GT)</E>
                                 means the gross tonnage measurement of the vessel under the Convention Measurement System.
                            </P>
                            <P>
                                <E T="03">Impaired waterbody</E>
                                 means a waterbody identified by a State, tribe, or EPA pursuant to section 303(d) of the CWA as not meeting applicable State or Tribal water quality standards (these waters are called “water quality limited segments” under 40 CFR 130.2(j)) and includes both waters with approved or established Total Maximum Daily Loads (TMDLs) and those for which a TMDL has not yet been approved or established.
                            </P>
                            <P>
                                <E T="03">Inherently biodegradable</E>
                                 means the property of being able to be biodegraded when subjected to sunlight, water, and naturally occurring microbes to the following level: greater than 70% biodegraded after 28 days using Organization for Economic Cooperation and Development (OECD) Test Guidelines 302C or greater than 20% but less than 60% biodegraded after 28 days using OECD Test Guidelines 301 A-F.
                            </P>
                            <P>
                                <E T="03">Internal waters</E>
                                 means:
                            </P>
                            <P>(1) With respect to the United States, the waters shoreward of the territorial sea baseline, including waters of the Great Lakes extending to the maritime boundary with Canada; and</P>
                            <P>(2) With respect to any other nation, the waters shoreward of its territorial sea baseline, as recognized by the United States.</P>
                            <P>
                                <E T="03">In-water cleaning with capture (IWCC)</E>
                                 means the use and operation of a cleaning system for vessel surfaces that is 
                                <PRTPAGE P="425"/>
                                designed to capture and transport coatings and biofouling organisms to an adjacent barge or shore-based facility for collection and processing.
                            </P>
                            <P>
                                <E T="03">In-water cleaning without capture</E>
                                 means any in-water cleaning of vessel surfaces that does not use in-water cleaning with capture.
                            </P>
                            <P>
                                <E T="03">Live or living,</E>
                                 notwithstanding any other provision of law (including regulations), does not:
                            </P>
                            <P>(1) Include an organism that has been rendered nonviable; or</P>
                            <P>(2) Preclude the consideration of any method of measuring the concentration of organisms in ballast water that are capable of reproduction.</P>
                            <P>
                                <E T="03">Macrofouling</E>
                                 means biofouling caused by the attachment and subsequent growth of visible plants and animals on surfaces and structures immersed in or exposed to the aquatic environment. Macrofouling includes large, distinct multicellular individual or colonial organisms visible to the human eye, such as barnacles, tubeworms, mussels, fronds/filaments of algae, bryozoans, sea squirts, and other large attached, encrusting, or mobile organisms.
                            </P>
                            <P>
                                <E T="03">Major conversion</E>
                                 means a conversion of an existing vessel:
                            </P>
                            <P>(1) That substantially alters the dimensions or carrying capacity of the vessel; or</P>
                            <P>(2) That changes the type of the vessel; or</P>
                            <P>(3) The intent of which, in the opinion of the government of the country under whose authority the vessel is operating, is substantially to prolong its life; or</P>
                            <P>(4) Which otherwise so alters the vessel that, if it were a new vessel, it would become subject to relevant provisions of the International Convention for the Prevention of Pollution from Ships (MARPOL) not applicable to it as an existing vessel.</P>
                            <P>
                                <E T="03">Marine Growth Prevention System (MGPS)</E>
                                 means an anti-fouling system used for the prevention of biofouling accumulation in seawater piping systems and sea chests.
                            </P>
                            <P>
                                <E T="03">Marine Inspector</E>
                                 means any person from the civilian or military branch of the Coast Guard assigned under the superintendence and direction of an Officer in Charge, Marine Inspection, or any other person as may be designated for the performance of duties with respect to inspection, enforcement, and administration of Subtitle II of Title 46, United States Code, Title 46 and Title 33 United States Code, and regulations issued under these statutes.
                            </P>
                            <P>
                                <E T="03">Marine pollution control device (MPCD)</E>
                                 means any equipment or management practice (or combination of equipment and management practice) for installation and use onboard a vessel that is:
                            </P>
                            <P>(1) Designed to receive, retain, treat, control, or discharge a discharge incidental to the normal operation of a vessel; and</P>
                            <P>(2) Determined by the Administrator and the Secretary to be the most effective equipment or management practice (or combination of equipment and a management practice) to reduce the environmental impacts of the discharge, consistent with the factors considered in developing the standards in this part.</P>
                            <P>
                                <E T="03">Master</E>
                                 means the officer having command of a vessel.
                            </P>
                            <P>
                                <E T="03">Microfouling</E>
                                 means biofouling caused by bacteria, fungi, microalgae, protozoans, and other microscopic organisms on structures and surfaces immersed in or exposed to the aquatic environment that creates a biofilm, also called a slime layer.
                            </P>
                            <P>
                                <E T="03">Midocean</E>
                                 means greater than 200 nautical miles (NM) from any shore, except when a ballast water exchange or saltwater flush outside of 50 NM is authorized in this part, then it means greater than 50 NM from any shore.
                            </P>
                            <P>
                                <E T="03">Minimally-toxic</E>
                                 means, for lubricants (all percentages are on a weight/weight basis):
                            </P>
                            <P>(1) If both the complete formulation and the main constituents (that is constituents making up greater than or equal to 5% of the complete formulation) are evaluated, then the acute aquatic toxicity of lubricants, other than greases and total loss lubricants, must be at least 100 mg/L and the LC50 of greases and total loss lubricants must be at least 1000 mg/L; or</P>
                            <P>
                                (2) If each constituent is evaluated, rather than the complete formulation and main constituents, then for each constituent present above 0.1%: up to 20% of the formulation can have an LC50 greater than 10 mg/L but less than 100 mg/L and an NOEC greater than 1 
                                <PRTPAGE P="426"/>
                                mg/L but less than 10 mg/L; up to 5% of the formulation can have an LC50 greater than 1 mg/L but less than 10 mg/L and an NOEC greater than 0.1 mg/L but less than 1 mg/L; and up to 1% of the formulation can have an LC50 less than 1 mg/L and an NOEC less than 0.1 mg/L.
                            </P>
                            <P>
                                <E T="03">Minimally-toxic, phosphate-free, and biodegradable</E>
                                 means properties of a substance or mixture of substances that:
                            </P>
                            <P>(1) Have an acute aquatic toxicity value corresponding to a concentration greater than 10 ppm;</P>
                            <P>(2) Do not produce residuals with an LC50 less than 10 ppm;</P>
                            <P>(3) Are not bioaccumulative;</P>
                            <P>(4) Do not cause the pH of the receiving water to go below 6.0 or above 9.0;</P>
                            <P>(5) Contain, by weight, 0.5% or less of phosphates or derivatives of phosphate; and</P>
                            <P>(6) Are biodegradable.</P>
                            <P>
                                <E T="03">Minimize</E>
                                 means to reduce or eliminate to the extent achievable using any control measure that is technologically available and economically practicable and achievable and supported by demonstrated best management practices such that compliance can be documented in shipboard logs and plans.
                            </P>
                            <P>
                                <E T="03">New ferry</E>
                                 means a ferry that is constructed after the effective date of USCG regulations promulgated pursuant to CWA section 312(p)(5)(A)(i).
                            </P>
                            <P>
                                <E T="03">New Laker</E>
                                 means a vessel 3,000 GT and above, and that operates exclusively in the Great Lakes and the St. Lawrence River west of a rhumb line drawn from Cap des Rosiers to Pointe-de-l'Ouest (West Point), Anticosti Island, and west of a line along 63° W longitude from Anticosti Island to the north shore of the St. Lawrence River, and constructed after the effective date of USCG regulations promulgated pursuant to CWA section 312(p)(5)(A)(i).
                            </P>
                            <P>
                                <E T="03">Niche areas</E>
                                 means a subset of the submerged surface area on a vessel that may be more susceptible to biofouling than the main hull due to structural complexity, different or variable hydrodynamic forces, susceptibility to anti-fouling coating wear or damage, or inadequate or no protection by an anti-fouling system.
                            </P>
                            <P>
                                <E T="03">Not bioaccumulative</E>
                                 means any of the following:
                            </P>
                            <P>(1) The partition coefficient in the marine environment is log KOW less than 3 or greater than 7;</P>
                            <P>(2) The molecular mass is greater than 800 Daltons;</P>
                            <P>(3) The molecular diameter is greater than 1.5 nanometer;</P>
                            <P>(4) The bioconcentration factor (BCF) or bioaccumulation factor (BAF) is less than 100 L/kg; or</P>
                            <P>(5) The polymer with molecular weight fraction below 1,000 g/mol is less than 1%.</P>
                            <P>
                                <E T="03">Oil</E>
                                 means oil of any kind or in any form, including but not limited to any petroleum, fuel oil, sludge, oil refuse, and oil mixed with wastes other than dredged spoil.
                            </P>
                            <P>
                                <E T="03">Oil-to-sea interface</E>
                                 means any seal or surface on shipboard equipment where the design is such that oil or oily mixtures can escape directly into surrounding waters. Oil-to-sea interfaces are found on equipment that is subject to submersion as well as equipment above the surface line that extends overboard or is mounted to the exterior of the hull.
                            </P>
                            <P>
                                <E T="03">Oily mixture</E>
                                 means a mixture, in any form, with any oil content, including but not limited to:
                            </P>
                            <P>(1) Slops from bilges;</P>
                            <P>(2) Slops from oil cargoes (such as cargo tank washings, oily waste, and oily refuse);</P>
                            <P>(3) Oil residue; and</P>
                            <P>(4) Oily ballast water from cargo or fuel oil tanks.</P>
                            <P>
                                <E T="03">Organism</E>
                                 means an animal, including fish and fish eggs and larvae; a plant; a pathogen; a microbe; a virus; a prokaryote (including any archean or bacterium); a fungus; and a protist.
                            </P>
                            <P>
                                <E T="03">Pacific Region</E>
                                 means any Federal or State water adjacent to the State of Alaska, California, Hawaii, Oregon, or Washington; and extending from shore. The term includes the entire exclusive economic zone (as defined in section 1001 of the Oil Pollution Act of 1990 (33 U.S.C. 2701)) adjacent to each Pacific Region State identified herein.
                            </P>
                            <P>
                                <E T="03">Passenger vessel</E>
                                 means a vessel of at least 100 gross tons:
                            </P>
                            <P>(1) Carrying more than 12 passengers, including at least one passenger for hire;</P>
                            <P>
                                (2) That is chartered and carrying more than 12 passengers;
                                <PRTPAGE P="427"/>
                            </P>
                            <P>(3) That is a submersible vessel carrying at least one passenger for hire; or</P>
                            <P>(4) That is a ferry carrying a passenger.</P>
                            <P>
                                <E T="03">Passive discharge of biofouling</E>
                                 means the discharge of biofouling from a vessel (for example, sloughing) during a period in which the vessel is not undergoing active cleaning activities.
                            </P>
                            <P>
                                <E T="03">Port or place of destination</E>
                                 means a port or place to which a vessel is bound to anchor, to moor, or be otherwise secured.
                            </P>
                            <P>
                                <E T="03">Reception facility</E>
                                 refers to any fixed, floating, or mobile facility capable of receiving wastes and residues from vessels and fit for that purpose.
                            </P>
                            <P>
                                <E T="03">Render nonviable</E>
                                 means, with respect to an organism in ballast water, the action of a ballast water management system that renders the organism permanently incapable of reproduction following treatment.
                            </P>
                            <P>
                                <E T="03">Saltwater flush</E>
                                 means the addition of as much midocean water into each empty ballast tank of a vessel as is safe for the vessel and crew; and the mixing of the flush water with residual ballast water and sediment through the motion of the vessel; and the discharge of that mixed water, such that the resultant residual water remaining in the tank has the highest salinity possible; and is at least 30 parts per thousand. A saltwater flush may require more than one fill-mix-empty sequence, particularly if only small quantities of water can be safely taken onboard a vessel at one time.
                            </P>
                            <P>
                                <E T="03">Seagoing vessel</E>
                                 means a vessel in commercial service that operates beyond either the boundary line established by 46 CFR part 7 or the St. Lawrence River west of a rhumb line drawn from Cap des Rosiers to Pointe-de-l'Ouest (West Point), Anticosti Island, and west of a line along 63° W longitude from Anticosti Island to the north shore of the St. Lawrence River. It does not include a vessel that navigates exclusively on internal waters.
                            </P>
                            <P>
                                <E T="03">Seawater piping system</E>
                                 means a system onboard a vessel that provides seawater for other vessel uses (e.g., ballast, engines, hydraulic systems, firefighting capacity, cleaning equipment, air conditioning, refrigeration, toilet systems) and includes any sea chest, grate, and similar appurtenances (e.g., strainers, filters, valves). Some components of a seawater piping system including sea chests, sea inlet pipes, and overboard discharges are also considered niche areas.
                            </P>
                            <P>
                                <E T="03">Secretary</E>
                                 means the Secretary of the department in which the United States Coast Guard (USCG) is operating.
                            </P>
                            <P>
                                <E T="03">Small vessel or fishing vessel</E>
                                 means a vessel with a vessel length that is less than 79 feet; or a fishing vessel, fish processing vessel, or fish tender vessel (as those terms are defined in section 2101 of title 46, United States Code), regardless of the vessel length.
                            </P>
                            <P>
                                <E T="03">Toxic or hazardous materials</E>
                                 means any toxic pollutant as defined in 40 CFR 401.15 or any hazardous material as defined in 49 CFR 171.8.
                            </P>
                            <P>
                                <E T="03">Underway</E>
                                 means a vessel is not at anchor, or made fast to the shore, or aground.
                            </P>
                            <P>
                                <E T="03">Vessel General Permit</E>
                                 (VGP) means the permit that is the subject of the notice of final permit issuance entitled “Final National Pollutant Discharge Elimination System (NPDES) General Permit for Discharges Incidental to the Normal Operation of a Vessel” (
                                <E T="04">Federal Register</E>
                                 publication on April 12, 2013).
                            </P>
                            <P>
                                <E T="03">Vessel length</E>
                                 means the horizontal distance between the foremost part of a vessel's stem to the aftermost part of its stern, excluding fittings and attachments.
                            </P>
                            <P>
                                <E T="03">Visible sheen</E>
                                 means, with respect to oil and oily mixtures, a silvery or metallic sheen or gloss, increased reflectivity, visual color, iridescence, or an oil slick on the surface of the water.
                            </P>
                            <P>
                                <E T="03">Voyage</E>
                                 means any transit by a vessel traveling from or destined for any United States port or place.
                            </P>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 139.3</SECTNO>
                            <SUBJECT>Other Federal laws.</SUBJECT>
                            <P>(a) Except as expressly provided in this part, nothing in this part affects the applicability to a vessel of any other provision of Federal law, including:</P>
                            <P>
                                (1) Sections 311 and 312 of the Federal Water Pollution Control Act (33 U.S.C. 1321 
                                <E T="03">et seq.</E>
                                 and 33 U.S.C. 1322 
                                <E T="03">et seq.</E>
                                ), also known as the CWA;
                            </P>
                            <P>
                                (2) The Act to Prevent Pollution from Ships (33 U.S.C. 1901 
                                <E T="03">et seq.</E>
                                );
                            </P>
                            <P>
                                (3) Title X of the Coast Guard Authorization Act of 2010 (33 U.S.C. 3801 
                                <E T="03">
                                    et 
                                    <PRTPAGE P="428"/>
                                    seq.
                                </E>
                                ), also known as the Clean Hulls Act;
                            </P>
                            <P>
                                (4) The Federal Insecticide, Fungicide, and Rodenticide Act (7 U.S.C. 136 
                                <E T="03">et seq.</E>
                                ); and
                            </P>
                            <P>
                                (5) The National Marine Sanctuaries Act (16 U.S.C. 1431 
                                <E T="03">et seq.</E>
                                ) and implementing regulations found at 15 CFR part 922 and 50 CFR part 404.
                            </P>
                            <P>(b) Nothing in this part affects the authority of the Secretary of Commerce or the Secretary of the Interior to administer any land or waters under the administrative control of the Secretary of Commerce or the Secretary of the Interior, respectively.</P>
                            <P>(c) Nothing in this part shall be construed to affect, supersede, or relieve the master of any otherwise applicable requirements or prohibitions associated with a vessel's right to innocent passage as provided for under customary international law.</P>
                        </SECTION>
                    </SUBPART>
                    <SUBPART>
                        <HD SOURCE="HED">Subpart B—General Standards for Discharges Incidental to the Normal Operation of a Vessel</HD>
                        <SECTION>
                            <SECTNO>§ 139.4</SECTNO>
                            <SUBJECT>General operation and maintenance.</SUBJECT>
                            <P>(a) The requirements in paragraph (b) of this section apply to any discharge incidental to the normal operation of a vessel subject to regulation under this part, including but not limited to those discharges identified in subpart C of this part.</P>
                            <P>(b) Vessels must implement the following practices:</P>
                            <P>(1) Minimize discharges through management practices including but not limited to storage onboard the vessel, proper storage or transfer of materials, or reduced production of discharge.</P>
                            <P>(2) Discharge while underway when practicable and as far from shore as practicable.</P>
                            <P>(3) Addition of any materials to a discharge, other than for treatment of the discharge, that is not incidental to the normal operation of the vessel is prohibited.</P>
                            <P>(4) Dilution of any discharge for the purpose of meeting any standard in this part is prohibited.</P>
                            <P>(5) Any material used onboard that will be subsequently discharged (e.g., disinfectants, cleaners, biocides, coatings, sacrificial anodes) must:</P>
                            <P>(i) Be used according to manufacturer specifications and only in the amount necessary to perform the intended function of that material;</P>
                            <P>(ii) Not contain any materials banned for use in the United States; and</P>
                            <P>(iii) If subject to FIFRA registration, be used according to the FIFRA label. Proper use includes labeling requirements for proper application sites, rates, frequency of application, and methods; maintenance; removal; and storage and disposal of wastes and containers.</P>
                            <P>(6) To minimize and prevent discharge of cargo or other onboard materials, cargo must be containerized or covered except for hopper barges without a fixed cover or where covering cargo would negatively impact safety of the vessel, risk loss of life at sea, or otherwise interfere with essential vessel operations.</P>
                            <P>(7) To minimize and prevent discharge of toxic or hazardous materials, vessels must:</P>
                            <P>(i) Store toxic or hazardous materials in appropriately sealed, labeled, and secured containers located in areas of the vessel that minimize exposure to ocean spray and precipitation consistent with vessel design, unless the master determines this would interfere with essential vessel operations or safety of the vessel or crew, or would violate any applicable regulations that establish specifications for safe transportation, handling, carriage, and storage of toxic or hazardous materials.</P>
                            <P>
                                (ii) Ensure containers holding toxic or hazardous materials are not overfilled and incompatible materials (
                                <E T="03">i.e.,</E>
                                 substances which, if mixed, will create hazards greater than posed by the individual substances) are not mixed.
                            </P>
                            <P>(8) The overboard discharge or disposal of any containers holding toxic or hazardous materials is prohibited.</P>
                            <P>(9) Prior to washing any compartment, tank, cargo or other space and discharging washwater overboard from the area, that space must be in broom clean condition or its equivalent.</P>
                            <P>
                                (10) Topside surfaces (e.g., exposed decks, hull above waterline, tank, cargo, and related appurtenances) must 
                                <PRTPAGE P="429"/>
                                be maintained to minimize the discharge of cleaning compounds, paint chips, non-skid material fragments, and other materials associated with exterior surface preservation.
                            </P>
                            <P>(11) Painting and coating techniques on topside surfaces must minimize the discharge of paints, coatings, surface preparation materials, and similar substances.</P>
                            <P>(12) Discharge of unused paint and coatings is prohibited.</P>
                            <P>(13) Any equipment that may release, drip, leak, or spill oil or oily mixtures, fuel, or other toxic or hazardous materials, including to the bilge, must be maintained to minimize or eliminate the discharges.</P>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 139.5</SECTNO>
                            <SUBJECT>Biofouling management.</SUBJECT>
                            <P>(a) The requirements in paragraph (b) of this section apply to any vessel subject to regulation under this part.</P>
                            <P>(b) A biofouling management plan must be developed to minimize the discharge of biofouling organisms. The plan elements must prioritize procedures and strategies to prevent macrofouling, thereby minimizing the potential for the introduction and spread of ANS. The plan must describe the vessel-specific anti-fouling systems and biofouling management practices necessary to comply with the requirements in this section. See §§ 139.13, 139.14, 139.22, 139.28, and 139.29 for additional biofouling management requirements.</P>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 139.6</SECTNO>
                            <SUBJECT>Oil management.</SUBJECT>
                            <P>(a) The requirements in paragraphs (b) through (e) of this section apply to vessel equipment and operations that use or discharge oil or oily mixtures.</P>
                            <P>(b) The discharge of used or spent oil no longer being used for its intended purpose is prohibited.</P>
                            <P>(c) The discharge of oil in such quantities as may be harmful is prohibited.</P>
                            <P>(d) During fueling, maintenance, and other vessel operations, control and response measures must be used to prevent, minimize, and contain spills and overflows.</P>
                            <P>(e) An environmentally acceptable lubricant (EAL) must be used in any oil-to-sea interface unless such use is technically infeasible. Operators of new build vessels should endeavor to use seawater-based systems for stern tube lubrication to eliminate the discharge of oil from these interfaces to the aquatic environment.</P>
                        </SECTION>
                    </SUBPART>
                    <SUBPART>
                        <HD SOURCE="HED">Subpart C—Standards for Specific Discharges Incidental to the Normal Operation of a Vessel</HD>
                        <SECTION>
                            <SECTNO>§ 139.10</SECTNO>
                            <SUBJECT>Ballast tanks.</SUBJECT>
                            <P>
                                (a) 
                                <E T="03">Applicability.</E>
                                 Except for any vessel otherwise excluded in paragraph (b) of this section, the requirements in paragraphs (c) through (h) of this section apply to any vessel equipped with one or more ballast tanks.
                            </P>
                            <P>
                                (b) 
                                <E T="03">Exclusions.</E>
                                 The requirements of this section do not apply to the following vessels:
                            </P>
                            <P>(1) A vessel that continuously takes on and discharges ballast water in a flow-through system, if the Administrator determines that system cannot materially contribute to the spread or introduction of ANS into waters of the United States;</P>
                            <P>(2) A vessel in the National Defense Reserve Fleet scheduled for disposal, if the vessel does not have an operable ballast water management system (BWMS);</P>
                            <P>
                                (3) A vessel that discharges ballast water consisting solely of water taken onboard from a public or commercial source that, at the time the water is taken onboard, meets the applicable requirements or permit requirements of the Safe Drinking Water Act (42 U.S.C. 300f 
                                <E T="03">et seq.</E>
                                );
                            </P>
                            <P>(4) A vessel that carries all permanent ballast water in sealed tanks that are not subject to discharge; or</P>
                            <P>(5) A vessel that only discharges ballast water to a reception facility.</P>
                            <P>
                                (c) 
                                <E T="03">Ballast Water Best Management Practices.</E>
                                 (1) Any vessel equipped with ballast tanks must minimize the introduction and spread of aquatic nuisance species (ANS) by adhering to the following practices:
                            </P>
                            <P>
                                (i) Maintain a ballast water management plan that addresses both the uptake and discharge of ballast water. The plan must describe the vessel-specific BWMSs and practices necessary to comply with the requirements in this section.
                                <PRTPAGE P="430"/>
                            </P>
                            <P>(ii) Minimize the use of gravity to drain ballast tanks in port.</P>
                            <P>(iii) Use high sea suction in port or where clearance to the bottom of the waterbody is less than 5 meters to the lower edge of the sea chest, as practicable.</P>
                            <P>(iv) Avoid the discharge or uptake of ballast water in areas with coral reefs. Discharge and uptake should be conducted as far from coral reefs as practicable.</P>
                            <P>(v) Periodically clean ballast tanks to remove sediment. Discharge of sediment from ballast tank cleaning is prohibited.</P>
                            <P>(vi) Maintain, and keep fully intact, sea chest screens.</P>
                            <P>(2) Any new Laker equipped with ballast tanks must install, operate, and maintain a BWMS that has been type-approved by the USCG.</P>
                            <P>
                                (d) 
                                <E T="03">Ballast Water Discharge Standard.</E>
                                 Unless exempted in paragraph (d)(3) of this section, any ballast water discharge must meet the following numeric discharge standard:
                            </P>
                            <P>(1) Biological parameters (expressed as instantaneous maximums).</P>
                            <P>(i) Organisms greater than or equal to 50 micrometers in minimum dimension: less than 10 living organisms per cubic meter.</P>
                            <P>(ii) Organisms less than 50 micrometers and greater than or equal to 10 micrometers: less than 10 living organisms per milliliter (mL).</P>
                            <P>
                                (iii) Toxicogenic 
                                <E T="03">Vibrio cholerae</E>
                                 (serotypes O1 and O139): less than 1 colony-forming unit (cfu) per 100 mL.
                            </P>
                            <P>
                                (iv) 
                                <E T="03">Escherichia coli:</E>
                                 a concentration of less than 250 cfu, or Most Probable Number (MPN), per 100 mL.
                            </P>
                            <P>(v) Intestinal enterococci: a concentration of less than 100 cfu, or MPN, per 100 mL.</P>
                            <P>(2) Biocide parameters (expressed as instantaneous maximums).</P>
                            <P>(i) Chlorine dioxide: for any discharge from a BWMS using chlorine dioxide, chlorine dioxide must not exceed 200 µg/L.</P>
                            <P>(ii) Total residual oxidizers: for any discharge from a BWMS using chlorine or ozone, total residual oxidizers must not exceed 100 µg/L.</P>
                            <P>(iii) Peracetic acid: for any discharge from a BWMS using peracetic acid, peracetic acid must not exceed 500 µg/L.</P>
                            <P>(iv) Hydrogen peroxide: for any discharge from a BWMS using peracetic acid, hydrogen peroxide must not exceed 1,000 µg/L.</P>
                            <P>(3) Exemptions: The ballast water discharge standards in paragraphs (d)(1) and (2) of this section do not apply to any vessel that:</P>
                            <P>(i) Is less than or equal to 3,000 GT (1,600 GRT if GT is not assigned), and does not operate outside of the EEZ;</P>
                            <P>(ii) Is a non-seagoing, unmanned, unpowered barge, except any barge that is part of a dedicated vessel combination such as an integrated or articulated tug and barge unit;</P>
                            <P>(iii) Takes on and discharges ballast water exclusively in the contiguous portions of a single COTP Zone;</P>
                            <P>(iv) Does not travel more than 10 NM and passes through no locks;</P>
                            <P>(v) Discharges ballast water at the same location where that ballast water originated, provided that no mixing with unmanaged ballast water or sediment from other areas has occurred;</P>
                            <P>(vi) Operates exclusively in the Great Lakes and the St. Lawrence River west of a rhumb line drawn from Cap des Rosiers to Pointe-de-l'Ouest (West Point), Anticosti Island, and west of a line along 63° W. longitude from Anticosti Island to the north shore of the St. Lawrence River;</P>
                            <P>(vii) Is enrolled in the USCG Shipboard Technology Evaluation Program (STEP); or</P>
                            <P>(viii) Discharges ballast water prior to an applicable ballast water discharge standard compliance date established in regulations promulgated by the Secretary as described in 139.1(d).</P>
                            <P>
                                (e) 
                                <E T="03">Ballast Water Exchange and Saltwater Flush.</E>
                                 Except for any vessel identified in paragraph (f) or (g) of this section, prior to an applicable ballast water discharge standard compliance date established in regulations promulgated by the Secretary as described in § 139.1(d), any vessel must meet the requirements in paragraphs (e)(1) and (2) of this section unless excluded under paragraph (e)(3) of this section.
                            </P>
                            <P>
                                (1) Any vessel that carries ballast water taken on in areas less than 200 NM from any shore that will subsequently operate outside the EEZ and more than 200 NM from any shore must:
                                <PRTPAGE P="431"/>
                            </P>
                            <P>(i) Conduct ballast water exchange in waters not less than 200 NM from any shore prior to discharging that ballast water; and</P>
                            <P>(ii) Commence ballast water exchange not less than 200 NM from any shore and as early in the vessel voyage as practicable.</P>
                            <P>(2) For any ballast tank that is empty or contains unpumpable residual water on a vessel bound for a port or place of destination subject to the jurisdiction of the United States, the master must, prior to arriving at that port or place of destination, either:</P>
                            <P>(i) Seal the tank so that there is no discharge or uptake and subsequent discharge of ballast water, or</P>
                            <P>(ii) Conduct a ballast water exchange or saltwater flush:</P>
                            <P>(A) Not less than 200 NM from any shore for a voyage originating outside the United States or Canadian EEZ; or</P>
                            <P>(B) Not less than 50 NM from any shore for a voyage originating within the United States or Canadian EEZ.</P>
                            <P>(3) Exceptions: Paragraphs (e)(1) and (2), do not apply under any of the following circumstances:</P>
                            <P>(i) If the unpumpable residual waters and sediments of an empty ballast tank were subject to treatment, in compliance with applicable requirements, through a BWMS approved or accepted by the Secretary;</P>
                            <P>(ii) Except as otherwise required under this part, if the unpumpable residual waters and sediments of an empty ballast tank were sourced solely within:</P>
                            <P>(A) The same port or place of destination; or</P>
                            <P>(B) Contiguous portions of a single COTP Zone;</P>
                            <P>(iii) If complying with an applicable requirement of this paragraph (e):</P>
                            <P>(A) Would compromise the safety of the vessel; or</P>
                            <P>(B) Is otherwise prohibited by any Federal, Canadian, or international law (including regulations) pertaining to vessel safety;</P>
                            <P>(iv) If design limitations of an existing vessel prevent a ballast water exchange or saltwater flush from being conducted in accordance with this paragraph (e); or</P>
                            <P>(v) If the vessel is operating exclusively within the internal waters of the United States and Canada.</P>
                            <P>
                                (f) 
                                <E T="03">Vessels entering the Great Lakes.</E>
                                 (1) Ballast Water Exchange: Except as provided in paragraph (f)(2) of this section, any vessel entering the St. Lawrence Seaway through the mouth of the St. Lawrence River must conduct a complete ballast water exchange or saltwater flush:
                            </P>
                            <P>(i) Not less than 200 NM from any shore for a voyage originating outside the EEZ; or</P>
                            <P>(ii) Not less than 50 NM from any shore for a voyage originating within the EEZ.</P>
                            <P>(2) Exceptions: The requirements of paragraph (f)(1) of this section do not apply to any vessel if:</P>
                            <P>(i) Complying with paragraph (f)(1) of this section:</P>
                            <P>(A) Would compromise the safety of the vessel; or</P>
                            <P>(B) Is otherwise prohibited by any Federal, Canadian, or international law (including regulations) pertaining to vessel safety.</P>
                            <P>(ii) Design limitations of an existing vessel prevent a ballast water exchange from being conducted in accordance with an applicable requirement of paragraph (f)(1) of this section.</P>
                            <P>(iii) The vessel has no residual ballast water or sediments onboard.</P>
                            <P>(iv) The vessel retains all ballast water while in waters subject to the requirement.</P>
                            <P>(v) The empty ballast tanks on the vessel are sealed in a manner that ensures that no discharge or uptake occurs, and any subsequent discharge of ballast water is subject to the requirement.</P>
                            <P>
                                (g) 
                                <E T="03">Pacific Region.</E>
                                 (1) Ballast Water Exchange:
                            </P>
                            <P>
                                (i) Except as provided in paragraphs (g)(1)(ii) and (g)(3) of this section, any vessel that operates either between two ports or places of destination within the Pacific Region; or a port or place of destination within the Pacific Region and a port or place of destination on the Pacific Coast of Canada or Mexico north of parallel 20 degrees north latitude, inclusive of the Gulf of California, must conduct a complete ballast water exchange in waters more than 50 NM from shore.
                                <PRTPAGE P="432"/>
                            </P>
                            <P>(ii) Exemptions: The requirements of paragraph (g)(1)(i) of this section do not apply to any vessel:</P>
                            <P>(A) Using, in compliance with applicable requirements, a type-approved BWMS approved or accepted by the Secretary.</P>
                            <P>(B) Voyaging:</P>
                            <P>
                                (
                                <E T="03">1</E>
                                ) Between or to a port or place of destination in the State of Washington, if the ballast water to be discharged from the commercial vessel originated solely from waters located between the parallel 46 degrees north latitude, including the internal waters of the Columbia River, and the internal waters of Canada south of parallel 50 degrees north latitude, including the waters of the Strait of Georgia and the Strait of Juan de Fuca;
                            </P>
                            <P>
                                (
                                <E T="03">2</E>
                                ) Between ports or places of destination in the State of Oregon, if the ballast water to be discharged from the commercial vessel originated solely from waters located between the parallel 40 degrees north latitude and the parallel 50 degrees north latitude;
                            </P>
                            <P>
                                (
                                <E T="03">3</E>
                                ) Between ports or places of destination in the State of California within the San Francisco Bay area east of the Golden Gate Bridge, including the Port of Stockton and the Port of Sacramento, if the ballast water to be discharged from the commercial vessel originated solely from ports or places within that area;
                            </P>
                            <P>
                                (
                                <E T="03">4</E>
                                ) Between the Port of Los Angeles, the Port of Long Beach, and the El Segundo offshore marine oil terminal, if the ballast water to be discharged from the commercial vessel originated solely from the Port of Los Angeles, the Port of Long Beach, or the El Segundo offshore marine oil terminal;
                            </P>
                            <P>
                                (
                                <E T="03">5</E>
                                ) Between a port or place of destination in the State of Alaska within a single COTP Zone;
                            </P>
                            <P>
                                (
                                <E T="03">6</E>
                                ) Between ports or places of destination in different counties of the State of Hawaii, if the vessel conducts a complete ballast water exchange in waters that are more than 10 NM from shore and at least 200 meters deep; or
                            </P>
                            <P>
                                (
                                <E T="03">7</E>
                                ) Between ports or places of destination within the same county of the State of Hawaii, if the vessel does not transit outside State marine waters during the voyage.
                            </P>
                            <P>(2) Low-Salinity Ballast Water:</P>
                            <P>(i) Except as provided in paragraphs (g)(2)(ii) and (g)(3) of this section, a complete ballast water exchange must be conducted for any commercial vessel that transports ballast water sourced from waters with a measured salinity of less than 18 parts per thousand and voyages to a Pacific Region port or place of destination with a measured salinity of less than 18 parts per thousand:</P>
                            <P>(A) Not less than 50 NM from shore, if the ballast water was sourced from a Pacific Region port or place of destination.</P>
                            <P>(B) More than 200 NM from shore, if the ballast water was not sourced from a Pacific Region port or place of destination.</P>
                            <P>(ii) Exception: The requirements of paragraph (g)(2)(i) of this section do not apply to any vessel voyaging to a port or place of destination in the Pacific Region that is using, in compliance with applicable requirements, a type-approved BWMS accepted by the Secretary, or a type-approved BWMS approved by the Secretary to achieve the following numeric discharge standard for biological parameters (expressed as instantaneous maximums):</P>
                            <P>(A) Organisms greater than or equal to 50 micrometers in minimum dimension: less than 1 living organism per 10 cubic meters.</P>
                            <P>(B) Organisms less than 50 micrometers and greater than or equal to 10 micrometers: Less than 1 living organisms per 10 milliliters (mL).</P>
                            <P>
                                (C) Toxicogenic 
                                <E T="03">Vibrio cholerae</E>
                                 (serotypes O1 and O139): less than 1 colony-forming unit (cfu) per 100 mL or less than 1 cfu per gram of wet weight of zoological samples.
                            </P>
                            <P>
                                (D) 
                                <E T="03">Escherichia coli:</E>
                                 less than 126 cfu, or MPN, per 100 mL.
                            </P>
                            <P>(E) Intestinal enterococci: less than 33 cfu, or MPN, per 100 mL.</P>
                            <P>(3) General Exceptions: The requirements of paragraphs (g)(1) and (2) of this section do not apply to a commercial vessel if:</P>
                            <P>
                                (i) Complying with the requirement would compromise the safety of the commercial vessel.
                                <PRTPAGE P="433"/>
                            </P>
                            <P>(ii) If design limitations of an existing vessel, prevent a ballast water exchange from being conducted in accordance with paragraphs (g)(1) and (2) of this section, as applicable.</P>
                            <P>(iii) The commercial vessel:</P>
                            <P>(A) Has no residual ballast water or sediments onboard; or</P>
                            <P>(B) Retains all ballast water while in waters subject to those requirements.</P>
                            <P>(iv) Empty ballast tanks on the commercial vessel are sealed in a manner that ensures that:</P>
                            <P>(A) No discharge or uptake occurs; and</P>
                            <P>(B) Any subsequent discharge of ballast water is subject to those requirements.</P>
                            <P>
                                (h) 
                                <E T="03">Federally-protected waters.</E>
                                 Additional standards applicable to discharges from ballast tanks when a vessel is operating in federally-protected waters are contained in § 139.40(b).
                            </P>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 139.11</SECTNO>
                            <SUBJECT>Bilges.</SUBJECT>
                            <P>(a) The requirements in paragraphs (b) through (d) of this section applies to bilgewater, which is the discharge of wastewater from the bilge consisting of water and residue that accumulates in a lower compartment of the vessel's hull below the waterline. This includes, but is not limited to, any water and residue from a cargo area that comes into contact with oily materials or a below-deck parking area or other storage area for motor vehicles or other motorized equipment.</P>
                            <P>(b) The discharge of bilgewater from any vessel must not contain any flocculants or other additives except when used with an oily water separator or to maintain or clean equipment. The use of any additives to remove the appearance of a visible sheen is prohibited.</P>
                            <P>(c) For any vessel of 400 GT and above, the discharge of bilgewater must:</P>
                            <P>(1) Occur when the vessel is underway;</P>
                            <P>(2) Not have an oil content that exceeds 15 ppm; and</P>
                            <P>(3) If technologically feasible, occur at least 1 NM from shore.</P>
                            <P>(d) Additional standards applicable to discharges from bilges when a vessel is operating in federally-protected waters are contained in § 139.40(c).</P>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 139.12</SECTNO>
                            <SUBJECT>Boilers.</SUBJECT>
                            <P>(a) The requirements in paragraphs (b) and (c) of this section apply to discharges resulting from boiler blowdown.</P>
                            <P>(b) The discharge from boiler blowdown must be minimized in port.</P>
                            <P>(c) Additional standards applicable to discharges from boilers when a vessel is operating in federally-protected waters are contained in § 139.40(d).</P>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 139.13</SECTNO>
                            <SUBJECT>Cathodic protection.</SUBJECT>
                            <P>(a) The requirements in paragraph (b) of this section apply to discharges resulting from a vessel's cathodic corrosion control protection device, including but not limited to sacrificial anodes and impressed current cathodic protection (ICCP) systems.</P>
                            <P>(b) Spaces between any flush-fit anode and backing must be filled to remove potential hotspots for biofouling organisms.</P>
                            <P>(c) The vessel operator must consider using, but is not required to use, less toxic metals when selecting sacrificial anodes.</P>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 139.14</SECTNO>
                            <SUBJECT>Chain lockers.</SUBJECT>
                            <P>(a) The requirements in paragraphs (b) through (e) of this section apply to accumulated biological organisms, sediment, precipitation, and seawater that is emptied from the compartment used to store the anchor chain on a vessel and are intended to prevent the discharge of accumulated biological organisms, sediment, precipitation, and seawater when deploying the anchor in a new port or place of destination.</P>
                            <P>(b) Anchors and anchor chains must be rinsed of biofouling organisms and sediment when the anchor is retrieved.</P>
                            <P>(c) The discharge of biological organisms, sediment, precipitation, and seawater from any chain locker is prohibited in port.</P>
                            <P>
                                (d) Anchors and anchor chains used beyond waters of the contiguous zone must be rinsed of biofouling organisms and sediment prior to entering the waters of the contiguous zone. This requirement may be satisfied by rinsing when the anchor is retrieved at the commencement of the voyage or when 
                                <PRTPAGE P="434"/>
                                the anchor was last retrieved on a previous voyage, so long as the rinsing occurs after the last use of the anchor beyond waters of the contiguous zone.
                            </P>
                            <P>(e) Additional standards applicable to a discharge from chain lockers when a vessel is operating in federally-protected waters are contained in § 139.40(e).</P>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 139.15</SECTNO>
                            <SUBJECT>Decks.</SUBJECT>
                            <P>(a) The requirements in paragraphs (b) through (i) of this section apply to the discharge of washdown and runoff from decks, well decks, and bulkhead areas, including but not limited to precipitation, condensation, seawater spray and wash over, and flooding, as well as waters pumped from below deck on a barge.</P>
                            <P>(b) Coamings or drip pans must be used for machinery that is expected to leak or otherwise release oil on the deck; accumulated oil must be collected.</P>
                            <P>(c) Where required by an applicable international treaty or convention or the Secretary, the vessel must be fitted with and use physical barriers (e.g., spill rails, scuppers and scupper plugs) during any washdown.</P>
                            <P>(d) Control measures must be used to minimize the introduction of on-deck debris, garbage, residue, spills, floating solids, visible foam, halogenated phenolic compounds, dispersants, and surfactants into deck washdown and runoff.</P>
                            <P>(e) Vessel decks must be kept in broom clean condition whenever the vessel is underway and prior to any deck washdown.</P>
                            <P>(f) Discharges from deck washdowns must be minimized in port.</P>
                            <P>(g) Any soap, cleaner, or detergent used for deck washdown must be minimally-toxic, phosphate-free, and biodegradable.</P>
                            <P>(h) Barges that discharge water pumped from below deck must minimize the contact of below deck condensation with oily or toxic materials and any materials containing hydrocarbons.</P>
                            <P>(i) Additional standards applicable to discharges from decks when a vessel is operating in federally-protected waters are contained in § 139.40(f).</P>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 139.16</SECTNO>
                            <SUBJECT>Desalination and purification systems.</SUBJECT>
                            <P>(a) The requirements in paragraph (b) of this section apply to discharges from onboard desalination and purification systems used to generate freshwater from seawater or otherwise purify water.</P>
                            <P>(b) The discharge resulting from the cleaning of desalination and purification systems with toxic or hazardous materials is prohibited.</P>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 139.17</SECTNO>
                            <SUBJECT>Elevator pits.</SUBJECT>
                            <P>(a) The requirements in paragraph (b) of this section apply to the liquid that accumulates in, and is discharged from, the sumps of elevator wells.</P>
                            <P>(b) The discharge of untreated accumulated water and sediment from any elevator pit is prohibited.</P>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 139.18</SECTNO>
                            <SUBJECT>Exhaust gas emission control systems.</SUBJECT>
                            <P>
                                (a) 
                                <E T="03">Applicability.</E>
                                 The requirements in paragraphs (b) through (d) of this section apply to discharges from the operation and cleaning of any exhaust gas cleaning system (EGCS) and exhaust gas recirculation (EGR) system.
                            </P>
                            <P>
                                (b) 
                                <E T="03">Discharge requirements.</E>
                                 Unless excluded in paragraph (c) of this section, any discharge identified in paragraph (a) of this section must meet the following discharge requirements.
                            </P>
                            <P>
                                (1) 
                                <E T="03">pH.</E>
                                 (i) The discharge must meet one of the following requirements:
                            </P>
                            <P>(A) The discharge must have a pH of no less than 6.5 as measured at the vessel's overboard discharge point with the exception that during maneuvering and transit, the maximum difference of two pH units is allowed between inlet water and overboard discharge values; or</P>
                            <P>
                                (B) The pH discharge limit is the value that will achieve a minimum pH of 6.5 at 4 meters from the overboard discharge point with the vessel stationary. This overboard pH discharge limit is to be determined at the overboard discharge monitoring point and is to be recorded as the vessel's discharge limit. The overboard pH limit can be determined either by means of direct measurement, or by using a calculation-based methodology (computational fluid dynamics or other equally 
                                <PRTPAGE P="435"/>
                                scientifically established empirical formulas).
                            </P>
                            <P>(ii) The pH numeric discharge standard may be exceeded for up to 15 minutes in any 12-hour period.</P>
                            <P>
                                (2) 
                                <E T="03">PAHs (Polycyclic Aromatic Hydrocarbons).</E>
                                 (i) The maximum continuous PAH concentration in the discharge must be no greater than 50 µg/L PAHphe (phenanthrene equivalents) above the inlet water PAH concentration. This standard applies downstream of any washwater treatment equipment including any reactant dosing unit but upstream of any seawater addition for control of pH prior to discharge.
                            </P>
                            <P>(ii) The 50 µg/L numeric discharge standard is normalized for a discharge flow rate, before any seawater neutralization for pH control, of 45 tons (t)/megawatt-hour (MWh) where the mega-watt (MW) refers to the Maximum Continuous Rating (MCR) or 80% of the power rating of the fuel oil combustion units whose EGCS discharge water PAH is being monitored at that point. In cases where sensors are installed in a separate measurement cell, the PAH limit applies to the flow in the main discharge pipe from which the water is bypassed. This numeric discharge standard is adjusted upward or downward for different discharge flow rates, pursuant to table 1 to paragraph (b)(2)(ii) of this section.</P>
                            <GPOTABLE COLS="3" OPTS="L2" CDEF="s100,25,xs90">
                                <TTITLE>
                                    Table 1 to Paragraph 
                                    <E T="01">(b)(2)(ii)</E>
                                </TTITLE>
                                <BOXHD>
                                    <CHED H="1">
                                        Discharge water flowrate before any seawater addition for pH control
                                        <LI>(t/MWh)</LI>
                                    </CHED>
                                    <CHED H="1">
                                        Numeric discharge standard
                                        <LI>(µg/L PAHphe equivalents)</LI>
                                    </CHED>
                                    <CHED H="1">Measurement technology</CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">0-1</ENT>
                                    <ENT>2,250</ENT>
                                    <ENT>Ultraviolet light</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">2.5</ENT>
                                    <ENT>900</ENT>
                                    <ENT>- ″ -</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">5</ENT>
                                    <ENT>450</ENT>
                                    <ENT>
                                        Fluorescence 
                                        <SU>a</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">11.25</ENT>
                                    <ENT>200</ENT>
                                    <ENT>- ″ -</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">22.5</ENT>
                                    <ENT>100</ENT>
                                    <ENT>- ″ -</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">45</ENT>
                                    <ENT>50</ENT>
                                    <ENT>- ″ -</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">90</ENT>
                                    <ENT>25</ENT>
                                    <ENT>- ″ -</ENT>
                                </ROW>
                                <TNOTE>
                                    <SU>a</SU>
                                     For any Flow Rate greater than 2.5 t/MWh, Fluorescence technology must be used.
                                </TNOTE>
                            </GPOTABLE>
                            <P>(iii) The continuous PAHphe numeric discharge standard may be exceeded by 100% for up to 15 minutes in any 12-hour period.</P>
                            <P>
                                (3) 
                                <E T="03">Turbidity/suspended particulate matter.</E>
                                 (i) The washwater treatment system must be designed to minimize suspended particulate matter, including but not limited to heavy metals and ash.
                            </P>
                            <P>(ii) The maximum continuous turbidity in the discharge must be no greater than 25 FNU (formazin nephlometric units) or 25 NTU (nephlometric turbidity units) or equivalent units above the inlet water turbidity. However, to account for periods of high inlet turbidity, readings must be a rolling average over a 15-minute period to a maximum of 25 FNU or NTU. This standard applies downstream of any washwater treatment equipment including any reactant dosing unit but upstream of any seawater addition for control of pH prior to discharge.</P>
                            <P>(iii) For an aggregated 15-minute period in any rolling 12-hour period, the continuous turbidity discharge limit may be exceeded by 20%.</P>
                            <P>
                                (4) 
                                <E T="03">Nitrates plus nitrites:</E>
                            </P>
                            <P>
                                (i) The washwater treatment system must prevent the discharge of nitrates plus nitrites beyond that associated with a 12% removal of NO
                                <E T="52">X</E>
                                 from the exhaust, or beyond 60 mg/L normalized for a discharge rate of 45 tons/MWh, whichever is greater, where the MW refers to the MCR or 80% of the power rating of all those fuel oil combustion units whose EGCS discharge water nitrates plus nitrites are being monitored at that point. This standard applies downstream of any washwater treatment equipment including any reactant dosing unit but upstream of any seawater addition for control of pH prior to discharge. The 60-mg/L limit is adjusted upward for lower washwater flow rates per MWh, and vice-versa, and the applicable permit limits are contained in table 2 to paragraph (b)(4)(i) of this section.
                                <PRTPAGE P="436"/>
                            </P>
                            <GPOTABLE COLS="2" OPTS="L2" CDEF="s100,29">
                                <TTITLE>
                                    Table 2 to Paragraph 
                                    <E T="01">(b)(4)(i)</E>
                                </TTITLE>
                                <BOXHD>
                                    <CHED H="1">
                                        Discharge water flowrate before any seawater addition for pH control
                                        <LI>(t/MWh)</LI>
                                    </CHED>
                                    <CHED H="1">
                                        Numeric discharge standard
                                        <LI>(mg/L nitrate + nitrite)</LI>
                                    </CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">0-1</ENT>
                                    <ENT>2,700</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">2.5</ENT>
                                    <ENT>1,080</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">5</ENT>
                                    <ENT>540</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">11.25</ENT>
                                    <ENT>240</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">22.5</ENT>
                                    <ENT>120</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">45</ENT>
                                    <ENT>60</ENT>
                                </ROW>
                            </GPOTABLE>
                            <P>
                                (5) 
                                <E T="03">Discharge water from temporary storage:</E>
                            </P>
                            <P>(i) pH. See § 139.18(b)(1).</P>
                            <P>(ii) PAH. Maximum of 50 µg/L PAHphe before any addition of seawater (or similar) for control of pH.</P>
                            <P>(iii) Turbidity. Not greater than 25 FNU or 25 NTU or equivalent units, before any addition of seawater (or similar) for pH control.</P>
                            <P>
                                (6) 
                                <E T="03">Treatment Residuals:</E>
                                 Discharges of sludge or residues generated from treatment of EGCS or EGR washwater or bleed-off water are prohibited.
                            </P>
                            <P>
                                (c) 
                                <E T="03">Exclusion.</E>
                                 For a vessel operating on fuel that meets the sulfur content limits specified in Regulation 14 of MARPOL Annex VI, discharge of EGR bleed-off water is excluded from paragraph (b) of this section if the vessel:
                            </P>
                            <P>(1) Does not retain the EGR bleed-off onboard in a holding tank prior to discharge, and</P>
                            <P>(2) Is underway, and</P>
                            <P>(3) Not in port.</P>
                            <P>
                                (d) 
                                <E T="03">Prohibition.</E>
                                 For a vessel not operating on fuel that meets the sulfur content limits specified in Regulation 14 of MARPOL Annex VI, discharge of EGR bleed-off water which is retained in a holding tank is prohibited unless the vessel:
                            </P>
                            <P>(1) Is underway;</P>
                            <P>(2) Not in port; and</P>
                            <P>(3) In compliance with the discharge standard in paragraph (b) of this section.</P>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 139.19</SECTNO>
                            <SUBJECT>Fire protection equipment.</SUBJECT>
                            <P>(a) The requirements in paragraphs (b) through (e) of this section apply to the discharge from fire protection equipment, including discharges for secondary purposes (e.g., anchor and anchor chain rinsing and deck washdown). As specified in § 139.1(b)(3), these requirements do not apply to discharges from fire protection equipment when used for emergencies or when compliance with such requirements would compromise the safety of the vessel or life at sea.</P>
                            <P>(b) The discharge of fluorinated firefighting foam is prohibited unless required for certification or inspection under 46 CFR 31.10 through 31.18(c), 46 CFR 107.235(b)(4), or by the marine inspector to ensure vessel safety and seaworthiness.</P>
                            <P>(c) The discharge from fire protection equipment to ensure operability (e.g., during testing, training, maintenance, inspection, or certification) is prohibited in port unless:</P>
                            <P>(1) The intake is drawn from surrounding waters or a potable water supply and contains no additives (e.g., firefighting foam); or</P>
                            <P>(2) Required in port by the Secretary for certification or inspection under 46 CFR 31.10 through 31.18(c), 46 CFR 107.235(b)(4), or by the marine inspector to ensure vessel safety.</P>
                            <P>(d) The discharge from fire protection equipment for secondary uses is prohibited in port unless:</P>
                            <P>(1) The intake is drawn from surrounding waters or a potable water supply and contains no additives (e.g., firefighting foam); and</P>
                            <P>(2) The discharge meets applicable requirements under this part for the secondary use.</P>
                            <P>(e) Additional requirements applicable to discharges from fire protection equipment when a vessel is operating in federally-protected waters are contained in § 139.40(g).</P>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 139.20</SECTNO>
                            <SUBJECT>Gas turbines.</SUBJECT>
                            <P>(a) The requirements in paragraph (b) of this section apply to discharges from the washing of gas turbine components.</P>
                            <P>(b) The discharge of untreated gas turbine washwater is prohibited unless infeasible.</P>
                        </SECTION>
                        <SECTION>
                            <PRTPAGE P="437"/>
                            <SECTNO>§ 139.21</SECTNO>
                            <SUBJECT>Graywater systems.</SUBJECT>
                            <P>(a) The requirements in paragraphs (b) through (g) of this section apply to discharges of graywater except for graywater from any commercial vessel on the Great Lakes that is subject to the requirements in 40 CFR part 140 and 33 CFR part 159.</P>
                            <P>(b) The introduction of kitchen waste, food, oils, and oily residues to the graywater system must be minimized.</P>
                            <P>(c) Any soaps, cleaners, detergents, and other substances used by vessel operators or provided by vessel operators to persons onboard and discharged in graywater must be minimally-toxic, phosphate-free, and biodegradable.</P>
                            <P>(d) The discharge of graywater is prohibited from any vessel:</P>
                            <P>(1) Within 3 NM from shore that voyages at least 3 NM from shore and has remaining available graywater storage capacity, unless the discharge meets the standards in paragraph (f) of this section; and</P>
                            <P>(2) Within 1 NM from shore that voyages at least 1 NM from shore but not beyond 3 NM from shore and has remaining available graywater storage capacity, unless the discharge meets the standards in paragraph (f) of this section.</P>
                            <P>(e) The discharge of graywater from the following vessels must meet the numeric discharge standard established in paragraph (f) of this section:</P>
                            <P>(1) Any new vessel of 400 GT (400 GRT if GT is not assigned) and above that is certificated to carry 15 or more persons and provides overnight accommodations to those persons;</P>
                            <P>(2) Any passenger vessel, excluding any ferry, with overnight accommodations for 500 or more persons;</P>
                            <P>(3) Any passenger vessel, excluding any ferry, with overnight accommodations for 100-499 persons unless the vessel was constructed before December 19, 2008, and does not voyage beyond 1 NM from shore; and</P>
                            <P>(4) Any new ferry authorized by the Secretary to carry 250 or more persons.</P>
                            <P>(f) A vessel identified in paragraph (d) or (e) of this section that is discharging graywater must meet the following numeric discharge standard:</P>
                            <P>
                                (1) 
                                <E T="03">Fecal coliform.</E>
                                 (i) The 30-day geometric mean must not exceed 20 cfu, or MPN, per 100 mL.
                            </P>
                            <P>(ii) Greater than 90% of samples must not exceed 40 cfu, or MPN, per 100 mL during any 30-day period.</P>
                            <P>
                                (2) 
                                <E T="03">BOD5.</E>
                                 (i) The 30-day average must not exceed 30 mg/L.
                            </P>
                            <P>(ii) The 7-day average must not exceed 45 mg/L.</P>
                            <P>
                                (3) 
                                <E T="03">Suspended solids.</E>
                                 (i) The 30-day average must not exceed 30 mg/L.
                            </P>
                            <P>(ii) The 7-day average must not exceed 45 mg/L.</P>
                            <P>
                                (4) 
                                <E T="03">pH.</E>
                                 (i) Must be maintained between 6.0 and 9.0.
                            </P>
                            <P>(ii) [Reserved]</P>
                            <P>
                                (5) 
                                <E T="03">Total residual oxidizers.</E>
                                 (i) For any discharge from a graywater system using chlorine, total residual oxidizers must not exceed 10.0 µg/L.
                            </P>
                            <P>(ii) [Reserved]</P>
                            <P>(g) Unless from a vessel subject to paragraph (e) of this section, the discharge of graywater from any vessel operating on the Great Lakes that is not a commercial vessel must not exceed 200 fecal coliform forming units per 100 milliliters and contain no more than 150 milligrams per liter of suspended solids.</P>
                            <P>(h) Additional standards applicable to discharges from graywater systems when a vessel is operating in federally-protected waters are contained in § 139.40(h).</P>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 139.22</SECTNO>
                            <SUBJECT>Hulls and associated niche areas.</SUBJECT>
                            <P>
                                (a) 
                                <E T="03">Applicability.</E>
                                 The requirements in paragraphs (b) through (d) of this section apply to the discharge of anti-fouling coatings, biofouling organisms, and other materials from vessel hull and niche areas.
                            </P>
                            <P>
                                (b) 
                                <E T="03">Transport and passive discharge.</E>
                                 The transport of attached living organisms and passive discharge of biofouling must be minimized when traveling into U.S. waters from outside the EEZ or between COTP Zones. Management measures to minimize the transport of attached living organisms and the passive discharge of biofouling are described in paragraphs (c) and (d) of this section.
                            </P>
                            <P>
                                (c) 
                                <E T="03">Anti-fouling coatings.</E>
                                 (1) Anti-fouling coatings applied to the vessel must be specific to the operational profile of 
                                <PRTPAGE P="438"/>
                                the vessel and the equipment to which it is applied, including, for biocidal coatings, having appropriate biocide release rates and components that are biodegradable once separated from the vessel surface.
                            </P>
                            <P>(2) Anti-fouling coatings must be applied, maintained, and reapplied consistent with manufacturer specifications, including but not limited to the thickness, the method of application, and the lifespan of the coating.</P>
                            <P>(3) Anti-fouling coatings must not contain tributyltin (TBT) or any other organotin compound used as a biocide.</P>
                            <P>(i) Any vessel hull previously covered with an anti-fouling coating containing TBT (whether or not used as a biocide) or any other organotin compound (if used as a biocide) must:</P>
                            <P>(A) Maintain an effective overcoat that forms a barrier so that no TBT or other organotin leaches from the underlying anti-fouling coating; or</P>
                            <P>(B) Remove any TBT or other organotin compound from the vessel hull.</P>
                            <P>(4) When an organotin compound other than TBT is used as a catalyst in the anti-fouling coating (e.g., dibutyltin), the anti-fouling coating must:</P>
                            <P>(i) Contain less than 2,500 mg total tin per kilogram of dry paint; and</P>
                            <P>(ii) Not be designed to slough or otherwise peel from the vessel hull, noting that incidental amounts of anti-fouling coating discharged by abrasion during cleaning or after contact with other hard surfaces (e.g., moorings) are acceptable.</P>
                            <P>(5) Anti-fouling coatings must not contain cybutryne.</P>
                            <P>(i) Any vessel that has previously applied an anti-fouling coating that contains cybutryne in the external coating layer of their hulls or external parts or surfaces must:</P>
                            <P>(A) Apply and maintain an effective overcoat that forms a barrier so that no cybutryne leaches from the underlying anti-fouling coating, noting that incidental amounts of anti-fouling coating discharged by abrasion during cleaning or after contact with other hard surfaces (e.g., moorings) are acceptable; or</P>
                            <P>(B) Remove any cybutryne coating.</P>
                            <P>(6) As appropriate based on vessel class and operations, alternatives to copper-based anti-fouling coatings (e.g., non-biocidal anti-fouling coatings) or coating with lower biocidal release rates must be considered for vessels spending 30 or more days per year in a copper-impaired waterbody or using these waters as their home port.</P>
                            <P>
                                (d) 
                                <E T="03">Cleaning.</E>
                                 (1) Cleanings should take place in drydock when practicable.
                            </P>
                            <P>(2) Hulls and niche areas must be managed to minimize biofouling such as through preventative cleaning of microfouling.</P>
                            <P>(3) Hull and niche area cleanings must minimize damage to the anti-fouling coating, minimize release of biocides, and follow applicable cleaning requirements found on the coating manufacturers' instructions and any applicable FIFRA label.</P>
                            <P>(4) Any discharge from in-water cleaning without capture of macrofouling is prohibited.</P>
                            <P>(5) Any discharge from in-water cleaning without capture of any copper-based hull coating in a copper-impaired water body within the first 365 days after application of that coating is prohibited.</P>
                            <P>(6) In-water cleaning must not be conducted on any section of an anti-fouling coating that shows excessive cleaning actions (e.g., brush marks) or blistering due to the internal failure of the paint system.</P>
                            <P>(7) Any soap, cleaner, or detergent used on vessel surfaces, including but not limited to a scum line of the hull, must be minimally toxic, phosphate-free, and biodegradable.</P>
                            <P>(8) Additional standards applicable to discharges from hulls and associated niche areas when a vessel is operating in federally-protected waters are contained in § 139.40(i).</P>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 139.23</SECTNO>
                            <SUBJECT>Inert gas systems.</SUBJECT>
                            <P>There are no additional discharge-specific requirements that apply to the discharge of washwater from an inert gas system and deck seal water when used as an integral part of that system.</P>
                        </SECTION>
                        <SECTION>
                            <PRTPAGE P="439"/>
                            <SECTNO>§ 139.24</SECTNO>
                            <SUBJECT>Motor gasoline and compensating systems.</SUBJECT>
                            <P>(a) The requirements in paragraph (b) of this section apply to the discharge of motor gasoline and compensating ambient water added to keep gasoline tanks full to prevent potentially explosive gasoline vapors from forming.</P>
                            <P>(b) Additional standards applicable to discharges from motor gasoline and compensating systems when a vessel is operating in federally-protected waters are contained in § 139.40(j).</P>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 139.25</SECTNO>
                            <SUBJECT>Non-oily machinery.</SUBJECT>
                            <P>(a) The requirements in paragraph (b) of this section apply to discharges from machinery that contains no oil, including but not limited to discharges from the operation of desalination systems, water chillers, valve packings, water piping, low- and high-pressure air compressors, propulsion engine jacket coolers, fire pumps, and seawater and potable water pumps.</P>
                            <P>(b) The discharge of untreated non-oily machinery wastewater and packing gland or stuffing box effluent containing toxic or bioaccumulative additives, or the discharge of oil in such quantities as may be harmful, is prohibited.</P>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 139.26</SECTNO>
                            <SUBJECT>Pools and spas.</SUBJECT>
                            <P>(a) The requirements in paragraphs (b) and (c) of this section apply to discharges from pools and spas.</P>
                            <P>(b) Except for unintentional or inadvertent releases from overflows across the decks and into overboard drains caused by, but not limited to, weather, vessel traffic, marine wildlife avoidance or navigational maneuvering, discharge of pool and spa water must:</P>
                            <P>(1) Occur only while the vessel is underway, unless determined to be infeasible; and</P>
                            <P>(2) Meet the following numeric discharge standard:</P>
                            <P>(i) For chlorine disinfection: total residual chlorine less than 100 µg/L; and</P>
                            <P>(ii) For bromine disinfection: total residual oxidant less than 25 µg/L.</P>
                            <P>(c) Additional standards applicable to discharges from pools and spas when a vessel is operating in federally-protected waters are contained in § 139.40(k).</P>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 139.27</SECTNO>
                            <SUBJECT>Refrigeration and air conditioning.</SUBJECT>
                            <P>(a) The requirements in paragraph (b) of this section apply to discharges of condensation from refrigeration, air conditioning, and similar chilling equipment.</P>
                            <P>(b) The direct overboard discharge of any condensate that contacts toxic or hazardous materials is prohibited.</P>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 139.28</SECTNO>
                            <SUBJECT>Seawater piping.</SUBJECT>
                            <P>(a) The requirements in paragraphs (b) through (d) of this section apply to discharges from seawater piping systems, including while a vessel is in port or in layup.</P>
                            <P>(b) Seawater piping systems must be inspected, maintained, and cleaned as necessary to minimize the accumulation and discharge of biofouling organisms.</P>
                            <P>(c) Seawater piping systems that accumulate macrofouling must be fitted with a Marine Growth Prevention System (MGPS).</P>
                            <P>(1) An MGPS must be selected to address:</P>
                            <P>(i) The level, frequency, and type of expected biofouling; and</P>
                            <P>(ii) The design, location, and area in which the system will be used.</P>
                            <P>(2) An MGPS must include one, or some combination of the following:</P>
                            <P>(i) Chemical injection;</P>
                            <P>(ii) Electrolysis, ultrasound, ultraviolet radiation, or electrochlorination;</P>
                            <P>(iii) Application of an antifouling coating;</P>
                            <P>(iv) Use of cupro-nickel piping; or</P>
                            <P>(v) Use of glass-reinforced/filament-wound epoxy-based composite piping.</P>
                            <P>(3) Upon identification of macrofouling in a seawater piping system, reactive measures to manage the macrofouling must be used. Discharges resulting from reactive measures to remove macrofouling are prohibited in port.</P>
                            <P>(d) Additional standards applicable to discharges from seawater piping systems when a vessel is operating in federally-protected waters are contained in § 139.40(l).</P>
                        </SECTION>
                        <SECTION>
                            <PRTPAGE P="440"/>
                            <SECTNO>§ 139.29</SECTNO>
                            <SUBJECT>Sonar domes.</SUBJECT>
                            <P>(a) The requirements in paragraphs (b) and (c) of this section apply to discharges from sonar domes.</P>
                            <P>(b) The discharge of water from inside the sonar dome is prohibited during maintenance or repair.</P>
                            <P>(c) Any discharge from the use of bioaccumulative biocides on the exterior of the sonar dome is prohibited when non-bioaccumulative alternatives are available.</P>
                        </SECTION>
                    </SUBPART>
                    <SUBPART>
                        <HD SOURCE="HED">Subpart D—Special Area Requirements</HD>
                        <SECTION>
                            <SECTNO>§ 139.40</SECTNO>
                            <SUBJECT>Federally-protected waters.</SUBJECT>
                            <P>
                                (a) 
                                <E T="03">Applicability.</E>
                                 The requirements in paragraphs (b) through (l) of this section are in addition to applicable standards in subparts B and C of this part and apply when a vessel is operating in federally-protected waters.
                            </P>
                            <P>
                                (b) 
                                <E T="03">Ballast tanks.</E>
                                 The discharge or uptake of ballast water in federally-protected waters must be avoided except for vessels:
                            </P>
                            <P>(1) Operating within the boundaries of any national marine sanctuary that preserves shipwrecks or maritime heritage in the Great Lakes, unless the designation documents for such sanctuary do not allow taking up or discharging ballast water in such sanctuary, pursuant to 16 U.S.C. 1431 note (Pub. L. 113-281, title VI, § 610, Dec. 18, 2014, 128 Stat. 3064, as amended by Pub. L. 114-120, title VI, § 602(1), Feb. 8, 2016, 130 Stat. 79); or</P>
                            <P>(2) That operate solely within federally-protected waters and take on and discharge ballast water exclusively in the contiguous portions of a single COTP Zone.</P>
                            <P>
                                (c) 
                                <E T="03">Bilges.</E>
                                 For any vessel of 400 GT and above, the discharge of bilgewater into federally-protected waters is prohibited.
                            </P>
                            <P>
                                (d) 
                                <E T="03">Boilers.</E>
                                 The discharge of boiler blowdown into federally-protected waters is prohibited.
                            </P>
                            <P>
                                (e) 
                                <E T="03">Chain lockers.</E>
                                 The discharge of accumulated water and sediment from any chain locker into federally-protected waters is prohibited.
                            </P>
                            <P>
                                (f) 
                                <E T="03">Decks.</E>
                                 The discharge of deck washdown into federally-protected waters is prohibited except for those vessels operating exclusively within these protected waters provided the discharge is in compliance with all other requirements in § 139.15.
                            </P>
                            <P>
                                (g) 
                                <E T="03">Fire protection equipment.</E>
                                 The discharge from fire protection equipment into federally-protected water is prohibited except to comply with USCG fire drill requirements or anchor and anchor chain requirements in § 139.14. When USCG fire drills are conducted, the discharge of any firefighting foam into federally-protected waters is prohibited except by any vessel owned or under contract with the United States, State, or local government to do business exclusively in any federally-protected waters.
                            </P>
                            <P>
                                (h) 
                                <E T="03">Graywater systems.</E>
                                 The discharge of graywater into federally-protected waters from any vessel with remaining available graywater storage capacity is prohibited.
                            </P>
                            <P>
                                (i) 
                                <E T="03">Hulls and associated niche areas.</E>
                                 The discharge from in-water cleaning of vessel hulls and niche areas into federally-protected waters is prohibited except by any vessel owned or under contract with the United States, State, or local government to do business exclusively in any federally-protected waters.
                            </P>
                            <P>
                                (j) 
                                <E T="03">Motor gasoline and compensating systems.</E>
                                 The discharge of motor gasoline and compensating discharges into federally-protected waters is prohibited.
                            </P>
                            <P>
                                (k) 
                                <E T="03">Pools and spas.</E>
                                 The discharge of pool or spa water into federally-protected waters is prohibited.
                            </P>
                            <P>
                                (l) 
                                <E T="03">Seawater piping systems.</E>
                                 The discharge of chemical dosing, as described in § 139.28, into federally-protected waters is prohibited.
                            </P>
                        </SECTION>
                    </SUBPART>
                    <SUBPART>
                        <HD SOURCE="HED">Subpart E—Procedures for States to Request Changes to Standards, Regulations, or Policy Promulgated by the Administrator</HD>
                        <SECTION>
                            <SECTNO>§ 139.50</SECTNO>
                            <SUBJECT>Petition by a Governor for the Administrator to establish an emergency order or review a standard, regulation, or policy.</SUBJECT>
                            <P>
                                (a) The Governor of a State (or a designee) may submit a petition to the Administrator:
                                <PRTPAGE P="441"/>
                            </P>
                            <P>(1) To issue an emergency order under CWA section 312(p)(4)(E); or</P>
                            <P>(2) To review any standard of performance, regulation, or policy promulgated by the Administrator under CWA section 312(p)(4) or (6), if there exists new information that could reasonably result in a change to:</P>
                            <P>(i) The standard of performance, regulation, or policy; or</P>
                            <P>(ii) A determination on which the standard of performance, regulation, or policy was based.</P>
                            <P>(b) A petition under paragraph (a) of this section shall be signed by the Governor (or a designee) and must include:</P>
                            <P>(1) The purpose of the petition (request for emergency order or a review of a standard, regulation, or policy);</P>
                            <P>(2) Any applicable scientific or technical information that forms the basis of the petition;</P>
                            <P>(3) The direct and indirect benefits if the requested petition were to be granted by the Administrator; and</P>
                            <P>(4) For a petition under paragraph (a)(2) of this section, the costs to the affected classes, types, and/or sizes of vessels if the requested petition were to be granted by the Administrator.</P>
                            <P>(c) The Administrator shall grant or deny:</P>
                            <P>(1) A petition under paragraph (a)(1) of this section by not later than the date that is 180 days after the date on which the petition is submitted; and</P>
                            <P>(2) A petition under paragraph (a)(2) of this section by not later than the date that is one year after the date on which the petition is submitted.</P>
                            <P>(d) If the Administrator determines to grant a petition:</P>
                            <P>(1) In the case of a petition under paragraph (a)(1) of this section, the Administrator shall immediately issue the relevant emergency order under CWA section 312(p)(4)(E); or</P>
                            <P>
                                (2) In the case of a petition under paragraph (a)(2) of this section, the Administrator shall sign a Notice of Proposed Rulemaking for publication in the 
                                <E T="04">Federal Register</E>
                                 to revise the relevant standard, requirement, regulation, or policy under CWA section 312(p)(4) or (6), as applicable, as soon as possible and not later than 30 days after the date of the determination.
                            </P>
                            <P>
                                (e) If the Administrator determines to deny a petition, the Administrator shall sign a notice of the determination for publication in the 
                                <E T="04">Federal Register</E>
                                 that includes a detailed explanation of the scientific, technical, or operational factors that form the basis of the determination, as soon as possible and not later than 30 days after the date of the determination.
                            </P>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 139.51</SECTNO>
                            <SUBJECT>Petition by a Governor for the Administrator to establish enhanced Great Lakes System requirements.</SUBJECT>
                            <P>(a) The Governors endorsing a proposed standard or requirement under CWA section 312(p)(10)(B)(ii)(III)(bb) may jointly submit to the Administrator and the Secretary for approval each proposed standard of performance or other requirement developed and endorsed pursuant to CWA section 312(p)(10)(B)(ii) with respect to any discharge that is subject to regulation under this part and occurs within the Great Lakes System.</P>
                            <P>(b) A petition under paragraph (a) of this section must include:</P>
                            <P>(1) An explanation regarding why the applicable standard of performance or other requirement is at least as stringent as a comparable standard of performance or other requirement under this part;</P>
                            <P>(2) An explanation regarding why the standard of performance or other requirement is in accordance with maritime safety; and</P>
                            <P>(3) An explanation regarding why the standard of performance or other requirement is in accordance with applicable maritime and navigation laws and regulations.</P>
                            <P>(c) On receipt of a proposed standard of performance or other requirement under paragraph (b) of this section, the Administrator and the Secretary shall sign and transmit to the Office of Federal Register for publication a joint notice that, at minimum:</P>
                            <P>(1) States that the proposed standard or requirement is publicly available; and</P>
                            <P>
                                (2) Provides an opportunity for public comment regarding the proposed standard or requirement during the 90-day period beginning on the date of receipt by the Administrator of the proposed standard or requirement.
                                <PRTPAGE P="442"/>
                            </P>
                            <P>(d) The Administrator shall commence a review of each proposed standard of performance or other requirement covered by the notice to determine whether that standard or requirement is at least as stringent as comparable standards and requirements under this part.</P>
                            <P>(e) In carrying out paragraph (d) of this section, the Administrator:</P>
                            <P>(1) Shall consult with the Secretary,</P>
                            <P>(2) Shall consult with the Governor of each Great Lakes State and representatives from the Federal and provincial governments of Canada;</P>
                            <P>(3) Shall take into consideration any relevant data or public comments received under paragraph (c)(2) of this section; and</P>
                            <P>(4) Shall not take into consideration any preliminary assessment by the Great Lakes Commission or any dissenting opinion by a Governor of a Great Lakes State, except to the extent that such an assessment or opinion is relevant to the criteria for the applicable determination under paragraph (d) of this section.</P>
                            <P>(f) If a Governor of a Great Lakes State withdraws the endorsement by not later than 90 days after the Administrator receives the proposed standard or requirement, and the withdrawal results in the proposed standard or requirement not having the applicable number of endorsements, the Administrator shall terminate review.</P>
                            <P>(g) Upon review and determination, the Administrator and the Secretary shall approve each proposed standard or other requirement, unless the Administrator determines that the proposed standard or other requirement is not at least as stringent as comparable standards and requirements under this part or the Secretary determines that the proposed standard or requirement is not in accordance with maritime safety or is not in accordance with applicable maritime and navigation laws and regulations.</P>
                            <P>(h) If the Administrator and the Secretary approve a proposed standard or other requirement, the Administrator and the Secretary shall sign a notice of the determination and transmit the notice to the Governor of each Great Lakes State and to the Office of Federal Register for publication.</P>
                            <P>(i) If the Administrator and the Secretary disapprove a proposed standard or other requirement, the Administrator and the Secretary shall sign a notice of the determination and transmit it to the Governor of each Great Lakes State and to the Office of Federal Register for publication. The notice must include:</P>
                            <P>(1) A description of the reasons why the standard or requirement is, as applicable, less stringent than a comparable standard or requirement under this part, and</P>
                            <P>(2) Any recommendations regarding changes the Governors of the Great Lakes states could make to conform the disapproved portion of the standard or requirement to the requirements of this section.</P>
                            <P>(j) The Administrator and the Secretary shall make an approval or disapproval determination under this section and transmit a notice of such determination to the Governor of each Great Lakes State and the Office of Federal Register not later than 180 days after the date of receipt of the proposed standard or regulation.</P>
                            <P>(k) On approval by the Administrator and the Secretary of a proposed standard of performance or other requirement, the Administrator shall establish, by regulation, the proposed standard or requirement within the Great Lakes System in lieu of any comparable standard or other requirement promulgated under CWA section 312(p)(4). A requirement to prohibit one or more types of discharge, whether treated or not treated, into waters within the Great Lakes System shall not apply outside the waters of the Great Lakes states of the Governors endorsing the requirement.</P>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 139.52</SECTNO>
                            <SUBJECT>Application by a State for the Administrator to establish a State no-discharge zone.</SUBJECT>
                            <P>
                                (a) If any State determines that the protection and enhancement of the quality of some or all of the waters within the State require greater environmental protection, the Governor of a State (or a designee) may submit an application to the Administrator to establish a regulation prohibiting one or more discharges, whether treated or 
                                <PRTPAGE P="443"/>
                                not treated, into such waters subject to the application.
                            </P>
                            <P>(b) A prohibition by the Administrator under paragraph (a) of this section shall not apply until the Administrator, in concurrence with the Secretary, reviews the State application and makes the applicable determinations described in paragraph (d) of this section and publishes a regulation establishing the prohibition.</P>
                            <P>(c) An application submitted by the State under paragraph (a) of this section shall be signed by the Governor (or a designee) and must include:</P>
                            <P>(1) A narrative explanation of the location of the proposed waters and a map delineating the boundaries of the requested prohibition using geographic coordinates;</P>
                            <P>(2) A certification that a prohibition of the discharge(s) would protect and enhance the quality of the specific waters within the State to a greater extent than the applicable Federal standard provides;</P>
                            <P>(3) A detailed analysis of the direct and indirect benefits of the requested prohibition for each individual discharge for which the State is seeking a prohibition;</P>
                            <P>(4) A table identifying the types and number of vessels operating in the waterbody and a table identifying the types and number of vessels that would be subject to the prohibition;</P>
                            <P>(5) A table identifying the location, operating schedule, draft requirements, pumpout capacity, pumpout flow rate, connections, and fee structure of each existing facility capable of servicing the vessels that would be subject to the prohibition and available to receive the prohibited discharge;</P>
                            <P>(6) A description of the wastewater handling procedures of each facility identified in paragraph (c)(5) of this section, including information on how wastewater is stored, transported, treated, and/or disposed by each facility;</P>
                            <P>(7) A map indicating the location of each stationary facility, and the coverage area of each mobile facility, identified in paragraph (c)(5) of this section within the proposed waters;</P>
                            <P>(8) A detailed analysis of the impacts to vessels subject to the prohibition, including a discussion of how these vessels may feasibly collect and store the discharge, the extent to which retrofitting may be required, costs that are incurred as a result of the discharge prohibition, and any safety implications.</P>
                            <P>(d) On application of a State, the Administrator, in concurrence with the Secretary, shall, by regulation, prohibit the discharge from a vessel of one or more discharges subject to regulation under this part, whether treated or not treated, into the waters covered by the application if the Administrator determines that:</P>
                            <P>(1) The prohibition of the discharge(s) would protect and enhance the quality of the specified waters within the State;</P>
                            <P>(2) Adequate facilities for the safe and sanitary removal and treatment of the prohibited discharge(s) are reasonably available, including taking costs into consideration, for the water and all vessels to which the prohibition would apply. A determination of adequacy shall consider, at a minimum, water depth, dock size, pumpout facility capacity and flow rate, availability of year-round operations, proximity to navigation routes, the availability of operational changes as a means to reduce the discharge, and the ratio of pumpout facilities to the population and discharge capacity of vessels operating in those waters;</P>
                            <P>(3) The discharge(s) can be safely collected and stored until a vessel reaches an appropriate facility or location for discharge;</P>
                            <P>(4) In the case of an application for the prohibition of the discharge of ballast water in port (or in any other location where cargo, passengers, or fuel are loaded and unloaded):</P>
                            <P>(i) The considerations for adequate facilities described in paragraph (d)(2) of this section apply; and</P>
                            <P>(ii) The prohibition will not unreasonably interfere with the safe loading and unloading of cargo, passengers, or fuel.</P>
                            <P>(e) The Administrator shall submit to the Secretary a request for written concurrence on a determination made to establish a prohibition.</P>
                            <P>
                                (1) A failure by the Secretary to concur with the Administrator 60 days 
                                <PRTPAGE P="444"/>
                                after the date on which the Administrator submits a request for concurrence shall not prevent the Administrator from prohibiting the discharge or discharges, subject to the condition that the Administrator shall include in the administrative record of the promulgation:
                            </P>
                            <P>(i) Documentation of the request for concurrence; and</P>
                            <P>(ii) The response of the Administrator to any written objections received from the Secretary relating to the prohibition during the 60-day period beginning on the date of the request for concurrence.</P>
                            <P>(f) If the Administrator determines that an application meets the criteria in paragraph (c) of this section and approves the application, the Administrator shall notify the State of the tentative approval and develop a Notice of Proposed Rulemaking for transmittal to the Office of the Federal Register.</P>
                        </SECTION>
                        <APPENDIX>
                            <HD SOURCE="HED">Appendix A to Part 139—Federally-Protected Waters</HD>
                            <P>The asterisk (“*”) modifier in appendix A to part 139 identifies those areas vessels subject to these Federal standards may be most likely to transit based on proximity to waters where these vessels may operate.</P>
                            <HD SOURCE="HD1">A.1 National Marine Sanctuaries</HD>
                            <FP SOURCE="FP-2">American Samoa National Marine Sanctuary *</FP>
                            <FP SOURCE="FP-2">Channel Islands National Marine Sanctuary *</FP>
                            <FP SOURCE="FP-2">Cordell Bank National Marine Sanctuary *</FP>
                            <FP SOURCE="FP-2">Florida Keys National Marine Sanctuary *</FP>
                            <FP SOURCE="FP-2">Greater Farallones National Marine Sanctuary *</FP>
                            <FP SOURCE="FP-2">Hawaiian Islands Humpback Whale National Marine Sanctuary *</FP>
                            <FP SOURCE="FP-2">Monterey Bay National Marine Sanctuary *</FP>
                            <FP SOURCE="FP-2">Olympic Coast National Marine Sanctuary *</FP>
                            <FP SOURCE="FP-2">Stellwagen Bank National Marine Sanctuary *</FP>
                            <HD SOURCE="HD1">A.2 Marine National Monuments</HD>
                            <FP SOURCE="FP-2">Mariana Trench Marine National Monument *</FP>
                            <FP SOURCE="FP-2">Northeast Canyons and Seamounts Marine National Monument *</FP>
                            <FP SOURCE="FP-2">Pacific Remote Islands Marine National Monument *</FP>
                            <FP SOURCE="FP-2">
                                Papaha
                                <AC T="8"/>
                                naumokua
                                <AC T="8"/>
                                kea Marine National Monument *
                            </FP>
                            <FP SOURCE="FP-2">Rose Atoll Marine National Monument</FP>
                            <HD SOURCE="HD1">A.3 National Parks (National Reserves and Monuments)</HD>
                            <HD SOURCE="HD1">Alabama</HD>
                            <FP SOURCE="FP-2">Birmingham Civil Rights National Monument</FP>
                            <FP SOURCE="FP-2">Freedom Riders National Monument</FP>
                            <FP SOURCE="FP-2">Horseshoe Bend National Military Park</FP>
                            <FP SOURCE="FP-2">Little River Canyon National Preserve</FP>
                            <FP SOURCE="FP-2">Muscle Shoals National Heritage Area</FP>
                            <FP SOURCE="FP-2">Natchez Trace National Scenic Trail *</FP>
                            <FP SOURCE="FP-2">Russell Cave National Monument</FP>
                            <FP SOURCE="FP-2">Selma to Montgomery National Historic Trail</FP>
                            <FP SOURCE="FP-2">Trail of Tears National Historic Trail</FP>
                            <FP SOURCE="FP-2">Tuskegee Airmen National Historic Site</FP>
                            <FP SOURCE="FP-2">Tuskegee Institute National Historic Site</FP>
                            <HD SOURCE="HD1">Alaska</HD>
                            <FP SOURCE="FP-2">Aleutian World War II National Historic Area</FP>
                            <FP SOURCE="FP-2">Aniakchak National Monument and Preserve *</FP>
                            <FP SOURCE="FP-2">Bering Land Bridge National Preserve *</FP>
                            <FP SOURCE="FP-2">Cape Krusenstern National Monument *</FP>
                            <FP SOURCE="FP-2">Chilkoot National Historic Trail</FP>
                            <FP SOURCE="FP-2">Denali National Park and Preserve</FP>
                            <FP SOURCE="FP-2">Gates of the Arctic National Park and Preserve *</FP>
                            <FP SOURCE="FP-2">Glacier Bay National Park and Preserve *</FP>
                            <FP SOURCE="FP-2">Iditarod National Historic Trail</FP>
                            <FP SOURCE="FP-2">Inupiat Heritage Center</FP>
                            <FP SOURCE="FP-2">Katmai National Park and Preserve *</FP>
                            <FP SOURCE="FP-2">Kenai Fjords National Park *</FP>
                            <FP SOURCE="FP-2">Kenai Mountains-Turnagain Arm National Heritage Area</FP>
                            <FP SOURCE="FP-2">Klondike Gold Rush National Historical Park *</FP>
                            <FP SOURCE="FP-2">Kobuk Valley National Park *</FP>
                            <FP SOURCE="FP-2">Lake Clark National Park and Preserve *</FP>
                            <FP SOURCE="FP-2">Noatak National Preserve *</FP>
                            <FP SOURCE="FP-2">Sitka National Historical Park *</FP>
                            <FP SOURCE="FP-2">Wrangell-St. Elias National Park and Preserve *</FP>
                            <FP SOURCE="FP-2">Yukon-Charley Rivers National Preserve *</FP>
                            <HD SOURCE="HD1">American Samoa</HD>
                            <FP SOURCE="FP-2">National Park of American Samoa *</FP>
                            <HD SOURCE="HD1">Arizona</HD>
                            <FP SOURCE="FP-2">Arizona National Scenic Trail</FP>
                            <FP SOURCE="FP-2">Butterfield Overland National Historic Trail</FP>
                            <FP SOURCE="FP-2">Canyon de Chelly National Monument</FP>
                            <FP SOURCE="FP-2">Casa Grande Ruins National Monument</FP>
                            <FP SOURCE="FP-2">Chiricahua National Monument</FP>
                            <FP SOURCE="FP-2">Coronado National Memorial</FP>
                            <FP SOURCE="FP-2">Fort Bowie National Historic Site</FP>
                            <FP SOURCE="FP-2">Glen Canyon National Recreation Area</FP>
                            <FP SOURCE="FP-2">Grand Canyon-Parashant National Monument</FP>
                            <FP SOURCE="FP-2">Grand Canyon National Park</FP>
                            <FP SOURCE="FP-2">Hohokam Pima National Monument</FP>
                            <FP SOURCE="FP-2">Hubbell Trading Post National Historic Site</FP>
                            <FP SOURCE="FP-2">Lake Mead National Recreation Area</FP>
                            <FP SOURCE="FP-2">Montezuma Castle National Monument</FP>
                            <FP SOURCE="FP-2">
                                Navajo National Monument
                                <PRTPAGE P="445"/>
                            </FP>
                            <FP SOURCE="FP-2">Old Spanish National Historic Trail</FP>
                            <FP SOURCE="FP-2">Organ Pipe Cactus National Monument</FP>
                            <FP SOURCE="FP-2">Petrified Forest National Park</FP>
                            <FP SOURCE="FP-2">Pipe Spring National Monument</FP>
                            <FP SOURCE="FP-2">Saguaro National Park</FP>
                            <FP SOURCE="FP-2">Santa Cruz Valley National Heritage Area</FP>
                            <FP SOURCE="FP-2">Sunset Crater Volcano National Monument</FP>
                            <FP SOURCE="FP-2">Tonto National Monument</FP>
                            <FP SOURCE="FP-2">Tumacacori National Historical Park</FP>
                            <FP SOURCE="FP-2">Tuzigoot National Monument</FP>
                            <FP SOURCE="FP-2">Walnut Canyon National Monument</FP>
                            <FP SOURCE="FP-2">Wupatki National Monument</FP>
                            <FP SOURCE="FP-2">Yuma Crossing National Heritage Area</FP>
                            <HD SOURCE="HD1">Arkansas</HD>
                            <FP SOURCE="FP-2">Arkansas Post National Memorial *</FP>
                            <FP SOURCE="FP-2">Buffalo National River *</FP>
                            <FP SOURCE="FP-2">Butterfield Overland National Historic Trail</FP>
                            <FP SOURCE="FP-2">Charleston National Commemorative Site</FP>
                            <FP SOURCE="FP-2">Fort Smith National Historic Site *</FP>
                            <FP SOURCE="FP-2">Hot Springs National Park</FP>
                            <FP SOURCE="FP-2">Little Rock Central High School National Historic Site</FP>
                            <FP SOURCE="FP-2">Mississippi Delta National Heritage Area</FP>
                            <FP SOURCE="FP-2">Pea Ridge National Military Park</FP>
                            <FP SOURCE="FP-2">President William Jefferson Clinton Birthplace Home National Historic Site</FP>
                            <FP SOURCE="FP-2">Trail of Tears National Historic Trail</FP>
                            <HD SOURCE="HD1">California</HD>
                            <FP SOURCE="FP-2">Butterfield Overland National Historic Trail</FP>
                            <FP SOURCE="FP-2">Cabrillo National Monument *</FP>
                            <FP SOURCE="FP-2">California National Historic Trail</FP>
                            <FP SOURCE="FP-2">Castle Mountains National Monument</FP>
                            <FP SOURCE="FP-2">Cesar E. Chavez National Monument</FP>
                            <FP SOURCE="FP-2">Channel Islands National Park *</FP>
                            <FP SOURCE="FP-2">Death Valley National Park</FP>
                            <FP SOURCE="FP-2">Devils Postpile National Monument</FP>
                            <FP SOURCE="FP-2">Eugene O'Neill National Historic Site</FP>
                            <FP SOURCE="FP-2">Fort Point National Historic Site *</FP>
                            <FP SOURCE="FP-2">Golden Gate National Recreation Area *</FP>
                            <FP SOURCE="FP-2">John Muir National Historic Site</FP>
                            <FP SOURCE="FP-2">Joshua Tree National Park</FP>
                            <FP SOURCE="FP-2">Juan Bautista de Anza National Historic Trail</FP>
                            <FP SOURCE="FP-2">Kings Canyon National Park</FP>
                            <FP SOURCE="FP-2">Lassen Volcanic National Park</FP>
                            <FP SOURCE="FP-2">Lava Beds National Monument</FP>
                            <FP SOURCE="FP-2">Manzanar National Historic Site</FP>
                            <FP SOURCE="FP-2">Mojave National Preserve</FP>
                            <FP SOURCE="FP-2">Muir Woods National Monument</FP>
                            <FP SOURCE="FP-2">Old Spanish National Historic Trail</FP>
                            <FP SOURCE="FP-2">Pacific Crest National Scenic Trail</FP>
                            <FP SOURCE="FP-2">Pinnacles National Park</FP>
                            <FP SOURCE="FP-2">Point Reyes National Seashore *</FP>
                            <FP SOURCE="FP-2">Pony Express National Historic Trail</FP>
                            <FP SOURCE="FP-2">Port Chicago Naval Magazine National Memorial *</FP>
                            <FP SOURCE="FP-2">Redwood National Park *</FP>
                            <FP SOURCE="FP-2">Roosevelt Campobello International Park</FP>
                            <FP SOURCE="FP-2">Rosie the Riveter/World War II Home Front National Historical Park *</FP>
                            <FP SOURCE="FP-2">Sacramento-San Joaquin Delta National Heritage Area</FP>
                            <FP SOURCE="FP-2">San Francisco Maritime National Historical Park *</FP>
                            <FP SOURCE="FP-2">Santa Monica Mountains National Recreation Area *</FP>
                            <FP SOURCE="FP-2">Sequoia National Park</FP>
                            <FP SOURCE="FP-2">Tule Lake National Monument</FP>
                            <FP SOURCE="FP-2">Whiskeytown-Shasta-Trinity National Recreation Area</FP>
                            <FP SOURCE="FP-2">Yosemite National Park</FP>
                            <HD SOURCE="HD1">Colorado</HD>
                            <FP SOURCE="FP-2">Amache National Historic Site</FP>
                            <FP SOURCE="FP-2">Bent's Old Fort National Historic Site</FP>
                            <FP SOURCE="FP-2">Black Canyon of the Gunnison National Park</FP>
                            <FP SOURCE="FP-2">Cache La Poudre River National Heritage Area</FP>
                            <FP SOURCE="FP-2">California National Historic Trail</FP>
                            <FP SOURCE="FP-2">Colorado National Monument</FP>
                            <FP SOURCE="FP-2">Continental Divide National Scenic Trail</FP>
                            <FP SOURCE="FP-2">Curecanti National Recreation Area</FP>
                            <FP SOURCE="FP-2">Dinosaur National Monument</FP>
                            <FP SOURCE="FP-2">Florissant Fossil Beds National Monument</FP>
                            <FP SOURCE="FP-2">Great Sand Dunes National Park and Preserve</FP>
                            <FP SOURCE="FP-2">Hovenweep National Monument</FP>
                            <FP SOURCE="FP-2">Mesa Verde National Park</FP>
                            <FP SOURCE="FP-2">Old Spanish National Historic Trail</FP>
                            <FP SOURCE="FP-2">Pony Express National Historic Trail</FP>
                            <FP SOURCE="FP-2">Rocky Mountain National Park</FP>
                            <FP SOURCE="FP-2">Sand Creek Massacre National Historic Site</FP>
                            <FP SOURCE="FP-2">Sangre de Cristo National Heritage Area</FP>
                            <FP SOURCE="FP-2">Santa Fe National Historic Trail</FP>
                            <FP SOURCE="FP-2">South Park National Heritage Area</FP>
                            <FP SOURCE="FP-2">Yucca House National Monument</FP>
                            <HD SOURCE="HD1">Connecticut</HD>
                            <FP SOURCE="FP-2">Appalachian National Scenic Trail *</FP>
                            <FP SOURCE="FP-2">Coltsville National Historical Park</FP>
                            <FP SOURCE="FP-2">New England National Scenic Trail</FP>
                            <FP SOURCE="FP-2">The Last Green Valley National Heritage Corridor</FP>
                            <FP SOURCE="FP-2">Upper Housantonic Valley National Heritage Area</FP>
                            <FP SOURCE="FP-2">Washington-Rochambeau Revolutionary Route National Historic Trail</FP>
                            <FP SOURCE="FP-2">Weir Farm National Historical Park</FP>
                            <HD SOURCE="HD1">Delaware</HD>
                            <P>Captain John Smith Chesapeake National Historic Trail</P>
                            <P>First State National Historical Park *</P>
                            <P>Washington-Rochambeau Revolutionary Route National Historic Trail</P>
                            <HD SOURCE="HD1">District of Columbia</HD>
                            <FP SOURCE="FP-2">Adams Memorial</FP>
                            <FP SOURCE="FP-2">Belmont-Paul Women's Equality National Monument</FP>
                            <FP SOURCE="FP-2">Captain John Smith Chesapeake National Historic Trail</FP>
                            <FP SOURCE="FP-2">Carter G. Woodson Home National Historic Site</FP>
                            <FP SOURCE="FP-2">Chesapeake and Ohio Canal National Historical Park *</FP>
                            <FP SOURCE="FP-2">Constitution Gardens</FP>
                            <FP SOURCE="FP-2">Desert Storm/Desert Shield Memorial</FP>
                            <FP SOURCE="FP-2">
                                Dwight D. Eisenhower Memorial
                                <PRTPAGE P="446"/>
                            </FP>
                            <FP SOURCE="FP-2">Ford's Theatre National Historic Site</FP>
                            <FP SOURCE="FP-2">Franklin Delano Roosevelt Memorial *</FP>
                            <FP SOURCE="FP-2">Frederick Douglass National Historic Site</FP>
                            <FP SOURCE="FP-2">George Washington Memorial Parkway</FP>
                            <FP SOURCE="FP-2">Global War on Terrorism Memorial</FP>
                            <FP SOURCE="FP-2">Korean War Veterans Memorial *</FP>
                            <FP SOURCE="FP-2">Lincoln Memorial *</FP>
                            <FP SOURCE="FP-2">Lyndon Baines Johnson Memorial Grove on the Potomac *</FP>
                            <FP SOURCE="FP-2">Martin Luther King Jr. Memorial *</FP>
                            <FP SOURCE="FP-2">Mary McLeod Bethune Council House National Historic Site</FP>
                            <FP SOURCE="FP-2">National Capital Parks—East *</FP>
                            <FP SOURCE="FP-2">National Mall and Memorial Parks</FP>
                            <FP SOURCE="FP-2">Pennsylvania Avenue National Historic Site</FP>
                            <FP SOURCE="FP-2">Potomac Heritage National Scenic Trail</FP>
                            <FP SOURCE="FP-2">Rock Creek Park</FP>
                            <FP SOURCE="FP-2">Star-Spangled Banner National Historic Trail</FP>
                            <FP SOURCE="FP-2">The White House and President's Park</FP>
                            <FP SOURCE="FP-2">Theodore Roosevelt Island *</FP>
                            <FP SOURCE="FP-2">Thomas Jefferson Memorial *</FP>
                            <FP SOURCE="FP-2">Vietnam Veterans Memorial</FP>
                            <FP SOURCE="FP-2">Washington-Rochambeau Revolutionary Route National Historic Trail</FP>
                            <FP SOURCE="FP-2">Washington Monument *</FP>
                            <FP SOURCE="FP-2">World War I Memorial</FP>
                            <FP SOURCE="FP-2">World War II Memorial *</FP>
                            <HD SOURCE="HD1">Florida</HD>
                            <FP SOURCE="FP-2">Big Cypress National Preserve *</FP>
                            <FP SOURCE="FP-2">Biscayne National Park *</FP>
                            <FP SOURCE="FP-2">Canaveral National Seashore *</FP>
                            <FP SOURCE="FP-2">Castillo de San Marcos National Monument *</FP>
                            <FP SOURCE="FP-2">De Soto National Memorial *</FP>
                            <FP SOURCE="FP-2">Dry Tortugas National Park *</FP>
                            <FP SOURCE="FP-2">Everglades National Park *</FP>
                            <FP SOURCE="FP-2">Florida National Scenic Trail</FP>
                            <FP SOURCE="FP-2">Fort Caroline National Memorial *</FP>
                            <FP SOURCE="FP-2">Fort Matanzas National Monument *</FP>
                            <FP SOURCE="FP-2">Gulf Islands National Seashore *</FP>
                            <FP SOURCE="FP-2">Gullah/Geechee Cultural Heritage Corridor</FP>
                            <FP SOURCE="FP-2">Timucuan Ecological and Historic Preserve *</FP>
                            <HD SOURCE="HD1">Georgia</HD>
                            <FP SOURCE="FP-2">Andersonville National Historic Site</FP>
                            <FP SOURCE="FP-2">Appalachian National Scenic Trail</FP>
                            <FP SOURCE="FP-2">Arabia Mountain National Heritage Area</FP>
                            <FP SOURCE="FP-2">Augusta Canal National Heritage Area</FP>
                            <FP SOURCE="FP-2">Chattahoochee River National Recreation Area</FP>
                            <FP SOURCE="FP-2">Chickamauga and Chattanooga National Military Park *</FP>
                            <FP SOURCE="FP-2">Cumberland Island National Seashore *</FP>
                            <FP SOURCE="FP-2">Fort Frederica National Monument *</FP>
                            <FP SOURCE="FP-2">Fort Pulaski National Monument *</FP>
                            <FP SOURCE="FP-2">Gullah/Geechee Cultural Heritage Corridor</FP>
                            <FP SOURCE="FP-2">Jimmy Carter National Historical Park</FP>
                            <FP SOURCE="FP-2">Kennesaw Mountain National Battlefield Park</FP>
                            <FP SOURCE="FP-2">Kettle Creek Battlefield</FP>
                            <FP SOURCE="FP-2">Martin Luther King Jr. National Historical Park</FP>
                            <FP SOURCE="FP-2">Ocmulgee Mounds National Historical Park *</FP>
                            <FP SOURCE="FP-2">Trail of Tears National Historic Trail</FP>
                            <HD SOURCE="HD1">Guam</HD>
                            <FP SOURCE="FP-2">War in the Pacific National Historical Park *</FP>
                            <HD SOURCE="HD1">Hawaii</HD>
                            <FP SOURCE="FP-2">Ala Kahakai National Historic Trail</FP>
                            <FP SOURCE="FP-2">
                                Haleakala
                                <AC T="8"/>
                                 National Park *
                            </FP>
                            <FP SOURCE="FP-2">Hawai`i Volcanoes National Park *</FP>
                            <FP SOURCE="FP-2">Honouliuli National Historic Site</FP>
                            <FP SOURCE="FP-2">Kalaupapa National Historical Park *</FP>
                            <FP SOURCE="FP-2">
                                Kaloko-Hono
                                <AC T="8"/>
                                khau National Historical Park *
                            </FP>
                            <FP SOURCE="FP-2">Pearl Harbor National Memorial *</FP>
                            <FP SOURCE="FP-2">
                                Pu`uhonua o Ho
                                <AC T="8"/>
                                naunau National Historical Park *
                            </FP>
                            <FP SOURCE="FP-2">
                                Pu`ukohola
                                <AC T="8"/>
                                 Heiau National Historic Site *
                            </FP>
                            <HD SOURCE="HD1">Idaho</HD>
                            <FP SOURCE="FP-2">California National Historic Trail</FP>
                            <FP SOURCE="FP-2">City of Rocks National Reserve</FP>
                            <FP SOURCE="FP-2">Continental Divide National Scenic Trail</FP>
                            <FP SOURCE="FP-2">Craters of the Moon National Monument and Preserve</FP>
                            <FP SOURCE="FP-2">Hagerman Fossil Beds National Monument</FP>
                            <FP SOURCE="FP-2">Lewis and Clark National Historic Trail</FP>
                            <FP SOURCE="FP-2">Minidoka National Historic Site *</FP>
                            <FP SOURCE="FP-2">Nez Perce (Nee-Me-Poo) National Historic Trail</FP>
                            <FP SOURCE="FP-2">Nez Perce National Historical Park</FP>
                            <FP SOURCE="FP-2">Oregon National Historic Trail</FP>
                            <FP SOURCE="FP-2">Pacific Northwest National Scenic Trail</FP>
                            <FP SOURCE="FP-2">Yellowstone National Park</FP>
                            <HD SOURCE="HD1">Illinois</HD>
                            <FP SOURCE="FP-2">Abraham Lincoln National Heritage Area</FP>
                            <FP SOURCE="FP-2">Chicago Portage National Historic Site</FP>
                            <FP SOURCE="FP-2">Emmett Till and Mamie Till-Mobley National Monument</FP>
                            <FP SOURCE="FP-2">Gateway Arch National Park *</FP>
                            <FP SOURCE="FP-2">Illinois and Michigan Canal National Heritage Corridor</FP>
                            <FP SOURCE="FP-2">Lewis and Clark National Historic Trail *</FP>
                            <FP SOURCE="FP-2">Lincoln Home National Historic Site</FP>
                            <FP SOURCE="FP-2">Mormon Pioneer National Historic Trail</FP>
                            <FP SOURCE="FP-2">New Philadelphia National Historic Site</FP>
                            <FP SOURCE="FP-2">Pullman National Historical Park</FP>
                            <FP SOURCE="FP-2">Ronald Reagan Boyhood Home National Historic Site</FP>
                            <FP SOURCE="FP-2">Trail of Tears National Historic Trail</FP>
                            <HD SOURCE="HD1">Indiana</HD>
                            <FP SOURCE="FP-2">George Rogers Clark National Historical Park</FP>
                            <FP SOURCE="FP-2">Indiana Dunes National Park *</FP>
                            <FP SOURCE="FP-2">Kennedy-King National Commemorative Site</FP>
                            <FP SOURCE="FP-2">Lewis and Clark National Historic Trail</FP>
                            <FP SOURCE="FP-2">Lincoln Boyhood National Memorial</FP>
                            <HD SOURCE="HD1">Iowa</HD>
                            <FP SOURCE="FP-2">America's Agricultural Heritage Partnership (Silos and Smokestacks National Heritage Area)</FP>
                            <FP SOURCE="FP-2">Effigy Mounds National Monument *</FP>
                            <FP SOURCE="FP-2">Herbert Hoover National Historic Site</FP>
                            <FP SOURCE="FP-2">Lewis and Clark National Historic Trail</FP>
                            <FP SOURCE="FP-2">
                                Mormon Pioneer National Historic Trail
                                <PRTPAGE P="447"/>
                            </FP>
                            <HD SOURCE="HD1">Kansas</HD>
                            <FP SOURCE="FP-2">Brown v. Board of Education National Historical Park</FP>
                            <FP SOURCE="FP-2">California National Historic Trail</FP>
                            <FP SOURCE="FP-2">Fort Larned National Historic Site</FP>
                            <FP SOURCE="FP-2">Fort Scott National Historic Site</FP>
                            <FP SOURCE="FP-2">Freedom's Frontier National Heritage Area</FP>
                            <FP SOURCE="FP-2">Lewis and Clark National Historic Trail</FP>
                            <FP SOURCE="FP-2">Nicodemus National Historic Site</FP>
                            <FP SOURCE="FP-2">Oregon National Historic Trail</FP>
                            <FP SOURCE="FP-2">Pony Express National Historic Trail</FP>
                            <FP SOURCE="FP-2">Quindaro Townsite</FP>
                            <FP SOURCE="FP-2">Santa Fe National Historic Trail</FP>
                            <FP SOURCE="FP-2">Tallgrass Prairie National Preserve</FP>
                            <HD SOURCE="HD1">Kentucky</HD>
                            <FP SOURCE="FP-2">Abraham Lincoln Birthplace National Historical Park</FP>
                            <FP SOURCE="FP-2">Big South Fork National River and Recreation Area</FP>
                            <FP SOURCE="FP-2">Camp Nelson National Monument *</FP>
                            <FP SOURCE="FP-2">Cumberland Gap National Historical Park</FP>
                            <FP SOURCE="FP-2">Fort Donelson National Battlefield *</FP>
                            <FP SOURCE="FP-2">Lewis and Clark National Historic Trail</FP>
                            <FP SOURCE="FP-2">Mammoth Cave National Park *</FP>
                            <FP SOURCE="FP-2">Mill Springs Battlefield National Monument *</FP>
                            <FP SOURCE="FP-2">Trail of Tears National Historic Trail</FP>
                            <HD SOURCE="HD1">Louisiana</HD>
                            <FP SOURCE="FP-2">Atchafalaya National Heritage Area</FP>
                            <FP SOURCE="FP-2">Cane River Creole National Historical Park</FP>
                            <FP SOURCE="FP-2">Cane River National Heritage Area</FP>
                            <FP SOURCE="FP-2">El Camino Real de los Tejas National Historic Trail</FP>
                            <FP SOURCE="FP-2">Jean Lafitte National Historical Park and Preserve *</FP>
                            <FP SOURCE="FP-2">Mississippi Delta National Heritage Area</FP>
                            <FP SOURCE="FP-2">New Orleans Jazz National Historical Park</FP>
                            <FP SOURCE="FP-2">Poverty Point National Monument</FP>
                            <FP SOURCE="FP-2">Vicksburg National Military Park *</FP>
                            <HD SOURCE="HD1">Maine</HD>
                            <FP SOURCE="FP-2">Acadia National Park *</FP>
                            <FP SOURCE="FP-2">Appalachian National Scenic Trail</FP>
                            <FP SOURCE="FP-2">Katahdin Woods and Waters National Monument</FP>
                            <FP SOURCE="FP-2">Saint Croix Island International Historic Site</FP>
                            <HD SOURCE="HD1">Maryland</HD>
                            <FP SOURCE="FP-2">Antietam National Battlefield</FP>
                            <FP SOURCE="FP-2">Appalachian Forest National Heritage Area</FP>
                            <FP SOURCE="FP-2">Appalachian National Scenic Trail</FP>
                            <FP SOURCE="FP-2">Assateague Island National Seashore *</FP>
                            <FP SOURCE="FP-2">Baltimore National Heritage Area</FP>
                            <FP SOURCE="FP-2">Captain John Smith Chesapeake National Historic Trail</FP>
                            <FP SOURCE="FP-2">Catoctin Mountain Park</FP>
                            <FP SOURCE="FP-2">Chesapeake and Ohio Canal National Historical Park</FP>
                            <FP SOURCE="FP-2">Clara Barton National Historic Site</FP>
                            <FP SOURCE="FP-2">Fort McHenry National Monument and Historic Shrine *</FP>
                            <FP SOURCE="FP-2">Fort Washington Park *</FP>
                            <FP SOURCE="FP-2">George Washington Memorial Parkway *</FP>
                            <FP SOURCE="FP-2">Greenbelt Park</FP>
                            <FP SOURCE="FP-2">Hampton National Historic Site</FP>
                            <FP SOURCE="FP-2">Harpers Ferry National Historical Park</FP>
                            <FP SOURCE="FP-2">Harriet Tubman Underground Railroad National Historical Park</FP>
                            <FP SOURCE="FP-2">Journey Through Hallowed Ground National Heritage Area</FP>
                            <FP SOURCE="FP-2">Monocacy National Battlefield</FP>
                            <FP SOURCE="FP-2">National Capital Parks—East *</FP>
                            <FP SOURCE="FP-2">Piscataway Park *</FP>
                            <FP SOURCE="FP-2">Potomac Heritage National Scenic Trail</FP>
                            <FP SOURCE="FP-2">Star-Spangled Banner National Historic Trail</FP>
                            <FP SOURCE="FP-2">Thomas Stone National Historic Site</FP>
                            <FP SOURCE="FP-2">Washington-Rochambeau Revolutionary Route National Historic Trail</FP>
                            <HD SOURCE="HD1">Massachusetts</HD>
                            <FP SOURCE="FP-2">Adams National Historical Park</FP>
                            <FP SOURCE="FP-2">Appalachian National Scenic Trail</FP>
                            <FP SOURCE="FP-2">Boston African American National Historic Site *</FP>
                            <FP SOURCE="FP-2">Boston Harbor Islands National Recreation Area *</FP>
                            <FP SOURCE="FP-2">Boston National Historical Park *</FP>
                            <FP SOURCE="FP-2">Cape Cod National Seashore *</FP>
                            <FP SOURCE="FP-2">Essex National Heritage Area</FP>
                            <FP SOURCE="FP-2">Frederick Law Olmsted National Historic Site</FP>
                            <FP SOURCE="FP-2">Freedom's Way National Heritage Area</FP>
                            <FP SOURCE="FP-2">John Fitzgerald Kennedy National Historic Site</FP>
                            <FP SOURCE="FP-2">John H. Chafee Blackstone River Valley National Heritage Corridor</FP>
                            <FP SOURCE="FP-2">Longfellow—Washington's Headquarters National Historic Site</FP>
                            <FP SOURCE="FP-2">Lowell National Historical Park</FP>
                            <FP SOURCE="FP-2">Minute Man National Historical Park</FP>
                            <FP SOURCE="FP-2">New Bedford Whaling National Historical Park *</FP>
                            <FP SOURCE="FP-2">New England National Scenic Trail</FP>
                            <FP SOURCE="FP-2">Salem Maritime National Historic Site *</FP>
                            <FP SOURCE="FP-2">Saugus Iron Works National Historic Site *</FP>
                            <FP SOURCE="FP-2">Springfield Armory National Historic Site</FP>
                            <FP SOURCE="FP-2">The Last Green Valley National Heritage Corridor</FP>
                            <FP SOURCE="FP-2">Upper Housantonic Valley National Heritage Area</FP>
                            <FP SOURCE="FP-2">Washington-Rochambeau Revolutionary Route National Historic Trail</FP>
                            <HD SOURCE="HD1">Michigan</HD>
                            <FP SOURCE="FP-2">Father Marquette National Memorial</FP>
                            <FP SOURCE="FP-2">Isle Royale National Park *</FP>
                            <FP SOURCE="FP-2">Keweenaw National Historical Park *</FP>
                            <FP SOURCE="FP-2">MotorCities National Heritage Area</FP>
                            <FP SOURCE="FP-2">North Country National Scenic Trail</FP>
                            <FP SOURCE="FP-2">Pictured Rocks National Lakeshore *</FP>
                            <FP SOURCE="FP-2">River Raisin National Battlefield Park *</FP>
                            <FP SOURCE="FP-2">Sleeping Bear Dunes National Lakeshore *</FP>
                            <HD SOURCE="HD1">Minnesota</HD>
                            <FP SOURCE="FP-2">Grand Portage National Monument *</FP>
                            <FP SOURCE="FP-2">
                                Mississippi National River and Recreation Areas *
                                <PRTPAGE P="448"/>
                            </FP>
                            <FP SOURCE="FP-2">North Country National Scenic Trail</FP>
                            <FP SOURCE="FP-2">Pipestone National Monument</FP>
                            <FP SOURCE="FP-2">Saint Croix National Scenic Riverway</FP>
                            <FP SOURCE="FP-2">Voyageurs National Park *</FP>
                            <HD SOURCE="HD1">Mississippi</HD>
                            <FP SOURCE="FP-2">Brices Cross Roads National Battlefield Site</FP>
                            <FP SOURCE="FP-2">Emmett Till and Mamie Till-Mobley National Monument</FP>
                            <FP SOURCE="FP-2">Gulf Islands National Seashore</FP>
                            <FP SOURCE="FP-2">Medgar and Myrlie Evers Home National Monument</FP>
                            <FP SOURCE="FP-2">Mississippi Delta National Heritage Area</FP>
                            <FP SOURCE="FP-2">Mississippi Gulf Coast National Heritage Area</FP>
                            <FP SOURCE="FP-2">Mississippi Hills National Heritage Area</FP>
                            <FP SOURCE="FP-2">Natchez National Historical Park *</FP>
                            <FP SOURCE="FP-2">Natchez Trace National Scenic Trail</FP>
                            <FP SOURCE="FP-2">Natchez Trace Parkway</FP>
                            <FP SOURCE="FP-2">Tupelo National Battlefield</FP>
                            <FP SOURCE="FP-2">Vicksburg National Military Park</FP>
                            <HD SOURCE="HD1">Missouri</HD>
                            <FP SOURCE="FP-2">Butterfield Overland National Historic Trail</FP>
                            <FP SOURCE="FP-2">California National Historic Trail</FP>
                            <FP SOURCE="FP-2">Freedom's Frontier National Heritage Area</FP>
                            <FP SOURCE="FP-2">Gateway Arch National Park</FP>
                            <FP SOURCE="FP-2">George Washington Carver National Monument</FP>
                            <FP SOURCE="FP-2">Harry S Truman National Historic Site</FP>
                            <FP SOURCE="FP-2">Lewis and Clark National Historic Trail</FP>
                            <FP SOURCE="FP-2">Oregon National Historic Trail</FP>
                            <FP SOURCE="FP-2">Ozark National Scenic Riverways</FP>
                            <FP SOURCE="FP-2">Pony Express National Historic Trail</FP>
                            <FP SOURCE="FP-2">Santa Fe National Historic Trail</FP>
                            <FP SOURCE="FP-2">Ste. Genevieve National Historical Park</FP>
                            <FP SOURCE="FP-2">Trail of Tears National Historic Trail</FP>
                            <FP SOURCE="FP-2">Ulysses S. Grant National Historic Site</FP>
                            <FP SOURCE="FP-2">Wilson's Creek National Battlefield</FP>
                            <HD SOURCE="HD1">Montana</HD>
                            <FP SOURCE="FP-2">Big Hole National Battlefield</FP>
                            <FP SOURCE="FP-2">Bighorn Canyon National Recreation Area</FP>
                            <FP SOURCE="FP-2">Continental Divide National Scenic Trail</FP>
                            <FP SOURCE="FP-2">Fort Union Trading Post National Historic Site</FP>
                            <FP SOURCE="FP-2">Glacier National Park</FP>
                            <FP SOURCE="FP-2">Grant-Kohrs Ranch National Historic Site</FP>
                            <FP SOURCE="FP-2">Lewis and Clark National Historic Trail</FP>
                            <FP SOURCE="FP-2">Little Bighorn Battlefield National Monument</FP>
                            <FP SOURCE="FP-2">Nez Perce (Nee-Me-Poo) National Historic Trail</FP>
                            <FP SOURCE="FP-2">Nez Perce National Historical Park</FP>
                            <FP SOURCE="FP-2">Pacific Northwest National Scenic Trail</FP>
                            <FP SOURCE="FP-2">Yellowstone National Park</FP>
                            <HD SOURCE="HD1">Nebraska</HD>
                            <FP SOURCE="FP-2">Agate Fossil Beds National Monument</FP>
                            <FP SOURCE="FP-2">California National Historic Trail</FP>
                            <FP SOURCE="FP-2">Chimney Rock National Historic Site</FP>
                            <FP SOURCE="FP-2">Homestead National Historical Park</FP>
                            <FP SOURCE="FP-2">Lewis and Clark National Historic Trail</FP>
                            <FP SOURCE="FP-2">Missouri National Recreational River *</FP>
                            <FP SOURCE="FP-2">Mormon Pioneer National Historic Trail</FP>
                            <FP SOURCE="FP-2">Niobrara National Scenic River</FP>
                            <FP SOURCE="FP-2">Oregon National Historic Trail</FP>
                            <FP SOURCE="FP-2">Pony Express National Historic Trail</FP>
                            <FP SOURCE="FP-2">Scotts Bluff National Monument</FP>
                            <HD SOURCE="HD1">Nevada</HD>
                            <FP SOURCE="FP-2">California National Historic Trail</FP>
                            <FP SOURCE="FP-2">Death Valley National Park</FP>
                            <FP SOURCE="FP-2">Great Basin National Heritage Route</FP>
                            <FP SOURCE="FP-2">Great Basin National Park</FP>
                            <FP SOURCE="FP-2">Lake Mead National Recreation Area</FP>
                            <FP SOURCE="FP-2">Old Spanish National Historic Trail</FP>
                            <FP SOURCE="FP-2">Pony Express National Historic Trail</FP>
                            <FP SOURCE="FP-2">Tule Springs Fossil Beds National Monument</FP>
                            <HD SOURCE="HD1">New Hampshire</HD>
                            <FP SOURCE="FP-2">Appalachian National Scenic Trail</FP>
                            <FP SOURCE="FP-2">Freedom's Way National Heritage Area</FP>
                            <FP SOURCE="FP-2">Saint-Gaudens National Historical Park</FP>
                            <HD SOURCE="HD1">New Jersey</HD>
                            <FP SOURCE="FP-2">Appalachian National Scenic Trail</FP>
                            <FP SOURCE="FP-2">Crossroads of the American Revolution National Heritage Area</FP>
                            <FP SOURCE="FP-2">Delaware Water Gap National Recreation Area</FP>
                            <FP SOURCE="FP-2">Gateway National Recreation Area *</FP>
                            <FP SOURCE="FP-2">Great Egg Harbor National Scenic and Recreational River</FP>
                            <FP SOURCE="FP-2">Middle Delaware National Scenic River</FP>
                            <FP SOURCE="FP-2">Morristown National Historical Park</FP>
                            <FP SOURCE="FP-2">Paterson Great Falls National Historical Park</FP>
                            <FP SOURCE="FP-2">Pinelands National Reserve</FP>
                            <FP SOURCE="FP-2">Statue of Liberty National Monument *</FP>
                            <FP SOURCE="FP-2">Thomas Edison National Historical Park</FP>
                            <FP SOURCE="FP-2">Washington-Rochambeau Revolutionary Route National Historic Trail</FP>
                            <HD SOURCE="HD1">New Mexico</HD>
                            <FP SOURCE="FP-2">Aztec Ruins National Monument</FP>
                            <FP SOURCE="FP-2">Bandelier National Monument</FP>
                            <FP SOURCE="FP-2">Butterfield Overland National Historic Trail</FP>
                            <FP SOURCE="FP-2">Capulin Volcano National Monument</FP>
                            <FP SOURCE="FP-2">Carlsbad Caverns National Park</FP>
                            <FP SOURCE="FP-2">Chaco Culture National Historical Park</FP>
                            <FP SOURCE="FP-2">Continental Divide National Scenic Trail</FP>
                            <FP SOURCE="FP-2">El Camino de Tierra Adentro National Historic Trail</FP>
                            <FP SOURCE="FP-2">El Malpais National Monument</FP>
                            <FP SOURCE="FP-2">El Morro National Monument</FP>
                            <FP SOURCE="FP-2">Fort Union National Monument</FP>
                            <FP SOURCE="FP-2">Gila Cliff Dwellings National Monument</FP>
                            <FP SOURCE="FP-2">Manhattan Project National Historical Park</FP>
                            <FP SOURCE="FP-2">Northern Rio Grande National Heritage Area</FP>
                            <FP SOURCE="FP-2">Old Spanish National Historic Trail</FP>
                            <FP SOURCE="FP-2">Pecos National Historical Park</FP>
                            <FP SOURCE="FP-2">Petroglyph National Monument</FP>
                            <FP SOURCE="FP-2">Salinas Pueblo Missions National Monument</FP>
                            <FP SOURCE="FP-2">Santa Fe National Historic Trail</FP>
                            <FP SOURCE="FP-2">Valles Caldera National Preserve</FP>
                            <FP SOURCE="FP-2">White Sands National Park</FP>
                            <HD SOURCE="HD1">New York</HD>
                            <FP SOURCE="FP-2">African Burial Ground National Monument</FP>
                            <FP SOURCE="FP-2">
                                Appalachian National Scenic Trail
                                <PRTPAGE P="449"/>
                            </FP>
                            <FP SOURCE="FP-2">Captain John Smith Chesapeake National Historic Trail</FP>
                            <FP SOURCE="FP-2">Castle Clinton National Monument *</FP>
                            <FP SOURCE="FP-2">Champlain Valley National Heritage Partnership</FP>
                            <FP SOURCE="FP-2">Eleanor Roosevelt National Historic Site</FP>
                            <FP SOURCE="FP-2">Erie Canalway National Heritage Corridor</FP>
                            <FP SOURCE="FP-2">Federal Hall National Memorial</FP>
                            <FP SOURCE="FP-2">Fire Island National Seashore *</FP>
                            <FP SOURCE="FP-2">Fort Stanwix National Monument</FP>
                            <FP SOURCE="FP-2">Gateway National Recreation Area *</FP>
                            <FP SOURCE="FP-2">General Grant National Memorial</FP>
                            <FP SOURCE="FP-2">Governors Island National Monument *</FP>
                            <FP SOURCE="FP-2">Hamilton Grange National Memorial</FP>
                            <FP SOURCE="FP-2">Harriet Tubman National Historical Park</FP>
                            <FP SOURCE="FP-2">Home of Franklin D. Roosevelt National Historic Site *</FP>
                            <FP SOURCE="FP-2">Kate Mullany National Historic Site</FP>
                            <FP SOURCE="FP-2">Lower East Side Tenement National Historic Site</FP>
                            <FP SOURCE="FP-2">Martin Van Buren National Historic Site</FP>
                            <FP SOURCE="FP-2">Maurice D. Hinchey Hudson River National Heritage Area</FP>
                            <FP SOURCE="FP-2">Middle Delaware National Scenic River</FP>
                            <FP SOURCE="FP-2">Niagara Falls National Heritage Area</FP>
                            <FP SOURCE="FP-2">North Country National Scenic Trail</FP>
                            <FP SOURCE="FP-2">Sagamore Hill National Historic Site *</FP>
                            <FP SOURCE="FP-2">Saint Paul's Church National Historic Site</FP>
                            <FP SOURCE="FP-2">Saratoga National Historical Park *</FP>
                            <FP SOURCE="FP-2">Statue of Liberty National Monument *</FP>
                            <FP SOURCE="FP-2">Stonewall National Monument</FP>
                            <FP SOURCE="FP-2">Theodore Roosevelt Birthplace National Historic Site</FP>
                            <FP SOURCE="FP-2">Theodore Roosevelt Inaugural National Historic Site</FP>
                            <FP SOURCE="FP-2">Thomas Cole National Historic Site</FP>
                            <FP SOURCE="FP-2">Upper Delaware Scenic and Recreational River</FP>
                            <FP SOURCE="FP-2">Vanderbilt Mansion National Historic Site *</FP>
                            <FP SOURCE="FP-2">Washington-Rochambeau Revolutionary Route National Historic Trail</FP>
                            <FP SOURCE="FP-2">Women's Rights National Historical Park *</FP>
                            <HD SOURCE="HD1">North Carolina</HD>
                            <FP SOURCE="FP-2">Appalachian National Scenic Trail</FP>
                            <FP SOURCE="FP-2">Blue Ridge National Heritage Area</FP>
                            <FP SOURCE="FP-2">Blue Ridge Parkway</FP>
                            <FP SOURCE="FP-2">Cape Hatteras National Seashore *</FP>
                            <FP SOURCE="FP-2">Cape Lookout National Seashore *</FP>
                            <FP SOURCE="FP-2">Carl Sandburg Home National Historic Site</FP>
                            <FP SOURCE="FP-2">Fort Raleigh National Historic Site *</FP>
                            <FP SOURCE="FP-2">Great Smoky Mountains National Park</FP>
                            <FP SOURCE="FP-2">Guilford Courthouse National Military Park</FP>
                            <FP SOURCE="FP-2">Gullah/Geechee Cultural Heritage Corridor</FP>
                            <FP SOURCE="FP-2">Moores Creek National Battlefield</FP>
                            <FP SOURCE="FP-2">Overmountain Victory National Historic Trail</FP>
                            <FP SOURCE="FP-2">Trail of Tears National Historic Trail</FP>
                            <FP SOURCE="FP-2">Wright Brothers National Memorial</FP>
                            <HD SOURCE="HD1">North Dakota</HD>
                            <FP SOURCE="FP-2">Fort Union Trading Post National Historic Site</FP>
                            <FP SOURCE="FP-2">International Peace Garden</FP>
                            <FP SOURCE="FP-2">Knife River Indian Villages National Historic Site</FP>
                            <FP SOURCE="FP-2">Lewis and Clark National Historic Trail</FP>
                            <FP SOURCE="FP-2">North Country National Scenic Trail</FP>
                            <FP SOURCE="FP-2">Northern Plains National Heritage Area</FP>
                            <FP SOURCE="FP-2">Theodore Roosevelt National Park</FP>
                            <HD SOURCE="HD1">Northern Mariana Islands</HD>
                            <FP SOURCE="FP-2">American Memorial Park *</FP>
                            <HD SOURCE="HD1">Ohio</HD>
                            <FP SOURCE="FP-2">Charles Young Buffalo Soldiers National Monument</FP>
                            <FP SOURCE="FP-2">Cuyahoga Valley National Park</FP>
                            <FP SOURCE="FP-2">Dayton Aviation Heritage National Historical Park</FP>
                            <FP SOURCE="FP-2">Fallen Timbers Battlefield and Fort Miamis National Historic Site</FP>
                            <FP SOURCE="FP-2">First Ladies National Historic Site</FP>
                            <FP SOURCE="FP-2">Hopewell Culture National Historical Park</FP>
                            <FP SOURCE="FP-2">James A. Garfield National Historic Site</FP>
                            <FP SOURCE="FP-2">Lewis and Clark National Historic Trail</FP>
                            <FP SOURCE="FP-2">National Aviation National Heritage Area</FP>
                            <FP SOURCE="FP-2">North Country National Scenic Trail</FP>
                            <FP SOURCE="FP-2">Ohio and Erie National Heritage Canalway</FP>
                            <FP SOURCE="FP-2">Perry's Victory and International Peace Memorial *</FP>
                            <FP SOURCE="FP-2">William Howard Taft National Historic Site</FP>
                            <HD SOURCE="HD1">Oklahoma</HD>
                            <FP SOURCE="FP-2">Butterfield Overland National Historic Trail</FP>
                            <FP SOURCE="FP-2">Chickasaw National Recreation Area</FP>
                            <FP SOURCE="FP-2">Fort Smith National Historic Site</FP>
                            <FP SOURCE="FP-2">Oklahoma City National Memorial</FP>
                            <FP SOURCE="FP-2">Santa Fe National Historic Trail</FP>
                            <FP SOURCE="FP-2">Trail of Tears National Historic Trail</FP>
                            <FP SOURCE="FP-2">Washita Battlefield National Historic Site</FP>
                            <HD SOURCE="HD1">Oregon</HD>
                            <FP SOURCE="FP-2">California National Historic Trail</FP>
                            <FP SOURCE="FP-2">Crater Lake National Park</FP>
                            <FP SOURCE="FP-2">John Day Fossil Beds National Monument</FP>
                            <FP SOURCE="FP-2">Lewis and Clark National Historic Trail</FP>
                            <FP SOURCE="FP-2">Lewis and Clark National Historical Park *</FP>
                            <FP SOURCE="FP-2">Nez Perce (Nee-Me-Poo) National Historic Trail</FP>
                            <FP SOURCE="FP-2">Nez Perce National Historical Park</FP>
                            <FP SOURCE="FP-2">Oregon Caves National Monument and Preserve</FP>
                            <FP SOURCE="FP-2">Oregon National Historic Trail</FP>
                            <FP SOURCE="FP-2">Pacific Crest National Scenic Trail</FP>
                            <HD SOURCE="HD1">Pennsylvania</HD>
                            <FP SOURCE="FP-2">Allegheny Portage Railroad National Historic Site</FP>
                            <FP SOURCE="FP-2">Appalachian National Scenic Trail</FP>
                            <FP SOURCE="FP-2">Benjamin Franklin National Memorial</FP>
                            <FP SOURCE="FP-2">Captain John Smith Chesapeake National Historic Trail</FP>
                            <FP SOURCE="FP-2">Delaware and Lehigh National Heritage Corridor</FP>
                            <FP SOURCE="FP-2">Delaware Water Gap National Recreation Area</FP>
                            <FP SOURCE="FP-2">Edgar Allan Poe National Historic Site</FP>
                            <FP SOURCE="FP-2">Eisenhower National Historic Site</FP>
                            <FP SOURCE="FP-2">Flight 93 National Memorial</FP>
                            <FP SOURCE="FP-2">Fort Necessity National Battlefield</FP>
                            <FP SOURCE="FP-2">
                                Friendship Hill National Historic Site *
                                <PRTPAGE P="450"/>
                            </FP>
                            <FP SOURCE="FP-2">Gettysburg National Military Park</FP>
                            <FP SOURCE="FP-2">Gloria Dei (Old Swedes') Church National Historic Site</FP>
                            <FP SOURCE="FP-2">Hopewell Furnace National Historic Site</FP>
                            <FP SOURCE="FP-2">Independence National Historical Park *</FP>
                            <FP SOURCE="FP-2">Johnstown Flood National Memorial</FP>
                            <FP SOURCE="FP-2">Journey Through Hallowed Ground National Heritage Area</FP>
                            <FP SOURCE="FP-2">Lackawanna Valley National Heritage Area</FP>
                            <FP SOURCE="FP-2">Lewis and Clark National Historic Trail</FP>
                            <FP SOURCE="FP-2">Middle Delaware National Scenic River</FP>
                            <FP SOURCE="FP-2">North Country National Scenic Trail</FP>
                            <FP SOURCE="FP-2">Oil Region National Heritage Area</FP>
                            <FP SOURCE="FP-2">Potomac Heritage National Scenic Trail</FP>
                            <FP SOURCE="FP-2">Rivers of Steel National Heritage Area</FP>
                            <FP SOURCE="FP-2">Schuylkill River Valley National Heritage Area</FP>
                            <FP SOURCE="FP-2">Southwestern Pennsylvania Industrial Heritage Route (Paths of Progress National Heritage Route)</FP>
                            <FP SOURCE="FP-2">Steamtown National Historic Site</FP>
                            <FP SOURCE="FP-2">Susquehanna National Heritage Area</FP>
                            <FP SOURCE="FP-2">Thaddeus Kosciuszko National Memorial</FP>
                            <FP SOURCE="FP-2">Upper Delaware Scenic and Recreational River</FP>
                            <FP SOURCE="FP-2">Valley Forge National Historical Park</FP>
                            <FP SOURCE="FP-2">Washington-Rochambeau Revolutionary Route National Historic Trail</FP>
                            <HD SOURCE="HD1">Puerto Rico</HD>
                            <FP SOURCE="FP-2">San Juan National Historic Site *</FP>
                            <HD SOURCE="HD1">Rhode Island</HD>
                            <FP SOURCE="FP-2">Blackstone River Valley National Historical Park</FP>
                            <FP SOURCE="FP-2">John H. Chafee Blackstone River Valley National Heritage Corridor</FP>
                            <FP SOURCE="FP-2">Roger Williams National Memorial</FP>
                            <FP SOURCE="FP-2">Touro Synagogue National Historic Site</FP>
                            <FP SOURCE="FP-2">Washington-Rochambeau Revolutionary Route National Historic Trail</FP>
                            <HD SOURCE="HD1">South Carolina</HD>
                            <FP SOURCE="FP-2">Charles Pinckney National Historic Site</FP>
                            <FP SOURCE="FP-2">Congaree National Park *</FP>
                            <FP SOURCE="FP-2">Cowpens National Battlefield</FP>
                            <FP SOURCE="FP-2">Eutaw Springs Battlefield</FP>
                            <FP SOURCE="FP-2">Fort Sumter and Fort Moultrie National Historical Park *</FP>
                            <FP SOURCE="FP-2">Gullah/Geechee Cultural Heritage Co</FP>
                            <FP SOURCE="FP-2">Historic Camden Revolutionary War Site</FP>
                            <FP SOURCE="FP-2">Kings Mountain National Military Park</FP>
                            <FP SOURCE="FP-2">Ninety Six National Historic Site</FP>
                            <FP SOURCE="FP-2">Overmountain Victory National Historic Trail</FP>
                            <FP SOURCE="FP-2">Reconstruction Era National Historical Park *</FP>
                            <FP SOURCE="FP-2">South Carolina National Heritage Corridor</FP>
                            <HD SOURCE="HD1">South Dakota</HD>
                            <FP SOURCE="FP-2">Badlands National Park</FP>
                            <FP SOURCE="FP-2">Jewel Cave National Monument</FP>
                            <FP SOURCE="FP-2">Lewis and Clark National Historic Trail</FP>
                            <FP SOURCE="FP-2">Minuteman Missile National Historic Site</FP>
                            <FP SOURCE="FP-2">Missouri National Recreational River</FP>
                            <FP SOURCE="FP-2">Mount Rushmore National Memorial</FP>
                            <FP SOURCE="FP-2">Wind Cave National Park</FP>
                            <HD SOURCE="HD1">Tennessee</HD>
                            <FP SOURCE="FP-2">Andrew Johnson National Historic Site</FP>
                            <FP SOURCE="FP-2">Appalachian National Scenic Trail</FP>
                            <FP SOURCE="FP-2">Big South Fork National River and Recreation Area</FP>
                            <FP SOURCE="FP-2">Chickamauga and Chattanooga National Military Park</FP>
                            <FP SOURCE="FP-2">Cumberland Gap National Historical Park</FP>
                            <FP SOURCE="FP-2">Fort Donelson National Battlefield</FP>
                            <FP SOURCE="FP-2">Great Smoky Mountains National Park</FP>
                            <FP SOURCE="FP-2">Manhattan Project National Historical Park *</FP>
                            <FP SOURCE="FP-2">Natchez Trace National Scenic Trail</FP>
                            <FP SOURCE="FP-2">Overmountain Victory National Historic Trail</FP>
                            <FP SOURCE="FP-2">Parkers Crossroads Battlefield</FP>
                            <FP SOURCE="FP-2">Shiloh National Military Park *</FP>
                            <FP SOURCE="FP-2">Stones River National Battlefield</FP>
                            <FP SOURCE="FP-2">Tennessee Civil War National Heritage Area</FP>
                            <FP SOURCE="FP-2">Trail of Tears National Historic Trail</FP>
                            <HD SOURCE="HD1">Texas</HD>
                            <FP SOURCE="FP-2">Alibates Flint Quarries National Monument</FP>
                            <FP SOURCE="FP-2">Amistad National Recreation Area *</FP>
                            <FP SOURCE="FP-2">Big Bend National Park</FP>
                            <FP SOURCE="FP-2">Big Thicket National Preserve</FP>
                            <FP SOURCE="FP-2">Blackwell School National Historic Site</FP>
                            <FP SOURCE="FP-2">Butterfield Overland National Historic Trail</FP>
                            <FP SOURCE="FP-2">Chamizal National Memorial</FP>
                            <FP SOURCE="FP-2">El Camino de Tierra Adentro National Historic Trail</FP>
                            <FP SOURCE="FP-2">El Camino Real de los Tejas National Historic Trail</FP>
                            <FP SOURCE="FP-2">Fort Davis National Historic Site</FP>
                            <FP SOURCE="FP-2">Guadalupe Mountains National Park</FP>
                            <FP SOURCE="FP-2">Lake Meredith National Recreation Area</FP>
                            <FP SOURCE="FP-2">Lyndon B. Johnson National Historical Park</FP>
                            <FP SOURCE="FP-2">Padre Island National Seashore *</FP>
                            <FP SOURCE="FP-2">Palo Alto Battlefield National Historical Park</FP>
                            <FP SOURCE="FP-2">Rio Grande Wild and Scenic River</FP>
                            <FP SOURCE="FP-2">San Antonio Missions National Historical Park</FP>
                            <FP SOURCE="FP-2">Waco Mammoth National Monument</FP>
                            <HD SOURCE="HD1">Utah</HD>
                            <FP SOURCE="FP-2">Arches National Park</FP>
                            <FP SOURCE="FP-2">Bryce Canyon National Park</FP>
                            <FP SOURCE="FP-2">California National Historic Trail</FP>
                            <FP SOURCE="FP-2">Canyonlands National Park</FP>
                            <FP SOURCE="FP-2">Capitol Reef National Park</FP>
                            <FP SOURCE="FP-2">Cedar Breaks National Monument</FP>
                            <FP SOURCE="FP-2">Dinosaur National Monument</FP>
                            <FP SOURCE="FP-2">Glen Canyon National Recreation Area</FP>
                            <FP SOURCE="FP-2">Golden Spike National Historical Park</FP>
                            <FP SOURCE="FP-2">Great Basin National Heritage Route</FP>
                            <FP SOURCE="FP-2">Hovenweep National Monument</FP>
                            <FP SOURCE="FP-2">Mormon Pioneer National Heritage Area</FP>
                            <FP SOURCE="FP-2">Mormon Pioneer National Historic Trail</FP>
                            <FP SOURCE="FP-2">Natural Bridges National Monument</FP>
                            <FP SOURCE="FP-2">Old Spanish National Historic Trail</FP>
                            <FP SOURCE="FP-2">Pony Express National Historic Trail</FP>
                            <FP SOURCE="FP-2">Rainbow Bridge National Monument</FP>
                            <FP SOURCE="FP-2">
                                Timpanogos Cave National Monument
                                <PRTPAGE P="451"/>
                            </FP>
                            <FP SOURCE="FP-2">Zion National Park</FP>
                            <HD SOURCE="HD1">Vermont</HD>
                            <FP SOURCE="FP-2">Appalachian National Scenic Trail</FP>
                            <FP SOURCE="FP-2">Champlain Valley National Heritage Partnership</FP>
                            <FP SOURCE="FP-2">Marsh-Billings-Rockefeller National Historical Park</FP>
                            <FP SOURCE="FP-2">North Country National Scenic Trail</FP>
                            <HD SOURCE="HD1">Virgin Islands</HD>
                            <FP SOURCE="FP-2">Buck Island Reef National Monument *</FP>
                            <FP SOURCE="FP-2">Christiansted National Historic Site *</FP>
                            <FP SOURCE="FP-2">Salt River Bay National Historical Park and Ecological Preserve *</FP>
                            <FP SOURCE="FP-2">Virgin Islands Coral Reef National Monument *</FP>
                            <FP SOURCE="FP-2">Virgin Islands National Park *</FP>
                            <HD SOURCE="HD1">Virginia</HD>
                            <FP SOURCE="FP-2">Appalachian National Scenic Trail</FP>
                            <FP SOURCE="FP-2">Appomattox Court House National Historical Park</FP>
                            <FP SOURCE="FP-2">Arlington House, The Robert E. Lee Memorial</FP>
                            <FP SOURCE="FP-2">Assateague Island National Seashore</FP>
                            <FP SOURCE="FP-2">Blue Ridge Parkway</FP>
                            <FP SOURCE="FP-2">Booker T. Washington National Monument</FP>
                            <FP SOURCE="FP-2">Captain John Smith Chesapeake National Historic Trail</FP>
                            <FP SOURCE="FP-2">Cedar Creek and Belle Grove National Historical Park</FP>
                            <FP SOURCE="FP-2">Colonial National Historical Park *</FP>
                            <FP SOURCE="FP-2">Cumberland Gap National Historical Park</FP>
                            <FP SOURCE="FP-2">Fort Monroe National Monument *</FP>
                            <FP SOURCE="FP-2">Fredericksburg and Spotsylvania County Battlefields Memorial National Military Park *</FP>
                            <FP SOURCE="FP-2">George Washington Birthplace National Monument *</FP>
                            <FP SOURCE="FP-2">George Washington Memorial Parkway</FP>
                            <FP SOURCE="FP-2">Green Springs National Historic Landmark District</FP>
                            <FP SOURCE="FP-2">Harpers Ferry National Historical Park</FP>
                            <FP SOURCE="FP-2">Jamestown National Historic Site</FP>
                            <FP SOURCE="FP-2">Journey Through Hallowed Ground National Heritage Area</FP>
                            <FP SOURCE="FP-2">Maggie L. Walker National Historic Site</FP>
                            <FP SOURCE="FP-2">Manassas National Battlefield Park</FP>
                            <FP SOURCE="FP-2">Natural Bridge State Park</FP>
                            <FP SOURCE="FP-2">Overmountain Victory National Historic Trail</FP>
                            <FP SOURCE="FP-2">Petersburg National Battlefield *</FP>
                            <FP SOURCE="FP-2">Potomac Heritage National Scenic Trail</FP>
                            <FP SOURCE="FP-2">Prince William Forest Park</FP>
                            <FP SOURCE="FP-2">Red Hill Patrick Henry National Memorial</FP>
                            <FP SOURCE="FP-2">Richmond National Battlefield Park *</FP>
                            <FP SOURCE="FP-2">Shenandoah National Park</FP>
                            <FP SOURCE="FP-2">Shenandoah Valley Battlefields National Historic District</FP>
                            <FP SOURCE="FP-2">Star-Spangled Banner National Historic Trail</FP>
                            <FP SOURCE="FP-2">Washington-Rochambeau Revolutionary Route National Historic Trail</FP>
                            <FP SOURCE="FP-2">Wolf Trap National Park for the Performing Arts</FP>
                            <HD SOURCE="HD1">Washington</HD>
                            <FP SOURCE="FP-2">Ebey's Landing National Historical Reserve *</FP>
                            <FP SOURCE="FP-2">Fort Vancouver National Historic Site *</FP>
                            <FP SOURCE="FP-2">Klondike Gold Rush National Historical Park</FP>
                            <FP SOURCE="FP-2">Lake Chelan National Recreation Area</FP>
                            <FP SOURCE="FP-2">Lake Roosevelt National Recreation Area *</FP>
                            <FP SOURCE="FP-2">Lewis and Clark National Historic Trail</FP>
                            <FP SOURCE="FP-2">Lewis and Clark National Historical Park</FP>
                            <FP SOURCE="FP-2">Manhattan Project National Historical Park</FP>
                            <FP SOURCE="FP-2">Maritime Washington National Heritage Area</FP>
                            <FP SOURCE="FP-2">Mount Rainier National Park</FP>
                            <FP SOURCE="FP-2">Mountains to Sound Greenway National Heritage Area</FP>
                            <FP SOURCE="FP-2">Nez Perce National Historical Park</FP>
                            <FP SOURCE="FP-2">North Cascades National Park</FP>
                            <FP SOURCE="FP-2">Olympic National Park *</FP>
                            <FP SOURCE="FP-2">Oregon National Historic Trail</FP>
                            <FP SOURCE="FP-2">Pacific Crest National Scenic Trail</FP>
                            <FP SOURCE="FP-2">Pacific Northwest National Scenic Trail</FP>
                            <FP SOURCE="FP-2">Ross Lake National Recreation Area</FP>
                            <FP SOURCE="FP-2">San Juan Island National Historical Park *</FP>
                            <FP SOURCE="FP-2">Whitman Mission National Historic Site</FP>
                            <FP SOURCE="FP-2">Wing Luke Museum of the Asian Pacific American Experience</FP>
                            <HD SOURCE="HD1">West Virginia</HD>
                            <FP SOURCE="FP-2">Appalachian Forest National Heritage Area</FP>
                            <FP SOURCE="FP-2">Appalachian National Scenic Trail</FP>
                            <FP SOURCE="FP-2">Bluestone National Scenic River</FP>
                            <FP SOURCE="FP-2">Chesapeake and Ohio Canal National Historical Park</FP>
                            <FP SOURCE="FP-2">Gauley River National Recreation Area</FP>
                            <FP SOURCE="FP-2">Harpers Ferry National Historical Park</FP>
                            <FP SOURCE="FP-2">Lewis and Clark National Historic Trail</FP>
                            <FP SOURCE="FP-2">National Coal National Heritage Area</FP>
                            <FP SOURCE="FP-2">New River Gorge National Park and Preserve</FP>
                            <FP SOURCE="FP-2">Wheeling National Heritage Area</FP>
                            <HD SOURCE="HD1">Wisconsin</HD>
                            <FP SOURCE="FP-2">Apostle Islands National Lakeshore *</FP>
                            <FP SOURCE="FP-2">Ice Age National Scenic Trail</FP>
                            <FP SOURCE="FP-2">Ice Age National Scientific Reserve</FP>
                            <FP SOURCE="FP-2">North Country National Scenic Trail</FP>
                            <FP SOURCE="FP-2">Saint Croix National Scenic Riverway</FP>
                            <HD SOURCE="HD1">Wyoming</HD>
                            <FP SOURCE="FP-2">Bighorn Canyon National Recreation Area</FP>
                            <FP SOURCE="FP-2">California National Historic Trail</FP>
                            <FP SOURCE="FP-2">Continental Divide National Scenic Trail</FP>
                            <FP SOURCE="FP-2">Devils Tower National Monument</FP>
                            <FP SOURCE="FP-2">Fort Laramie National Historic Site</FP>
                            <FP SOURCE="FP-2">Fossil Butte National Monument</FP>
                            <FP SOURCE="FP-2">Grand Teton National Park</FP>
                            <FP SOURCE="FP-2">John D. Rockefeller Jr. Memorial Parkway</FP>
                            <FP SOURCE="FP-2">Mormon Pioneer National Historic Trail</FP>
                            <FP SOURCE="FP-2">Nez Perce (Nee-Me-Poo) National Historic Trail</FP>
                            <FP SOURCE="FP-2">Oregon National Historic Trail</FP>
                            <FP SOURCE="FP-2">Pony Express National Historic Trail</FP>
                            <FP SOURCE="FP-2">
                                Yellowstone National Park
                                <PRTPAGE P="452"/>
                            </FP>
                            <HD SOURCE="HD1">A.4 National Wildlife Refuges</HD>
                            <HD SOURCE="HD1">Alabama</HD>
                            <FP SOURCE="FP-2">Bon Secour National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Cahaba River National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Choctaw National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Eufaula National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Fern Cave National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Grand Bay National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Key Cave National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Mountain Longleaf National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Sauta Cave National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Watercress Darter National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Wheeler National Wildlife Refuge *</FP>
                            <HD SOURCE="HD1">Alaska</HD>
                            <FP SOURCE="FP-2">Alaska Maritime National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Alaska Peninsula National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Arctic National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Becharof National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Innoko National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Izembek National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Kanuti National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Kenai National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Kodiak National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Koyukuk National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Nowitna National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Selawik National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Tetlin National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Togiak National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Yukon Delta National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Yukon Flats National Wildlife Refuge *</FP>
                            <HD SOURCE="HD1">American Samoa</HD>
                            <FP SOURCE="FP-2">Rose Atoll National Wildlife Refuge *</FP>
                            <HD SOURCE="HD1">Arizona</HD>
                            <FP SOURCE="FP-2">Bill Williams River National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Buenos Aires National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Cabeza Prieta National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Cibola National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Havasu National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Imperial National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Kofa National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Leslie Canyon National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">San Bernardino National Wildlife Refuge</FP>
                            <HD SOURCE="HD1">Arkansas</HD>
                            <FP SOURCE="FP-2">Bald Knob National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Big Lake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Cache River National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Dale Bumpers White River National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Felsenthal National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Holla Bend National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Logan Cave National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Overflow National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Pond Creek National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Wapanocca National Wildlife Refuge</FP>
                            <HD SOURCE="HD1">California</HD>
                            <FP SOURCE="FP-2">Antioch Dunes National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Bitter Creek National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Blue Ridge National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Butte Sink Wildlife Management Area</FP>
                            <FP SOURCE="FP-2">Castle Rock National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Cibola National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Clear Lake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Coachella Valley National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Colusa National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Delevan National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Don Edwards San Francisco Bay National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Ellicott Slough National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Farallon Islands National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Grasslands Wildlife Management Area</FP>
                            <FP SOURCE="FP-2">Guadalupe-Nipomo Dunes National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Havasu National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Hopper Mountain National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Humboldt Bay National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Imperial National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Kern National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Lower Klamath National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Marin Islands National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Merced National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Modoc National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Pixley National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Sacramento National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Sacramento River National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Salinas River National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">San Diego Bay National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">San Diego National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">San Joaquin River National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">San Luis National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">San Pablo Bay National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Seal Beach National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Sonny Bono Salton Sea National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Steve Thompson North Central Valley Wildlife Management Area *</FP>
                            <FP SOURCE="FP-2">Stone Lakes National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Sutter National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Tijuana Slough National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Tulare Basin Wildlife Management Area</FP>
                            <FP SOURCE="FP-2">Tule Lake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Willow Creek-Lurline Wildlife Management Area</FP>
                            <HD SOURCE="HD1">Colorado</HD>
                            <FP SOURCE="FP-2">Alamosa National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Arapaho National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Baca National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Browns Park National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Colorado River Wildlife Management Area</FP>
                            <FP SOURCE="FP-2">Monte Vista National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Rocky Flats National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Rocky Mountain Arsenal National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">San Luis Valley Conservation Area</FP>
                            <FP SOURCE="FP-2">Sangre De Cristo Conservation Area</FP>
                            <FP SOURCE="FP-2">Two Ponds National Wildlife Refuge</FP>
                            <HD SOURCE="HD1">Connecticut</HD>
                            <FP SOURCE="FP-2">Great Thicket National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Silvio O. Conte National Fish And Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Stewart B. Mckinney National Wildlife Refuge *</FP>
                            <HD SOURCE="HD1">Delaware</HD>
                            <FP SOURCE="FP-2">
                                Bombay Hook National Wildlife Refuge *
                                <PRTPAGE P="453"/>
                            </FP>
                            <FP SOURCE="FP-2">Prime Hook National Wildlife Refuge *</FP>
                            <HD SOURCE="HD1">Florida</HD>
                            <FP SOURCE="FP-2">Archie Carr National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Arthur R. Marshall Loxahatchee National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Caloosahatchee National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Cedar Keys National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Chassahowitzka National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Crocodile Lake National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Crystal River National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Egmont Key National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Everglades Headwaters National Wildlife Refuge And Conservation Area</FP>
                            <FP SOURCE="FP-2">Everglades To Gulf Conservation Area</FP>
                            <FP SOURCE="FP-2">Florida Panther National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Great White Heron National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Island Bay National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">J. N. Ding Darling National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Key West National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Lake Wales Ridge National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Lake Woodruff National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Lower Suwannee National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Matlacha Pass National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Merritt Island National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Nathaniel P. Reed Hobe Sound National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">National Key Deer Refuge *</FP>
                            <FP SOURCE="FP-2">Okefenokee National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Passage Key National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Pelican Island National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Pine Island National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Pinellas National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">St. Johns National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">St. Marks National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">St. Vincent National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Ten Thousand Islands National Wildlife Refuge *</FP>
                            <HD SOURCE="HD1">Georgia</HD>
                            <FP SOURCE="FP-2">Banks Lake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Blackbeard Island National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Bond Swamp National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Eufaula National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Harris Neck National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Okefenokee National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Piedmont National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Savannah National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Wassaw National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Wolf Island National Wildlife Refuge *</FP>
                            <HD SOURCE="HD1">Guam</HD>
                            <FP SOURCE="FP-2">Guam National Wildlife Refuge *</FP>
                            <HD SOURCE="HD1">Hawaii</HD>
                            <FP SOURCE="FP-2">Hakalau Forest National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Hanalei National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Hawaiian Islands National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Hul`ia National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">James Campbell National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Kakahai`a National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Kelia Pond National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Kilauea Point National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Ohahu Forest National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Pearl Harbor National Wildlife Refuge *</FP>
                            <HD SOURCE="HD1">Idaho</HD>
                            <FP SOURCE="FP-2">Bear Lake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Bear River Watershed Conservation Area</FP>
                            <FP SOURCE="FP-2">Camas National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Deer Flat National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Grays Lake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Kootenai National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Minidoka National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Oxford Slough Waterfowl Production Area</FP>
                            <HD SOURCE="HD1">Illinois</HD>
                            <FP SOURCE="FP-2">Chautauqua National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Clarence Cannon National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Crab Orchard National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Cypress Creek National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Emiquon National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Great River National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Hackmatack National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Kankakee National Wildlife Refuge And Conservation Area</FP>
                            <FP SOURCE="FP-2">Meredosia National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Middle Mississippi River National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Port Louisa National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Two Rivers National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Upper Mississippi River National Wildlife And Fish Refuge *</FP>
                            <HD SOURCE="HD1">Indiana</HD>
                            <FP SOURCE="FP-2">Big Oaks National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Muscatatuck National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Patoka River National Wildlife Refuge and Management Area</FP>
                            <HD SOURCE="HD1">Iowa</HD>
                            <FP SOURCE="FP-2">Desoto National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Driftless Area National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Iowa Wetland Management District</FP>
                            <FP SOURCE="FP-2">Neal Smith National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Northern Tallgrass Prairie National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Port Louisa National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Union Slough National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Upper Mississippi River National Wildlife and Fish Refuge *</FP>
                            <HD SOURCE="HD1">Kansas</HD>
                            <FP SOURCE="FP-2">Flint Hills Legacy Conservation Area</FP>
                            <FP SOURCE="FP-2">Flint Hills National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Kirwin National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Marais Des Cygnes National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Quivira National Wildlife Refuge</FP>
                            <HD SOURCE="HD1">Kentucky</HD>
                            <FP SOURCE="FP-2">Clarks River National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Green River National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Ohio River Islands National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Reelfoot National Wildlife Refuge</FP>
                            <HD SOURCE="HD1">Louisiana</HD>
                            <FP SOURCE="FP-2">Atchafalaya National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Bayou Cocodrie National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Bayou Sauvage Urban National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">
                                Bayou Teche National Wildlife Refuge *
                                <PRTPAGE P="454"/>
                            </FP>
                            <FP SOURCE="FP-2">Big Branch Marsh National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Black Bayou Lake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Bogue Chitto National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Breton National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Cameron Prairie National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Cat Island National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Catahoula National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">D'Arbonne National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Delta National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Grand Cote National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Handy Brake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Lacassine National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Lake Ophelia National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Mandalay National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Red River National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Sabine National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Shell Keys National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Tensas River National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Upper Ouachita National Wildlife Refuge *</FP>
                            <HD SOURCE="HD1">Maine</HD>
                            <FP SOURCE="FP-2">Aroostook National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Carlton Pond Waterfowl Production Area</FP>
                            <FP SOURCE="FP-2">Cross Island National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Franklin Island National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Great Thicket National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Moosehorn National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Petit Manan National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Pond Island National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Rachel Carson National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Seal Island National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Sunkhaze Meadows National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Umbagog National Wildlife Refuge</FP>
                            <HD SOURCE="HD1">Maryland</HD>
                            <FP SOURCE="FP-2">Blackwater National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Chincoteague National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Eastern Neck National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Martin National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Patuxent Research Refuge</FP>
                            <FP SOURCE="FP-2">Susquehanna National Wildlife Refuge *</FP>
                            <HD SOURCE="HD1">Massachusetts</HD>
                            <FP SOURCE="FP-2">Assabet River National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Great Meadows National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Mashpee National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Massasoit National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Monomoy National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Nantucket National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Nomans Land Island National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Oxbow National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Parker River National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Silvio O. Conte National Fish And Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Thacher Island National Wildlife Refuge *</FP>
                            <HD SOURCE="HD1">Michigan</HD>
                            <FP SOURCE="FP-2">Detroit River International Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Green Bay National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Harbor Island National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Huron National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Kirtland's Warbler Wildlife Management Area</FP>
                            <FP SOURCE="FP-2">Michigan Islands National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Michigan Wetland Management District</FP>
                            <FP SOURCE="FP-2">Seney National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Shiawassee National Wildlife Refuge</FP>
                            <HD SOURCE="HD1">Minnesota</HD>
                            <FP SOURCE="FP-2">Agassiz National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Big Stone National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Big Stone Wetland Management District</FP>
                            <FP SOURCE="FP-2">Crane Meadows National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Detroit Lakes Wetland Management District</FP>
                            <FP SOURCE="FP-2">Fergus Falls Wetland Management District</FP>
                            <FP SOURCE="FP-2">Glacial Ridge National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Hamden Slough National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Litchfield Wetland Management District</FP>
                            <FP SOURCE="FP-2">Mille Lacs National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Minnesota Valley National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Minnesota Valley Wetland Management District</FP>
                            <FP SOURCE="FP-2">Morris Wetland Management District</FP>
                            <FP SOURCE="FP-2">Northern Tallgrass Prairie National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Rice Lake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Rydell National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Sherburne National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Tamarac National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Tamarac Wetland Management District</FP>
                            <FP SOURCE="FP-2">Upper Mississippi River National Wildlife And Fish Refuge *</FP>
                            <FP SOURCE="FP-2">Windom Wetland Management District</FP>
                            <HD SOURCE="HD1">Mississippi</HD>
                            <FP SOURCE="FP-2">Bogue Chitto National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Coldwater River National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Dahomey National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Grand Bay National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Hillside National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Holt Collier National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Mathews Brake National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Mississippi Sandhill Crane National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Morgan Brake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Panther Swamp National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Sam D. Hamilton Noxubee National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">St. Catherine Creek National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Tallahatchie National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Theodore Roosevelt National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Yazoo National Wildlife Refuge</FP>
                            <HD SOURCE="HD1">Missouri</HD>
                            <FP SOURCE="FP-2">Big Muddy National Fish And Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Clarence Cannon National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Great River National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Loess Bluffs National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Middle Mississippi River National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Mingo National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Ozark Cavefish National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Pilot Knob National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Swan Lake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Two Rivers National Wildlife Refuge</FP>
                            <HD SOURCE="HD1">Montana</HD>
                            <FP SOURCE="FP-2">
                                Benton Lake National Wildlife Refuge
                                <PRTPAGE P="455"/>
                            </FP>
                            <FP SOURCE="FP-2">Benton Lake Wetland Management District</FP>
                            <FP SOURCE="FP-2">Black Coulee National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Blackfoot Valley Conservation Area</FP>
                            <FP SOURCE="FP-2">Bowdoin National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Bowdoin Wetland Management District</FP>
                            <FP SOURCE="FP-2">Charles M. Russell National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Charles M. Russell Wetland Management District</FP>
                            <FP SOURCE="FP-2">Creedman Coulee National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Grass Lake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Hailstone National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Hewitt Lake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Lake Mason National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Lake Thibadeau National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Lamesteer National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Lee Metcalf National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Lost Trail Conservation Area</FP>
                            <FP SOURCE="FP-2">Lost Trail National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Medicine Lake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Ninepipe National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Northeast Montana Wetland Management District</FP>
                            <FP SOURCE="FP-2">Northwest Montana Wetland Management District</FP>
                            <FP SOURCE="FP-2">Pablo National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Red Rock Lakes National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Rocky Mountain Front Conservation Area</FP>
                            <FP SOURCE="FP-2">Swan River National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Swan Valley Conservation Area</FP>
                            <FP SOURCE="FP-2">UL</FP>
                            <FP SOURCE="FP-2">Bend National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">War Horse National Wildlife Refuge</FP>
                            <HD SOURCE="HD1">Nebraska</HD>
                            <FP SOURCE="FP-2">Boyer Chute National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Crescent Lake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Desoto National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Fort Niobrara National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">John W. and Louise Seier National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Karl E. Mundt National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">North Platte National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Rainwater Basin Wetland Management District</FP>
                            <FP SOURCE="FP-2">Valentine National Wildlife Refuge</FP>
                            <HD SOURCE="HD1">Nevada</HD>
                            <FP SOURCE="FP-2">Anaho Island National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Ash Meadows National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Desert National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Fallon National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Moapa Valley National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Pahranagat National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Ruby Lake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Sheldon National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Stillwater National Wildlife Refuge</FP>
                            <HD SOURCE="HD1">New Hampshire</HD>
                            <FP SOURCE="FP-2">Great Bay National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">John Hay National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Silvio O. Conte National Fish And Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Umbagog National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Wapack National Wildlife Refuge</FP>
                            <HD SOURCE="HD1">New Jersey</HD>
                            <FP SOURCE="FP-2">Cape May National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Edwin B. Forsythe National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Great Swamp National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Supawna Meadows National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Wallkill River National Wildlife Refuge</FP>
                            <HD SOURCE="HD1">New Mexico</HD>
                            <FP SOURCE="FP-2">Bitter Lake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Bosque Del Apache National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Grulla National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Las Vegas National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Maxwell National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Rio Mora National Wildlife Refuge and Conservation Area</FP>
                            <FP SOURCE="FP-2">San Andres National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Sangre De Cristo Conservation Area</FP>
                            <FP SOURCE="FP-2">Sevilleta National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Valle De Oro National Wildlife Refuge</FP>
                            <HD SOURCE="HD1">New York</HD>
                            <FP SOURCE="FP-2">Amagansett National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Congressman Lester Wolff Oyster Bay National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Conscience Point National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Elizabeth A. Morton National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Great Thicket National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Iroquois National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Lido Beach Wildlife Management Area *</FP>
                            <FP SOURCE="FP-2">Montezuma National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Seatuck National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Shawangunk Grasslands National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Target Rock National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Wallkill River National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Wertheim National Wildlife Refuge *</FP>
                            <HD SOURCE="HD1">North Carolina</HD>
                            <FP SOURCE="FP-2">Alligator River National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Cedar Island National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Currituck National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Great Dismal Swamp National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Mackay Island National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Mattamuskeet National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Mountain Bogs National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Pea Island National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Pee Dee National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Pocosin Lakes National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Roanoke River National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Swanquarter National Wildlife Refuge *</FP>
                            <HD SOURCE="HD1">North Dakota</HD>
                            <FP SOURCE="FP-2">Appert Lake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Ardoch National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Arrowwood National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Arrowwood Wetland Management District</FP>
                            <FP SOURCE="FP-2">Audubon National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Audubon Wetland Management District</FP>
                            <FP SOURCE="FP-2">Bone Hill National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Brumba National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Buffalo Lake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Camp Lake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">
                                Canfield Lake National Wildlife Refuge
                                <PRTPAGE P="456"/>
                            </FP>
                            <FP SOURCE="FP-2">Chase Lake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Chase Lake Wetland Management District</FP>
                            <FP SOURCE="FP-2">Cottonwood Lake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Crosby Wetland Management District</FP>
                            <FP SOURCE="FP-2">Dakota Grassland Conservation Area</FP>
                            <FP SOURCE="FP-2">Dakota Lake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Dakota Tallgrass Prairie Wildlife Management Area</FP>
                            <FP SOURCE="FP-2">Des Lacs National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Devils Lake Wetland Management District</FP>
                            <FP SOURCE="FP-2">Florence Lake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Half-Way Lake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Hiddenwood National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Hobart Lake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Hutchinson Lake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">J. Clark Salyer National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">J. Clark Salyer Wetland Management District</FP>
                            <FP SOURCE="FP-2">Johnson Lake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Kellys Slough National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Kulm Wetland Management District</FP>
                            <FP SOURCE="FP-2">Lake Alice National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Lake George National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Lake Ilo National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Lake Nettie National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Lake Otis National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Lake Patricia National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Lake Zahl National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Lambs Lake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Little Goose National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Long Lake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Long Lake Wetland Management District</FP>
                            <FP SOURCE="FP-2">Lords Lake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Lost Lake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Lostwood National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Lostwood Wetland Management District</FP>
                            <FP SOURCE="FP-2">Maple River National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Mclean National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">North Dakota Wildlife Management Area</FP>
                            <FP SOURCE="FP-2">Pleasant Lake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Pretty Rock National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Rabb Lake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Rock Lake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Rose Lake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">School Section Lake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Shell Lake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Sheyenne Lake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Sibley Lake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Silver Lake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Slade National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Snyder Lake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Springwater National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Stewart Lake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Stoney Slough National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Storm Lake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Stump Lake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Sunburst Lake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Tewaukon National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Tewaukon Wetland Management District</FP>
                            <FP SOURCE="FP-2">Tomahawk National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Upper Souris National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Valley City Wetland Management District</FP>
                            <FP SOURCE="FP-2">White Horse Hill National Game Preserve</FP>
                            <FP SOURCE="FP-2">White Lake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Wild Rice Lake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Willow Lake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Wintering River National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Wood Lake National Wildlife Refuge</FP>
                            <HD SOURCE="HD1">Ohio</HD>
                            <FP SOURCE="FP-2">Cedar Point National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Ottawa National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">West Sister Island National Wildlife Refuge *</FP>
                            <HD SOURCE="HD1">Oklahoma</HD>
                            <FP SOURCE="FP-2">Deep Fork National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Little River National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Optima National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Ozark Plateau National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Salt Plains National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Sequoyah National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Tishomingo National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Washita National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Wichita Mountains Wildlife Refuge</FP>
                            <HD SOURCE="HD1">Oregon</HD>
                            <FP SOURCE="FP-2">Ankeny National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Bandon Marsh National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Baskett Slough National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Bear Valley National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Cape Meares National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Cold Springs National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Deer Flat National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Hart Mountain National Antelope Refuge</FP>
                            <FP SOURCE="FP-2">Julia Butler Hansen Refuge For The Columbian White Tail Deer *</FP>
                            <FP SOURCE="FP-2">Klamath Marsh National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Lewis And Clark National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Lower Klamath National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Malheur National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Mckay Creek National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Mcnary National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Nestucca Bay National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Oregon Islands National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Sheldon National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Siletz Bay National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Three Arch Rocks National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Tualatin River National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Umatilla National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Upper Klamath National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Wapato Lake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">William L. Finley National Wildlife Refuge</FP>
                            <HD SOURCE="HD1">Pennsylvania</HD>
                            <FP SOURCE="FP-2">Cherry Valley National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Erie National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">John Heinz National Wildlife Refuge At Tinicum</FP>
                            <FP SOURCE="FP-2">Ohio River Islands National Wildlife Refuge *</FP>
                            <HD SOURCE="HD1">Puerto Rico</HD>
                            <FP SOURCE="FP-2">Cabo Rojo National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Culebra National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Desecheo National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Laguna Cartagena National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Vieques National Wildlife Refuge *</FP>
                            <HD SOURCE="HD1">Rhode Island</HD>
                            <FP SOURCE="FP-2">Block Island National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">John H. Chafee National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">
                                Ninigret National Wildlife Refuge *
                                <PRTPAGE P="457"/>
                            </FP>
                            <FP SOURCE="FP-2">Sachuest Point National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Trustom Pond National Wildlife Refuge *</FP>
                            <HD SOURCE="HD1">South Carolina</HD>
                            <FP SOURCE="FP-2">Cape Romain National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Carolina Sandhills National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Ernest F. Hollings Ace Basin National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Pinckney Island National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Santee National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Savannah National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Tybee National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Waccamaw National Wildlife Refuge *</FP>
                            <HD SOURCE="HD1">South Dakota</HD>
                            <FP SOURCE="FP-2">Bear Butte National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Dakota Grassland Conservation Area</FP>
                            <FP SOURCE="FP-2">Dakota Tallgrass Prairie Wildlife Management Area</FP>
                            <FP SOURCE="FP-2">Huron Wetland Management District</FP>
                            <FP SOURCE="FP-2">Karl E. Mundt National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Lacreek National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Lake Andes National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Lake Andes Wetland Management District</FP>
                            <FP SOURCE="FP-2">Madison Wetland Management District</FP>
                            <FP SOURCE="FP-2">Sand Lake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Sand Lake Wetland Management District</FP>
                            <FP SOURCE="FP-2">Waubay National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Waubay Wetland Management District</FP>
                            <HD SOURCE="HD1">Tennessee</HD>
                            <FP SOURCE="FP-2">Chickasaw National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Cross Creeks National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Hatchie National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Lake Isom National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Lower Hatchie National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Paint Rock River National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Reelfoot National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Tennessee National Wildlife Refuge *</FP>
                            <HD SOURCE="HD1">Texas</HD>
                            <FP SOURCE="FP-2">Anahuac National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Aransas National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Attwater Prairie Chicken National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Balcones Canyonlands National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Big Boggy National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Brazoria National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Buffalo Lake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Caddo Lake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Grulla National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Hagerman National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Laguna Atascosa National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Little Sandy National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Lower Rio Grande Valley National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Mcfaddin National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Moody National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Muleshoe National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Neches River National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">San Bernard National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Santa Ana National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Texas Point National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Trinity River National Wildlife Refuge *</FP>
                            <HD SOURCE="HD1">United States Minor Outlying Islands</HD>
                            <FP SOURCE="FP-2">Baker Island National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Howland Island National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Jarvis Island National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Johnston Atoll National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Kingman Reef National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Mariana Arc Of Fire National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Mariana Trench National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Midway Atoll National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Navassa Island National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Palmyra Atoll National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Wake Atoll National Wildlife Refuge *</FP>
                            <HD SOURCE="HD1">Utah</HD>
                            <FP SOURCE="FP-2">Bear River Migratory Bird Refuge</FP>
                            <FP SOURCE="FP-2">Bear River Watershed Conservation Area</FP>
                            <FP SOURCE="FP-2">Colorado River Wildlife Management Area</FP>
                            <FP SOURCE="FP-2">Fish Springs National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Ouray National Wildlife Refuge</FP>
                            <HD SOURCE="HD1">Vermont</HD>
                            <FP SOURCE="FP-2">Missisquoi National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Silvio O. Conte National Fish And Wildlife Refuge *</FP>
                            <HD SOURCE="HD1">Virgin Islands</HD>
                            <FP SOURCE="FP-2">Buck Island National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Green Cay National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Sandy Point National Wildlife Refuge *</FP>
                            <HD SOURCE="HD1">Virginia</HD>
                            <FP SOURCE="FP-2">Back Bay National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Chincoteague National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Eastern Shore Of Virginia National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Elizabeth Hartwell Mason Neck National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Featherstone National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Fisherman Island National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Great Dismal Swamp National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">James River National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Mackay Island National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Martin National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Nansemond National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Occoquan Bay National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Plum Tree Island National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Presquile National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Rappahannock River Valley National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Wallops Island National Wildlife Refuge *</FP>
                            <HD SOURCE="HD1">Washington</HD>
                            <FP SOURCE="FP-2">Billy Frank Jr. Nisqually National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Columbia National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Conboy Lake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Copalis National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Dungeness National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Flattery Rocks National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Franz Lake National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Grays Harbor National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">
                                Julia Butler Hansen Refuge For The Columbian White Tail Deer
                                <PRTPAGE P="458"/>
                            </FP>
                            <FP SOURCE="FP-2">Little Pend Oreille National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Mcnary National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Pierce National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Protection Island National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Quillayute Needles National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Ridgefield National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Saddle Mountain National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">San Juan Islands National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Steigerwald Lake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Toppenish National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Turnbull National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Umatilla National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Willapa National Wildlife Refuge *</FP>
                            <HD SOURCE="HD1">West Virginia</HD>
                            <FP SOURCE="FP-2">Canaan Valley National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Ohio River Islands National Wildlife Refuge *</FP>
                            <HD SOURCE="HD1">Wisconsin</HD>
                            <FP SOURCE="FP-2">Fox River National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Gravel Island National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Green Bay National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Hackmatack National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Horicon National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Leopold Wetland Management District</FP>
                            <FP SOURCE="FP-2">Necedah National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">St. Croix Wetland Management District</FP>
                            <FP SOURCE="FP-2">Trempealeau National Wildlife Refuge *</FP>
                            <FP SOURCE="FP-2">Upper Mississippi River National Wildlife And Fish Refuge *</FP>
                            <FP SOURCE="FP-2">Whittlesey Creek National Wildlife Refuge *</FP>
                            <HD SOURCE="HD1">Wyoming</HD>
                            <FP SOURCE="FP-2">Bamforth National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Bear River Watershed Conservation Area</FP>
                            <FP SOURCE="FP-2">Cokeville Meadows National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Hutton Lake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Mortenson Lake National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">National Elk Refuge</FP>
                            <FP SOURCE="FP-2">Pathfinder National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Seedskadee National Wildlife Refuge</FP>
                            <FP SOURCE="FP-2">Wyoming Toad Conservation Area</FP>
                            <HD SOURCE="HD1">A.5 National Wilderness Areas</HD>
                            <HD SOURCE="HD1">Alabama</HD>
                            <FP SOURCE="FP-2">Cheaha Wilderness</FP>
                            <FP SOURCE="FP-2">Dugger Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Sipsey Wilderness</FP>
                            <HD SOURCE="HD1">Alaska</HD>
                            <FP SOURCE="FP-2">Aleutian Islands Wilderness *</FP>
                            <FP SOURCE="FP-2">Andreafsky Wilderness</FP>
                            <FP SOURCE="FP-2">Becharof Wilderness *</FP>
                            <FP SOURCE="FP-2">Bering Sea Wilderness *</FP>
                            <FP SOURCE="FP-2">Bogoslof Wilderness *</FP>
                            <FP SOURCE="FP-2">Chamisso Wilderness *</FP>
                            <FP SOURCE="FP-2">Chuck River Wilderness *</FP>
                            <FP SOURCE="FP-2">Coronation Island Wilderness *</FP>
                            <FP SOURCE="FP-2">Denali Wilderness</FP>
                            <FP SOURCE="FP-2">Endicott River Wilderness</FP>
                            <FP SOURCE="FP-2">Forrester Island Wilderness *</FP>
                            <FP SOURCE="FP-2">Gates of the Arctic Wilderness *</FP>
                            <FP SOURCE="FP-2">Glacier Bay Wilderness *</FP>
                            <FP SOURCE="FP-2">Hazy Islands Wilderness *</FP>
                            <FP SOURCE="FP-2">Innoko Wilderness</FP>
                            <FP SOURCE="FP-2">Izembek Wilderness *</FP>
                            <FP SOURCE="FP-2">Jay S. Hammond Wilderness *</FP>
                            <FP SOURCE="FP-2">Karta River Wilderness *</FP>
                            <FP SOURCE="FP-2">Katmai Wilderness *</FP>
                            <FP SOURCE="FP-2">Kenai Wilderness *</FP>
                            <FP SOURCE="FP-2">Kobuk Valley Wilderness *</FP>
                            <FP SOURCE="FP-2">Kootznoowoo Wilderness *</FP>
                            <FP SOURCE="FP-2">Koyukuk Wilderness *</FP>
                            <FP SOURCE="FP-2">Kuiu Wilderness *</FP>
                            <FP SOURCE="FP-2">Maurelle Islands Wilderness *</FP>
                            <FP SOURCE="FP-2">Misty Fjords National Monument Wilderness *</FP>
                            <FP SOURCE="FP-2">Mollie Beattie Wilderness *</FP>
                            <FP SOURCE="FP-2">Noatak Wilderness</FP>
                            <FP SOURCE="FP-2">Nunivak Wilderness *</FP>
                            <FP SOURCE="FP-2">Petersburg Creek-Duncan Salt Chuck Wilderness *</FP>
                            <FP SOURCE="FP-2">Pleasant/Lemusurier/Inian Islands Wilderness *</FP>
                            <FP SOURCE="FP-2">Russell Fjord Wilderness *</FP>
                            <FP SOURCE="FP-2">Saint Lazaria Wilderness *</FP>
                            <FP SOURCE="FP-2">Selawik Wilderness</FP>
                            <FP SOURCE="FP-2">Semidi Wilderness *</FP>
                            <FP SOURCE="FP-2">Simeonof Wilderness *</FP>
                            <FP SOURCE="FP-2">South Baranof Wilderness *</FP>
                            <FP SOURCE="FP-2">South Etolin Wilderness *</FP>
                            <FP SOURCE="FP-2">South Prince of Wales Wilderness *</FP>
                            <FP SOURCE="FP-2">Stikine-LeConte Wilderness *</FP>
                            <FP SOURCE="FP-2">Tebenkof Bay Wilderness *</FP>
                            <FP SOURCE="FP-2">Togiak Wilderness</FP>
                            <FP SOURCE="FP-2">Tracy Arm-Fords Terror Wilderness *</FP>
                            <FP SOURCE="FP-2">Tuxedni Wilderness *</FP>
                            <FP SOURCE="FP-2">Unimak Wilderness *</FP>
                            <FP SOURCE="FP-2">Warren Island Wilderness *</FP>
                            <FP SOURCE="FP-2">West Chichagof-Yakobi Wilderness *</FP>
                            <FP SOURCE="FP-2">Wrangell-Saint Elias Wilderness *</FP>
                            <HD SOURCE="HD1">Arizona</HD>
                            <FP SOURCE="FP-2">Apache Creek Wilderness</FP>
                            <FP SOURCE="FP-2">Aravaipa Canyon Wilderness</FP>
                            <FP SOURCE="FP-2">Arrastra Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Aubrey Peak Wilderness</FP>
                            <FP SOURCE="FP-2">Baboquivari Peak Wilderness</FP>
                            <FP SOURCE="FP-2">Bear Wallow Wilderness</FP>
                            <FP SOURCE="FP-2">Beaver Dam Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">Big Horn Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">Cabeza Prieta Wilderness</FP>
                            <FP SOURCE="FP-2">Castle Creek Wilderness</FP>
                            <FP SOURCE="FP-2">Cedar Bench Wilderness</FP>
                            <FP SOURCE="FP-2">Chiricahua National Monument Wilderness</FP>
                            <FP SOURCE="FP-2">Chiricahua Wilderness</FP>
                            <FP SOURCE="FP-2">Cottonwood Point Wilderness</FP>
                            <FP SOURCE="FP-2">Coyote Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">Dos Cabezas Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">Eagletail Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">East Cactus Plain Wilderness</FP>
                            <FP SOURCE="FP-2">Escudilla Wilderness</FP>
                            <FP SOURCE="FP-2">Fishhooks Wilderness</FP>
                            <FP SOURCE="FP-2">Fossil Springs Wilderness</FP>
                            <FP SOURCE="FP-2">Four Peaks Wilderness</FP>
                            <FP SOURCE="FP-2">Galiuro Wilderness</FP>
                            <FP SOURCE="FP-2">Gibraltar Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Grand Wash Cliffs Wilderness</FP>
                            <FP SOURCE="FP-2">Granite Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Harcuvar Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">
                                Harquahala Mountains Wilderness
                                <PRTPAGE P="459"/>
                            </FP>
                            <FP SOURCE="FP-2">Hassayampa River Canyon Wilderness</FP>
                            <FP SOURCE="FP-2">Havasu Wilderness</FP>
                            <FP SOURCE="FP-2">Hells Canyon Wilderness</FP>
                            <FP SOURCE="FP-2">Hellsgate Wilderness</FP>
                            <FP SOURCE="FP-2">Hummingbird Springs Wilderness</FP>
                            <FP SOURCE="FP-2">Imperial Refuge Wilderness</FP>
                            <FP SOURCE="FP-2">Juniper Mesa Wilderness</FP>
                            <FP SOURCE="FP-2">Kachina Peaks Wilderness</FP>
                            <FP SOURCE="FP-2">Kanab Creek Wilderness</FP>
                            <FP SOURCE="FP-2">Kendrick Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Kofa Wilderness</FP>
                            <FP SOURCE="FP-2">Mazatzal Wilderness</FP>
                            <FP SOURCE="FP-2">Miller Peak Wilderness</FP>
                            <FP SOURCE="FP-2">Mount Baldy Wilderness</FP>
                            <FP SOURCE="FP-2">Mount Logan Wilderness</FP>
                            <FP SOURCE="FP-2">Mount Nutt Wilderness</FP>
                            <FP SOURCE="FP-2">Mount Tipton Wilderness</FP>
                            <FP SOURCE="FP-2">Mount Trumbull Wilderness</FP>
                            <FP SOURCE="FP-2">Mount Wilson Wilderness</FP>
                            <FP SOURCE="FP-2">Mt. Wrightson Wilderness</FP>
                            <FP SOURCE="FP-2">Muggins Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Munds Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Needle's Eye Wilderness</FP>
                            <FP SOURCE="FP-2">New Water Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">North Maricopa Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">North Santa Teresa Wilderness</FP>
                            <FP SOURCE="FP-2">Organ Pipe Cactus Wilderness</FP>
                            <FP SOURCE="FP-2">Paiute Wilderness</FP>
                            <FP SOURCE="FP-2">Pajarita Wilderness</FP>
                            <FP SOURCE="FP-2">Paria Canyon-Vermilion Cliffs Wilderness</FP>
                            <FP SOURCE="FP-2">Peloncillo Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">Petrified Forest National Wilderness Area</FP>
                            <FP SOURCE="FP-2">Pine Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Pusch Ridge Wilderness</FP>
                            <FP SOURCE="FP-2">Rawhide Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">Red Rock-Secret Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Redfield Canyon Wilderness</FP>
                            <FP SOURCE="FP-2">Rincon Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Saddle Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Saguaro Wilderness</FP>
                            <FP SOURCE="FP-2">Salome Wilderness</FP>
                            <FP SOURCE="FP-2">Salt River Canyon Wilderness</FP>
                            <FP SOURCE="FP-2">Santa Teresa Wilderness</FP>
                            <FP SOURCE="FP-2">Sierra Ancha Wilderness</FP>
                            <FP SOURCE="FP-2">Sierra Estrella Wilderness</FP>
                            <FP SOURCE="FP-2">Signal Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">South Maricopa Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">Strawberry Crater Wilderness</FP>
                            <FP SOURCE="FP-2">Superstition Wilderness</FP>
                            <FP SOURCE="FP-2">Swansea Wilderness</FP>
                            <FP SOURCE="FP-2">Sycamore Canyon Wilderness</FP>
                            <FP SOURCE="FP-2">Table Top Wilderness</FP>
                            <FP SOURCE="FP-2">Tres Alamos Wilderness</FP>
                            <FP SOURCE="FP-2">Trigo Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Upper Burro Creek Wilderness</FP>
                            <FP SOURCE="FP-2">Wabayuma Peak Wilderness</FP>
                            <FP SOURCE="FP-2">Warm Springs Wilderness</FP>
                            <FP SOURCE="FP-2">West Clear Creek Wilderness</FP>
                            <FP SOURCE="FP-2">Wet Beaver Wilderness</FP>
                            <FP SOURCE="FP-2">White Canyon Wilderness</FP>
                            <FP SOURCE="FP-2">Woodchute Wilderness</FP>
                            <FP SOURCE="FP-2">Woolsey Peak Wilderness</FP>
                            <HD SOURCE="HD1">Arkansas</HD>
                            <FP SOURCE="FP-2">Big Lake Wilderness</FP>
                            <FP SOURCE="FP-2">Black Fork Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Buffalo National River Wilderness *</FP>
                            <FP SOURCE="FP-2">Caney Creek Wilderness</FP>
                            <FP SOURCE="FP-2">Dry Creek Wilderness</FP>
                            <FP SOURCE="FP-2">East Fork Wilderness</FP>
                            <FP SOURCE="FP-2">Flatside Wilderness</FP>
                            <FP SOURCE="FP-2">Hurricane Creek Wilderness</FP>
                            <FP SOURCE="FP-2">Leatherwood Wilderness</FP>
                            <FP SOURCE="FP-2">Poteau Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Richland Creek Wilderness</FP>
                            <FP SOURCE="FP-2">Upper Buffalo Wilderness</FP>
                            <HD SOURCE="HD1">California</HD>
                            <FP SOURCE="FP-2">Agua Tibia Wilderness</FP>
                            <FP SOURCE="FP-2">Ansel Adams Wilderness</FP>
                            <FP SOURCE="FP-2">Argus Range Wilderness</FP>
                            <FP SOURCE="FP-2">Avawatz Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">Beauty Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Big Maria Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">Bigelow Cholla Garden Wilderness</FP>
                            <FP SOURCE="FP-2">Bighorn Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Black Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Bright Star Wilderness</FP>
                            <FP SOURCE="FP-2">Bristol Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">Bucks Lake Wilderness</FP>
                            <FP SOURCE="FP-2">Buzzards Peak Wilderness</FP>
                            <FP SOURCE="FP-2">Cache Creek Wilderness</FP>
                            <FP SOURCE="FP-2">Cadiz Dunes Wilderness</FP>
                            <FP SOURCE="FP-2">Cahuilla Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Caribou Wilderness</FP>
                            <FP SOURCE="FP-2">Carrizo Gorge Wilderness</FP>
                            <FP SOURCE="FP-2">Carson-Iceberg Wilderness</FP>
                            <FP SOURCE="FP-2">Castle Crags Wilderness</FP>
                            <FP SOURCE="FP-2">Cedar Roughs Wilderness</FP>
                            <FP SOURCE="FP-2">Chanchelulla Wilderness</FP>
                            <FP SOURCE="FP-2">Chemehuevi Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">Chimney Peak Wilderness</FP>
                            <FP SOURCE="FP-2">Chuckwalla Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">Chumash Wilderness</FP>
                            <FP SOURCE="FP-2">Cleghorn Lakes Wilderness</FP>
                            <FP SOURCE="FP-2">Clipper Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Coso Range Wilderness</FP>
                            <FP SOURCE="FP-2">Coyote Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">Cucamonga Wilderness</FP>
                            <FP SOURCE="FP-2">Darwin Falls Wilderness</FP>
                            <FP SOURCE="FP-2">Dead Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">Death Valley Wilderness</FP>
                            <FP SOURCE="FP-2">Desolation Wilderness</FP>
                            <FP SOURCE="FP-2">Dick Smith Wilderness</FP>
                            <FP SOURCE="FP-2">Dinkey Lakes Wilderness</FP>
                            <FP SOURCE="FP-2">Domeland Wilderness</FP>
                            <FP SOURCE="FP-2">El Paso Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">Elkhorn Ridge Wilderness</FP>
                            <FP SOURCE="FP-2">Emigrant Wilderness</FP>
                            <FP SOURCE="FP-2">Farallon Wilderness *</FP>
                            <FP SOURCE="FP-2">Fish Creek Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">Funeral Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">Garcia Wilderness</FP>
                            <FP SOURCE="FP-2">Golden Trout Wilderness</FP>
                            <FP SOURCE="FP-2">Golden Valley Wilderness</FP>
                            <FP SOURCE="FP-2">Granite Chief Wilderness</FP>
                            <FP SOURCE="FP-2">Granite Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Grass Valley Wilderness</FP>
                            <FP SOURCE="FP-2">Great Falls Basin Wilderness</FP>
                            <FP SOURCE="FP-2">Hain Wilderness</FP>
                            <FP SOURCE="FP-2">Hauser Wilderness</FP>
                            <FP SOURCE="FP-2">Havasu Wilderness</FP>
                            <FP SOURCE="FP-2">Hollow Hills Wilderness</FP>
                            <FP SOURCE="FP-2">
                                Hoover Wilderness
                                <PRTPAGE P="460"/>
                            </FP>
                            <FP SOURCE="FP-2">Ibex Wilderness</FP>
                            <FP SOURCE="FP-2">Imperial Refuge Wilderness</FP>
                            <FP SOURCE="FP-2">Indian Pass Wilderness</FP>
                            <FP SOURCE="FP-2">Inyo Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">Ishi Wilderness</FP>
                            <FP SOURCE="FP-2">Jacumba Wilderness *</FP>
                            <FP SOURCE="FP-2">Jennie Lakes Wilderness</FP>
                            <FP SOURCE="FP-2">John Krebs Wilderness</FP>
                            <FP SOURCE="FP-2">John Muir Wilderness</FP>
                            <FP SOURCE="FP-2">Joshua Tree Wilderness</FP>
                            <FP SOURCE="FP-2">Kaiser Wilderness</FP>
                            <FP SOURCE="FP-2">Kelso Dunes Wilderness</FP>
                            <FP SOURCE="FP-2">Kiavah Wilderness</FP>
                            <FP SOURCE="FP-2">King Range Wilderness *</FP>
                            <FP SOURCE="FP-2">Kingston Range Wilderness</FP>
                            <FP SOURCE="FP-2">Lassen Volcanic Wilderness</FP>
                            <FP SOURCE="FP-2">Lava Beds Wilderness</FP>
                            <FP SOURCE="FP-2">Little Chuckwalla Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">Little Picacho Wilderness</FP>
                            <FP SOURCE="FP-2">Machesna Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Magic Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Malpais Mesa Wilderness</FP>
                            <FP SOURCE="FP-2">Manly Peak Wilderness</FP>
                            <FP SOURCE="FP-2">Marble Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Matilija Wilderness</FP>
                            <FP SOURCE="FP-2">Mecca Hills Wilderness</FP>
                            <FP SOURCE="FP-2">Mesquite Wilderness</FP>
                            <FP SOURCE="FP-2">Milpitas Wash Wilderness</FP>
                            <FP SOURCE="FP-2">Mojave Wilderness</FP>
                            <FP SOURCE="FP-2">Mokelumne Wilderness</FP>
                            <FP SOURCE="FP-2">Monarch Wilderness</FP>
                            <FP SOURCE="FP-2">Mount Lassic Wilderness</FP>
                            <FP SOURCE="FP-2">Mt. Shasta Wilderness</FP>
                            <FP SOURCE="FP-2">Newberry Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">Nopah Range Wilderness</FP>
                            <FP SOURCE="FP-2">North Algodones Dunes Wilderness</FP>
                            <FP SOURCE="FP-2">North Fork Wilderness</FP>
                            <FP SOURCE="FP-2">North Mesquite Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">Old Woman Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">Orocopia Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">Otay Mountain Wilderness *</FP>
                            <FP SOURCE="FP-2">Owens Peak Wilderness</FP>
                            <FP SOURCE="FP-2">Owens River Headwaters Wilderness</FP>
                            <FP SOURCE="FP-2">Pahrump Valley Wilderness</FP>
                            <FP SOURCE="FP-2">Palen/McCoy Wilderness</FP>
                            <FP SOURCE="FP-2">Palo Verde Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">Phillip Burton Wilderness *</FP>
                            <FP SOURCE="FP-2">Picacho Peak Wilderness</FP>
                            <FP SOURCE="FP-2">Pine Creek Wilderness</FP>
                            <FP SOURCE="FP-2">Pinto Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">Piper Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Piute Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">Pleasant View Ridge Wilderness</FP>
                            <FP SOURCE="FP-2">Red Buttes Wilderness</FP>
                            <FP SOURCE="FP-2">Resting Spring Range Wilderness</FP>
                            <FP SOURCE="FP-2">Rice Valley Wilderness</FP>
                            <FP SOURCE="FP-2">Riverside Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">Rocks and Islands Wilderness *</FP>
                            <FP SOURCE="FP-2">Rodman Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">Russian Wilderness</FP>
                            <FP SOURCE="FP-2">Sacatar Trail Wilderness</FP>
                            <FP SOURCE="FP-2">Saddle Peak Hills Wilderness</FP>
                            <FP SOURCE="FP-2">San Gabriel Wilderness</FP>
                            <FP SOURCE="FP-2">San Gorgonio Wilderness</FP>
                            <FP SOURCE="FP-2">San Jacinto Wilderness</FP>
                            <FP SOURCE="FP-2">San Mateo Canyon Wilderness</FP>
                            <FP SOURCE="FP-2">San Rafael Wilderness</FP>
                            <FP SOURCE="FP-2">Sanhedrin Wilderness</FP>
                            <FP SOURCE="FP-2">Santa Lucia Wilderness</FP>
                            <FP SOURCE="FP-2">Santa Rosa Wilderness</FP>
                            <FP SOURCE="FP-2">Sawtooth Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">Sequoia-Kings Canyon Wilderness</FP>
                            <FP SOURCE="FP-2">Sespe Wilderness</FP>
                            <FP SOURCE="FP-2">Sheep Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Sheephole Valley Wilderness</FP>
                            <FP SOURCE="FP-2">Silver Peak Wilderness</FP>
                            <FP SOURCE="FP-2">Siskiyou Wilderness</FP>
                            <FP SOURCE="FP-2">Snow Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Soda Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">South Fork Eel River Wilderness</FP>
                            <FP SOURCE="FP-2">South Fork San Jacinto Wilderness</FP>
                            <FP SOURCE="FP-2">South Nopah Range Wilderness</FP>
                            <FP SOURCE="FP-2">South Sierra Wilderness</FP>
                            <FP SOURCE="FP-2">South Warner Wilderness</FP>
                            <FP SOURCE="FP-2">Stateline Wilderness</FP>
                            <FP SOURCE="FP-2">Stepladder Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">Surprise Canyon Wilderness</FP>
                            <FP SOURCE="FP-2">Sylvania Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">Thousand Lakes Wilderness</FP>
                            <FP SOURCE="FP-2">Trilobite Wilderness</FP>
                            <FP SOURCE="FP-2">Trinity Alps Wilderness</FP>
                            <FP SOURCE="FP-2">Turtle Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">Ventana Wilderness</FP>
                            <FP SOURCE="FP-2">Whipple Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">White Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">Yolla Bolly-Middle Eel Wilderness</FP>
                            <FP SOURCE="FP-2">Yosemite Wilderness</FP>
                            <FP SOURCE="FP-2">Yuki Wilderness</FP>
                            <HD SOURCE="HD1">Colorado</HD>
                            <FP SOURCE="FP-2">Black Canyon of the Gunnison Wilderness</FP>
                            <FP SOURCE="FP-2">Black Ridge Canyons Wilderness</FP>
                            <FP SOURCE="FP-2">Buffalo Peaks Wilderness</FP>
                            <FP SOURCE="FP-2">Byers Peak Wilderness</FP>
                            <FP SOURCE="FP-2">Cache La Poudre Wilderness</FP>
                            <FP SOURCE="FP-2">Collegiate Peaks Wilderness</FP>
                            <FP SOURCE="FP-2">Comanche Peak Wilderness</FP>
                            <FP SOURCE="FP-2">Dominguez Canyon Wilderness</FP>
                            <FP SOURCE="FP-2">Eagles Nest Wilderness</FP>
                            <FP SOURCE="FP-2">Flat Tops Wilderness</FP>
                            <FP SOURCE="FP-2">Fossil Ridge Wilderness</FP>
                            <FP SOURCE="FP-2">Great Sand Dunes Wilderness</FP>
                            <FP SOURCE="FP-2">Greenhorn Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Gunnison Gorge Wilderness</FP>
                            <FP SOURCE="FP-2">Hermosa Creek Wilderness</FP>
                            <FP SOURCE="FP-2">Holy Cross Wilderness</FP>
                            <FP SOURCE="FP-2">Hunter-Fryingpan Wilderness</FP>
                            <FP SOURCE="FP-2">Indian Peaks Wilderness</FP>
                            <FP SOURCE="FP-2">James Peak Wilderness</FP>
                            <FP SOURCE="FP-2">La Garita Wilderness</FP>
                            <FP SOURCE="FP-2">Lizard Head Wilderness</FP>
                            <FP SOURCE="FP-2">Lost Creek Wilderness</FP>
                            <FP SOURCE="FP-2">Maroon Bells-Snowmass Wilderness</FP>
                            <FP SOURCE="FP-2">Mesa Verde Wilderness</FP>
                            <FP SOURCE="FP-2">Mount Evans Wilderness</FP>
                            <FP SOURCE="FP-2">Mount Massive Wilderness</FP>
                            <FP SOURCE="FP-2">Mount Sneffels Wilderness</FP>
                            <FP SOURCE="FP-2">Mount Zirkel Wilderness</FP>
                            <FP SOURCE="FP-2">Neota Wilderness</FP>
                            <FP SOURCE="FP-2">Never Summer Wilderness</FP>
                            <FP SOURCE="FP-2">Platte River Wilderness</FP>
                            <FP SOURCE="FP-2">Powderhorn Wilderness</FP>
                            <FP SOURCE="FP-2">Ptarmigan Peak Wilderness</FP>
                            <FP SOURCE="FP-2">
                                Raggeds Wilderness
                                <PRTPAGE P="461"/>
                            </FP>
                            <FP SOURCE="FP-2">Rawah Wilderness</FP>
                            <FP SOURCE="FP-2">Rocky Mountain National Park Wilderness</FP>
                            <FP SOURCE="FP-2">Sangre de Cristo Wilderness</FP>
                            <FP SOURCE="FP-2">Sarvis Creek Wilderness</FP>
                            <FP SOURCE="FP-2">South San Juan Wilderness</FP>
                            <FP SOURCE="FP-2">Spanish Peaks Wilderness</FP>
                            <FP SOURCE="FP-2">Uncompahgre Wilderness</FP>
                            <FP SOURCE="FP-2">Vasquez Peak Wilderness</FP>
                            <FP SOURCE="FP-2">Weminuche Wilderness</FP>
                            <FP SOURCE="FP-2">West Elk Wilderness</FP>
                            <HD SOURCE="HD1">Florida</HD>
                            <FP SOURCE="FP-2">Alexander Springs Wilderness *</FP>
                            <FP SOURCE="FP-2">Big Gum Swamp Wilderness</FP>
                            <FP SOURCE="FP-2">Billies Bay Wilderness</FP>
                            <FP SOURCE="FP-2">Bradwell Bay Wilderness</FP>
                            <FP SOURCE="FP-2">Cedar Keys Wilderness *</FP>
                            <FP SOURCE="FP-2">Chassahowitzka Wilderness *</FP>
                            <FP SOURCE="FP-2">Florida Keys Wilderness *</FP>
                            <FP SOURCE="FP-2">Island Bay Wilderness *</FP>
                            <FP SOURCE="FP-2">J.N. “Ding” Darling Wilderness *</FP>
                            <FP SOURCE="FP-2">Juniper Prairie Wilderness</FP>
                            <FP SOURCE="FP-2">Lake Woodruff Wilderness *</FP>
                            <FP SOURCE="FP-2">Little Lake George Wilderness *</FP>
                            <FP SOURCE="FP-2">Marjory Stoneman Douglas Wilderness *</FP>
                            <FP SOURCE="FP-2">Mud Swamp/New River Wilderness</FP>
                            <FP SOURCE="FP-2">Passage Key Wilderness *</FP>
                            <FP SOURCE="FP-2">Pelican Island Wilderness *</FP>
                            <FP SOURCE="FP-2">St. Marks Wilderness *</FP>
                            <HD SOURCE="HD1">Georgia</HD>
                            <FP SOURCE="FP-2">Big Frog Wilderness</FP>
                            <FP SOURCE="FP-2">Blackbeard Island Wilderness *</FP>
                            <FP SOURCE="FP-2">Blood Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Brasstown Wilderness</FP>
                            <FP SOURCE="FP-2">Cohutta Wilderness</FP>
                            <FP SOURCE="FP-2">Cumberland Island Wilderness *</FP>
                            <FP SOURCE="FP-2">Ellicott Rock Wilderness</FP>
                            <FP SOURCE="FP-2">Mark Trail Wilderness</FP>
                            <FP SOURCE="FP-2">Okefenokee Wilderness</FP>
                            <FP SOURCE="FP-2">Raven Cliffs Wilderness</FP>
                            <FP SOURCE="FP-2">Rich Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Southern Nantahala Wilderness</FP>
                            <FP SOURCE="FP-2">Tray Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Wolf Island Wilderness *</FP>
                            <HD SOURCE="HD1">Hawaii</HD>
                            <FP SOURCE="FP-2">Haleakalā Wilderness</FP>
                            <FP SOURCE="FP-2">Hawai`i Volcanoes Wilderness *</FP>
                            <HD SOURCE="HD1">Idaho</HD>
                            <FP SOURCE="FP-2">Big Jacks Creek Wilderness</FP>
                            <FP SOURCE="FP-2">Bruneau-Jarbidge Rivers Wilderness</FP>
                            <FP SOURCE="FP-2">Cecil D. Andrus-White Clouds Wilderness</FP>
                            <FP SOURCE="FP-2">Craters of the Moon National Wilderness Area</FP>
                            <FP SOURCE="FP-2">Frank Church-River of No Return Wilderness</FP>
                            <FP SOURCE="FP-2">Gospel-Hump Wilderness</FP>
                            <FP SOURCE="FP-2">Hells Canyon Wilderness</FP>
                            <FP SOURCE="FP-2">Hemingway-Boulders Wilderness</FP>
                            <FP SOURCE="FP-2">Jim McClure-Jerry Peak Wilderness</FP>
                            <FP SOURCE="FP-2">Little Jacks Creek Wilderness</FP>
                            <FP SOURCE="FP-2">North Fork Owyhee Wilderness</FP>
                            <FP SOURCE="FP-2">Owyhee River Wilderness</FP>
                            <FP SOURCE="FP-2">Pole Creek Wilderness</FP>
                            <FP SOURCE="FP-2">Sawtooth Wilderness</FP>
                            <FP SOURCE="FP-2">Selway-Bitterroot Wilderness</FP>
                            <HD SOURCE="HD1">Illinois</HD>
                            <FP SOURCE="FP-2">Bald Knob Wilderness</FP>
                            <FP SOURCE="FP-2">Bay Creek Wilderness</FP>
                            <FP SOURCE="FP-2">Burden Falls Wilderness</FP>
                            <FP SOURCE="FP-2">Clear Springs Wilderness</FP>
                            <FP SOURCE="FP-2">Crab Orchard Wilderness</FP>
                            <FP SOURCE="FP-2">Garden of the Gods Wilderness</FP>
                            <FP SOURCE="FP-2">Lusk Creek Wilderness</FP>
                            <FP SOURCE="FP-2">Panther Den Wilderness</FP>
                            <HD SOURCE="HD1">Indiana</HD>
                            <FP SOURCE="FP-2">Charles C. Deam Wilderness</FP>
                            <HD SOURCE="HD1">Kentucky</HD>
                            <FP SOURCE="FP-2">Beaver Creek Wilderness</FP>
                            <FP SOURCE="FP-2">Clifty Wilderness</FP>
                            <HD SOURCE="HD1">Louisiana</HD>
                            <FP SOURCE="FP-2">Breton Wilderness *</FP>
                            <FP SOURCE="FP-2">Kisatchie Hills Wilderness</FP>
                            <FP SOURCE="FP-2">Lacassine Wilderness</FP>
                            <HD SOURCE="HD1">Maine</HD>
                            <FP SOURCE="FP-2">Caribou-Speckled Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Moosehorn (Baring Unit) Wilderness</FP>
                            <FP SOURCE="FP-2">Moosehorn Wilderness *</FP>
                            <HD SOURCE="HD1">Massachusetts</HD>
                            <FP SOURCE="FP-2">Monomoy Wilderness *</FP>
                            <HD SOURCE="HD1">Michigan</HD>
                            <FP SOURCE="FP-2">Beaver Basin Wilderness *</FP>
                            <FP SOURCE="FP-2">Big Island Lake Wilderness</FP>
                            <FP SOURCE="FP-2">Delirium Wilderness</FP>
                            <FP SOURCE="FP-2">Horseshoe Bay Wilderness *</FP>
                            <FP SOURCE="FP-2">Huron Islands Wilderness *</FP>
                            <FP SOURCE="FP-2">Isle Royale Wilderness *</FP>
                            <FP SOURCE="FP-2">Mackinac Wilderness</FP>
                            <FP SOURCE="FP-2">McCormick Wilderness</FP>
                            <FP SOURCE="FP-2">Michigan Islands Wilderness *</FP>
                            <FP SOURCE="FP-2">Nordhouse Dunes Wilderness *</FP>
                            <FP SOURCE="FP-2">Rock River Canyon Wilderness</FP>
                            <FP SOURCE="FP-2">Round Island Wilderness *</FP>
                            <FP SOURCE="FP-2">Seney Wilderness</FP>
                            <FP SOURCE="FP-2">Sleeping Bear Dunes Wilderness *</FP>
                            <FP SOURCE="FP-2">Sturgeon River Gorge Wilderness</FP>
                            <FP SOURCE="FP-2">Sylvania Wilderness</FP>
                            <HD SOURCE="HD1">Minnesota</HD>
                            <FP SOURCE="FP-2">Agassiz Wilderness</FP>
                            <FP SOURCE="FP-2">Boundary Waters Canoe Area Wilderness *</FP>
                            <FP SOURCE="FP-2">Tamarac Wilderness</FP>
                            <HD SOURCE="HD1">Mississippi</HD>
                            <FP SOURCE="FP-2">Black Creek Wilderness</FP>
                            <FP SOURCE="FP-2">Gulf Islands Wilderness *</FP>
                            <FP SOURCE="FP-2">Leaf Wilderness</FP>
                            <HD SOURCE="HD1">Missouri</HD>
                            <FP SOURCE="FP-2">Bell Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Devils Backbone Wilderness</FP>
                            <FP SOURCE="FP-2">
                                Hercules-Glades Wilderness
                                <PRTPAGE P="462"/>
                            </FP>
                            <FP SOURCE="FP-2">Irish Wilderness</FP>
                            <FP SOURCE="FP-2">Mingo Wilderness</FP>
                            <FP SOURCE="FP-2">Paddy Creek Wilderness</FP>
                            <FP SOURCE="FP-2">Piney Creek Wilderness</FP>
                            <FP SOURCE="FP-2">Rockpile Mountain Wilderness</FP>
                            <HD SOURCE="HD1">Montana</HD>
                            <FP SOURCE="FP-2">Absaroka-Beartooth Wilderness</FP>
                            <FP SOURCE="FP-2">Anaconda Pintler Wilderness</FP>
                            <FP SOURCE="FP-2">Bob Marshall Wilderness</FP>
                            <FP SOURCE="FP-2">Cabinet Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">Gates of the Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">Great Bear Wilderness</FP>
                            <FP SOURCE="FP-2">Lee Metcalf Wilderness</FP>
                            <FP SOURCE="FP-2">Medicine Lake Wilderness</FP>
                            <FP SOURCE="FP-2">Mission Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">Rattlesnake Wilderness</FP>
                            <FP SOURCE="FP-2">Red Rock Lakes Wilderness</FP>
                            <FP SOURCE="FP-2">Scapegoat Wilderness</FP>
                            <FP SOURCE="FP-2">Selway-Bitterroot Wilderness</FP>
                            <FP SOURCE="FP-2">UL Bend Wilderness</FP>
                            <FP SOURCE="FP-2">Welcome Creek Wilderness</FP>
                            <HD SOURCE="HD1">Nebraska</HD>
                            <FP SOURCE="FP-2">Fort Niobrara Wilderness</FP>
                            <FP SOURCE="FP-2">Soldier Creek Wilderness</FP>
                            <HD SOURCE="HD1">Nevada</HD>
                            <FP SOURCE="FP-2">Alta Toquima Wilderness</FP>
                            <FP SOURCE="FP-2">Arc Dome Wilderness</FP>
                            <FP SOURCE="FP-2">Arrow Canyon Wilderness</FP>
                            <FP SOURCE="FP-2">Bald Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Becky Peak Wilderness</FP>
                            <FP SOURCE="FP-2">Big Rocks Wilderness</FP>
                            <FP SOURCE="FP-2">Black Canyon Wilderness</FP>
                            <FP SOURCE="FP-2">Black Rock Desert Wilderness</FP>
                            <FP SOURCE="FP-2">Boundary Peak Wilderness</FP>
                            <FP SOURCE="FP-2">Bridge Canyon Wilderness</FP>
                            <FP SOURCE="FP-2">Bristlecone Wilderness</FP>
                            <FP SOURCE="FP-2">Cain Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Calico Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">Clan Alpine Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">Clover Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">Currant Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Death Valley Wilderness</FP>
                            <FP SOURCE="FP-2">Delamar Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">Desatoya Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">East Fork High Rock Canyon Wilderness</FP>
                            <FP SOURCE="FP-2">East Humboldts Wilderness</FP>
                            <FP SOURCE="FP-2">Eldorado Wilderness</FP>
                            <FP SOURCE="FP-2">Far South Egans Wilderness</FP>
                            <FP SOURCE="FP-2">Fortification Range Wilderness</FP>
                            <FP SOURCE="FP-2">Goshute Canyon Wilderness</FP>
                            <FP SOURCE="FP-2">Government Peak Wilderness</FP>
                            <FP SOURCE="FP-2">Grant Range Wilderness</FP>
                            <FP SOURCE="FP-2">High Rock Canyon Wilderness</FP>
                            <FP SOURCE="FP-2">High Rock Lake Wilderness</FP>
                            <FP SOURCE="FP-2">High Schells Wilderness</FP>
                            <FP SOURCE="FP-2">Highland Ridge Wilderness</FP>
                            <FP SOURCE="FP-2">Ireteba Peaks Wilderness</FP>
                            <FP SOURCE="FP-2">Jarbidge Wilderness</FP>
                            <FP SOURCE="FP-2">Jimbilnan Wilderness</FP>
                            <FP SOURCE="FP-2">Jumbo Springs Wilderness</FP>
                            <FP SOURCE="FP-2">La Madre Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Lime Canyon Wilderness</FP>
                            <FP SOURCE="FP-2">Little High Rock Canyon Wilderness</FP>
                            <FP SOURCE="FP-2">Meadow Valley Range Wilderness</FP>
                            <FP SOURCE="FP-2">Mormon Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">Mount Grafton Wilderness</FP>
                            <FP SOURCE="FP-2">Mt. Charleston Wilderness</FP>
                            <FP SOURCE="FP-2">Mt. Irish Wilderness</FP>
                            <FP SOURCE="FP-2">Mt. Moriah Wilderness</FP>
                            <FP SOURCE="FP-2">Mt. Rose Wilderness</FP>
                            <FP SOURCE="FP-2">Muddy Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">Nellis Wash Wilderness</FP>
                            <FP SOURCE="FP-2">North Black Rock Range Wilderness</FP>
                            <FP SOURCE="FP-2">North Jackson Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">North McCullough Wilderness</FP>
                            <FP SOURCE="FP-2">Pahute Peak Wilderness</FP>
                            <FP SOURCE="FP-2">Parsnip Peak Wilderness</FP>
                            <FP SOURCE="FP-2">Pine Forest Range Wilderness</FP>
                            <FP SOURCE="FP-2">Pinto Valley Wilderness</FP>
                            <FP SOURCE="FP-2">Quinn Canyon Wilderness</FP>
                            <FP SOURCE="FP-2">Rainbow Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Red Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Ruby Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">Santa Rosa-Paradise Peak Wilderness</FP>
                            <FP SOURCE="FP-2">Shellback Wilderness</FP>
                            <FP SOURCE="FP-2">South Egan Range Wilderness</FP>
                            <FP SOURCE="FP-2">South Jackson Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">South McCullough Wilderness</FP>
                            <FP SOURCE="FP-2">South Pahroc Range Wilderness</FP>
                            <FP SOURCE="FP-2">Spirit Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Table Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Tunnel Spring Wilderness</FP>
                            <FP SOURCE="FP-2">Wee Thump Joshua Tree Wilderness</FP>
                            <FP SOURCE="FP-2">Weepah Spring Wilderness</FP>
                            <FP SOURCE="FP-2">White Pine Range Wilderness</FP>
                            <FP SOURCE="FP-2">White Rock Range Wilderness</FP>
                            <FP SOURCE="FP-2">Worthington Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">Wovoka Wilderness</FP>
                            <HD SOURCE="HD1">New Hampshire</HD>
                            <FP SOURCE="FP-2">Great Gulf Wilderness</FP>
                            <FP SOURCE="FP-2">Pemigewasset Wilderness</FP>
                            <FP SOURCE="FP-2">Presidential Range-Dry River Wilderness</FP>
                            <FP SOURCE="FP-2">Sandwich Range Wilderness</FP>
                            <FP SOURCE="FP-2">Wild River Wilderness</FP>
                            <HD SOURCE="HD1">New Jersey</HD>
                            <FP SOURCE="FP-2">Brigantine Wilderness *</FP>
                            <FP SOURCE="FP-2">Great Swamp National Wildlife Refuge Wilderness</FP>
                            <HD SOURCE="HD1">New Mexico</HD>
                            <FP SOURCE="FP-2">Aden Lava Flow Wilderness</FP>
                            <FP SOURCE="FP-2">Ah-shi-sle-pah Wilderness</FP>
                            <FP SOURCE="FP-2">Aldo Leopold Wilderness</FP>
                            <FP SOURCE="FP-2">Apache Kid Wilderness</FP>
                            <FP SOURCE="FP-2">Bandelier Wilderness</FP>
                            <FP SOURCE="FP-2">Bisti/De-Na-Zin Wilderness</FP>
                            <FP SOURCE="FP-2">Blue Range Wilderness</FP>
                            <FP SOURCE="FP-2">Bosque del Apache Wilderness</FP>
                            <FP SOURCE="FP-2">Broad Canyon Wilderness</FP>
                            <FP SOURCE="FP-2">Capitan Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">Carlsbad Caverns Wilderness</FP>
                            <FP SOURCE="FP-2">Cebolla Wilderness</FP>
                            <FP SOURCE="FP-2">Cerro del Yuta Wilderness</FP>
                            <FP SOURCE="FP-2">Chama River Canyon Wilderness</FP>
                            <FP SOURCE="FP-2">Cinder Cone Wilderness</FP>
                            <FP SOURCE="FP-2">Columbine-Hondo Wilderness</FP>
                            <FP SOURCE="FP-2">
                                Cruces Basin Wilderness
                                <PRTPAGE P="463"/>
                            </FP>
                            <FP SOURCE="FP-2">Dome Wilderness</FP>
                            <FP SOURCE="FP-2">East Potrillo Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">Gila Wilderness</FP>
                            <FP SOURCE="FP-2">Latir Peak Wilderness</FP>
                            <FP SOURCE="FP-2">Manzano Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Mount Riley Wilderness</FP>
                            <FP SOURCE="FP-2">Ojito Wilderness</FP>
                            <FP SOURCE="FP-2">Organ Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">Pecos Wilderness</FP>
                            <FP SOURCE="FP-2">Potrillo Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">Rio San Antonio Wilderness</FP>
                            <FP SOURCE="FP-2">Robledo Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">Sabinoso Wilderness</FP>
                            <FP SOURCE="FP-2">Salt Creek Wilderness</FP>
                            <FP SOURCE="FP-2">San Pedro Parks Wilderness</FP>
                            <FP SOURCE="FP-2">Sandia Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Sierra de las Uvas Wilderness</FP>
                            <FP SOURCE="FP-2">West Malpais Wilderness</FP>
                            <FP SOURCE="FP-2">Wheeler Peak Wilderness</FP>
                            <FP SOURCE="FP-2">White Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Whitethorn Wilderness</FP>
                            <FP SOURCE="FP-2">Withington Wilderness</FP>
                            <HD SOURCE="HD1">New York</HD>
                            <FP SOURCE="FP-2">Otis Pike Fire Island High Dune Wilderness *</FP>
                            <HD SOURCE="HD1">North Carolina</HD>
                            <FP SOURCE="FP-2">Birkhead Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">Catfish Lake South Wilderness</FP>
                            <FP SOURCE="FP-2">Ellicott Rock Wilderness</FP>
                            <FP SOURCE="FP-2">Joyce Kilmer-Slickrock Wilderness</FP>
                            <FP SOURCE="FP-2">Linville Gorge Wilderness</FP>
                            <FP SOURCE="FP-2">Middle Prong Wilderness</FP>
                            <FP SOURCE="FP-2">Pocosin Wilderness</FP>
                            <FP SOURCE="FP-2">Pond Pine Wilderness</FP>
                            <FP SOURCE="FP-2">Sheep Ridge Wilderness</FP>
                            <FP SOURCE="FP-2">Shining Rock Wilderness</FP>
                            <FP SOURCE="FP-2">Southern Nantahala Wilderness</FP>
                            <FP SOURCE="FP-2">Swanquarter Wilderness *</FP>
                            <HD SOURCE="HD1">North Dakota</HD>
                            <FP SOURCE="FP-2">Chase Lake Wilderness</FP>
                            <FP SOURCE="FP-2">Lostwood Wilderness</FP>
                            <FP SOURCE="FP-2">Theodore Roosevelt Wilderness</FP>
                            <HD SOURCE="HD1">Ohio</HD>
                            <FP SOURCE="FP-2">West Sister Island Wilderness *</FP>
                            <HD SOURCE="HD1">Oklahoma</HD>
                            <FP SOURCE="FP-2">Black Fork Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Upper Kiamichi River Wilderness</FP>
                            <FP SOURCE="FP-2">Wichita Mountains Wilderness</FP>
                            <HD SOURCE="HD1">Oregon</HD>
                            <FP SOURCE="FP-2">Badger Creek Wilderness</FP>
                            <FP SOURCE="FP-2">Black Canyon Wilderness</FP>
                            <FP SOURCE="FP-2">Boulder Creek Wilderness</FP>
                            <FP SOURCE="FP-2">Bridge Creek Wilderness</FP>
                            <FP SOURCE="FP-2">Bull of the Woods Wilderness</FP>
                            <FP SOURCE="FP-2">Clackamas Wilderness</FP>
                            <FP SOURCE="FP-2">Copper Salmon Wilderness</FP>
                            <FP SOURCE="FP-2">Cummins Creek Wilderness</FP>
                            <FP SOURCE="FP-2">Devil's Staircase Wilderness *</FP>
                            <FP SOURCE="FP-2">Diamond Peak Wilderness</FP>
                            <FP SOURCE="FP-2">Drift Creek Wilderness</FP>
                            <FP SOURCE="FP-2">Eagle Cap Wilderness</FP>
                            <FP SOURCE="FP-2">Gearhart Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Grassy Knob Wilderness</FP>
                            <FP SOURCE="FP-2">Hells Canyon Wilderness</FP>
                            <FP SOURCE="FP-2">Kalmiopsis Wilderness</FP>
                            <FP SOURCE="FP-2">Lower White River Wilderness</FP>
                            <FP SOURCE="FP-2">Mark O. Hatfield Wilderness *</FP>
                            <FP SOURCE="FP-2">Menagerie Wilderness</FP>
                            <FP SOURCE="FP-2">Middle Santiam Wilderness</FP>
                            <FP SOURCE="FP-2">Mill Creek Wilderness</FP>
                            <FP SOURCE="FP-2">Monument Rock Wilderness</FP>
                            <FP SOURCE="FP-2">Mount Hood Wilderness</FP>
                            <FP SOURCE="FP-2">Mount Jefferson Wilderness</FP>
                            <FP SOURCE="FP-2">Mount Thielsen Wilderness</FP>
                            <FP SOURCE="FP-2">Mount Washington Wilderness</FP>
                            <FP SOURCE="FP-2">Mountain Lakes Wilderness</FP>
                            <FP SOURCE="FP-2">North Fork John Day Wilderness</FP>
                            <FP SOURCE="FP-2">North Fork Umatilla Wilderness</FP>
                            <FP SOURCE="FP-2">Opal Creek Wilderness</FP>
                            <FP SOURCE="FP-2">Oregon Badlands Wilderness</FP>
                            <FP SOURCE="FP-2">Oregon Islands Wilderness *</FP>
                            <FP SOURCE="FP-2">Red Buttes Wilderness</FP>
                            <FP SOURCE="FP-2">Roaring River Wilderness</FP>
                            <FP SOURCE="FP-2">Rock Creek Wilderness</FP>
                            <FP SOURCE="FP-2">Rogue-Umpqua Divide Wilderness</FP>
                            <FP SOURCE="FP-2">Salmon-Huckleberry Wilderness</FP>
                            <FP SOURCE="FP-2">Sky Lakes Wilderness</FP>
                            <FP SOURCE="FP-2">Soda Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Spring Basin Wilderness</FP>
                            <FP SOURCE="FP-2">Steens Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Strawberry Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Table Rock Wilderness</FP>
                            <FP SOURCE="FP-2">Three Arch Rocks Wilderness *</FP>
                            <FP SOURCE="FP-2">Three Sisters Wilderness</FP>
                            <FP SOURCE="FP-2">Waldo Lake Wilderness</FP>
                            <FP SOURCE="FP-2">Wenaha-Tucannon Wilderness</FP>
                            <FP SOURCE="FP-2">Wild Rogue Wilderness</FP>
                            <HD SOURCE="HD1">Pennsylvania</HD>
                            <FP SOURCE="FP-2">Allegheny Islands Wilderness</FP>
                            <FP SOURCE="FP-2">Hickory Creek Wilderness</FP>
                            <HD SOURCE="HD1">Puerto Rico</HD>
                            <FP SOURCE="FP-2">El Toro Wilderness</FP>
                            <HD SOURCE="HD1">South Carolina</HD>
                            <FP SOURCE="FP-2">Cape Romain Wilderness *</FP>
                            <FP SOURCE="FP-2">Congaree National Park Wilderness *</FP>
                            <FP SOURCE="FP-2">Ellicott Rock Wilderness</FP>
                            <FP SOURCE="FP-2">Hell Hole Bay Wilderness</FP>
                            <FP SOURCE="FP-2">Little Wambaw Swamp Wilderness</FP>
                            <FP SOURCE="FP-2">Wambaw Creek Wilderness</FP>
                            <FP SOURCE="FP-2">Wambaw Swamp Wilderness</FP>
                            <HD SOURCE="HD1">South Dakota</HD>
                            <FP SOURCE="FP-2">Badlands Wilderness</FP>
                            <FP SOURCE="FP-2">Black Elk Wilderness</FP>
                            <HD SOURCE="HD1">Tennessee</HD>
                            <FP SOURCE="FP-2">Bald River Gorge Wilderness</FP>
                            <FP SOURCE="FP-2">Big Frog Wilderness</FP>
                            <FP SOURCE="FP-2">Big Laurel Branch Wilderness</FP>
                            <FP SOURCE="FP-2">Citico Creek Wilderness</FP>
                            <FP SOURCE="FP-2">Cohutta Wilderness</FP>
                            <FP SOURCE="FP-2">Gee Creek Wilderness</FP>
                            <FP SOURCE="FP-2">
                                Joyce Kilmer-Slickrock Wilderness
                                <PRTPAGE P="464"/>
                            </FP>
                            <FP SOURCE="FP-2">Little Frog Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Pond Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Sampson Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Unaka Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Upper Bald River Wilderness</FP>
                            <HD SOURCE="HD1">Texas</HD>
                            <FP SOURCE="FP-2">Big Slough Wilderness</FP>
                            <FP SOURCE="FP-2">Guadalupe Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">Indian Mounds Wilderness</FP>
                            <FP SOURCE="FP-2">Little Lake Creek Wilderness</FP>
                            <FP SOURCE="FP-2">Turkey Hill Wilderness</FP>
                            <FP SOURCE="FP-2">Upland Island Wilderness</FP>
                            <HD SOURCE="HD1">Utah</HD>
                            <FP SOURCE="FP-2">Ashdown Gorge Wilderness</FP>
                            <FP SOURCE="FP-2">Beartrap Canyon Wilderness</FP>
                            <FP SOURCE="FP-2">Beaver Dam Mountains Wilderness</FP>
                            <FP SOURCE="FP-2">Big Wild Horse Mesa Wilderness</FP>
                            <FP SOURCE="FP-2">Black Ridge Canyons Wilderness</FP>
                            <FP SOURCE="FP-2">Blackridge Wilderness</FP>
                            <FP SOURCE="FP-2">Box-Death Hollow Wilderness</FP>
                            <FP SOURCE="FP-2">Canaan Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Cedar Mountain Wilderness Area</FP>
                            <FP SOURCE="FP-2">Cold Wash Wilderness</FP>
                            <FP SOURCE="FP-2">Cottonwood Canyon Wilderness</FP>
                            <FP SOURCE="FP-2">Cottonwood Forest Wilderness</FP>
                            <FP SOURCE="FP-2">Cougar Canyon Wilderness</FP>
                            <FP SOURCE="FP-2">Dark Canyon Wilderness</FP>
                            <FP SOURCE="FP-2">Deep Creek North Wilderness</FP>
                            <FP SOURCE="FP-2">Deep Creek Wilderness</FP>
                            <FP SOURCE="FP-2">Deseret Peak Wilderness</FP>
                            <FP SOURCE="FP-2">Desolation Canyon Wilderness</FP>
                            <FP SOURCE="FP-2">Devil's Canyon Wilderness</FP>
                            <FP SOURCE="FP-2">Doc's Pass Wilderness</FP>
                            <FP SOURCE="FP-2">Eagle Canyon Wilderness</FP>
                            <FP SOURCE="FP-2">Goose Creek Wilderness</FP>
                            <FP SOURCE="FP-2">High Uintas Wilderness</FP>
                            <FP SOURCE="FP-2">Horse Valley Wilderness</FP>
                            <FP SOURCE="FP-2">Labyrinth Canyon Wilderness</FP>
                            <FP SOURCE="FP-2">LaVerkin Creek Wilderness</FP>
                            <FP SOURCE="FP-2">Little Ocean Draw Wilderness</FP>
                            <FP SOURCE="FP-2">Little Wild Horse Canyon Wilderness</FP>
                            <FP SOURCE="FP-2">Lone Peak Wilderness</FP>
                            <FP SOURCE="FP-2">Lower Last Chance Wilderness</FP>
                            <FP SOURCE="FP-2">Mexican Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Middle Wild Horse Mesa Wilderness</FP>
                            <FP SOURCE="FP-2">Mount Naomi Wilderness</FP>
                            <FP SOURCE="FP-2">Mount Nebo Wilderness</FP>
                            <FP SOURCE="FP-2">Mount Olympus Wilderness</FP>
                            <FP SOURCE="FP-2">Mount Timpanogos Wilderness</FP>
                            <FP SOURCE="FP-2">Muddy Creek Wilderness</FP>
                            <FP SOURCE="FP-2">Nelson Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Paria Canyon-Vermilion Cliffs Wilderness</FP>
                            <FP SOURCE="FP-2">Pine Valley Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Red's Canyon Wilderness</FP>
                            <FP SOURCE="FP-2">Red Butte Wilderness</FP>
                            <FP SOURCE="FP-2">Red Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">San Rafael Reef Wilderness</FP>
                            <FP SOURCE="FP-2">Sid's Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Slaughter Creek Wilderness</FP>
                            <FP SOURCE="FP-2">Taylor Creek Wilderness</FP>
                            <FP SOURCE="FP-2">Turtle Canyon Wilderness</FP>
                            <FP SOURCE="FP-2">Twin Peaks Wilderness</FP>
                            <FP SOURCE="FP-2">Wellsville Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Zion Wilderness</FP>
                            <HD SOURCE="HD1">Vermont</HD>
                            <FP SOURCE="FP-2">Big Branch Wilderness</FP>
                            <FP SOURCE="FP-2">Breadloaf Wilderness</FP>
                            <FP SOURCE="FP-2">Bristol Cliffs Wilderness</FP>
                            <FP SOURCE="FP-2">George D. Aiken Wilderness</FP>
                            <FP SOURCE="FP-2">Glastenbury Wilderness</FP>
                            <FP SOURCE="FP-2">Joseph Battell Wilderness</FP>
                            <FP SOURCE="FP-2">Lye Brook Wilderness</FP>
                            <FP SOURCE="FP-2">Peru Peak Wilderness</FP>
                            <HD SOURCE="HD1">Virginia</HD>
                            <FP SOURCE="FP-2">Barbours Creek Wilderness</FP>
                            <FP SOURCE="FP-2">Beartown Wilderness</FP>
                            <FP SOURCE="FP-2">Brush Mountain East Wilderness</FP>
                            <FP SOURCE="FP-2">Brush Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Garden Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Hunting Camp Creek Wilderness</FP>
                            <FP SOURCE="FP-2">James River Face Wilderness</FP>
                            <FP SOURCE="FP-2">Kimberling Creek Wilderness</FP>
                            <FP SOURCE="FP-2">Lewis Fork Wilderness</FP>
                            <FP SOURCE="FP-2">Little Dry Run Wilderness</FP>
                            <FP SOURCE="FP-2">Little Wilson Creek Wilderness</FP>
                            <FP SOURCE="FP-2">Mountain Lake Wilderness</FP>
                            <FP SOURCE="FP-2">Peters Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Priest Wilderness</FP>
                            <FP SOURCE="FP-2">Raccoon Branch Wilderness</FP>
                            <FP SOURCE="FP-2">Ramseys Draft Wilderness</FP>
                            <FP SOURCE="FP-2">Rich Hole Wilderness</FP>
                            <FP SOURCE="FP-2">Rough Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Saint Mary's Wilderness</FP>
                            <FP SOURCE="FP-2">Shawvers Run Wilderness</FP>
                            <FP SOURCE="FP-2">Shenandoah Wilderness</FP>
                            <FP SOURCE="FP-2">Stone Mountain Wilderness</FP>
                            <FP SOURCE="FP-2">Three Ridges Wilderness</FP>
                            <FP SOURCE="FP-2">Thunder Ridge Wilderness</FP>
                            <HD SOURCE="HD1">Washington</HD>
                            <FP SOURCE="FP-2">Alpine Lakes Wilderness</FP>
                            <FP SOURCE="FP-2">Boulder River Wilderness</FP>
                            <FP SOURCE="FP-2">Buckhorn Wilderness</FP>
                            <FP SOURCE="FP-2">Clearwater Wilderness</FP>
                            <FP SOURCE="FP-2">Colonel Bob Wilderness</FP>
                            <FP SOURCE="FP-2">Daniel J. Evans Wilderness *</FP>
                            <FP SOURCE="FP-2">Glacier Peak Wilderness</FP>
                            <FP SOURCE="FP-2">Glacier View Wilderness</FP>
                            <FP SOURCE="FP-2">Goat Rocks Wilderness</FP>
                            <FP SOURCE="FP-2">Henry M. Jackson Wilderness</FP>
                            <FP SOURCE="FP-2">Indian Heaven Wilderness</FP>
                            <FP SOURCE="FP-2">Juniper Dunes Wilderness</FP>
                            <FP SOURCE="FP-2">Lake Chelan-Sawtooth Wilderness</FP>
                            <FP SOURCE="FP-2">Mount Adams Wilderness</FP>
                            <FP SOURCE="FP-2">Mount Baker Wilderness *</FP>
                            <FP SOURCE="FP-2">Mount Rainier Wilderness</FP>
                            <FP SOURCE="FP-2">Mount Skokomish Wilderness</FP>
                            <FP SOURCE="FP-2">Noisy-Diobsud Wilderness</FP>
                            <FP SOURCE="FP-2">Norse Peak Wilderness</FP>
                            <FP SOURCE="FP-2">Pasayten Wilderness *</FP>
                            <FP SOURCE="FP-2">Salmo-Priest Wilderness *</FP>
                            <FP SOURCE="FP-2">San Juan Wilderness *</FP>
                            <FP SOURCE="FP-2">Stephen Mather Wilderness *</FP>
                            <FP SOURCE="FP-2">Tatoosh Wilderness</FP>
                            <FP SOURCE="FP-2">The Brothers Wilderness</FP>
                            <FP SOURCE="FP-2">Trapper Creek Wilderness</FP>
                            <FP SOURCE="FP-2">Washington Islands Wilderness *</FP>
                            <FP SOURCE="FP-2">Wenaha-Tucannon Wilderness</FP>
                            <FP SOURCE="FP-2">
                                Wild Sky Wilderness
                                <PRTPAGE P="465"/>
                            </FP>
                            <FP SOURCE="FP-2">William O. Douglas Wilderness</FP>
                            <FP SOURCE="FP-2">Wonder Mountain Wilderness</FP>
                            <HD SOURCE="HD1">West Virginia</HD>
                            <FP SOURCE="FP-2">Big Draft Wilderness</FP>
                            <FP SOURCE="FP-2">Cranberry Wilderness</FP>
                            <FP SOURCE="FP-2">Dolly Sods Wilderness</FP>
                            <FP SOURCE="FP-2">Laurel Fork North Wilderness</FP>
                            <FP SOURCE="FP-2">Laurel Fork South Wilderness</FP>
                            <FP SOURCE="FP-2">Mountain Lake Wilderness</FP>
                            <FP SOURCE="FP-2">Otter Creek Wilderness</FP>
                            <FP SOURCE="FP-2">Roaring Plains West Wilderness</FP>
                            <FP SOURCE="FP-2">Spice Run Wilderness</FP>
                            <HD SOURCE="HD1">Wisconsin</HD>
                            <FP SOURCE="FP-2">Blackjack Springs Wilderness</FP>
                            <FP SOURCE="FP-2">Gaylord Nelson Wilderness *</FP>
                            <FP SOURCE="FP-2">Headwaters Wilderness</FP>
                            <FP SOURCE="FP-2">Porcupine Lake Wilderness</FP>
                            <FP SOURCE="FP-2">Rainbow Lake Wilderness</FP>
                            <FP SOURCE="FP-2">Whisker Lake Wilderness</FP>
                            <FP SOURCE="FP-2">Wisconsin Islands Wilderness *</FP>
                            <HD SOURCE="HD1">Wyoming</HD>
                            <FP SOURCE="FP-2">Absaroka-Beartooth Wilderness</FP>
                            <FP SOURCE="FP-2">Bridger Wilderness</FP>
                            <FP SOURCE="FP-2">Cloud Peak Wilderness</FP>
                            <FP SOURCE="FP-2">Encampment River Wilderness</FP>
                            <FP SOURCE="FP-2">Fitzpatrick Wilderness</FP>
                            <FP SOURCE="FP-2">Gros Ventre Wilderness</FP>
                            <FP SOURCE="FP-2">Huston Park Wilderness</FP>
                            <FP SOURCE="FP-2">Jedediah Smith Wilderness</FP>
                            <FP SOURCE="FP-2">North Absaroka Wilderness</FP>
                            <FP SOURCE="FP-2">Platte River Wilderness</FP>
                            <FP SOURCE="FP-2">Popo Agie Wilderness</FP>
                            <FP SOURCE="FP-2">Savage Run Wilderness</FP>
                            <FP SOURCE="FP-2">Teton Wilderness</FP>
                            <FP SOURCE="FP-2">Washakie Wilderness</FP>
                            <FP SOURCE="FP-2">Winegar Hole Wilderness</FP>
                            <HD SOURCE="HD1">A.6 National Wild and Scenic River</HD>
                            <HD SOURCE="HD1">Alabama</HD>
                            <FP SOURCE="FP-2">Sipsey Fork of the West Fork River</FP>
                            <HD SOURCE="HD1">Alaska</HD>
                            <FP SOURCE="FP-2">Alagnak River</FP>
                            <FP SOURCE="FP-2">Alatna River</FP>
                            <FP SOURCE="FP-2">Andreafsky River *</FP>
                            <FP SOURCE="FP-2">Aniakchak River</FP>
                            <FP SOURCE="FP-2">Beaver Creek</FP>
                            <FP SOURCE="FP-2">Birch Creek</FP>
                            <FP SOURCE="FP-2">Charley River *</FP>
                            <FP SOURCE="FP-2">Chilikadrotna River</FP>
                            <FP SOURCE="FP-2">Delta River</FP>
                            <FP SOURCE="FP-2">Fortymile River *</FP>
                            <FP SOURCE="FP-2">Gulkana River</FP>
                            <FP SOURCE="FP-2">Ivishak River</FP>
                            <FP SOURCE="FP-2">John River</FP>
                            <FP SOURCE="FP-2">Kobuk River</FP>
                            <FP SOURCE="FP-2">Mulchatna River</FP>
                            <FP SOURCE="FP-2">Noatak River</FP>
                            <FP SOURCE="FP-2">North Fork Koyukuk River *</FP>
                            <FP SOURCE="FP-2">Nowitna River</FP>
                            <FP SOURCE="FP-2">Salmon River *</FP>
                            <FP SOURCE="FP-2">Selawik River</FP>
                            <FP SOURCE="FP-2">Sheenjek River</FP>
                            <FP SOURCE="FP-2">Tinayguk River</FP>
                            <FP SOURCE="FP-2">Tlikakila River *</FP>
                            <FP SOURCE="FP-2">Unalakleet River</FP>
                            <FP SOURCE="FP-2">Wind River</FP>
                            <HD SOURCE="HD1">Arizona</HD>
                            <FP SOURCE="FP-2">Fossil Creek</FP>
                            <FP SOURCE="FP-2">Verde River</FP>
                            <HD SOURCE="HD1">Arkansas</HD>
                            <FP SOURCE="FP-2">Big Piney Creek</FP>
                            <FP SOURCE="FP-2">Buffalo River</FP>
                            <FP SOURCE="FP-2">Cossatot River</FP>
                            <FP SOURCE="FP-2">Hurricane Creek</FP>
                            <FP SOURCE="FP-2">Little Missouri River</FP>
                            <FP SOURCE="FP-2">Mulberry River</FP>
                            <FP SOURCE="FP-2">North Sylamore Creek</FP>
                            <FP SOURCE="FP-2">Richland Creek</FP>
                            <HD SOURCE="HD1">California</HD>
                            <FP SOURCE="FP-2">Amargosa River</FP>
                            <FP SOURCE="FP-2">American (Lower) River *</FP>
                            <FP SOURCE="FP-2">Bautista Creek</FP>
                            <FP SOURCE="FP-2">Big Sur River</FP>
                            <FP SOURCE="FP-2">Black Butte River</FP>
                            <FP SOURCE="FP-2">Cottonwood Creek</FP>
                            <FP SOURCE="FP-2">Deep Creek</FP>
                            <FP SOURCE="FP-2">Eel River *</FP>
                            <FP SOURCE="FP-2">Feather River</FP>
                            <FP SOURCE="FP-2">Fuller Mill Creek</FP>
                            <FP SOURCE="FP-2">Kern River</FP>
                            <FP SOURCE="FP-2">Kings River</FP>
                            <FP SOURCE="FP-2">Klamath River *</FP>
                            <FP SOURCE="FP-2">Merced River</FP>
                            <FP SOURCE="FP-2">North Fork American River *</FP>
                            <FP SOURCE="FP-2">North Fork San Jacinto River</FP>
                            <FP SOURCE="FP-2">Owens River Headwaters</FP>
                            <FP SOURCE="FP-2">Palm Canyon Creek</FP>
                            <FP SOURCE="FP-2">Piru Creek</FP>
                            <FP SOURCE="FP-2">Sespe Creek</FP>
                            <FP SOURCE="FP-2">Sisquoc River</FP>
                            <FP SOURCE="FP-2">Smith River *</FP>
                            <FP SOURCE="FP-2">Surprise Canyon Creek</FP>
                            <FP SOURCE="FP-2">Trinity River</FP>
                            <FP SOURCE="FP-2">Tuolumne River</FP>
                            <FP SOURCE="FP-2">Whitewater River</FP>
                            <HD SOURCE="HD1">Colorado</HD>
                            <FP SOURCE="FP-2">Cache la Poudre River</FP>
                            <HD SOURCE="HD1">Connecticut</HD>
                            <FP SOURCE="FP-2">Eightmile River *</FP>
                            <FP SOURCE="FP-2">Farmington (Lower) River and Salmon Brook *</FP>
                            <FP SOURCE="FP-2">Housatonic River</FP>
                            <FP SOURCE="FP-2">West Branch Farmington River</FP>
                            <FP SOURCE="FP-2">Wood-Pawcatuck Rivers Watershed *</FP>
                            <HD SOURCE="HD1">Delaware</HD>
                            <FP SOURCE="FP-2">White Clay Creek *</FP>
                            <HD SOURCE="HD1">Florida</HD>
                            <FP SOURCE="FP-2">Loxahatchee River</FP>
                            <FP SOURCE="FP-2">
                                Wekiva River *
                                <PRTPAGE P="466"/>
                            </FP>
                            <HD SOURCE="HD1">Georgia</HD>
                            <FP SOURCE="FP-2">Chattooga River</FP>
                            <HD SOURCE="HD1">Idaho</HD>
                            <FP SOURCE="FP-2">Battle Creek</FP>
                            <FP SOURCE="FP-2">Big Jacks Creek</FP>
                            <FP SOURCE="FP-2">Bruneau River</FP>
                            <FP SOURCE="FP-2">Cottonwood Creek</FP>
                            <FP SOURCE="FP-2">Deep Creek</FP>
                            <FP SOURCE="FP-2">Dickshooter Creek</FP>
                            <FP SOURCE="FP-2">Duncan Creek</FP>
                            <FP SOURCE="FP-2">Jarbidge River</FP>
                            <FP SOURCE="FP-2">Little Jacks Creek</FP>
                            <FP SOURCE="FP-2">Middle Fork Clearwater River</FP>
                            <FP SOURCE="FP-2">Middle Fork Salmon River</FP>
                            <FP SOURCE="FP-2">North Fork Owyhee River</FP>
                            <FP SOURCE="FP-2">Owyhee River</FP>
                            <FP SOURCE="FP-2">Rapid River</FP>
                            <FP SOURCE="FP-2">Red Canyon</FP>
                            <FP SOURCE="FP-2">Saint Joe River *</FP>
                            <FP SOURCE="FP-2">Salmon River</FP>
                            <FP SOURCE="FP-2">Sheep Creek</FP>
                            <FP SOURCE="FP-2">Snake River *</FP>
                            <FP SOURCE="FP-2">South Fork Owyhee River</FP>
                            <FP SOURCE="FP-2">West Fork Bruneau River</FP>
                            <FP SOURCE="FP-2">Wickahoney Creek</FP>
                            <HD SOURCE="HD1">Illinois</HD>
                            <FP SOURCE="FP-2">Middle Fork Vermilion River</FP>
                            <HD SOURCE="HD1">Kentucky</HD>
                            <FP SOURCE="FP-2">Red River</FP>
                            <HD SOURCE="HD1">Louisiana</HD>
                            <FP SOURCE="FP-2">Saline Bayou</FP>
                            <HD SOURCE="HD1">Maine</HD>
                            <FP SOURCE="FP-2">Allagash River</FP>
                            <FP SOURCE="FP-2">York River *</FP>
                            <HD SOURCE="HD1">Massachusetts</HD>
                            <FP SOURCE="FP-2">Nashua, Squannacook and Nissitissit Rivers</FP>
                            <FP SOURCE="FP-2">Sudbury, Assabet and Concord Rivers</FP>
                            <FP SOURCE="FP-2">Taunton River *</FP>
                            <FP SOURCE="FP-2">Westfield River</FP>
                            <HD SOURCE="HD1">Michigan</HD>
                            <FP SOURCE="FP-2">Au Sable River</FP>
                            <FP SOURCE="FP-2">Bear Creek</FP>
                            <FP SOURCE="FP-2">Black River *</FP>
                            <FP SOURCE="FP-2">Carp River *</FP>
                            <FP SOURCE="FP-2">East Branch Tahquamenon River</FP>
                            <FP SOURCE="FP-2">Indian River</FP>
                            <FP SOURCE="FP-2">Manistee River</FP>
                            <FP SOURCE="FP-2">Ontonagon River</FP>
                            <FP SOURCE="FP-2">Paint River</FP>
                            <FP SOURCE="FP-2">Pere Marquette River</FP>
                            <FP SOURCE="FP-2">Pine River</FP>
                            <FP SOURCE="FP-2">Presque Isle River</FP>
                            <FP SOURCE="FP-2">Sturgeon River (Hiawatha National Forest) *</FP>
                            <FP SOURCE="FP-2">Sturgeon River (Ottawa National Forest) *</FP>
                            <FP SOURCE="FP-2">Whitefish River *</FP>
                            <FP SOURCE="FP-2">Yellow Dog River</FP>
                            <HD SOURCE="HD1">Minnesota</HD>
                            <FP SOURCE="FP-2">St. Croix River *</FP>
                            <HD SOURCE="HD1">Mississippi</HD>
                            <FP SOURCE="FP-2">Black Creek</FP>
                            <HD SOURCE="HD1">Missouri</HD>
                            <FP SOURCE="FP-2">Eleven Point River</FP>
                            <HD SOURCE="HD1">Montana</HD>
                            <FP SOURCE="FP-2">East Rosebud Creek</FP>
                            <FP SOURCE="FP-2">Flathead River</FP>
                            <FP SOURCE="FP-2">Missouri River *</FP>
                            <HD SOURCE="HD1">Nebraska</HD>
                            <FP SOURCE="FP-2">Missouri River *</FP>
                            <FP SOURCE="FP-2">Niobrara River</FP>
                            <HD SOURCE="HD1">New Hampshire</HD>
                            <FP SOURCE="FP-2">Lamprey River *</FP>
                            <FP SOURCE="FP-2">Nashua, Squannacook and Nissitissit Rivers</FP>
                            <FP SOURCE="FP-2">Wildcat River</FP>
                            <HD SOURCE="HD1">New Jersey</HD>
                            <FP SOURCE="FP-2">Delaware (Lower) River *</FP>
                            <FP SOURCE="FP-2">Delaware (Middle) River</FP>
                            <FP SOURCE="FP-2">Great Egg Harbor River *</FP>
                            <FP SOURCE="FP-2">Maurice River *</FP>
                            <FP SOURCE="FP-2">Musconetcong River</FP>
                            <HD SOURCE="HD1">New Mexico</HD>
                            <FP SOURCE="FP-2">East Fork Jemez River</FP>
                            <FP SOURCE="FP-2">Pecos River</FP>
                            <FP SOURCE="FP-2">Rio Chama</FP>
                            <FP SOURCE="FP-2">Rio Grande</FP>
                            <HD SOURCE="HD1">New York</HD>
                            <FP SOURCE="FP-2">Delaware (Upper) River</FP>
                            <HD SOURCE="HD1">North Carolina</HD>
                            <FP SOURCE="FP-2">Chattooga River</FP>
                            <FP SOURCE="FP-2">Horsepasture River</FP>
                            <FP SOURCE="FP-2">Lumber River</FP>
                            <FP SOURCE="FP-2">New River</FP>
                            <FP SOURCE="FP-2">Wilson Creek</FP>
                            <HD SOURCE="HD1">Ohio</HD>
                            <FP SOURCE="FP-2">Big and Little Darby Creeks</FP>
                            <FP SOURCE="FP-2">Little Beaver Creek *</FP>
                            <FP SOURCE="FP-2">Little Miami River *</FP>
                            <HD SOURCE="HD1">Oregon</HD>
                            <FP SOURCE="FP-2">Big Marsh Creek</FP>
                            <FP SOURCE="FP-2">Chetco River</FP>
                            <FP SOURCE="FP-2">Clackamas River</FP>
                            <FP SOURCE="FP-2">Collawash River</FP>
                            <FP SOURCE="FP-2">Crescent Creek</FP>
                            <FP SOURCE="FP-2">Crooked River</FP>
                            <FP SOURCE="FP-2">Deschutes River</FP>
                            <FP SOURCE="FP-2">Donner und Blitzen River</FP>
                            <FP SOURCE="FP-2">Eagle Creek (Mt. Hood National Forest)</FP>
                            <FP SOURCE="FP-2">Eagle Creek (Wallowa-Whitman National Forest)</FP>
                            <FP SOURCE="FP-2">
                                East Fork Hood River
                                <PRTPAGE P="467"/>
                            </FP>
                            <FP SOURCE="FP-2">Elk Creek</FP>
                            <FP SOURCE="FP-2">Elk River</FP>
                            <FP SOURCE="FP-2">Elkhorn Creek</FP>
                            <FP SOURCE="FP-2">Fifteenmile Creek</FP>
                            <FP SOURCE="FP-2">Fish Creek</FP>
                            <FP SOURCE="FP-2">Franklin Creek *</FP>
                            <FP SOURCE="FP-2">Grande Ronde River</FP>
                            <FP SOURCE="FP-2">Illinois River *</FP>
                            <FP SOURCE="FP-2">Imnaha River</FP>
                            <FP SOURCE="FP-2">Jenny Creek</FP>
                            <FP SOURCE="FP-2">John Day River</FP>
                            <FP SOURCE="FP-2">Joseph Creek</FP>
                            <FP SOURCE="FP-2">Klamath River</FP>
                            <FP SOURCE="FP-2">Little Deschutes River</FP>
                            <FP SOURCE="FP-2">Lobster Creek</FP>
                            <FP SOURCE="FP-2">Lostine River</FP>
                            <FP SOURCE="FP-2">Malheur River</FP>
                            <FP SOURCE="FP-2">McKenzie River</FP>
                            <FP SOURCE="FP-2">Metolius River</FP>
                            <FP SOURCE="FP-2">Middle Fork Hood River</FP>
                            <FP SOURCE="FP-2">Minam River</FP>
                            <FP SOURCE="FP-2">Molalla River</FP>
                            <FP SOURCE="FP-2">Nestucca River</FP>
                            <FP SOURCE="FP-2">North Fork Crooked River</FP>
                            <FP SOURCE="FP-2">North Fork John Day River</FP>
                            <FP SOURCE="FP-2">North Fork Malheur River</FP>
                            <FP SOURCE="FP-2">North Fork Middle Fork Willamette River</FP>
                            <FP SOURCE="FP-2">North Fork Owyhee River</FP>
                            <FP SOURCE="FP-2">North Fork Silver Creek</FP>
                            <FP SOURCE="FP-2">North Fork Smith River</FP>
                            <FP SOURCE="FP-2">North Fork Sprague River</FP>
                            <FP SOURCE="FP-2">North Powder River</FP>
                            <FP SOURCE="FP-2">North Umpqua River</FP>
                            <FP SOURCE="FP-2">Owyhee River</FP>
                            <FP SOURCE="FP-2">Powder River</FP>
                            <FP SOURCE="FP-2">Quartzville Creek</FP>
                            <FP SOURCE="FP-2">River Styx</FP>
                            <FP SOURCE="FP-2">Roaring River</FP>
                            <FP SOURCE="FP-2">Rogue (Upper) River</FP>
                            <FP SOURCE="FP-2">Rogue River *</FP>
                            <FP SOURCE="FP-2">Salmon River</FP>
                            <FP SOURCE="FP-2">Sandy River</FP>
                            <FP SOURCE="FP-2">Snake River *</FP>
                            <FP SOURCE="FP-2">South Fork Clackamas River</FP>
                            <FP SOURCE="FP-2">South Fork John Day River</FP>
                            <FP SOURCE="FP-2">South Fork Roaring River</FP>
                            <FP SOURCE="FP-2">Spring Creek</FP>
                            <FP SOURCE="FP-2">Sycan River</FP>
                            <FP SOURCE="FP-2">Walker Creek</FP>
                            <FP SOURCE="FP-2">Wallowa River</FP>
                            <FP SOURCE="FP-2">Wasson Creek</FP>
                            <FP SOURCE="FP-2">Wenaha River</FP>
                            <FP SOURCE="FP-2">West Little Owyhee River</FP>
                            <FP SOURCE="FP-2">White River</FP>
                            <FP SOURCE="FP-2">Whychus Creek</FP>
                            <FP SOURCE="FP-2">Wildhorse and Kiger Creeks</FP>
                            <FP SOURCE="FP-2">Zig Zag River</FP>
                            <HD SOURCE="HD1">Pennsylvania</HD>
                            <FP SOURCE="FP-2">Allegheny River *</FP>
                            <FP SOURCE="FP-2">Clarion River</FP>
                            <FP SOURCE="FP-2">Delaware (Lower) River *</FP>
                            <FP SOURCE="FP-2">Delaware (Middle) River</FP>
                            <FP SOURCE="FP-2">Delaware (Upper) River</FP>
                            <FP SOURCE="FP-2">White Clay Creek</FP>
                            <HD SOURCE="HD1">Puerto Rico</HD>
                            <FP SOURCE="FP-2">Rio de la Mina</FP>
                            <FP SOURCE="FP-2">Rio Icacos</FP>
                            <FP SOURCE="FP-2">Rio Mameyes</FP>
                            <HD SOURCE="HD1">Rhode Island</HD>
                            <FP SOURCE="FP-2">Wood-Pawcatuck Rivers Watershed *</FP>
                            <HD SOURCE="HD1">South Carolina</HD>
                            <FP SOURCE="FP-2">Chattooga River</FP>
                            <HD SOURCE="HD1">South Dakota</HD>
                            <FP SOURCE="FP-2">Missouri River *</FP>
                            <HD SOURCE="HD1">Tennessee</HD>
                            <FP SOURCE="FP-2">Obed River</FP>
                            <HD SOURCE="HD1">Texas</HD>
                            <FP SOURCE="FP-2">Rio Grande</FP>
                            <HD SOURCE="HD1">Utah</HD>
                            <FP SOURCE="FP-2">Green River</FP>
                            <FP SOURCE="FP-2">Virgin River</FP>
                            <HD SOURCE="HD1">Vermont</HD>
                            <FP SOURCE="FP-2">Missisquoi and Trout Rivers</FP>
                            <HD SOURCE="HD1">Washington</HD>
                            <FP SOURCE="FP-2">Illabot Creek</FP>
                            <FP SOURCE="FP-2">Klickitat River *</FP>
                            <FP SOURCE="FP-2">Middle Fork Snoqualmie River</FP>
                            <FP SOURCE="FP-2">Pratt River</FP>
                            <FP SOURCE="FP-2">Skagit River *</FP>
                            <FP SOURCE="FP-2">White Salmon River</FP>
                            <HD SOURCE="HD1">West Virginia</HD>
                            <FP SOURCE="FP-2">Bluestone River</FP>
                            <HD SOURCE="HD1">Wisconsin</HD>
                            <FP SOURCE="FP-2">St. Croix River *</FP>
                            <FP SOURCE="FP-2">Wolf River</FP>
                            <HD SOURCE="HD1">Wyoming</HD>
                            <FP SOURCE="FP-2">Clarks Fork River</FP>
                            <FP SOURCE="FP-2">Snake River Headwaters</FP>
                        </APPENDIX>
                    </SUBPART>
                </PART>
                <PART>
                    <EAR>Pt. 140</EAR>
                    <HD SOURCE="HED">PART 140—MARINE SANITATION DEVICE STANDARD</HD>
                    <CONTENTS>
                        <SECHD>Sec.</SECHD>
                        <SECTNO>140.1</SECTNO>
                        <SUBJECT>Definitions.</SUBJECT>
                        <SECTNO>140.2</SECTNO>
                        <SUBJECT>Scope of standard.</SUBJECT>
                        <SECTNO>140.3</SECTNO>
                        <SUBJECT>Standard.</SUBJECT>
                        <SECTNO>140.4</SECTNO>
                        <SUBJECT>Complete prohibition.</SUBJECT>
                        <SECTNO>140.5</SECTNO>
                        <SUBJECT>Analytical procedures.</SUBJECT>
                    </CONTENTS>
                    <AUTH>
                        <HD SOURCE="HED">Authority:</HD>
                        <P>33 U.S.C. 1322, as amended.</P>
                    </AUTH>
                    <SOURCE>
                        <HD SOURCE="HED">Source:</HD>
                        <P>41 FR 4453, Jan. 29, 1976, unless otherwise noted.</P>
                    </SOURCE>
                    <SECTION>
                        <PRTPAGE P="468"/>
                        <SECTNO>§ 140.1</SECTNO>
                        <SUBJECT>Definitions.</SUBJECT>
                        <P>For the purpose of these standards the following definitions shall apply:</P>
                        <P>
                            (a) 
                            <E T="03">Sewage</E>
                             means human body wastes and the wastes from toilets and other receptacles intended to receive or retain body wastes;
                        </P>
                        <P>
                            (b) 
                            <E T="03">Discharge</E>
                             includes, but is not limited to, any spilling, leaking, pumping, pouring, emitting, emptying, or dumping;
                        </P>
                        <P>
                            (c) 
                            <E T="03">Marine sanitation device</E>
                             includes any equipment for installation onboard a vessel and which is designed to receive, retain, treat, or discharge sewage and any process to treat such sewage;
                        </P>
                        <P>
                            (d) 
                            <E T="03">Vessel</E>
                             includes every description of watercraft or other artificial contrivance used, or capable of being used, as a means of transportation on waters of the United States;
                        </P>
                        <P>
                            (e) 
                            <E T="03">New vessel</E>
                             refers to any vessel on which construction was initiated on or after January 30, 1975;
                        </P>
                        <P>
                            (f) 
                            <E T="03">Existing vessel</E>
                             refers to any vessel on which construction was initiated before January 30, 1975;
                        </P>
                        <P>
                            (g) 
                            <E T="03">Fecal coliform bacteria</E>
                             are those organisms associated with the intestines of warm-blooded animals that are commonly used to indicate the presence of fecal material and the potential presence of organisms capable of causing human disease.
                        </P>
                    </SECTION>
                    <SECTION>
                        <SECTNO>§ 140.2</SECTNO>
                        <SUBJECT>Scope of standard.</SUBJECT>
                        <P>The standard adopted herein applies only to vessels on which a marine sanitation device has been installed. The standard does not require the installation of a marine sanitation device on any vessel that is not so equipped. The standard applies to vessels owned and operated by the United States unless the Secretary of Defense finds that compliance would not be in the interest of national security.</P>
                    </SECTION>
                    <SECTION>
                        <SECTNO>§ 140.3</SECTNO>
                        <SUBJECT>Standard.</SUBJECT>
                        <P>(a) (1) In freshwater lakes, freshwater reservoirs or other freshwater impoundments whose inlets or outlets are such as to prevent the ingress or egress by vessel traffic subject to this regulation, or in rivers not capable of navigation by interstate vessel traffic subject to this regulation, marine sanitation devices certified by the U.S. Coast Guard (see 33 CFR part 159, published in 40 FR 4622, January 30, 1975), installed on all vessels shall be designed and operated to prevent the overboard discharge of sewage, treated or untreated, or of any waste derived from sewage. This shall not be construed to prohibit the carriage of Coast Guard-certified flow-through treatment devices which have been secured so as to prevent such discharges.</P>
                        <P>(2) In all other waters, Coast Guard-certified marine sanitation devices installed on all vessels shall be designed and operated to either retain, dispose of, or discharge sewage. If the device has a discharge, subject to paragraph (d) of this section, the effluent shall not have a fecal coliform bacterial count of greater than 1,000 per 100 milliliters nor visible floating solids. Waters where a Coast Guard-certified marine sanitation device permitting discharge is allowed include coastal waters and estuaries, the Great Lakes and inter-connected waterways, fresh-water lakes and impoundments accessible through locks, and other flowing waters that are navigable interstate by vessels subject to this regulation.</P>
                        <P>(b) This standard shall become effective on January 30, 1977 for new vessels and on January 30, 1980 for existing vessels (or, in the case of vessels owned and operated by the Department of Defense, two years and five years, for new and existing vessels, respectively, after promulgation of implementing regulations by the Secretary of Defense under section 312(d) of the Act).</P>
                        <P>(c) Any vessel which is equipped as of the date of promulgation of this regulation with a Coast Guard-certified flow-through marine sanitation device meeting the requirements of paragraph (a)(2) of this section, shall not be required to comply with the provisions designed to prevent the overboard discharge of sewage, treated or untreated, in paragraph (a)(1) of this section, for the operable life of that device.</P>
                        <P>
                            (d) After January 30, 1980, subject to paragraphs (e) and (f) of this section, marine sanitation devices on all vessels on waters that are not subject to a prohibition of the overboard discharge of sewage, treated or untreated, as specified in paragraph (a)(1) of this section, shall be designed and operated to 
                            <PRTPAGE P="469"/>
                            either retain, dispose of, or discharge sewage, and shall be certified by the U.S. Coast Guard. If the device has a discharge, the effluent shall not have a fecal coliform bacterial count of greater than 200 per 100 milliliters, nor suspended solids greater than 150 mg/1.
                        </P>
                        <P>(e) Any existing vessel on waters not subject to a prohibition of the overboard discharge of sewage in paragraph (a)(1) of this section, and which is equipped with a certified device on or before January 30, 1978, shall not be required to comply with paragraph (d) of this section, for the operable life of that device.</P>
                        <P>(f) Any new vessel on waters not subject to the prohibition of the overboard discharge of sewage in paragraph (a)(1) of this section, and on which construction is initiated before January 31, 1980, which is equipped with a marine sanitation device before January 31, 1980, certified under paragraph (a)(2) of this section, shall not be required to comply with paragraph (d) of this section, for the operable life of that device.</P>
                        <P>(g) The degrees of treatment described in paragraphs (a) and (d) of this section are “appropriate standards” for purposes of Coast Guard and Department of Defense certification pursuant to section 312(g)(2) of the Act.</P>
                        <CITA>[41 FR 4453, Jan. 29, 1976, as amended at 60 FR 33932, June 29, 1995]</CITA>
                    </SECTION>
                    <SECTION>
                        <SECTNO>§ 140.4</SECTNO>
                        <SUBJECT>Complete prohibition.</SUBJECT>
                        <P>(a) Prohibition pursuant to CWA section 312(f)(3): a State may completely prohibit the discharge from all vessels of any sewage, whether treated or not, into some or all of the waters within such State by making a written application to the Administrator, Environmental Protection Agency, and by receiving the Administrator's affirmative determination pursuant to section 312(f)(3) of the Act. Upon receipt of an application under section 312(f)(3) of the Act, the Administrator will determine within 90 days whether adequate facilities for the safe and sanitary removal and treatment of sewage from all vessels using such waters are reasonably available. Applications made by States pursuant to section 312(f)(3) of the Act shall include:</P>
                        <P>(1) A certification that the protection and enhancement of the waters described in the petition require greater environmental protection than the applicable Federal standard;</P>
                        <P>(2) A map showing the location of commercial and recreational pump-out facilities;</P>
                        <P>(3) A description of the location of pump-out facilities within waters designated for no discharge;</P>
                        <P>(4) The general schedule of operating hours of the pump-out facilities;</P>
                        <P>(5) The draught requirements on vessels that may be excluded because of insufficient water depth adjacent to the facility;</P>
                        <P>(6) Information indicating that treatment of wastes from such pump-out facilities is in conformance with Federal law; and</P>
                        <P>(7) Information on vessel population and vessel usage of the subject waters.</P>
                        <P>
                            (b) Prohibition pursuant to CWA section 312(f)(4)(A): a State may make a written application to the Administrator, Environmental Protection Agency, under section 312(f)(4)(A) of the Act, for the issuance of a regulation completely prohibiting discharge from a vessel of any sewage, whether treated or not, into particular waters of the United States or specified portions thereof, which waters are located within the boundaries of such State. Such application shall specify with particularly the waters, or portions thereof, for which a complete prohibition is desired. The application shall include identification of water recreational areas, drinking water intakes, aquatic sanctuaries, identifiable fish-spawning and nursery areas, and areas of intensive boating activities. If, on the basis of the State's application and any other information available to him, the Administrator is unable to make a finding that the waters listed in the application require a complete prohibition of any discharge in the waters or portions thereof covered by the application, he shall state the reasons why he cannot make such a finding, and shall deny the application. If the Administrator makes a finding that the waters listed in the application require a complete prohibition of any discharge in all or any part of the waters or portions thereof covered by 
                            <PRTPAGE P="470"/>
                            the State's application, he shall publish notice of such findings together with a notice of proposed rule making, and then shall proceed in accordance with 5 U.S.C. 553. If the Administrator's finding is that applicable water quality standards require a complete prohibition covering a more restricted or more expanded area than that applied for by the State, he shall state the reasons why his finding differs in scope from that requested in the State's application.
                        </P>
                        <P>(1) For the following waters the discharge from a vessel of any sewage (whether treated or not) is completely prohibited pursuant to CWA section 312(f)(4)(A):</P>
                        <P>(i) Boundary Waters Canoe Area, formerly designated as the Superior, Little Indian Sioux, and Caribou Roadless Areas, in the Superior National Forest, Minnesota, as described in 16 U.S.C. 577-577d1.</P>
                        <P>
                            (ii) Waters of the State of Florida within the boundaries of the Florida Keys National Marine Sanctuary as delineated on a map of the Sanctuary at 
                            <E T="03">http://www.fknms.nos.noaa.gov</E>
                            /.
                        </P>
                        <P>(2)(i) For the marine waters of the State of California, the following vessels are completely prohibited from discharging any sewage (whether treated or not):</P>
                        <P>(A) A large passenger vessel;</P>
                        <P>
                            (B) A large oceangoing vessel equipped with a holding tank which has not fully used the holding tank's capacity, or which contains more than 
                            <E T="03">de minimis</E>
                             amounts of sewage generated while the vessel was outside of the marine waters of the State of California.
                        </P>
                        <P>(ii) For purposes of paragraph (b)(2) of this section:</P>
                        <P>
                            (A) “Marine waters of the State of California” means the territorial sea measured from the baseline as determined in accordance with the Convention on the Territorial Sea and the Contiguous Zone and extending seaward a distance of three miles, and all enclosed bays and estuaries subject to tidal influences from the Oregon border (41.999325 North Latitude, 124.212110 West Longitude, decimal degrees, NAD 1983) to the Mexican border (32.471231 North Latitude, 117.137814 West Longitude, decimal degrees, NAD 1983). A map illustrating these waters can be obtained from EPA or viewed at 
                            <E T="03">http://www.epa.gov/region9/water/no-discharge/overview.html.</E>
                        </P>
                        <P>(B) A “large passenger vessel” means a passenger vessel, as defined in section 2101(22) of title 46, United States Code, of 300 gross tons or more, as measured under the International Convention on Tonnage Measurement of Ships, 1969, measurement system in 46 U.S.C. 14302, or the regulatory measurement system of 46 U.S.C. 14502 for vessels not measured under 46 U.S.C. 14302, that has berths or overnight accommodations for passengers.</P>
                        <P>(C) A “large oceangoing vessel” means a private, commercial, government, or military vessel of 300 gross tons or more, as measured under the International Convention on Tonnage Measurement of Ships, 1969, measurement system in 46 U.S.C. 14302, or the regulatory measurement system of 46 U.S.C. 14502 for vessels not measured under 46 U.S.C.14302, that is not a large passenger vessel.</P>
                        <P>(D) A “holding tank” means a tank specifically designed, constructed, and fitted for the retention of treated or untreated sewage, that has been designated and approved by the ship's flag Administration on the ship's stability plan; a designated ballast tank is not a holding tank for this purpose.</P>
                        <P>
                            (c)(1) 
                            <E T="03">Prohibition pursuant to CWA</E>
                             section 312(f)(4)(B): A State may make written application to the Administrator of the Environmental Protection Agency under section 312(f)(4)(B) of the Act for the issuance of a regulation establishing a drinking water intake no discharge zone which completely prohibits discharge from a vessel of any sewage, whether treated or untreated, into that zone in particular waters, or portions thereof, within such State. Such application shall:
                        </P>
                        <P>(i) Identify and describe exactly and in detail the location of the drinking water supply intake(s) and the community served by the intake(s), including average and maximum expected amounts of inflow;</P>
                        <P>
                            (ii) Specify and describe exactly and in detail, the waters, or portions thereof, for which a complete prohibition is desired, and where appropriate, average, maximum and low flows in million 
                            <PRTPAGE P="471"/>
                            gallons per day (MGD) or the metric equivalent;
                        </P>
                        <P>(iii) Include a map, either a USGS topographic quadrant map or a NOAA nautical chart, as applicable, clearly marking by latitude and longitude the waters or portions thereof to be designated a drinking water intake zone; and</P>
                        <P>(iv) Include a statement of basis justifying the size of the requested drinking water intake zone, for example, identifying areas of intensive boating activities.</P>
                        <P>(2) If the Administrator finds that a complete prohibition is appropriate under this paragraph, he or she shall publish notice of such finding together with a notice of proposed rulemaking, and then shall proceed in accordance with 5 U.S.C. 553. If the Administrator's finding is that a complete prohibition covering a more restricted or more expanded area than that applied for by the State is appropriate, he or she shall also include a statement of the reasons why the finding differs in scope from that requested in the State's application.</P>
                        <P>(3) If the Administrator finds that a complete prohibition is inappropriate under this paragraph, he or she shall deny the application and state the reasons for such denial.</P>
                        <P>(4) For the following waters the discharge from a vessel of any sewage, whether treated or not, is completely prohibited pursuant to CWA section 312(f)(4)(B):</P>
                        <P>(i) Two portions of the Hudson River in New York State, the first is bounded by an east-west line through the most northern confluence of the Mohawk River which will be designated by the Troy-Waterford Bridge (126th Street Bridge) on the south and Lock 2 on the north, and the second of which is bounded on the north by the southern end of Houghtaling Island and on the south by a line between the Village of Roseton on the western shore and Low Point on the eastern shore in the vicinity of Chelsea, as described in Items 2 and 3 of 6 NYCRR Part 858.4.</P>
                        <P>(ii) [Reserved]</P>
                        <CITA>[41 FR 4453, Jan. 29, 1976, as amended at 42 FR 43837, Aug. 31, 1977; 60 FR 63945, Dec. 13, 1995; 63 FR 1320, Jan. 8, 1998; 67 FR 35743, May 21, 2002; 77 FR 11411, Feb. 27, 2012]</CITA>
                    </SECTION>
                    <SECTION>
                        <SECTNO>§ 140.5</SECTNO>
                        <SUBJECT>Analytical procedures.</SUBJECT>
                        <P>In determining the composition and quality of effluent discharge from marine sanitation devices, the procedures contained in 40 CFR part 136, “Guidelines Establishing Test Procedures for the Analysis of Pollutants,” or subsequent revisions or amendments thereto, shall be employed.</P>
                    </SECTION>
                </PART>
                <PART>
                    <EAR>Pt. 141</EAR>
                    <HD SOURCE="HED">PART 141—NATIONAL PRIMARY DRINKING WATER REGULATIONS</HD>
                    <CONTENTS>
                        <SUBPART>
                            <HD SOURCE="HED">Subpart A—General</HD>
                            <SECHD>Sec.</SECHD>
                            <SECTNO>141.1</SECTNO>
                            <SUBJECT>Applicability.</SUBJECT>
                            <SECTNO>141.2</SECTNO>
                            <SUBJECT>Definitions.</SUBJECT>
                            <SECTNO>141.3</SECTNO>
                            <SUBJECT>Coverage.</SUBJECT>
                            <SECTNO>141.4</SECTNO>
                            <SUBJECT>Variances and exemptions.</SUBJECT>
                            <SECTNO>141.5</SECTNO>
                            <SUBJECT>Siting requirements.</SUBJECT>
                            <SECTNO>141.6</SECTNO>
                            <SUBJECT>Effective dates.</SUBJECT>
                        </SUBPART>
                        <SUBPART>
                            <HD SOURCE="HED">Subpart B—Maximum Contaminant Levels</HD>
                            <SECTNO>141.11</SECTNO>
                            <SUBJECT>Maximum contaminant levels for inorganic chemicals.</SUBJECT>
                            <SECTNO>141.12</SECTNO>
                            <SUBJECT>[Reserved]</SUBJECT>
                            <SECTNO>141.13</SECTNO>
                            <SUBJECT>Maximum contaminant levels for turbidity.</SUBJECT>
                        </SUBPART>
                        <SUBPART>
                            <HD SOURCE="HED">Subpart C—Monitoring and Analytical Requirements</HD>
                            <SECTNO>141.21</SECTNO>
                            <SUBJECT>Coliform sampling.</SUBJECT>
                            <SECTNO>141.22</SECTNO>
                            <SUBJECT>Turbidity sampling and analytical requirements.</SUBJECT>
                            <SECTNO>141.23</SECTNO>
                            <SUBJECT>Inorganic chemical sampling and analytical requirements.</SUBJECT>
                            <SECTNO>141.24</SECTNO>
                            <SUBJECT>Organic chemicals, sampling and analytical requirements.</SUBJECT>
                            <SECTNO>141.25</SECTNO>
                            <SUBJECT>Analytical methods for radioactivity.</SUBJECT>
                            <SECTNO>141.26</SECTNO>
                            <SUBJECT>Monitoring frequency and compliance requirements for radionuclides in community water systems</SUBJECT>
                            <SECTNO>141.27</SECTNO>
                            <SUBJECT>Alternate analytical techniques.</SUBJECT>
                            <SECTNO>141.28</SECTNO>
                            <SUBJECT>Certified laboratories.</SUBJECT>
                            <SECTNO>141.29</SECTNO>
                            <SUBJECT>Monitoring of consecutive public water systems.</SUBJECT>
                            <APP>Appendix A to Subpart C of Part 141—Alternative Testing Methods Approved for Analyses Under the Safe Drinking Water Act</APP>
                        </SUBPART>
                        <SUBPART>
                            <HD SOURCE="HED">Subpart D—Reporting and Recordkeeping</HD>
                            <SECTNO>141.31</SECTNO>
                            <SUBJECT>Reporting requirements.</SUBJECT>
                            <SECTNO>141.32</SECTNO>
                            <SUBJECT>[Reserved]</SUBJECT>
                            <SECTNO>141.33</SECTNO>
                            <SUBJECT>Record maintenance.</SUBJECT>
                            <SECTNO>141.34</SECTNO>
                            <SUBJECT>[Reserved]</SUBJECT>
                            <SECTNO>141.35</SECTNO>
                            <SUBJECT>Reporting for unregulated contaminant monitoring results.</SUBJECT>
                        </SUBPART>
                        <SUBPART>
                            <PRTPAGE P="472"/>
                            <HD SOURCE="HED">Subpart E—Special Regulations, Including Monitoring</HD>
                            <SECTNO>141.40</SECTNO>
                            <SUBJECT>Monitoring requirements for unregulated contaminants.</SUBJECT>
                            <SECTNO>141.41</SECTNO>
                            <SUBJECT>Special monitoring for sodium.</SUBJECT>
                            <SECTNO>141.42</SECTNO>
                            <SUBJECT>Special monitoring for corrosivity characteristics.</SUBJECT>
                        </SUBPART>
                        <SUBPART>
                            <HD SOURCE="HED">Subpart F—Maximum Contaminant Level Goals and Maximum Residual Disinfectant Level Goals</HD>
                            <SECTNO>141.50</SECTNO>
                            <SUBJECT>Maximum contaminant level goals for organic contaminants.</SUBJECT>
                            <SECTNO>141.51</SECTNO>
                            <SUBJECT>Maximum contaminant level goals for inorganic contaminants.</SUBJECT>
                            <SECTNO>141.52</SECTNO>
                            <SUBJECT>Maximum contaminant level goals for microbiological contaminants.</SUBJECT>
                            <SECTNO>141.53</SECTNO>
                            <SUBJECT>Maximum contaminant level goals for disinfection byproducts.</SUBJECT>
                            <SECTNO>141.54</SECTNO>
                            <SUBJECT>Maximum residual disinfectant level goals for disinfectants.</SUBJECT>
                            <SECTNO>141.55</SECTNO>
                            <SUBJECT>Maximum contaminant level goals for radionuclides.</SUBJECT>
                        </SUBPART>
                        <SUBPART>
                            <HD SOURCE="HED">Subpart G—National Primary Drinking Water Regulations: Maximum Contaminant Levels and Maximum Residual Disinfectant Levels</HD>
                            <SECTNO>141.60</SECTNO>
                            <SUBJECT>Effective dates.</SUBJECT>
                            <SECTNO>141.61</SECTNO>
                            <SUBJECT>Maximum contaminant levels for organic contaminants.</SUBJECT>
                            <SECTNO>141.62</SECTNO>
                            <SUBJECT>Maximum contaminant levels for inorganic contaminants.</SUBJECT>
                            <SECTNO>141.63</SECTNO>
                            <SUBJECT>Maximum contaminant levels (MCLs) for microbiological contaminants.</SUBJECT>
                            <SECTNO>141.64</SECTNO>
                            <SUBJECT>Maximum contaminant levels for disinfection byproducts.</SUBJECT>
                            <SECTNO>141.65</SECTNO>
                            <SUBJECT>Maximum residual disinfectant levels.</SUBJECT>
                            <SECTNO>141.66</SECTNO>
                            <SUBJECT>Maximum contaminant levels for radionuclides.</SUBJECT>
                        </SUBPART>
                        <SUBPART>
                            <HD SOURCE="HED">Subpart H—Filtration and Disinfection</HD>
                            <SECTNO>141.70</SECTNO>
                            <SUBJECT>General requirements.</SUBJECT>
                            <SECTNO>141.71</SECTNO>
                            <SUBJECT>Criteria for avoiding filtration.</SUBJECT>
                            <SECTNO>141.72</SECTNO>
                            <SUBJECT>Disinfection.</SUBJECT>
                            <SECTNO>141.73</SECTNO>
                            <SUBJECT>Filtration.</SUBJECT>
                            <SECTNO>141.74</SECTNO>
                            <SUBJECT>Analytical and monitoring requirements.</SUBJECT>
                            <SECTNO>141.75</SECTNO>
                            <SUBJECT>Reporting and recordkeeping requirements.</SUBJECT>
                            <SECTNO>141.76</SECTNO>
                            <SUBJECT>Recycle provisions.</SUBJECT>
                        </SUBPART>
                        <SUBPART>
                            <HD SOURCE="HED">Subpart I—Control of Lead and Copper</HD>
                            <SECTNO>141.80</SECTNO>
                            <SUBJECT>General requirements and action level.</SUBJECT>
                            <SECTNO>141.81</SECTNO>
                            <SUBJECT>Applicability of corrosion control treatment steps to small, medium, and large water systems.</SUBJECT>
                            <SECTNO>141.82</SECTNO>
                            <SUBJECT>Description of corrosion control treatment requirements.</SUBJECT>
                            <SECTNO>141.83</SECTNO>
                            <SUBJECT>Source water treatment requirements.</SUBJECT>
                            <SECTNO>141.84</SECTNO>
                            <SUBJECT>Service line inventory and replacement requirements.</SUBJECT>
                            <SECTNO>141.85</SECTNO>
                            <SUBJECT>Public education and supplemental monitoring and mitigation requirements.</SUBJECT>
                            <SECTNO>141.86</SECTNO>
                            <SUBJECT>Monitoring requirements for lead and copper in tap water.</SUBJECT>
                            <SECTNO>141.87</SECTNO>
                            <SUBJECT>Monitoring requirements for water quality parameters.</SUBJECT>
                            <SECTNO>141.88</SECTNO>
                            <SUBJECT>Monitoring requirements for lead and copper in source water.</SUBJECT>
                            <SECTNO>141.89</SECTNO>
                            <SUBJECT>Analytical methods.</SUBJECT>
                            <SECTNO>141.90</SECTNO>
                            <SUBJECT>Reporting requirements.</SUBJECT>
                            <SECTNO>141.91</SECTNO>
                            <SUBJECT>Recordkeeping requirements.</SUBJECT>
                            <SECTNO>141.92</SECTNO>
                            <SUBJECT>Monitoring for lead in schools and child care facilities.</SUBJECT>
                            <SECTNO>141.93</SECTNO>
                            <SUBJECT>Small water system compliance flexibility.</SUBJECT>
                        </SUBPART>
                        <SUBPART>
                            <HD SOURCE="HED">Subpart J—Use of Non-Centralized Treatment Devices</HD>
                            <SECTNO>141.100</SECTNO>
                            <SUBJECT>Criteria and procedures for public water systems using point-of-entry devices.</SUBJECT>
                            <SECTNO>141.101</SECTNO>
                            <SUBJECT>Use of bottled water.</SUBJECT>
                        </SUBPART>
                        <SUBPART>
                            <HD SOURCE="HED">Subpart K—Treatment Techniques</HD>
                            <SECTNO>141.110</SECTNO>
                            <SUBJECT>General requirements.</SUBJECT>
                            <SECTNO>141.111</SECTNO>
                            <SUBJECT>Treatment techniques for acrylamide and epichlorohydrin.</SUBJECT>
                        </SUBPART>
                        <SUBPART>
                            <HD SOURCE="HED">Subpart L—Disinfectant Residuals, Disinfection Byproducts, and Disinfection Byproduct Precursors</HD>
                            <SECTNO>141.130</SECTNO>
                            <SUBJECT>General requirements.</SUBJECT>
                            <SECTNO>141.131</SECTNO>
                            <SUBJECT>Analytical requirements.</SUBJECT>
                            <SECTNO>141.132</SECTNO>
                            <SUBJECT>Monitoring requirements.</SUBJECT>
                            <SECTNO>141.133</SECTNO>
                            <SUBJECT>Compliance requirements.</SUBJECT>
                            <SECTNO>141.134</SECTNO>
                            <SUBJECT>Reporting and recordkeeping requirements.</SUBJECT>
                            <SECTNO>141.135</SECTNO>
                            <SUBJECT>Treatment technique for control of disinfection byproduct (DBP) precursors.</SUBJECT>
                        </SUBPART>
                        <SUBPART>
                            <RESERVED>Subparts M-N [Reserved]</RESERVED>
                        </SUBPART>
                        <SUBPART>
                            <HD SOURCE="HED">Subpart O—Consumer Confidence Reports</HD>
                            <SECTNO>141.151</SECTNO>
                            <SUBJECT>Purpose and applicability of this subpart.</SUBJECT>
                            <SECTNO>141.152</SECTNO>
                            <SUBJECT>Compliance dates.</SUBJECT>
                            <SECTNO>141.153</SECTNO>
                            <SUBJECT>Content of the reports.</SUBJECT>
                            <SECTNO>141.154</SECTNO>
                            <SUBJECT>Required additional health information.</SUBJECT>
                            <SECTNO>141.155</SECTNO>
                            <SUBJECT>Report delivery and recordkeeping.</SUBJECT>
                            <SECTNO>141.156</SECTNO>
                            <SUBJECT>Summary of report contents.</SUBJECT>
                            <APP>Appendix A to Subpart O of Part 141—Regulated Contaminants</APP>
                        </SUBPART>
                        <SUBPART>
                            <HD SOURCE="HED">Subpart P—Enhanced Filtration and Disinfection—Systems Serving 10,000 or More People</HD>
                            <SECTNO>141.170</SECTNO>
                            <SUBJECT>
                                General requirements.
                                <PRTPAGE P="473"/>
                            </SUBJECT>
                            <SECTNO>141.171</SECTNO>
                            <SUBJECT>Criteria for avoiding filtration.</SUBJECT>
                            <SECTNO>141.172</SECTNO>
                            <SUBJECT>Disinfection profiling and benchmarking.</SUBJECT>
                            <SECTNO>141.173</SECTNO>
                            <SUBJECT>Filtration.</SUBJECT>
                            <SECTNO>141.174</SECTNO>
                            <SUBJECT>Filtration sampling requirements.</SUBJECT>
                            <SECTNO>141.175</SECTNO>
                            <SUBJECT>Reporting and recordkeeping requirements.</SUBJECT>
                        </SUBPART>
                        <SUBPART>
                            <HD SOURCE="HED">Subpart Q—Public Notification of Drinking Water Violations</HD>
                            <SECTNO>141.201</SECTNO>
                            <SUBJECT>General public notification requirements.</SUBJECT>
                            <SECTNO>141.202</SECTNO>
                            <SUBJECT>
                                <E T="03">Tier 1 Public Notice</E>
                                —Form, manner, and frequency of notice.
                            </SUBJECT>
                            <SECTNO>141.203</SECTNO>
                            <SUBJECT>
                                <E T="03">Tier 2 Public Notice</E>
                                —Form, manner, and frequency of notice.
                            </SUBJECT>
                            <SECTNO>141.204</SECTNO>
                            <SUBJECT>
                                <E T="03">Tier 3 Public Notice</E>
                                —Form, manner, and frequency of notice.
                            </SUBJECT>
                            <SECTNO>141.205</SECTNO>
                            <SUBJECT>Content of the public notice.</SUBJECT>
                            <SECTNO>141.206</SECTNO>
                            <SUBJECT>Notice to new billing units or new customers.</SUBJECT>
                            <SECTNO>141.207</SECTNO>
                            <SUBJECT>Special notice of the availability of unregulated contaminant monitoring results.</SUBJECT>
                            <SECTNO>141.208</SECTNO>
                            <SUBJECT>Special notice for exceedance of the SMCL for fluoride.</SUBJECT>
                            <SECTNO>141.209</SECTNO>
                            <SUBJECT>Special notice for nitrate exceedances above MCL by non-community water systems (NCWS), where granted permission by the primacy agency under § 141.11(d).</SUBJECT>
                            <SECTNO>141.210</SECTNO>
                            <SUBJECT>Notice by primacy agency on behalf of the public water system.</SUBJECT>
                            <SECTNO>141.211</SECTNO>
                            <SUBJECT>
                                Special notice for repeated failure to conduct monitoring of the source water for 
                                <E T="03">Cryptosporidium</E>
                                 and for failure to determine bin classification or mean 
                                <E T="03">Cryptosporidium</E>
                                 level.
                            </SUBJECT>
                            <APP>Appendix A to Subpart Q of Part 141—NPDWR Violations and Situations Requiring Public Notice</APP>
                            <APP>Appendix B to Subpart Q of Part 141—Standard Health Effects Language for Public Notification</APP>
                            <APP>Appendix C to Subpart Q of Part 141—List of Acronyms Used in Public Notification Regulation</APP>
                        </SUBPART>
                        <SUBPART>
                            <RESERVED>Subpart R [Reserved]</RESERVED>
                        </SUBPART>
                        <SUBPART>
                            <HD SOURCE="HED">Subpart S—Ground Water Rule</HD>
                            <SECTNO>141.400</SECTNO>
                            <SUBJECT>General requirements and applicability.</SUBJECT>
                            <SECTNO>141.401</SECTNO>
                            <SUBJECT>Sanitary surveys for ground water systems.</SUBJECT>
                            <SECTNO>141.402</SECTNO>
                            <SUBJECT>Ground water source microbial monitoring and analytical methods.</SUBJECT>
                            <SECTNO>141.403</SECTNO>
                            <SUBJECT>Treatment technique requirements for ground water systems.</SUBJECT>
                            <SECTNO>141.404</SECTNO>
                            <SUBJECT>Treatment technique violations for ground water systems.</SUBJECT>
                            <SECTNO>141.405</SECTNO>
                            <SUBJECT>Reporting and recordkeeping for ground water systems.</SUBJECT>
                        </SUBPART>
                        <SUBPART>
                            <HD SOURCE="HED">Subpart T—Enhanced Filtration and Disinfection—Systems Serving Fewer Than 10,000 People</HD>
                            <SUBJGRP>
                                <HD SOURCE="HED">General Requirements</HD>
                                <SECTNO>141.500</SECTNO>
                                <SUBJECT>General requirements.</SUBJECT>
                                <SECTNO>141.501</SECTNO>
                                <SUBJECT>Who is subject to the requirements of subpart T?</SUBJECT>
                                <SECTNO>141.502</SECTNO>
                                <SUBJECT>When must my system comply with these requirements?</SUBJECT>
                                <SECTNO>141.503</SECTNO>
                                <SUBJECT>What does subpart T require?</SUBJECT>
                            </SUBJGRP>
                            <SUBJGRP>
                                <HD SOURCE="HED">Finished Water Reservoirs</HD>
                                <SECTNO>141.510</SECTNO>
                                <SUBJECT>Is my system subject to the new finished water reservoir requirements?</SUBJECT>
                                <SECTNO>141.511</SECTNO>
                                <SUBJECT>What is required of new finished water reservoirs?</SUBJECT>
                            </SUBJGRP>
                            <SUBJGRP>
                                <HD SOURCE="HED">Additional Watershed Control Requirements for Unfiltered Systems</HD>
                                <SECTNO>141.520</SECTNO>
                                <SUBJECT>Is my system subject to the updated watershed control requirements?</SUBJECT>
                                <SECTNO>141.521</SECTNO>
                                <SUBJECT>What updated watershed control requirements must my unfiltered system implement to continue to avoid filtration?</SUBJECT>
                                <SECTNO>141.522</SECTNO>
                                <SUBJECT>How does the State determine whether my system's watershed control requirements are adequate?</SUBJECT>
                            </SUBJGRP>
                            <SUBJGRP>
                                <HD SOURCE="HED">Disinfection Profile</HD>
                                <SECTNO>141.530</SECTNO>
                                <SUBJECT>What is a disinfection profile and who must develop one?</SUBJECT>
                                <SECTNO>141.531</SECTNO>
                                <SUBJECT>What criteria must a State use to determine that a profile is unnecessary?</SUBJECT>
                                <SECTNO>141.532</SECTNO>
                                <SUBJECT>How does my system develop a disinfection profile and when must it begin?</SUBJECT>
                                <SECTNO>141.533</SECTNO>
                                <SUBJECT>What data must my system collect to calculate a disinfection profile?</SUBJECT>
                                <SECTNO>141.534</SECTNO>
                                <SUBJECT>How does my system use this data to calculate an inactivation ratio?</SUBJECT>
                                <SECTNO>141.535</SECTNO>
                                <SUBJECT>What if my system uses chloramines, ozone, or chlorine dioxide for primary disinfection?</SUBJECT>
                                <SECTNO>141.536</SECTNO>
                                <SUBJECT>My system has developed an inactivation ratio; what must we do now?</SUBJECT>
                            </SUBJGRP>
                            <SUBJGRP>
                                <HD SOURCE="HED">Disinfection Benchmark</HD>
                                <SECTNO>141.540</SECTNO>
                                <SUBJECT>Who has to develop a disinfection benchmark?</SUBJECT>
                                <SECTNO>141.541</SECTNO>
                                <SUBJECT>What are significant changes to disinfection practice?</SUBJECT>
                                <SECTNO>141.542</SECTNO>
                                <SUBJECT>What must my system do if we are considering a significant change to disinfection practices?</SUBJECT>
                                <SECTNO>141.543</SECTNO>
                                <SUBJECT>How is the disinfection benchmark calculated?</SUBJECT>
                                <SECTNO>141.544</SECTNO>
                                <SUBJECT>What if my system uses chloramines, ozone, or chlorine dioxide for primary disinfection?</SUBJECT>
                            </SUBJGRP>
                            <SUBJGRP>
                                <PRTPAGE P="474"/>
                                <HD SOURCE="HED">Combined Filter Effluent Requirements</HD>
                                <SECTNO>141.550</SECTNO>
                                <SUBJECT>Is my system required to meet subpart T combined filter effluent turbidity limits?</SUBJECT>
                                <SECTNO>141.551</SECTNO>
                                <SUBJECT>What strengthened combined filter effluent turbidity limits must my system meet?</SUBJECT>
                                <SECTNO>141.552</SECTNO>
                                <SUBJECT>My system consists of “alternative filtration” and is required to conduct a demonstration—what is required of my system and how does the State establish my turbidity limits?</SUBJECT>
                                <SECTNO>141.553</SECTNO>
                                <SUBJECT>My system practices lime softening—is there any special provision regarding my combined filter effluent?</SUBJECT>
                            </SUBJGRP>
                            <SUBJGRP>
                                <HD SOURCE="HED">Individual Filter Turbidity Requirements</HD>
                                <SECTNO>141.560</SECTNO>
                                <SUBJECT>Is my system subject to individual filter turbidity requirements?</SUBJECT>
                                <SECTNO>141.561</SECTNO>
                                <SUBJECT>What happens if my system's turbidity monitoring equipment fails?</SUBJECT>
                                <SECTNO>141.562</SECTNO>
                                <SUBJECT>My system only has two or fewer filters—is there any special provision regarding individual filter turbidity monitoring?</SUBJECT>
                                <SECTNO>141.563</SECTNO>
                                <SUBJECT>What follow-up action is my system required to take based on continuous turbidity monitoring?</SUBJECT>
                                <SECTNO>141.564</SECTNO>
                                <SUBJECT>My system practices lime softening—is there any special provision regarding my individual filter turbidity monitoring?</SUBJECT>
                            </SUBJGRP>
                            <SUBJGRP>
                                <HD SOURCE="HED">Reporting and Recordkeeping Requirements</HD>
                                <SECTNO>141.570</SECTNO>
                                <SUBJECT>What does subpart T require that my system report to the State?</SUBJECT>
                                <SECTNO>141.571</SECTNO>
                                <SUBJECT>What records does subpart T require my system to keep?</SUBJECT>
                            </SUBJGRP>
                        </SUBPART>
                        <SUBPART>
                            <HD SOURCE="HED">Subpart U—Initial Distribution System Evaluations</HD>
                            <SECTNO>141.600</SECTNO>
                            <SUBJECT>General requirements.</SUBJECT>
                            <SECTNO>141.601</SECTNO>
                            <SUBJECT>Standard monitoring.</SUBJECT>
                            <SECTNO>141.602</SECTNO>
                            <SUBJECT>System specific studies.</SUBJECT>
                            <SECTNO>141.603</SECTNO>
                            <SUBJECT>40/30 certification.</SUBJECT>
                            <SECTNO>141.604</SECTNO>
                            <SUBJECT>Very small system waivers.</SUBJECT>
                            <SECTNO>141.605</SECTNO>
                            <SUBJECT>Subpart V compliance monitoring location recommendations.</SUBJECT>
                        </SUBPART>
                        <SUBPART>
                            <HD SOURCE="HED">Subpart V—Stage 2 Disinfection Byproducts Requirements</HD>
                            <SECTNO>141.620</SECTNO>
                            <SUBJECT>General requirements.</SUBJECT>
                            <SECTNO>141.621</SECTNO>
                            <SUBJECT>Routine monitoring.</SUBJECT>
                            <SECTNO>141.622</SECTNO>
                            <SUBJECT>Subpart V monitoring plan.</SUBJECT>
                            <SECTNO>141.623</SECTNO>
                            <SUBJECT>Reduced monitoring.</SUBJECT>
                            <SECTNO>141.624</SECTNO>
                            <SUBJECT>Additional requirements for consecutive systems.</SUBJECT>
                            <SECTNO>141.625</SECTNO>
                            <SUBJECT>Conditions requiring increased monitoring.</SUBJECT>
                            <SECTNO>141.626</SECTNO>
                            <SUBJECT>Operational evaluation levels.</SUBJECT>
                            <SECTNO>141.627</SECTNO>
                            <SUBJECT>Requirements for remaining on reduced TTHM and HAA5 monitoring based on subpart L results.</SUBJECT>
                            <SECTNO>141.628</SECTNO>
                            <SUBJECT>Requirements for remaining on increased TTHM and HAA5 monitoring based on subpart L results.</SUBJECT>
                            <SECTNO>141.629</SECTNO>
                            <SUBJECT>Reporting and recordkeeping requirements.</SUBJECT>
                        </SUBPART>
                        <SUBPART>
                            <HD SOURCE="HED">
                                Subpart W—Enhanced Treatment for 
                                <E T="0714">Cryptosporidium</E>
                            </HD>
                            <SUBJGRP>
                                <HD SOURCE="HED">General Requirements</HD>
                                <SECTNO>141.700</SECTNO>
                                <SUBJECT>General requirements.</SUBJECT>
                            </SUBJGRP>
                            <SUBJGRP>
                                <HD SOURCE="HED">Source Water Monitoring Requirements</HD>
                                <SECTNO>141.701</SECTNO>
                                <SUBJECT>Source water monitoring.</SUBJECT>
                                <SECTNO>141.702</SECTNO>
                                <SUBJECT>Sampling schedules.</SUBJECT>
                                <SECTNO>141.703</SECTNO>
                                <SUBJECT>Sampling locations.</SUBJECT>
                                <SECTNO>141.704</SECTNO>
                                <SUBJECT>Analytical methods.</SUBJECT>
                                <SECTNO>141.705</SECTNO>
                                <SUBJECT>Approved laboratories.</SUBJECT>
                                <SECTNO>141.706</SECTNO>
                                <SUBJECT>Reporting source water monitoring results.</SUBJECT>
                                <SECTNO>141.707</SECTNO>
                                <SUBJECT>Grandfathering previously collected data.</SUBJECT>
                            </SUBJGRP>
                            <SUBJGRP>
                                <HD SOURCE="HED">Disinfection Profiling and Benchmarking Requirements</HD>
                                <SECTNO>141.708</SECTNO>
                                <SUBJECT>Requirements when making a significant change in disinfection practice.</SUBJECT>
                                <SECTNO>141.709</SECTNO>
                                <SUBJECT>Developing the disinfection profile and benchmark.</SUBJECT>
                            </SUBJGRP>
                            <SUBJGRP>
                                <HD SOURCE="HED">Treatment Technique Requirements</HD>
                                <SECTNO>141.710</SECTNO>
                                <SUBJECT>Bin classification for filtered systems.</SUBJECT>
                                <SECTNO>141.711</SECTNO>
                                <SUBJECT>
                                    Filtered system additional 
                                    <E T="03">Cryptosporidium</E>
                                     treatment requirements.
                                </SUBJECT>
                                <SECTNO>141.712</SECTNO>
                                <SUBJECT>
                                    Unfiltered system 
                                    <E T="03">Cryptosporidium</E>
                                     treatment requirements.
                                </SUBJECT>
                                <SECTNO>141.713</SECTNO>
                                <SUBJECT>
                                    Schedule for compliance with 
                                    <E T="03">Cryptosporidium</E>
                                     treatment requirements.
                                </SUBJECT>
                                <SECTNO>141.714</SECTNO>
                                <SUBJECT>Requirements for uncovered finished water storage facilities.</SUBJECT>
                            </SUBJGRP>
                            <SUBJGRP>
                                <HD SOURCE="HED">Requirements for Microbial Toolbox Components</HD>
                                <SECTNO>141.715</SECTNO>
                                <SUBJECT>
                                    Microbial toolbox options for meeting 
                                    <E T="03">Cryptosporidium</E>
                                     treatment requirements.
                                </SUBJECT>
                                <SECTNO>141.716</SECTNO>
                                <SUBJECT>Source toolbox components.</SUBJECT>
                                <SECTNO>141.717</SECTNO>
                                <SUBJECT>Pre-filtration treatment toolbox components.</SUBJECT>
                                <SECTNO>141.718</SECTNO>
                                <SUBJECT>Treatment performance toolbox components.</SUBJECT>
                                <SECTNO>141.719</SECTNO>
                                <SUBJECT>Additional filtration toolbox components.</SUBJECT>
                                <SECTNO>141.720</SECTNO>
                                <SUBJECT>Inactivation toolbox components.</SUBJECT>
                            </SUBJGRP>
                            <SUBJGRP>
                                <HD SOURCE="HED">Reporting and Recordkeeping Requirements</HD>
                                <SECTNO>141.721</SECTNO>
                                <SUBJECT>Reporting requirements.</SUBJECT>
                                <SECTNO>141.722</SECTNO>
                                <SUBJECT>Recordkeeping requirements.</SUBJECT>
                            </SUBJGRP>
                            <SUBJGRP>
                                <PRTPAGE P="475"/>
                                <HD SOURCE="HED">Requirements for Sanitary Surveys Performed by EPA</HD>
                                <SECTNO>141.723</SECTNO>
                                <SUBJECT>Requirements to respond to significant deficiencies identified in sanitary surveys performed by EPA.</SUBJECT>
                            </SUBJGRP>
                        </SUBPART>
                        <SUBPART>
                            <HD SOURCE="HED">Subpart X—Aircraft Drinking Water Rule</HD>
                            <SECTNO>141.800</SECTNO>
                            <SUBJECT>Applicability and compliance date.</SUBJECT>
                            <SECTNO>141.801</SECTNO>
                            <SUBJECT>Definitions.</SUBJECT>
                            <SECTNO>141.802</SECTNO>
                            <SUBJECT>Coliform sampling plan.</SUBJECT>
                            <SECTNO>141.803</SECTNO>
                            <SUBJECT>Coliform sampling.</SUBJECT>
                            <SECTNO>141.804</SECTNO>
                            <SUBJECT>Aircraft water system operations and maintenance plan.</SUBJECT>
                            <SECTNO>141.805</SECTNO>
                            <SUBJECT>Notification to passengers and crew.</SUBJECT>
                            <SECTNO>141.806</SECTNO>
                            <SUBJECT>Reporting requirements.</SUBJECT>
                            <SECTNO>141.807</SECTNO>
                            <SUBJECT>Recordkeeping requirements.</SUBJECT>
                            <SECTNO>141.808</SECTNO>
                            <SUBJECT>Audits and inspections.</SUBJECT>
                            <SECTNO>141.809</SECTNO>
                            <SUBJECT>Supplemental treatment.</SUBJECT>
                            <SECTNO>141.810</SECTNO>
                            <SUBJECT>Violations.</SUBJECT>
                        </SUBPART>
                        <SUBPART>
                            <HD SOURCE="HED">Subpart Y—Revised Total Coliform Rule</HD>
                            <SECTNO>141.851</SECTNO>
                            <SUBJECT>General.</SUBJECT>
                            <SECTNO>141.852</SECTNO>
                            <SUBJECT>Analytical methods and laboratory certification.</SUBJECT>
                            <SECTNO>141.853</SECTNO>
                            <SUBJECT>General monitoring requirements for all public water systems.</SUBJECT>
                            <SECTNO>141.854</SECTNO>
                            <SUBJECT>Routine monitoring requirements for non-community water systems serving 1,000 or fewer people using only ground water.</SUBJECT>
                            <SECTNO>141.855</SECTNO>
                            <SUBJECT>Routine monitoring requirements for community water systems serving 1,000 or fewer people using only ground water.</SUBJECT>
                            <SECTNO>141.856</SECTNO>
                            <SUBJECT>Routine monitoring requirements for subpart H public water systems serving 1,000 or fewer people.</SUBJECT>
                            <SECTNO>141.857</SECTNO>
                            <SUBJECT>Routine monitoring requirements for public water systems serving more than 1,000 people.</SUBJECT>
                            <SECTNO>141.858</SECTNO>
                            <SUBJECT>
                                Repeat monitoring and 
                                <E T="03">E. coli</E>
                                 requirements.
                            </SUBJECT>
                            <SECTNO>141.859</SECTNO>
                            <SUBJECT>Coliform treatment technique triggers and assessment requirements for protection against potential fecal contamination.</SUBJECT>
                            <SECTNO>141.860</SECTNO>
                            <SUBJECT>Violations.</SUBJECT>
                            <SECTNO>141.861</SECTNO>
                            <SUBJECT>Reporting and recordkeeping.</SUBJECT>
                        </SUBPART>
                        <SUBPART>
                            <HD SOURCE="HED">Subpart Z—Control of Per- and Polyfluoroalkyl Substances (PFAS)</HD>
                            <SECTNO>141.900</SECTNO>
                            <SUBJECT>General requirements.</SUBJECT>
                            <SECTNO>141.901</SECTNO>
                            <SUBJECT>Analytical requirements.</SUBJECT>
                            <SECTNO>141.902</SECTNO>
                            <SUBJECT>Monitoring requirements.</SUBJECT>
                            <SECTNO>141.903</SECTNO>
                            <SUBJECT>Compliance requirements.</SUBJECT>
                            <SECTNO>141.904</SECTNO>
                            <SUBJECT>Reporting and recordkeeping requirements.</SUBJECT>
                            <SECTNO>141.905</SECTNO>
                            <SUBJECT>Violations.</SUBJECT>
                        </SUBPART>
                    </CONTENTS>
                    <AUTH>
                        <HD SOURCE="HED">Authority:</HD>
                        <P>42 U.S.C. 300f, 300g-1, 300g-2, 300g-3, 300g-4, 300g-5, 300g-6, 300j-4, 300j-9, and 300j-11.</P>
                    </AUTH>
                    <SOURCE>
                        <HD SOURCE="HED">Source:</HD>
                        <P>40 FR 59570, Dec. 24, 1975, unless otherwise noted.</P>
                    </SOURCE>
                    <EDNOTE>
                        <HD SOURCE="HED">Editorial Note:</HD>
                        <P>Nomenclature changes to part 141 appear at 69 FR 18803, Apr. 9, 2004.</P>
                    </EDNOTE>
                    <NOTE>
                        <HD SOURCE="HED">Note:</HD>
                        <P>For community water systems serving 75,000 or more persons, monitoring must begin 1 year following promulgation and the effective date of the MCL is 2 years following promulgation. For community water systems serving 10,000 to 75,000 persons, monitoring must begin within 3 years from the date of promulgation and the effective date of the MCL is 4 years from the date of promulgation. Effective immediately, systems that plan to make significant modifications to their treatment processes for the purpose of complying with the TTHM MCL are required to seek and obtain State approval of their treatment modification plans. This note affects §§ 141.2, 141.6, 141.12, 141.24 and 141.30. For additional information see 44 FR 68641, Nov. 29, 1979.</P>
                    </NOTE>
                    <SUBPART>
                        <HD SOURCE="HED">Subpart A—General</HD>
                        <SECTION>
                            <SECTNO>§ 141.1</SECTNO>
                            <SUBJECT>Applicability.</SUBJECT>
                            <P>This part establishes primary drinking water regulations pursuant to section 1412 of the Public Health Service Act, as amended by the Safe Drinking Water Act (Pub. L. 93-523); and related regulations applicable to public water systems.</P>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 141.2</SECTNO>
                            <SUBJECT>Definitions.</SUBJECT>
                            <P>As used in this part, the term:</P>
                            <P>
                                <E T="03">Act</E>
                                 means the Public Health Service Act, as amended by the Safe Drinking Water Act, Public Law 93-523.
                            </P>
                            <P>
                                <E T="03">Action level,</E>
                                 for the purpose of subpart I of this part only, means the concentrations of lead or copper in water as specified in § 141.80(c) which determines requirements under subpart I of this part. The lead action level is 0.010 mg/L and the copper action level is 1.3 mg/L.
                            </P>
                            <P>
                                <E T="03">Aerator</E>
                                 means the device embedded in the water faucet to enhance air flow with the water stream and to prevent splashing.
                            </P>
                            <P>
                                <E T="03">Bag filters</E>
                                 are pressure-driven separation devices that remove particulate matter larger than 1 micrometer using an engineered porous filtration media. They are typically constructed of a non-rigid, fabric filtration media housed in a pressure vessel in which the direction of flow is from the inside of the bag to outside.
                                <PRTPAGE P="476"/>
                            </P>
                            <P>
                                <E T="03">Bank filtration</E>
                                 is a water treatment process that uses a well to recover surface water that has naturally infiltrated into ground water through a river bed or bank(s). Infiltration is typically enhanced by the hydraulic gradient imposed by a nearby pumping water supply or other well(s).
                            </P>
                            <P>
                                <E T="03">Best available technology</E>
                                 or 
                                <E T="03">BAT</E>
                                 means the best technology, treatment techniques, or other means which the Administrator finds, after examination for efficacy under field conditions and not solely under laboratory conditions, are available (taking cost into consideration). For the purposes of setting MCLs for synthetic organic chemicals, any BAT must be at least as effective as granular activated carbon.
                            </P>
                            <P>
                                <E T="03">Cartridge filters</E>
                                 are pressure-driven separation devices that remove particulate matter larger than 1 micrometer using an engineered porous filtration media. They are typically constructed as rigid or semi-rigid, self-supporting filter elements housed in pressure vessels in which flow is from the outside of the cartridge to the inside.
                            </P>
                            <P>
                                <E T="03">Child care facility,</E>
                                 for the purpose of subpart I of this part only, means a location that houses a provider of child care, day care, or early learning services to children, as licensed by the State, local, or Tribal licensing agency.
                            </P>
                            <P>
                                <E T="03">Clean compliance history</E>
                                 is, for the purposes of subpart Y, a record of no MCL violations under § 141.63; no monitoring violations under § 141.21 or subpart Y; and no coliform treatment technique trigger exceedances or treatment technique violations under subpart Y.
                            </P>
                            <P>
                                <E T="03">Coagulation</E>
                                 means a process using coagulant chemicals and mixing by which colloidal and suspended materials are destabilized and agglomerated into flocs.
                            </P>
                            <P>
                                <E T="03">Combined distribution system</E>
                                 is the interconnected distribution system consisting of the distribution systems of wholesale systems and of the consecutive systems that receive finished water.
                            </P>
                            <P>
                                <E T="03">Community water system</E>
                                 means a public water system which serves at least 15 service connections used by year-round residents or regularly serves at least 25 year-round residents.
                            </P>
                            <P>
                                <E T="03">Compliance cycle</E>
                                 means the nine-year calendar year cycle during which public water systems must monitor. Each compliance cycle consists of three three-year compliance periods. The first calendar year cycle begins January 1, 1993 and ends December 31, 2001; the second begins January 1, 2002 and ends December 31, 2010; the third begins January 1, 2011 and ends December 31, 2019.
                            </P>
                            <P>
                                <E T="03">Compliance period</E>
                                 means a three-year calendar year period within a compliance cycle. Each compliance cycle has three three-year compliance periods. Within the first compliance cycle, the first compliance period runs from January 1, 1993 to December 31, 1995; the second from January 1, 1996 to December 31, 1998; the third from January 1, 1999 to December 31, 2001.
                            </P>
                            <P>
                                <E T="03">Comprehensive performance evaluation (CPE)</E>
                                 is a thorough review and analysis of a treatment plant's performance-based capabilities and associated administrative, operation and maintenance practices. It is conducted to identify factors that may be adversely impacting a plant's capability to achieve compliance and emphasizes approaches that can be implemented without significant capital improvements. For purpose of compliance with subparts P and T of this part, the comprehensive performance evaluation must consist of at least the following components: Assessment of plant performance; evaluation of major unit processes; identification and prioritization of performance limiting factors; assessment of the applicability of comprehensive technical assistance; and preparation of a CPE report.
                            </P>
                            <P>
                                <E T="03">Confluent growth</E>
                                 means a continuous bacterial growth covering the entire filtration area of a membrane filter, or a portion thereof, in which bacterial colonies are not discrete.
                            </P>
                            <P>
                                <E T="03">Connector,</E>
                                 also referred to as a gooseneck or pigtail, means a short segment of piping not exceeding three feet that can be bent and is used for connections between service piping, typically connecting the 
                                <E T="03">service line</E>
                                 to the main. For purposes of subpart I of this part, lead connectors are not considered to be part of the service line.
                            </P>
                            <P>
                                <E T="03">Consecutive system</E>
                                 is a public water system that receives some or all of its 
                                <PRTPAGE P="477"/>
                                finished water from one or more wholesale systems. Delivery may be through a direct connection or through the distribution system of one or more consecutive systems.
                            </P>
                            <P>
                                <E T="03">Contaminant</E>
                                 means any physical, chemical, biological, or radiological substance or matter in water.
                            </P>
                            <P>
                                <E T="03">Conventional filtration treatment</E>
                                 means a series of processes including coagulation, flocculation, sedimentation, and filtration resulting in substantial particulate removal.
                            </P>
                            <P>
                                <E T="03">Corrosion inhibitor</E>
                                 means a substance capable of reducing the corrosivity of water toward metal plumbing materials, especially lead and copper, by forming a protective film on the interior surface of those materials.
                            </P>
                            <P>
                                <E T="03">CT</E>
                                 or 
                                <E T="03">CTcalc</E>
                                 is the product of “residual disinfectant concentration” (C) in mg/1 determined before or at the first customer, and the corresponding “disinfectant contact time” (T) in minutes, 
                                <E T="03">i.e.</E>
                                , “C” × “T”. If a public water system applies disinfectants at more than one point prior to the first customer, it must determine the CT of each disinfectant sequence before or at the first customer to determine the total percent inactivation or “total inactivation ratio.” In determining the total inactivation ratio, the public water system must determine the residual disinfectant concentration of each disinfection sequence and corresponding contact time before any subsequent disinfection application point(s). “CT
                                <E T="52">99.9</E>
                                ” is the CT value required for 99.9 percent (3-log) inactivation of 
                                <E T="03">Giardia lamblia</E>
                                 cysts. CT
                                <E T="52">99.9</E>
                                 for a variety of disinfectants and conditions appear in tables 1.1-1.6, 2.1, and 3.1 of § 141.74(b)(3).
                            </P>
                            <MATH SPAN="1" DEEP="31">
                                <MID>EC15NO91.129</MID>
                            </MATH>
                            <FP>is the inactivation ratio. The sum of the inactivation ratios, or total inactivation ratio shown as</FP>
                            <MATH SPAN="1" DEEP="28">
                                <MID>EC15NO91.130</MID>
                            </MATH>
                            <FP>
                                is calculated by adding together the inactivation ratio for each disinfection sequence. A total inactivation ratio equal to or greater than 1.0 is assumed to provide a 3-log inactivation of 
                                <E T="03">Giardia lamblia</E>
                                 cysts.
                            </FP>
                            <P>
                                <E T="03">Diatomaceous earth filtration</E>
                                 means a process resulting in substantial particulate removal in which (1) a precoat cake of diatomaceous earth filter media is deposited on a support membrane (septum), and (2) while the water is filtered by passing through the cake on the septum, additional filter media known as body feed is continuously added to the feed water to maintain the permeability of the filter cake.
                            </P>
                            <P>
                                <E T="03">Direct filtration</E>
                                 means a series of processes including coagulation and filtration but excluding sedimentation resulting in substantial particulate removal.
                            </P>
                            <P>
                                <E T="03">Disinfectant</E>
                                 means any oxidant, including but not limited to chlorine, chlorine dioxide, chloramines, and ozone added to water in any part of the treatment or distribution process, that is intended to kill or inactivate pathogenic microorganisms.
                            </P>
                            <P>
                                <E T="03">Disinfectant contact time</E>
                                 (“T” in CT calculations) means the time in minutes that it takes for water to move from the point of disinfectant application or the previous point of disinfectant residual measurement to a point before or at the point where residual disinfectant concentration (“C”) is measured. Where only one “C” is measured, “T” is the time in minutes that it takes for water to move from the point of disinfectant application to a point before or at where residual disinfectant concentration (“C”) is measured. Where more than one “C” is measured, “T” is (a) for the first measurement of “C”, the time in minutes that it takes for water to move from the first or only point of disinfectant application to a point before or at the point where the first “C” is measured and (b) for subsequent measurements of “C”, the time in minutes that it takes for water to move from the previous “C” measurement point to the “C” measurement point for which the particular “T” is being calculated. Disinfectant contact time in pipelines must be calculated based on “plug flow” by dividing the internal volume of the pipe by the maximum hourly flow rate through that pipe. Disinfectant contact time within mixing basins 
                                <PRTPAGE P="478"/>
                                and storage reservoirs must be determined by tracer studies or an equivalent demonstration.
                            </P>
                            <P>
                                <E T="03">Disinfection</E>
                                 means a process which inactivates pathogenic organisms in water by chemical oxidants or equivalent agents.
                            </P>
                            <P>
                                <E T="03">Disinfection profile</E>
                                 is a summary of 
                                <E T="03">Giardia lamblia</E>
                                 inactivation through the treatment plant. The procedure for developing a disinfection profile is contained in § 141.172 (Disinfection profiling and benchmarking) in subpart P and §§ 141.530-141.536 (Disinfection profile) in subpart T of this part.
                            </P>
                            <P>
                                <E T="03">Distribution System and Site Assessment</E>
                                 means the requirements under subpart I of this part, pursuant to § 141.82(j), that water systems must perform at every tap sampling site that yields a lead result above the lead action level of 0.010 mg/L.
                            </P>
                            <P>
                                <E T="03">Domestic or other non-distribution system plumbing problem</E>
                                 means a coliform contamination problem in a public water system with more than one service connection that is limited to the specific service connection from which the coliform-positive sample was taken.
                            </P>
                            <P>
                                <E T="03">Dose equivalent</E>
                                 means the product of the absorbed dose from ionizing radiation and such factors as account for differences in biological effectiveness due to the type of radiation and its distribution in the body as specified by the International Commission on Radiological Units and Measurements (ICRU).
                            </P>
                            <P>
                                <E T="03">Dual sample set</E>
                                 is a set of two samples collected at the same time and same location, with one sample analyzed for TTHM and the other sample analyzed for HAA5. Dual sample sets are collected for the purposes of conducting an IDSE under subpart U of this part and determining compliance with the TTHM and HAA5 MCLs under subpart V of this part.
                            </P>
                            <P>
                                <E T="03">Effective corrosion inhibitor residual,</E>
                                 for the purpose of subpart I of this part only, means a concentration sufficient to form a passivating film on the interior walls of a pipe.
                            </P>
                            <P>
                                <E T="03">Elementary school,</E>
                                 for the purpose of subpart I of this part only, means a 
                                <E T="03">school</E>
                                 classified as elementary by State and local practice and composed of any span of grades (including pre-school) not above grade 8.
                            </P>
                            <P>
                                <E T="03">Enhanced coagulation</E>
                                 means the addition of sufficient coagulant for improved removal of disinfection byproduct precursors by conventional filtration treatment.
                            </P>
                            <P>
                                <E T="03">Enhanced softening</E>
                                 means the improved removal of disinfection byproduct precursors by precipitative softening.
                            </P>
                            <P>
                                <E T="03">Fifth liter sample,</E>
                                 for purposes of subpart I of this part, means a one-liter sample of tap water collected in accordance with § 141.86(b).
                            </P>
                            <P>
                                <E T="03">Filter profile</E>
                                 is a graphical representation of individual filter performance, based on continuous turbidity measurements or total particle counts versus time for an entire filter run, from startup to backwash inclusively, that includes an assessment of filter performance while another filter is being backwashed.
                            </P>
                            <P>
                                <E T="03">Filtration</E>
                                 means a process for removing particulate matter from water by passage through porous media.
                            </P>
                            <P>
                                <E T="03">Finished water</E>
                                 is water that is introduced into the distribution system of a public water system and is intended for distribution and consumption without further treatment, except as treatment necessary to maintain water quality in the distribution system (e.g., booster disinfection, addition of corrosion control chemicals).
                            </P>
                            <P>
                                <E T="03">First-liter sample,</E>
                                 for the purpose of subpart I of this part only, means a sample collected of the first one-liter volume of tap water drawn in accordance with § 141.86(b).
                            </P>
                            <P>
                                <E T="03">Flocculation</E>
                                 means a process to enhance agglomeration or collection of smaller floc particles into larger, more easily settleable particles through gentle stirring by hydraulic or mechanical means.
                            </P>
                            <P>
                                <E T="03">Flowing stream</E>
                                 is a course of running water flowing in a definite channel.
                            </P>
                            <P>
                                <E T="03">GAC10</E>
                                 means granular activated carbon filter beds with an empty-bed contact time of 10 minutes based on average daily flow and a carbon reactivation frequency of every 180 days, except that the reactivation frequency for GAC10 used as a best available technology for compliance with subpart V MCLs under § 141.64(b)(2) shall be 120 days.
                                <PRTPAGE P="479"/>
                            </P>
                            <P>
                                <E T="03">GAC20</E>
                                 means granular activated carbon filter beds with an empty-bed contact time of 20 minutes based on average daily flow and a carbon reactivation frequency of every 240 days.
                            </P>
                            <P>
                                <E T="03">Galvanized requiring replacement service line,</E>
                                 for the purpose of subpart I of this part only, means a 
                                <E T="03">galvanized service line</E>
                                 that currently is or ever was downstream of a 
                                <E T="03">lead service line;</E>
                                 or is currently downstream of a 
                                <E T="03">lead status unknown service line.</E>
                                 For this definition, downstream means in the direction of flow through the service line. If the water system is unable to demonstrate that the 
                                <E T="03">galvanized service line</E>
                                 was never downstream of a 
                                <E T="03">lead service line,</E>
                                 it is a 
                                <E T="03">galvanized requiring replacement service line</E>
                                 for purposes of the service line inventory and replacement requirements pursuant to § 141.84.
                            </P>
                            <P>
                                <E T="03">Galvanized service line,</E>
                                 for the purpose of subpart I of this part only, means a 
                                <E T="03">service line</E>
                                 that is made of iron or steel that has been dipped in zinc to prevent corrosion and rusting.
                            </P>
                            <P>
                                <E T="03">Ground water under the direct influence of surface water</E>
                                 (GWUDI) means any water beneath the surface of the ground with significant occurrence of insects or other macroorganisms, algae, or large-diameter pathogens such as 
                                <E T="03">Giardia lamblia</E>
                                 or 
                                <E T="03">Cryptosporidium,</E>
                                 or significant and relatively rapid shifts in water characteristics such as turbidity, temperature, conductivity, or pH which closely correlate to climatological or surface water conditions. Direct influence must be determined for individual sources in accordance with criteria established by the State. The State determination of direct influence may be based on site-specific measurements of water quality and/or documentation of well construction characteristics and geology with field evaluation.
                            </P>
                            <P>
                                <E T="03">Gross alpha particle activity</E>
                                 means the total radioactivity due to alpha particle emission as inferred from measurements on a dry sample.
                            </P>
                            <P>
                                <E T="03">Gross beta particle activity</E>
                                 means the total radioactivity due to beta particle emission as inferred from measurements on a dry sample.
                            </P>
                            <P>
                                <E T="03">Haloacetic acids (five) (HAA5)</E>
                                 mean the sum of the concentrations in milligrams per liter of the haloacetic acid compounds (monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, monobromoacetic acid, and dibromoacetic acid), rounded to two significant figures after addition.
                            </P>
                            <P>
                                <E T="03">Halogen</E>
                                 means one of the chemical elements chlorine, bromine or iodine.
                            </P>
                            <P>
                                <E T="03">Hazard Index (HI)</E>
                                 is the sum of component hazard quotients (HQs), which are calculated by dividing the measured regulated PFAS component contaminant concentration in water (e.g., expressed as parts per trillion (ppt) or nanograms per liter (ng/l)) by the associated health-based water concentration (HBWC) expressed in the same units as the measured concentration (e.g., ppt or ng/l). For PFAS, a mixture Hazard Index greater than 1 (unitless) is an exceedance of the MCL.
                            </P>
                            <P>
                                <E T="03">Hazard quotient (HQ)</E>
                                 means the ratio of the measured concentration in drinking water to the health-based water concentration (HBWC).
                            </P>
                            <P>
                                <E T="03">Health-based water concentration (HBWC)</E>
                                 means level below which there are no known or anticipated adverse health effects over a lifetime of exposure, including sensitive populations and life stages, and allows for an adequate margin of safety.
                            </P>
                            <P>
                                <E T="03">HFPO-DA</E>
                                 or 
                                <E T="03">GenX chemicals</E>
                                 means Chemical Abstract Service registration number 122499-17-6, chemical formula C6F11O3-, International Union of Pure and Applied Chemistry preferred name 2,3,3,3-tetrafluoro-2-(heptafluoropropoxy)propanoate, along with its conjugate acid and any salts, derivatives, isomers, or combinations thereof.
                            </P>
                            <P>
                                <E T="03">Initial compliance period</E>
                                 means the first full three-year compliance period which begins at least 18 months after promulgation, except for contaminants listed at § 141.61(a) (19)-(21), (c) (19)-(33), and § 141.62(b) (11)-(15), initial compliance period means the first full three-year compliance period after promulgation for systems with 150 or more service connections (January 1993-December 1995), and first full three-year compliance period after the effective date of the regulation (January 1996-December 1998) for systems having fewer than 150 service connections.
                            </P>
                            <P>
                                <E T="03">Lake/reservoir</E>
                                 refers to a natural or man made basin or hollow on the Earth's surface in which water collects 
                                <PRTPAGE P="480"/>
                                or is stored that may or may not have a current or single direction of flow.
                            </P>
                            <P>
                                <E T="03">Large water system,</E>
                                 for the purpose of subpart I of this part only, means a water system that serves more than 50,000 persons.
                            </P>
                            <P>
                                <E T="03">Lead service line,</E>
                                 for the purpose of subpart I of this part only, means a 
                                <E T="03">service line</E>
                                 that is made of lead or where a portion of the 
                                <E T="03">service line</E>
                                 is made of lead. A lead-lined galvanized service line is defined as a 
                                <E T="03">lead service line.</E>
                            </P>
                            <P>
                                <E T="03">Lead status unknown service line,</E>
                                 for the purpose of subpart I of this part only, means a 
                                <E T="03">service line</E>
                                 whose pipe material has not been demonstrated to be a 
                                <E T="03">lead service line, galvanized requiring replacement service line,</E>
                                 or a non-lead service line pursuant to § 141.84(a)(3).
                            </P>
                            <P>
                                <E T="03">Legionella</E>
                                 means a genus of bacteria, some species of which have caused a type of pneumonia called Legionnaires Disease.
                            </P>
                            <P>
                                <E T="03">Level 1 assessment</E>
                                 is an evaluation to identify the possible presence of sanitary defects, defects in distribution system coliform monitoring practices, and (when possible) the likely reason that the system triggered the assessment. It is conducted by the system operator or owner. Minimum elements include review and identification of atypical events that could affect distributed water quality or indicate that distributed water quality was impaired; changes in distribution system maintenance and operation that could affect distributed water quality (including water storage); source and treatment considerations that bear on distributed water quality, where appropriate (e.g., whether a ground water system is disinfected); existing water quality monitoring data; and inadequacies in sample sites, sampling protocol, and sample processing. The system must conduct the assessment consistent with any State directives that tailor specific assessment elements with respect to the size and type of the system and the size, type, and characteristics of the distribution system.
                            </P>
                            <P>
                                <E T="03">Level 2 assessment</E>
                                 is an evaluation to identify the possible presence of sanitary defects, defects in distribution system coliform monitoring practices, and (when possible) the likely reason that the system triggered the assessment. A Level 2 assessment provides a more detailed examination of the system (including the system's monitoring and operational practices) than does a Level 1 assessment through the use of more comprehensive investigation and review of available information, additional internal and external resources, and other relevant practices. It is conducted by an individual approved by the State, which may include the system operator. Minimum elements include review and identification of atypical events that could affect distributed water quality or indicate that distributed water quality was impaired; changes in distribution system maintenance and operation that could affect distributed water quality (including water storage); source and treatment considerations that bear on distributed water quality, where appropriate (e.g., whether a ground water system is disinfected); existing water quality monitoring data; and inadequacies in sample sites, sampling protocol, and sample processing. The system must conduct the assessment consistent with any State directives that tailor specific assessment elements with respect to the size and type of the system and the size, type, and characteristics of the distribution system. The system must comply with any expedited actions or additional actions required by the State in the case of an 
                                <E T="03">E. coli</E>
                                 MCL violation.
                            </P>
                            <P>
                                <E T="03">Locational running annual average</E>
                                 (LRAA) is the average of sample analytical results for samples taken at a particular monitoring location during the previous four calendar quarters.
                            </P>
                            <P>
                                <E T="03">Man-made beta particle and photon emitters</E>
                                 means all radionuclides emitting beta particles and/or photons listed in Maximum Permissible Body Burdens and Maximum Permissible Concentration of Radionuclides in Air or Water for Occupational Exposure, NBS Handbook 69, except the daughter products of thorium-232, uranium-235 and uranium-238.
                            </P>
                            <P>
                                <E T="03">Maximum contaminant level</E>
                                 means the maximum permissible level of a contaminant in water which is delivered to any user of a public water system.
                            </P>
                            <P>
                                <E T="03">Maximum contaminant level goal</E>
                                 or 
                                <E T="03">MCLG</E>
                                 means the maximum level of a 
                                <PRTPAGE P="481"/>
                                contaminant in drinking water at which no known or anticipated adverse effect on the health of persons would occur, and which allows an adequate margin of safety. Maximum contaminant level goals are nonenforceable health goals.
                            </P>
                            <P>
                                <E T="03">Maximum residual disinfectant level (MRDL)</E>
                                 means a level of a disinfectant added for water treatment that may not be exceeded at the consumer's tap without an unacceptable possibility of adverse health effects. For chlorine and chloramines, a PWS is in compliance with the MRDL when the running annual average of monthly averages of samples taken in the distribution system, computed quarterly, is less than or equal to the MRDL. For chlorine dioxide, a PWS is in compliance with the MRDL when daily samples are taken at the entrance to the distribution system and no two consecutive daily samples exceed the MRDL. MRDLs are enforceable in the same manner as maximum contaminant levels under Section 1412 of the Safe Drinking Water Act. There is convincing evidence that addition of a disinfectant is necessary for control of waterborne microbial contaminants. Notwithstanding the MRDLs listed in § 141.65, operators may increase residual disinfectant levels of chlorine or chloramines (but not chlorine dioxide) in the distribution system to a level and for a time necessary to protect public health to address specific microbiological contamination problems caused by circumstances such as distribution line breaks, storm runoff events, source water contamination, or cross-connections.
                            </P>
                            <P>
                                <E T="03">Maximum residual disinfectant level goal (MRDLG)</E>
                                 means the maximum level of a disinfectant added for water treatment at which no known or anticipated adverse effect on the health of persons would occur, and which allows an adequate margin of safety. MRDLGs are nonenforceable health goals and do not reflect the benefit of the addition of the chemical for control of waterborne microbial contaminants.
                            </P>
                            <P>
                                <E T="03">Maximum Total Trihalomethane Potential (MTP)</E>
                                 means the maximum concentration of total trihalomethanes produced in a given water containing a disinfectant residual after 7 days at a temperature of 25 °C or above.
                            </P>
                            <P>
                                <E T="03">Medium water system,</E>
                                 for the purpose of subpart I of this part only, means a water system that serves greater than 10,000 persons and less than or equal to 50,000 persons.
                            </P>
                            <P>
                                <E T="03">Membrane filtration</E>
                                 is a pressure or vacuum driven separation process in which particulate matter larger than 1 micrometer is rejected by an engineered barrier, primarily through a size-exclusion mechanism, and which has a measurable removal efficiency of a target organism that can be verified through the application of a direct integrity test. This definition includes the common membrane technologies of microfiltration, ultrafiltration, nanofiltration, and reverse osmosis.
                            </P>
                            <P>
                                <E T="03">Method detection limit (MDL)</E>
                                 means the minimum concentration of a substance that can be measured and reported with 99 percent confidence that the analyte concentration is greater than zero and is determined from analysis of a sample in a given matrix containing the analyte.
                            </P>
                            <P>
                                <E T="03">Near the first service connection</E>
                                 means at one of the 20 percent of all service connections in the entire system that are nearest the water supply treatment facility, as measured by water transport time within the distribution system.
                            </P>
                            <P>
                                <E T="03">Newly regulated public water system,</E>
                                 for the purpose of subpart I only, refers to either:
                            </P>
                            <P>
                                (1) An existing 
                                <E T="03">public water system</E>
                                 that was not subject to National Primary Drinking Water Regulations in this part on October 16, 2024, because the system met the requirements of section 1411 of the Safe Drinking Water Act and § 141.3; or
                            </P>
                            <P>
                                (2) An existing water system that did not meet the definition of a 
                                <E T="03">public water system</E>
                                 in § 141.2 on October 16, 2024. This term does not include existing water systems under new or restructured ownership or management.
                            </P>
                            <P>
                                <E T="03">Non-community water system</E>
                                 means a public water system that is not a community water system. A non-community water system is either a “transient non-community water system (TWS)” or a “non-transient non-community water system (NTNCWS).”
                                <PRTPAGE P="482"/>
                            </P>
                            <P>
                                <E T="03">Non-transient non-community water system</E>
                                 or 
                                <E T="03">NTNCWS</E>
                                 means a public water system that is not a community water system and that regularly serves at least 25 of the same persons over 6 months per year.
                            </P>
                            <P>
                                <E T="03">Optimal corrosion control treatment (OCCT),</E>
                                 for the purpose of subpart I of this part only, means the corrosion control treatment that minimizes the lead and copper concentrations at users' taps while ensuring that the treatment does not cause the water system to violate any National Primary Drinking Water Regulations in this part.
                            </P>
                            <P>
                                <E T="03">Partial service line replacement,</E>
                                 for the purpose of subpart I of this part only, means replacement of any portion of a 
                                <E T="03">lead service line</E>
                                 or 
                                <E T="03">galvanized requiring replacement service line,</E>
                                 as defined in this section, that leaves in service any length of lead or galvanized requiring replacement service line upon completion of the work.
                            </P>
                            <P>
                                <E T="03">Performance evaluation sample</E>
                                 means a reference sample provided to a laboratory for the purpose of demonstrating that the laboratory can successfully analyze the sample within limits of performance specified by the Agency. The true value of the concentration of the reference material is unknown to the laboratory at the time of the analysis.
                            </P>
                            <P>
                                <E T="03">Person</E>
                                 means an individual; corporation; company; association; partnership; municipality; or State, Federal, or tribal agency.
                            </P>
                            <P>
                                <E T="03">PFBS</E>
                                 means Chemical Abstract Service registration number 45187-15-3, chemical formula C4F9SO3-, perfluorobutane sulfonate, along with its conjugate acid and any salts, derivatives, isomers, or combinations thereof.
                            </P>
                            <P>
                                <E T="03">PFHxS</E>
                                 means Chemical Abstract Service registration number 108427-53-8, chemical formula C6F13SO3-, perfluorohexane sulfonate, along with its conjugate acid and any salts, derivatives, isomers, or combinations thereof.
                            </P>
                            <P>
                                <E T="03">PFNA</E>
                                 means Chemical Abstract Service registration number 72007-68-2, chemical formula C9F17O2-, perfluorononanoate, along with its conjugate acid and any salts, derivatives, isomers, or combinations thereof.
                            </P>
                            <P>
                                <E T="03">PFOA</E>
                                 means Chemical Abstract Service registration number 45285-51-6, chemical formula C8F15O2-, perfluorooctanoate, along with its conjugate acid and any salts, derivatives, isomers, or combinations thereof.
                            </P>
                            <P>
                                <E T="03">PFOS</E>
                                 means Chemical Abstract Service registration number 45298-90-6, chemical formula C8F17SO3-, perfluorooctanesulfonate, along with its conjugate acid and any salts, derivatives, isomers, or combinations thereof.
                            </P>
                            <P>
                                <E T="03">Picocurie (pCi)</E>
                                 means the quantity of radioactive material producing 2.22 nuclear transformations per minute.
                            </P>
                            <P>
                                <E T="03">Pitcher filter</E>
                                 means a non-plumbed water filtration device, which consists of a gravity fed water filtration cartridge and a filtered drinking water reservoir, that is certified by an American National Standards Institute accredited certifier to reduce lead in drinking water.
                            </P>
                            <P>
                                <E T="03">Plant intake</E>
                                 refers to the works or structures at the head of a conduit through which water is diverted from a source (e.g., river or lake) into the treatment plant.
                            </P>
                            <P>
                                <E T="03">Point of disinfectant application</E>
                                 is the point where the disinfectant is applied and water downstream of that point is not subject to recontamination by surface water runoff.
                            </P>
                            <P>
                                <E T="03">Point-of-entry treatment device (POE)</E>
                                 is a treatment device applied to the drinking water entering a house or building for the purpose of reducing contaminants in the drinking water distributed throughout the house or building.
                            </P>
                            <P>
                                <E T="03">Point-of-use treatment device or point of use device (POU)</E>
                                 is a water treatment device physically installed or connected to a single fixture, outlet, or tap to reduce or remove contaminants in drinking water. For the purposes of subpart I of this part, it must be certified by an American National Standards Institute accredited certifier to reduce lead in drinking water.
                            </P>
                            <P>
                                <E T="03">Practical quantitation limit (PQL)</E>
                                 means the minimum concentration of an analyte (substance) that can be measured with a high degree of confidence that the analyte is present at or above that concentration.
                                <PRTPAGE P="483"/>
                            </P>
                            <P>
                                <E T="03">Presedimentation</E>
                                 is a preliminary treatment process used to remove gravel, sand and other particulate material from the source water through settling before the water enters the primary clarification and filtration processes in a treatment plant.
                            </P>
                            <P>
                                <E T="03">Pre-stagnation flushing</E>
                                 is the opening of tap(s) to flush standing water from plumbing prior to the minimum 6-hour stagnation period in anticipation of lead and copper tap sampling under subpart I of this part.
                            </P>
                            <P>
                                <E T="03">Public water system</E>
                                 means a system for the provision to the public of water for human consumption through pipes or, after August 5, 1998, other constructed conveyances, if such system has at least fifteen service connections or regularly serves an average of at least twenty-five individuals daily at least 60 days out of the year. Such term includes: any collection, treatment, storage, and distribution facilities under control of the operator of such system and used primarily in connection with such system; and any collection or pretreatment storage facilities not under such control which are used primarily in connection with such system. Such term does not include any “special irrigation district.” A public water system is either a “community water system” or a “noncommunity water system.”
                            </P>
                            <P>
                                <E T="03">Rem</E>
                                 means the unit of dose equivalent from ionizing radiation to the total body or any internal organ or organ system. A “millirem (mrem)” is 
                                <FR>1/1000</FR>
                                 of a rem.
                            </P>
                            <P>
                                <E T="03">Repeat compliance period</E>
                                 means any subsequent compliance period after the initial compliance period.
                            </P>
                            <P>
                                <E T="03">Residual disinfectant concentration</E>
                                 (“C” in CT calculations) means the concentration of disinfectant measured in mg/l in a representative sample of water.
                            </P>
                            <P>
                                <E T="03">Sanitary defect</E>
                                 is a defect that could provide a pathway of entry for microbial contamination into the distribution system or that is indicative of a failure or imminent failure in a barrier that is already in place.
                            </P>
                            <P>
                                <E T="03">Sanitary survey</E>
                                 means an onsite review of the water source, facilities, equipment, operation and maintenance of a public water system for the purpose of evaluating the adequacy of such source, facilities, equipment, operation and maintenance for producing and distributing safe drinking water.
                            </P>
                            <P>
                                <E T="03">School,</E>
                                 for the purpose of subpart I of this part only, means any building(s) associated with public, private, or charter institutions that primarily provides teaching and learning for elementary or secondary students.
                            </P>
                            <P>
                                <E T="03">Seasonal system</E>
                                 is a non-community water system that is not operated as a public water system on a year-round basis and starts up and shuts down at the beginning and end of each operating season.
                            </P>
                            <P>
                                <E T="03">Secondary school,</E>
                                 for the purpose of subpart I of this part only, means a school comprising any span of grades beginning with the next grade following an elementary school (usually 7, 8, or 9) and ending with grade 12. Secondary schools include both junior high schools and senior high schools and typically span grades 7 through 12.
                            </P>
                            <P>
                                <E T="03">Sedimentation</E>
                                 means a process for removal of solids before filtration by gravity or separation.
                            </P>
                            <P>
                                <E T="03">Service connection,</E>
                                 as used in the definition of 
                                <E T="03">public water system,</E>
                                 does not include a connection to a system that delivers water by a constructed conveyance other than a pipe if:
                            </P>
                            <P>(1) The water is used exclusively for purposes other than residential uses (consisting of drinking, bathing, and cooking, or other similar uses);</P>
                            <P>(2) The State determines that alternative water to achieve the equivalent level of public health protection provided by the applicable national primary drinking water regulation is provided for residential or similar uses for drinking and cooking; or</P>
                            <P>(3) The State determines that the water provided for residential or similar uses for drinking, cooking, and bathing is centrally treated or treated at the point of entry by the provider, a pass-through entity, or the user to achieve the equivalent level of protection provided by the applicable national primary drinking water regulations.</P>
                            <P>
                                <E T="03">Service line,</E>
                                 for the purpose of subpart I of this part only, means a portion of pipe that connects the water main (or other conduit for distributing water to individual consumers or groups of consumers) to the building inlet. Where a 
                                <PRTPAGE P="484"/>
                                building is not present, the service line connects the water main (or other conduit for distributing water to individual consumers or groups of consumers) to the outlet.
                            </P>
                            <P>
                                <E T="03">Single family structure,</E>
                                 for the purpose of subpart I of this part only, means a building constructed as a single-family residence that is currently used as either a residence or a place of business.
                            </P>
                            <P>
                                <E T="03">Slow sand filtration</E>
                                 means a process involving passage of raw water through a bed of sand at low velocity (generally less than 0.4 m/h) resulting in substantial particulate removal by physical and biological mechanisms.
                            </P>
                            <P>
                                <E T="03">Small water system,</E>
                                 for the purpose of subpart I of this part only, means a water system that serves 10,000 persons or fewer.
                            </P>
                            <P>
                                <E T="03">Special irrigation district</E>
                                 means an irrigation district in existence prior to May 18, 1994 that provides primarily agricultural service through a piped water system with only incidental residential or similar use where the system or the residential or similar users of the system comply with the exclusion provisions in section 1401(4)(B)(i)(II) or (III).
                            </P>
                            <P>
                                <E T="03">Standard sample</E>
                                 means the aliquot of finished drinking water that is examined for the presence of coliform bacteria.
                            </P>
                            <P>
                                <E T="03">State</E>
                                 means the agency of the State or Tribal government which has jurisdiction over public water systems. During any period when a State or Tribal government does not have primary enforcement responsibility pursuant to section 1413 of the Act, the term “State” means the Regional Administrator, U.S. Environmental Protection Agency.
                            </P>
                            <P>
                                <E T="03">Subpart H systems</E>
                                 means public water systems using surface water or ground water under the direct influence of surface water as a source that are subject to the requirements of subpart H of this part.
                            </P>
                            <P>
                                <E T="03">Supplier of water</E>
                                 means any person who owns or operates a public water system.
                            </P>
                            <P>
                                <E T="03">Surface water</E>
                                 means all water which is open to the atmosphere and subject to surface runoff.
                            </P>
                            <P>
                                <E T="03">SUVA</E>
                                 means Specific Ultraviolet Absorption at 254 nanometers (nm), an indicator of the humic content of water. It is a calculated parameter obtained by dividing a sample's ultraviolet absorption at a wavelength of 254 nm (UV 
                                <E T="52">254</E>
                                ) (in m 
                                <SU>= 1</SU>
                                ) by its concentration of dissolved organic carbon (DOC) (in mg/L).
                            </P>
                            <P>
                                <E T="03">System with a single service connection</E>
                                 means a system which supplies drinking water to consumers via a single service line.
                            </P>
                            <P>
                                <E T="03">System without corrosion control treatment,</E>
                                 for the purpose of subpart I of this part, means a water system that does not have or purchases all of its water from a system that does not have:
                            </P>
                            <P>(1) An optimal corrosion control treatment approved by the State; or</P>
                            <P>(2) Any pH adjustment, alkalinity adjustment, and/or corrosion inhibitor addition resulting from other water quality adjustments as part of its treatment train infrastructure.</P>
                            <P>
                                <E T="03">Tap monitoring period,</E>
                                 for the purpose of subpart I of this part only, means the period of time during which each water system must conduct tap sampling for lead and copper analysis. The applicable tap monitoring period is determined by lead and copper concentrations in tap samples. The length of the tap monitoring period can range from six months to nine years.
                            </P>
                            <P>
                                <E T="03">Tap sampling period,</E>
                                 for the purpose of subpart I of this part only, means the time period, within a tap monitoring period, during which the water system is required to collect samples for lead and copper analysis.
                            </P>
                            <P>
                                <E T="03">Tap sampling protocol</E>
                                 means the method for collecting tap samples pursuant to § 141.86(b).
                            </P>
                            <P>
                                <E T="03">Too numerous to count</E>
                                 means that the total number of bacterial colonies exceeds 200 on a 47-mm diameter membrane filter used for coliform detection.
                            </P>
                            <P>
                                <E T="03">Total Organic Carbon (TOC)</E>
                                 means total organic carbon in mg/L measured using heat, oxygen, ultraviolet irradiation, chemical oxidants, or combinations of these oxidants that convert organic carbon to carbon dioxide, rounded to two significant figures.
                            </P>
                            <P>
                                <E T="03">Total trihalomethanes</E>
                                 (TTHM) means the sum of the concentration in milligrams per liter of the trihalomethane compounds (trichloromethane [chloroform], dibromochloromethane, 
                                <PRTPAGE P="485"/>
                                bromodichloromethane and tribromomethane [bromoform]), rounded to two significant figures.
                            </P>
                            <P>
                                <E T="03">Transient non-community water system</E>
                                 or 
                                <E T="03">TWS</E>
                                 means a non-community water system that does not regularly serve at least 25 of the same persons over six months per year.
                            </P>
                            <P>
                                <E T="03">Trihalomethane</E>
                                 (THM) means one of the family of organic compounds, named as derivatives of methane, wherein three of the four hydrogen atoms in methane are each substituted by a halogen atom in the molecular structure.
                            </P>
                            <P>
                                <E T="03">Two-stage lime softening</E>
                                 is a process in which chemical addition and hardness precipitation occur in each of two distinct unit clarification processes in series prior to filtration.
                            </P>
                            <P>
                                <E T="03">Uncovered finished water storage facility</E>
                                 is a tank, reservoir, or other facility used to store water that will undergo no further treatment to reduce microbial pathogens except residual disinfection and is directly open to the atmosphere.
                            </P>
                            <P>
                                <E T="03">Virus</E>
                                 means a virus of fecal origin which is infectious to humans by waterborne transmission.
                            </P>
                            <P>
                                <E T="03">Waterborne disease outbreak</E>
                                 means the significant occurrence of acute infectious illness, epidemiologically associated with the ingestion of water from a public water system which is deficient in treatment, as determined by the appropriate local or State agency.
                            </P>
                            <P>
                                <E T="03">Wholesale system</E>
                                 is a public water system that treats source water as necessary to produce finished water and then delivers some or all of that finished water to another public water system. Delivery may be through a direct connection or through the distribution system of one or more consecutive systems.
                            </P>
                            <P>
                                <E T="03">Wide-mouth bottles,</E>
                                 for the purpose of subpart I of this part only, means bottles one liter in volume that have a mouth with an inner diameter that measures at least 40 millimeters wide.
                            </P>
                            <CITA>[40 FR 59570, Dec. 24, 1975]</CITA>
                            <EDNOTE>
                                <HD SOURCE="HED">Editorial Note:</HD>
                                <P>
                                    For 
                                    <E T="04">Federal Register</E>
                                     citations affecting § 141.2, see the List of CFR Sections Affected, which appears in the Finding Aids section of the printed volume and at 
                                    <E T="03">www.govinfo.gov.</E>
                                </P>
                            </EDNOTE>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 141.3</SECTNO>
                            <SUBJECT>Coverage.</SUBJECT>
                            <P>This part shall apply to each public water system, unless the public water system meets all of the following conditions:</P>
                            <P>(a) Consists only of distribution and storage facilities (and does not have any collection and treatment facilities);</P>
                            <P>(b) Obtains all of its water from, but is not owned or operated by, a public water system to which such regulations apply:</P>
                            <P>(c) Does not sell water to any person; and</P>
                            <P>(d) Is not a carrier which conveys passengers in interstate commerce.</P>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 141.4</SECTNO>
                            <SUBJECT>Variances and exemptions.</SUBJECT>
                            <P>
                                (a) Variances or exemptions from certain provisions of these regulations may be granted pursuant to sections 1415 and 1416 of the Act and subpart K of part 142 of this chapter (for small system variances) by the entity with primary enforcement responsibility, except that variances or exemptions from the MCLs for total coliforms and 
                                <E T="03">E. coli</E>
                                 and variances from any of the treatment technique requirements of subpart H of this part may not be granted.
                            </P>
                            <P>(b) EPA has stayed the effective date of this section relating to the total coliform MCL of § 141.63(a) for systems that demonstrate to the State that the violation of the total coliform MCL is due to a persistent growth of total coliforms in the distribution system rather than fecal or pathogenic contamination, a treatment lapse or deficiency, or a problem in the operation or maintenance of the distribution system. This is stayed until March 31, 2016, at which time the total coliform MCL is no longer effective.</P>
                            <NOTE>
                                <HD SOURCE="HED">
                                    Note to paragraph (
                                    <E T="01">a</E>
                                    ):
                                </HD>
                                <P>As provided in § 142.304(a), small system variances are not available for rules addressing microbial contaminants, which would include subparts H, P, S, T, W, and Y of this part.</P>
                            </NOTE>
                            <CITA>[78 FR 10346, Feb. 13, 2013]</CITA>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 141.5</SECTNO>
                            <SUBJECT>Siting requirements.</SUBJECT>
                            <P>
                                Before a person may enter into a financial commitment for or initiate 
                                <PRTPAGE P="486"/>
                                construction of a new public water system or increase the capacity of an existing public water system, he shall notify the State and, to the extent practicable, avoid locating part or all of the new or expanded facility at a site which:
                            </P>
                            <P>(a) Is subject to a significant risk from earthquakes, floods, fires or other disasters which could cause a breakdown of the public water system or a portion thereof; or</P>
                            <P>(b) Except for intake structures, is within the floodplain of a 100-year flood or is lower than any recorded high tide where appropriate records exist. The U.S. Environmental Protection Agency will not seek to override land use decisions affecting public water systems siting which are made at the State or local government levels.</P>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 141.6</SECTNO>
                            <SUBJECT>Effective dates.</SUBJECT>
                            <P>(a) Except as provided in paragraphs (b) through (l) of this section the regulations set forth in this part take effect on June 24, 1977.</P>
                            <P>(b) The regulations for total trihalomethanes set forth in § 141.12(c) shall take effect 2 years after the date of promulgation of these regulations for community water systems serving 75,000 or more individuals, and 4 years after the date of promulgation for communities serving 10,000 to 74,999 individuals.</P>
                            <P>(c) The regulations set forth in §§ 141.11(d); 141.21(a), (c) and (i); 141.22(a) and (e); 141.23(a)(3) and (a)(4); 141.23(f); 141.24(e) and (f); 141.25(e); 141.27(a); 141.28(a) and (b); 141.31(a), (d) and (e); 141.32(b)(3); and 141.32(d) shall take effect immediately upon promulgation.</P>
                            <P>(d) The regulations set forth in § 141.41 shall take effect 18 months from the date of promulgation. Suppliers must complete the first round of sampling and reporting within 12 months following the effective date.</P>
                            <P>(e) The regulations set forth in § 141.42 shall take effect 18 months from the date of promulgation. All requirements in § 141.42 must be completed within 12 months following the effective date.</P>
                            <P>(f) The regulations set forth in § 141.11(c) and § 141.23(g) are effective May 2, 1986. Section 141.23(g)(4) is effective October 2, 1987.</P>
                            <P>(g) The regulations contained in § 141.6, paragraph (c) of the table in § 141.12, and § 141.62(b)(1) are effective July 1, 1991. The regulations contained in §§ 141.11(b), 141.23, 141.24, 142.57(b), 143.4(b)(12) and (b)(13), are effective July 30, 1992. The regulations contained in the revisions to §§ 141.32(e) (16), (25) through (27) and (46); 141.61(c)(16); and 141.62(b)(3) are effective January 1, 1993. The effective date of regulations contained in § 141.61(c) (2), (3), and (4) is postponed.</P>
                            <P>(h) Regulations for the analytic methods listed at § 141.23(k)(4) for measuring antimony, beryllium, cyanide, nickel, and thallium are effective August 17, 1992. Regulations for the analytic methods listed at § 141.24(f)(16) for dichloromethane, 1,2,4-trichlorobenzene, and 1,1,2-trichloroethane are effective August 17, 1992. Regulations for the analytic methods listed at § 141.24(h)(12) for measuring dalapon, dinoseb, diquat, endothall, endrin, glyphosate, oxamyl, picloram, simazine, benzo(a)pyrene, di(2-ethylhexyl)adipate, di(2-ethylhexyl)phthalate, hexachlorobenzene, hexachlorocyclopentadiene, and 2,3,7,8-TCDD are effective August 17, 1992. The revision to § 141.12(a) promulgated on July 17, 1992 is effective on August 17, 1992.</P>
                            <P>(i) [Reserved]</P>
                            <P>(j) The arsenic maximum contaminant levels (MCL) listed in § 141.62 is effective for the purpose of compliance on January 23, 2006. Requirements relating to arsenic set forth in §§ 141.23(i)(4), 141.23(k)(3) introductory text, 141.23(k)(3)(ii), 141.51(b), 141.62(b), 141.62(b)(16), 141.62(c), 141.62(d), and 142.62(b) revisions in appendix A of subpart O for the consumer confidence rule, and appendices A and B of subpart Q for the public notification rule are effective for the purpose of compliance on January 23, 2006. However, the consumer confidence rule reporting requirements relating to arsenic listed in § 141.154(b) and (f) are effective for the purpose of compliance on February 22, 2002.</P>
                            <P>
                                (k) Regulations set forth in §§ 141.23(i)(1), 141.23(i)(2), 141.24(f)(15), 
                                <PRTPAGE P="487"/>
                                141.24(f)(22), 141.24(h)(11), 141.24(h)(20), 142.16(e), 142.16(j), and 142.16(k) are effective for the purpose of compliance on January 22, 2004.
                            </P>
                            <P>(l) The regulations pertaining to the per- and polyfluoroalkyl substances (PFAS) chemicals set forth in subpart Z of this part are effective June 25, 2024. See § 141.900 for the compliance dates for provisions under subpart Z. Compliance with reporting requirements under subpart Z, in accordance with subparts O (the consumer confidence rule) and Q (the public notification rule) of this part are required on April 26, 2027, except for notification requirements in § 141.203 related to violations of the MCLs. The compliance date for the PFAS MCLs in § 141.61, as specified in § 141.60, and for § 141.203 notifications of violations of the PFAS MCLs is April 26, 2029.</P>
                            <CITA>[44 FR 68641, Nov. 29, 1979, as amended at 45 FR 57342, Aug. 27, 1980; 47 FR 10998, Mar. 12, 1982; 51 FR 11410, Apr. 2, 1986; 56 FR 30274, July 1, 1991; 57 FR 22178, May 27, 1992; 57 FR 31838, July 17, 1992; 59 FR 34322, July 1, 1994; 61 FR 24368, May 14, 1996; 66 FR 7061, Jan. 22, 2001; 66 FR 28350, May 22, 2001; 89 FR 32744, Apr. 26, 2024]</CITA>
                        </SECTION>
                    </SUBPART>
                    <SUBPART>
                        <HD SOURCE="HED">Subpart B—Maximum Contaminant Levels</HD>
                        <SECTION>
                            <SECTNO>§ 141.11</SECTNO>
                            <SUBJECT>Maximum contaminant levels for inorganic chemicals.</SUBJECT>
                            <P>(a) The maximum contaminant level for arsenic applies only to community water systems. The analyses and determination of compliance with the 0.05 milligrams per liter maximum contaminant level for arsenic use the requirements of § 141.23.</P>
                            <P>(b) The maximum contaminant level for arsenic is 0.05 milligrams per liter for community water systems until January 23, 2006.</P>
                            <P>(c) [Reserved]</P>
                            <P>(d) At the discretion of the State, nitrate levels not to exceed 20 mg/l may be allowed in a non-community water system if the supplier of water demonstrates to the satisfaction of the State that:</P>
                            <P>(1) Such water will not be available to children under 6 months of age; and</P>
                            <P>(2) The non-community water system is meeting the public notification requirements under § 141.209, including continuous posting of the fact that nitrate levels exceed 10 mg/l and the potential health effects of exposure; and</P>
                            <P>(3) Local and State public health authorities will be notified annually of nitrate levels that exceed 10 mg/l; and</P>
                            <P>(4) No adverse health effects shall result.</P>
                            <CITA>[40 FR 59570, Dec. 24, 1975, as amended at 45 FR 57342, Aug. 27, 1980; 47 FR 10998, Mar. 12, 1982; 51 FR 11410, Apr. 2, 1986; 56 FR 3578, Jan. 30, 1991; 56 FR 26548, June 7, 1991; 56 FR 30274, July 1, 1991; 56 FR 32113, July 15, 1991; 60 FR 33932, June 29, 1995; 65 FR 26022, May 4, 2000; 66 FR 7061, Jan. 22, 2001]</CITA>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 141.12</SECTNO>
                            <RESERVED>[Reserved]</RESERVED>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 141.13</SECTNO>
                            <SUBJECT>Maximum contaminant levels for turbidity.</SUBJECT>
                            <P>The maximum contaminant levels for turbidity are applicable to both community water systems and non-community water systems using surface water sources in whole or in part. The maximum contaminant levels for turbidity in drinking water, measured at a representative entry point(s) to the distribution system, are:</P>
                            <P>(a) One turbidity unit (TU), as determined by a monthly average pursuant to § 141.22, except that five or fewer turbidity units may be allowed if the supplier of water can demonstrate to the State that the higher turbidity does not do any of the following:</P>
                            <P>(1) Interfere with disinfection;</P>
                            <P>(2) Prevent maintenance of an effective disinfectant agent throughout the distribution system; or</P>
                            <P>(3) Interfere with microbiological determinations.</P>
                            <P>(b) Five turbidity units based on an average for two consecutive days pursuant to § 141.22.</P>
                            <CITA>[40 FR 59570, Dec. 24, 1975]</CITA>
                        </SECTION>
                    </SUBPART>
                    <SUBPART>
                        <HD SOURCE="HED">Subpart C—Monitoring and Analytical Requirements</HD>
                        <SECTION>
                            <SECTNO>§ 141.21</SECTNO>
                            <SUBJECT>Coliform sampling.</SUBJECT>
                            <P>
                                (a) 
                                <E T="03">Routine monitoring.</E>
                                 (1) Public water systems must collect total coliform samples at sites which are representative of water throughout the distribution system according to a written sample siting plan. These plans are subject to State review and revision.
                                <PRTPAGE P="488"/>
                            </P>
                            <P>(2) The monitoring frequency for total coliforms for community water systems is based on the population served by the system, as follows:</P>
                            <GPOTABLE COLS="2" OPTS="L2" CDEF="s50,8">
                                <TTITLE>Total Coliform Monitoring Frequency for Community Water Systems</TTITLE>
                                <BOXHD>
                                    <CHED H="1">Population served</CHED>
                                    <CHED H="1">Minimum number of samples per month</CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">
                                        25 to 1,000 
                                        <SU>1</SU>
                                    </ENT>
                                    <ENT>1</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">1,001 to 2,500</ENT>
                                    <ENT>2</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">2,501 to 3,300</ENT>
                                    <ENT>3</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">3,301 to 4,100</ENT>
                                    <ENT>4</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">4,101 to 4,900</ENT>
                                    <ENT>5</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">4,901 to 5,800</ENT>
                                    <ENT>6</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">5,801 to 6,700</ENT>
                                    <ENT>7</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">6,701 to 7,600</ENT>
                                    <ENT>8</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">7,601 to 8,500</ENT>
                                    <ENT>9</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">8,501 to 12,900</ENT>
                                    <ENT>10</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">12,901 to 17,200</ENT>
                                    <ENT>15</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">17,201 to 21,500</ENT>
                                    <ENT>20</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">21,501 to 25,000</ENT>
                                    <ENT>25</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">25,001 to 33,000</ENT>
                                    <ENT>30</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">33,001 to 41,000</ENT>
                                    <ENT>40</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">41,001 to 50,000</ENT>
                                    <ENT>50</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">50,001 to 59,000</ENT>
                                    <ENT>60</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">59,001 to 70,000</ENT>
                                    <ENT>70</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">70,001 to 83,000</ENT>
                                    <ENT>80</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">83,001 to 96,000</ENT>
                                    <ENT>90</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">96,001 to 130,000</ENT>
                                    <ENT>100</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">130,001 to 220,000</ENT>
                                    <ENT>120</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">220,001 to 320,000</ENT>
                                    <ENT>150</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">320,001 to 450,000</ENT>
                                    <ENT>180</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">450,001 to 600,000</ENT>
                                    <ENT>210</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">600,001 to 780,000</ENT>
                                    <ENT>240</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">780,001 to 970,000</ENT>
                                    <ENT>270</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">970,001 to 1,230,000</ENT>
                                    <ENT>300</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">1,230,001 to 1,520,000</ENT>
                                    <ENT>330</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">1,520,001 to 1,850,000</ENT>
                                    <ENT>360</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">1,850,001 to 2,270,000</ENT>
                                    <ENT>390</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">2,270,001 to 3,020,000</ENT>
                                    <ENT>420</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">3,020,001 to 3,960,000</ENT>
                                    <ENT>450</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">3,960,001 or more</ENT>
                                    <ENT>480</ENT>
                                </ROW>
                                <TNOTE>
                                    <SU>1</SU>
                                     Includes public water systems which have at least 15 service connections, but serve fewer than 25 persons.
                                </TNOTE>
                            </GPOTABLE>
                            <FP>If a community water system serving 25 to 1,000 persons has no history of total coliform contamination in its current configuration and a sanitary survey conducted in the past five years shows that the system is supplied solely by a protected groundwater source and is free of sanitary defects, the State may reduce the monitoring frequency specified above, except that in no case may the State reduce the monitoring frequency to less than one sample per quarter. The State must approve the reduced monitoring frequency in writing.</FP>
                            <P>(3) The monitoring frequency for total coliforms for non-community water systems is as follows:</P>
                            <P>(i) A non-community water system using only ground water (except ground water under the direct influence of surface water, as defined in § 141.2) and serving 1,000 persons or fewer must monitor each calendar quarter that the system provides water to the public, except that the State may reduce this monitoring frequency, in writing, if a sanitary survey shows that the system is free of sanitary defects. Beginning June 29, 1994, the State cannot reduce the monitoring frequency for a non-community water system using only ground water (except ground water under the direct influence of surface water, as defined in § 141.2) and serving 1,000 persons or fewer to less than once/year.</P>
                            <P>(ii) A non-community water system using only ground water (except ground water under the direct influence of surface water, as defined in § 141.2) and serving more than 1,000 persons during any month must monitor at the same frequency as a like-sized community water system, as specified in paragraph (a)(2) of this section, except the State may reduce this monitoring frequency, in writing, for any month the system serves 1,000 persons or fewer. The State cannot reduce the monitoring frequency to less than once/year. For systems using ground water under the direct influence of surface water, paragraph (a)(3)(iv) of this section applies.</P>
                            <P>(iii) A non-community water system using surface water, in total or in part, must monitor at the same frequency as a like-sized community water system, as specified in paragraph (a)(2) of this section, regardless of the number of persons it serves.</P>
                            <P>(iv) A non-community water system using ground water under the direct influence of surface water, as defined in § 141.2, must monitor at the same frequency as a like-sized community water system, as specified in paragraph (a)(2) of this section. The system must begin monitoring at this frequency beginning six months after the State determines that the ground water is under the direct influence of surface water.</P>
                            <P>
                                (4) The public water system must collect samples at regular time intervals throughout the month, except that a 
                                <PRTPAGE P="489"/>
                                system which uses only ground water (except ground water under the direct influence of surface water, as defined in § 141.2), and serves 4,900 persons or fewer, may collect all required samples on a single day if they are taken from different sites.
                            </P>
                            <P>(5) A public water system that uses surface water or ground water under the direct influence of surface water, as defined in § 141.2, and does not practice filtration in compliance with Subpart H must collect at least one sample near the first service connection each day the turbidity level of the source water, measured as specified in § 141.74(b)(2), exceeds 1 NTU. This sample must be analyzed for the presence of total coliforms. When one or more turbidity measurements in any day exceed 1 NTU, the system must collect this coliform sample within 24 hours of the first exceedance, unless the State determines that the system, for logistical reasons outside the system's control, cannot have the sample analyzed within 30 hours of collection. Sample results from this coliform monitoring must be included in determining compliance with the MCL for total coliforms in § 141.63.</P>
                            <P>(6) Special purpose samples, such as those taken to determine whether disinfection practices are sufficient following pipe placement, replacement, or repair, shall not be used to determine compliance with the MCL for total coliforms in § 141.63. Repeat samples taken pursuant to paragraph (b) of this section are not considered special purpose samples, and must be used to determine compliance with the MCL for total coliforms in § 141.63.</P>
                            <P>
                                (b) 
                                <E T="03">Repeat monitoring.</E>
                                 (1) If a routine sample is total coliform-positive, the public water system must collect a set of repeat samples within 24 hours of being notified of the positive result. A system which collects more than one routine sample/month must collect no fewer than three repeat samples for each total coliform-positive sample found. A system which collects one routine sample/month or fewer must collect no fewer than four repeat samples for each total coliform-positive sample found. The State may extend the 24-hour limit on a case-by-case basis if the system has a logistical problem in collecting the repeat samples within 24 hours that is beyond its control. In the case of an extension, the State must specify how much time the system has to collect the repeat samples.
                            </P>
                            <P>(2) The system must collect at least one repeat sample from the sampling tap where the original total coliform-positive sample was taken, and at least one repeat sample at a tap within five service connections upstream and at least one repeat sample at a tap within five service connections downstream of the original sampling site. If a total coliform-positive sample is at the end of the distribution system, or one away from the end of the distribution system, the State may waive the requirement to collect at least one repeat sample upstream or downstream of the original sampling site.</P>
                            <P>(3) The system must collect all repeat samples on the same day, except that the State may allow a system with a single service connection to collect the required set of repeat samples over a four-day period or to collect a larger volume repeat sample(s) in one or more sample containers of any size, as long as the total volume collected is at least 400 ml (300 ml for systems which collect more than one routine sample/month).</P>
                            <P>(4) If one or more repeat samples in the set is total coliform-positive, the public water system must collect an additional set of repeat samples in the manner specified in paragraphs (b) (1)-(3) of this section. The additional samples must be collected within 24 hours of being notified of the positive result, unless the State extends the limit as provided in paragraph (b)(1) of this section. The system must repeat this process until either total coliforms are not detected in one complete set of repeat samples or the system determines that the MCL for total coliforms in § 141.63 has been exceeded and notifies the State.</P>
                            <P>
                                (5) If a system collecting fewer than five routine samples/month has one or more total coliform-positive samples and the State does not invalidate the sample(s) under paragraph (c) of this section, it must collect at least five routine samples during the next month 
                                <PRTPAGE P="490"/>
                                the system provides water to the public, except that the State may waive this requirement if the conditions of paragraph (b)(5) (i) or (ii) of this section are met. The State cannot waive the requirement for a system to collect repeat samples in paragraphs (b) (1)-(4) of this section.
                            </P>
                            <P>(i) The State may waive the requirement to collect five routine samples the next month the system provides water to the public if the State, or an agent approved by the State, performs a site visit before the end of the next month the system provides water to the public. Although a sanitary survey need not be performed, the site visit must be sufficiently detailed to allow the State to determine whether additional monitoring and/or any corrective action is needed. The State cannot approve an employee of the system to perform this site visit, even if the employee is an agent approved by the State to perform sanitary surveys.</P>
                            <P>(ii) The State may waive the requirement to collect five routine samples the next month the system provides water to the public if the State has determined why the sample was total coliform-positive and establishes that the system has corrected the problem or will correct the problem before the end of the next month the system serves water to the public. In this case, the State must document this decision to waive the following month's additional monitoring requirement in writing, have it approved and signed by the supervisor of the State official who recommends such a decision, and make this document available to the EPA and public. The written documentation must describe the specific cause of the total coliform-positive sample and what action the system has taken and/or will take to correct this problem. The State cannot waive the requirement to collect five routine samples the next month the system provides water to the public solely on the grounds that all repeat samples are total coliform-negative. Under this paragraph, a system must still take at least one routine sample before the end of the next month it serves water to the public and use it to determine compliance with the MCL for total coliforms in § 141.63, unless the State has determined that the system has corrected the contamination problem before the system took the set of repeat samples required in paragraphs (b) (1)-(4) of this section, and all repeat samples were total coliform-negative.</P>
                            <P>(6) After a system collects a routine sample and before it learns the results of the analysis of that sample, if it collects another routine sample(s) from within five adjacent service connections of the initial sample, and the initial sample, after analysis, is found to contain total coliforms, then the system may count the subsequent sample(s) as a repeat sample instead of as a routine sample.</P>
                            <P>(7) Results of all routine and repeat samples not invalidated by the State must be included in determining compliance with the MCL for total coliforms in § 141.63.</P>
                            <P>
                                (c) 
                                <E T="03">Invalidation of total coliform samples.</E>
                                 A total coliform-positive sample invalidated under this paragraph (c) does not count towards meeting the minimum monitoring requirements of this section.
                            </P>
                            <P>(1) The State may invalidate a total coliform-positive sample only if the conditions of paragraph (c)(1) (i), (ii), or (iii) of this section are met.</P>
                            <P>(i) The laboratory establishes that improper sample analysis caused the total coliform-positive result.</P>
                            <P>
                                (ii) The State, on the basis of the results of repeat samples collected as required by paragraphs (b) (1) through (4) of this section, determines that the total coliform-positive sample resulted from a domestic or other non-distribution system plumbing problem. The State cannot invalidate a sample on the basis of repeat sample results unless all repeat sample(s) collected at the same tap as the original total coliform-positive sample are also total coliform-positive, and all repeat samples collected within five service connections of the original tap are total coliform-negative (e.g., a State cannot invalidate a total coliform-positive sample on the basis of repeat samples if all the repeat samples are total coliform-negative, or if the public water system has only one service connection).
                                <PRTPAGE P="491"/>
                            </P>
                            <P>(iii) The State has substantial grounds to believe that a total coliform-positive result is due to a circumstance or condition which does not reflect water quality in the distribution system. In this case, the system must still collect all repeat samples required under paragraphs (b) (1)-(4) of this section, and use them to determine compliance with the MCL for total coliforms in § 141.63. To invalidate a total coliform-positive sample under this paragraph, the decision with the rationale for the decision must be documented in writing, and approved and signed by the supervisor of the State official who recommended the decision. The State must make this document available to EPA and the public. The written documentation must state the specific cause of the total coliform-positive sample, and what action the system has taken, or will take, to correct this problem. The State may not invalidate a total coliform-positive sample solely on the grounds that all repeat samples are total coliform-negative.</P>
                            <P>(2) A laboratory must invalidate a total coliform sample (unless total coliforms are detected) if the sample produces a turbid culture in the absence of gas production using an analytical method where gas formation is examined (e.g., the Multiple-Tube Fermentation Technique), produces a turbid culture in the absence of an acid reaction in the Presence-Absence (P-A) Coliform Test, or exhibits confluent growth or produces colonies too numerous to count with an analytical method using a membrane filter (e.g., Membrane Filter Technique). If a laboratory invalidates a sample because of such interference, the system must collect another sample from the same location as the original sample within 24 hours of being notified of the interference problem, and have it analyzed for the presence of total coliforms. The system must continue to re-sample within 24 hours and have the samples analyzed until it obtains a valid result. The State may waive the 24-hour time limit on a case-by-case basis.</P>
                            <P>
                                (d) 
                                <E T="03">Sanitary surveys.</E>
                                 (1)(i) Public water systems which do not collect five or more routine samples/month must undergo an initial sanitary survey by June 29, 1994, for community public water systems and June 29, 1999, for non-community water systems. Thereafter, systems must undergo another sanitary survey every five years, except that non-community water systems using only protected and disinfected ground water, as defined by the State, must undergo subsequent sanitary surveys at least every ten years after the initial sanitary survey. The State must review the results of each sanitary survey to determine whether the existing monitoring frequency is adequate and what additional measures, if any, the system needs to undertake to improve drinking water quality.
                            </P>
                            <P>(ii) In conducting a sanitary survey of a system using ground water in a State having an EPA-approved wellhead protection program under section 1428 of the Safe Drinking Water Act, information on sources of contamination within the delineated wellhead protection area that was collected in the course of developing and implementing the program should be considered instead of collecting new information, if the information was collected since the last time the system was subject to a sanitary survey.</P>
                            <P>(2) Sanitary surveys must be performed by the State or an agent approved by the State. The system is responsible for ensuring the survey takes place.</P>
                            <P>(3) Sanitary surveys conducted by the State under the provisions of § 142.16(o)(2) of this chapter may be used to meet the sanitary survey requirements of this section.</P>
                            <P>
                                (e) 
                                <E T="03">Fecal coliforms/Escherichia coli (E. coli) testing.</E>
                                 (1) If any routine or repeat sample is total coliform-positive, the system must analyze that total coliform-positive culture medium to determine if fecal coliforms are present, except that the system may test for 
                                <E T="03">E. coli</E>
                                 in lieu of fecal coliforms. If fecal coliforms or 
                                <E T="03">E. coli</E>
                                 are present, the system must notify the State by the end of the day when the system is notified of the test result, unless the system is notified of the result after the State office is closed, in which case the system must notify the State before the end of the next business day.
                                <PRTPAGE P="492"/>
                            </P>
                            <P>
                                (2) The State has the discretion to allow a public water system, on a case-by-case basis, to forgo fecal coliform or 
                                <E T="03">E. coli</E>
                                 testing on a total coliform-positive sample if that system assumes that the total coliform-positive sample is fecal coliform-positive or 
                                <E T="03">E. coli</E>
                                -positive. Accordingly, the system must notify the State as specified in paragraph (e)(1) of this section and the provisions of § 141.63(b) apply.
                            </P>
                            <P>
                                (f) 
                                <E T="03">Analytical methodology.</E>
                                 (1) The standard sample volume required for total coliform analysis, regardless of analytical method used, is 100 ml.
                            </P>
                            <P>(2) Public water systems need only determine the presence or absence of total coliforms; a determination of total coliform density is not required.</P>
                            <P>(3) Public water systems must conduct total coliform analyses in accordance with one of the analytical methods in the following table or one of the alternative methods listed in appendix A to subpart C of this part.</P>
                            <GPOTABLE COLS="3" OPTS="L2" CDEF="s50,r150,xs60">
                                <BOXHD>
                                    <CHED H="1">Organism</CHED>
                                    <CHED H="1">
                                        Methodology 
                                        <SU>12</SU>
                                    </CHED>
                                    <CHED H="1">
                                        Citation 
                                        <SU>1</SU>
                                    </CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">
                                        Total Coliforms 
                                        <SU>2</SU>
                                    </ENT>
                                    <ENT>
                                        Total Coliform Fermentation Technique 
                                        <SU>3 4 5</SU>
                                    </ENT>
                                    <ENT>9221A, B.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>
                                        Total Coliform Membrane Filter Technique 
                                        <SU>6</SU>
                                    </ENT>
                                    <ENT>9222A, B, C.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>
                                        Presence-Absence (P-A) Coliform Test 
                                        <SU>5 7</SU>
                                    </ENT>
                                    <ENT>9221D.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>
                                        ONPG-MUG Test 
                                        <SU>8</SU>
                                    </ENT>
                                    <ENT>9223.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="xl">
                                        Colisure Test. 
                                        <SU>9</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="xl">
                                        E*Colite ® Test. 
                                        <SU>10</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="xl">
                                        m-ColiBlue24 ® Test. 
                                        <SU>11</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="xl">
                                        Readycult ® Coliforms 100 Presence/Absence Test. 
                                        <SU>13</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="xl">
                                        Membrane Filter Technique using Chromocult ® Coliform Agar. 
                                        <SU>14</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="xl">
                                        Colitag ® Test. 
                                        <SU>15</SU>
                                    </ENT>
                                </ROW>
                                <TNOTE>
                                    The procedures shall be done in accordance with the documents listed below. The incorporation by reference of the following documents listed in footnotes 1, 6, 8, 9, 10 , 11, 13, 14 and 15 was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies of the documents may be obtained from the sources listed below. Information regarding obtaining these documents can be obtained from the Safe Drinking Water Hotline at 800-426-4791. Documents may be inspected at EPA's Drinking Water Docket, EPA West, 1301 Constitution Avenue, NW., EPA West, Room B102, Washington DC 20460 (Telephone: 202-566-2426); or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: 
                                    <E T="03">http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.</E>
                                </TNOTE>
                                <TNOTE>
                                    <SU>1</SU>
                                     
                                    <E T="03">Standard Methods for the Examination of Water and Wastewater,</E>
                                     18th edition (1992), 19th edition (1995), or 20th edition (1998). American Public Health Association, 1015 Fifteenth Street, NW., Washington, DC 20005. The cited methods published in any of these three editions may be used. In addition, the following online versions may also be used: 9221 A, B, D-99, 9222 A, B, C-97, and 9223 B-97. Standard Methods Online are available at 
                                    <E T="03">http://www.standardmethods.org.</E>
                                     The year in which each method was approved by the Standard Methods Committee is designated by the last two digits in the method number. The methods listed are the only Online versions that may be used.
                                </TNOTE>
                                <TNOTE>
                                    <SU>2</SU>
                                     The time from sample collection to initiation of analysis may not exceed 30 hours. Systems are encouraged but not required to hold samples below 10 deg. C during transit.
                                </TNOTE>
                                <TNOTE>
                                    <SU>3</SU>
                                     Lactose broth, as commercially available, may be used in lieu of lauryl tryptose broth, if the system conducts at least 25 parallel tests between this medium and lauryl tryptose broth using the water normally tested, and this comparison demonstrates that the false-positive rate and false-negative rate for total coliform, using lactose broth, is less than 10 percent.
                                </TNOTE>
                                <TNOTE>
                                    <SU>4</SU>
                                     If inverted tubes are used to detect gas production, the media should cover these tubes at least one-half to two-thirds after the sample is added.
                                </TNOTE>
                                <TNOTE>
                                    <SU>5</SU>
                                     No requirement exists to run the completed phase on 10 percent of all total coliform-positive confirmed tubes.
                                </TNOTE>
                                <TNOTE>
                                    <SU>6</SU>
                                     MI agar also may be used. Preparation and use of MI agar is set forth in the article, “New medium for the simultaneous detection of total coliform and 
                                    <E T="03">Escherichia coli</E>
                                     in water” by Brenner, K.P., 
                                    <E T="03">et. al.,</E>
                                     1993, Appl. Environ. Microbiol. 59:3534-3544. Also available from the Office of Water Resource Center (RC-4100T), 1200 Pennsylvania Avenue, NW., Washington, DC 20460, EPA/600/J-99/225. Verification of colonies is not required.
                                </TNOTE>
                                <TNOTE>
                                    <SU>7</SU>
                                     Six-times formulation strength may be used if the medium is filter-sterilized rather than autoclaved.
                                </TNOTE>
                                <TNOTE>
                                    <SU>8</SU>
                                     The ONPG-MUG Test is also known as the Autoanalysis Collect System.
                                </TNOTE>
                                <TNOTE>
                                    <SU>9</SU>
                                     A description of the Colisure Test, Feb 28, 1994, may be obtained from IDEXX Laboratories, Inc., One IDEXX Drive, Westbrook, Maine 04092. The Colisure Test may be read after an incubation time of 24 hours.
                                </TNOTE>
                                <TNOTE>
                                    <SU>10</SU>
                                     A description of the E*Colite ® Test, “Presence/Absence for Coliforms and 
                                    <E T="03">E. Coli</E>
                                     in Water,” Dec 21, 1997, is available from Charm Sciences, Inc., 36 Franklin Street, Malden, MA 02148-4120.
                                </TNOTE>
                                <TNOTE>
                                    <SU>11</SU>
                                     A description of the m-ColiBlue24 ® Test, Aug 17, 1999, is available from the Hach Company, 100 Dayton Avenue, Ames, IA 50010.
                                </TNOTE>
                                <TNOTE>
                                    <SU>12</SU>
                                     EPA strongly recommends that laboratories evaluate the false-positive and negative rates for the method(s) they use for monitoring total coliforms. EPA also encourages laboratories to establish false-positive and false-negative rates within their own laboratory and sample matrix (drinking water or source water) with the intent that if the method they choose has an unacceptable false-positive or negative rate, another method can be used. The Agency suggests that laboratories perform these studies on a minimum of 5% of all total coliform-positive samples, except for those methods where verification/confirmation is already required, e.g., the M-Endo and LES Endo Membrane Filter Tests, Standard Total Coliform Fermentation Technique, and Presence-Absence Coliform Test. Methods for establishing false-positive and negative-rates may be based on lactose fermentation, the rapid test for β-galactosidase and cytochrome oxidase, multi-test identification systems, or equivalent confirmation tests. False-positive and false-negative information is often available in published studies and/or from the manufacturer(s).
                                </TNOTE>
                                <TNOTE>
                                    <SU>13</SU>
                                     The Readycult ® Coliforms 100 Presence/Absence Test is described in the document, “Readycult ® Coliforms 100 Presence/Absence Test for Detection and Identification of Coliform Bacteria and 
                                    <E T="03">Escherichla coli</E>
                                     in Finished Waters”, November 2000, Version 1.0, available from EM Science (an affiliate of Merck KGgA, Darmstadt Germany), 480 S. Democrat Road, Gibbstown, NJ 08027-1297. Telephone number is (800) 222-0342, e-mail address is: 
                                    <E T="03">adellenbusch@emscience.com.</E>
                                </TNOTE>
                                <TNOTE>
                                    <SU>14</SU>
                                     Membrane Filter Technique using Chromocult ® Coliform Agar is described in the document, “Chromocult ® Coliform Agar Presence/Absence Membrane Filter Test Method for Detection and Identification of Coliform Bacteria and 
                                    <E T="03">Escherichla coli</E>
                                     in Finished Waters”, November 2000, Version 1.0, available from EM Science (an affiliate of Merck KGgA, Darmstadt Germany), 480 S. Democrat Road, Gibbstown, NJ 08027-1297. Telephone number is (800) 222-0342, e-mail address is: 
                                    <E T="03">adellenbusch@emscience.com.</E>
                                    <PRTPAGE P="493"/>
                                </TNOTE>
                                <TNOTE>
                                    <SU>15</SU>
                                     Colitag ® product for the determination of the presence/absence of total coliforms and 
                                    <E T="03">E. coli</E>
                                     is described in “Colitag ® Product as a Test for Detection and Identification of Coliforms and 
                                    <E T="03">E. coli</E>
                                     Bacteria in Drinking Water and Source Water as Required in National Primary Drinking Water Regulations,” August 2001, available from CPI International, Inc., 5580 Skylane Blvd., Santa Rosa, CA, 95403, telephone (800) 878-7654, Fax (707) 545-7901, Internet address 
                                    <E T="03">http://www.cpiinternational.com.</E>
                                </TNOTE>
                            </GPOTABLE>
                            <P>(4) [Reserved]</P>
                            <P>(5) Public water systems must conduct fecal coliform analysis in accordance with the following procedure. When the MTF Technique or Presence-Absence (PA) Coliform Test is used to test for total coliforms, shake the lactose-positive presumptive tube or P-A vigorously and transfer the growth with a sterile 3-mm loop or sterile applicator stick into brilliant green lactose bile broth and EC medium to determine the presence of total and fecal coliforms, respectively. For EPA-approved analytical methods which use a membrane filter, transfer the total coliform-positive culture by one of the following methods: remove the membrane containing the total coliform colonies from the substrate with a sterile forceps and carefully curl and insert the membrane into a tube of EC medium (the laboratory may first remove a small portion of selected colonies for verification), swab the entire membrane filter surface with a sterile cotton swab and transfer the inoculum to EC medium (do not leave the cotton swab in the EC medium), or inoculate individual total coliform-positive colonies into EC Medium. Gently shake the inoculated tubes of EC medium to insure adequate mixing and incubate in a waterbath at 44.5 ±0.2 °C for 24 ±2 hours. Gas production of any amount in the inner fermentation tube of the EC medium indicates a positive fecal coliform test. The preparation of EC medium is described in Method 9221E (paragraph 1a) in Standard Methods for the Examination of Water and Wastewater, 18th edition (1992), 19th edition (1995), and 20th edition (1998); the cited method in any one of these three editions may be used. Public water systems need only determine the presence or absence of fecal coliforms; a determination of fecal coliform density is not required.</P>
                            <P>(6) Public water systems must conduct analysis of Escherichia coli in accordance with one of the following analytical methods or one of the alternative methods listed in appendix A to subpart C of this part.</P>
                            <P>(i) EC medium supplemented with 50 µg/mL of 4-methylumbelliferyl-beta-D-glucuronide (MUG) (final concentration), as described in Method 9222G in Standard Methods for the Examination of Water and Wastewater, 19th edition (1995) and 20th edition (1998). Either edition may be used. Alternatively, the 18th edition (1992) may be used if at least 10 mL of EC medium, as described in paragraph (f)(5) of this section, is supplemented with 50 µg/mL of MUG before autoclaving. The inner inverted fermentation tube may be omitted. If the 18th edition is used, apply the procedure in paragraph (f)(5) of this section for transferring a total coliform-positive culture to EC medium supplemented with MUG, incubate the tube at 44.5 ±0.2 °C for 24 ±2 hours, and then observe fluorescence with an ultraviolet light (366 nm) in the dark. If fluorescence is visible, E. coli are present.</P>
                            <P>(ii) Nutrient agar supplemented with 100 µg/mL of 4-methylumbelliferyl-beta-D-glucuronide (MUG) (final concentration), as described in Method 9222G in Standard Methods for the Examination of Water and Wastewater, 19th edition (1995) and 20th edition (1998). Either edition may be used for determining if a total coliform-positive sample, as determined by a membrane filter technique, contains E. coli. Alternatively, the 18th edition (1992) may be used if the membrane filter containing a total coliform-positive colony(ies) is transferred to nutrient agar, as described in Method 9221B (paragraph 3) of Standard Methods (18th edition), supplemented with 100 µg/mL of MUG. If the 18th edition is used, incubate the agar plate at 35 °C for 4 hours and then observe the colony(ies) under ultraviolet light (366 nm) in the dark for fluorescence. If fluorescence is visible, E. coli are present.</P>
                            <P>
                                (iii) Minimal Medium ONPG-MUG (MMO-MUG) Test, as set forth in the article “National Field Evaluation of a Defined Substrate Method for the Simultaneous Detection of Total Coliforms and 
                                <E T="03">Escherichia coli</E>
                                 from Drinking Water: Comparison with Presence-
                                <PRTPAGE P="494"/>
                                Absence Techniques” (Edberg et al.), Applied and Environmental Microbiology, Volume 55, pp. 1003-1008, April 1989. (Note: The Autoanalysis Colilert System is an MMO-MUG test). If the MMO-MUG test is total coliform-positive after a 24-hour incubation, test the medium for fluorescence with a 366-nm ultraviolet light (preferably with a 6-watt lamp) in the dark. If fluorescence is observed, the sample is 
                                <E T="03">E. coli</E>
                                -positive. If fluorescence is questionable (cannot be definitively read) after 24 hours incubation, incubate the culture for an additional four hours (but not to exceed 28 hours total), and again test the medium for fluorescence. The MMO-MUG Test with hepes buffer in lieu of phosphate buffer is the only approved formulation for the detection of 
                                <E T="03">E. coli.</E>
                            </P>
                            <P>
                                (iv) 
                                <E T="03">The Colisure Test.</E>
                                 A description of the Colisure Test may be obtained from the Millipore Corporation, Technical Services Department, 80 Ashby Road, Bedford, MA 01730.
                            </P>
                            <P>(v) The membrane filter method with MI agar, a description of which is cited in footnote 6 to the table in paragraph (f)(3) of this section.</P>
                            <P>(vi) E*Colite ® Test, a description of which is cited in footnote 10 to the table at paragraph (f)(3) of this section.</P>
                            <P>(vii) m-ColiBlue24 ® Test, a description of which is cited in footnote 11 to the table in paragraph (f)(3) of this section.</P>
                            <P>(viii) Readycult ® Coliforms 100 Presence/Absence Test, a description of which is cited in footnote 13 to the table at paragraph (f)(3) of this section.</P>
                            <P>(ix) Membrane Filter Technique using Chromocult ® Coliform Agar, a description of which is cited in footnote 14 to the table at paragraph (f)(3) of this section.</P>
                            <P>(x) Colitag ®, a description of which is cited in footnote 15 to the table at paragraph (f)(3) of this section.</P>
                            <P>
                                (7) As an option to paragraph (f)(6)(iii) of this section, a system with a total coliform-positive, MUG-negative, MMO-MUG test may further analyze the culture for the presence of 
                                <E T="03">E. coli</E>
                                 by transferring a 0.1 ml, 28-hour MMO-MUG culture to EC Medium + MUG with a pipet. The formulation and incubation conditions of EC Medium + MUG, and observation of the results are described in paragraph (f)(6)(i) of this section.
                            </P>
                            <P>
                                (8) The following materials are incorporated by reference in this section with the approval of the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies of the analytical methods cited in Standard Methods for the Examination of Water and Wastewater (18th, 19th, and 20th editions) may be obtained from the American Public Health Association 
                                <E T="03">et al.</E>
                                ; 1015 Fifteenth Street, NW., Washington, DC 20005-2605. Copies of the MMO-MUG Test, as set forth in the article “National Field Evaluation of a Defined Substrate Method for the Simultaneous Enumeration of Total Coliforms and Escherichia coli from Drinking Water: Comparison with the Standard Multiple Tube Fermentation Method” (Edberg 
                                <E T="03">et al.</E>
                                ) may be obtained from the American Water Works Association Research Foundation, 6666 West Quincy Avenue, Denver, CO 80235. Copies of the MMO-MUG Test as set forth in the article “National Field Evaluation of a Defined Substrate Method for the Simultaneous Enumeration of Total Coliforms and 
                                <E T="03">Escherichia coli</E>
                                 from Drinking Water: Comparison with the Standard Multiple Tube Fermentation Method” (Edberg 
                                <E T="03">et al.</E>
                                ) may be obtained from the American Water Works Association Research Foundation, 6666 West Quincy Avenue, Denver, CO 80235. A description of the Colisure Test may be obtained from the Millipore Corp., Technical Services Department, 80 Ashby Road, Bedford, MA 01730. Copies may be inspected at EPA's Drinking Water Docket; 401 M St., SW.; Washington, DC 20460, or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: 
                                <E T="03">http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.</E>
                            </P>
                            <P>
                                (g) 
                                <E T="03">Response to violation.</E>
                                 (1) A public water system which has exceeded the MCL for total coliforms in § 141.63 must report the violation to the State no later than the end of the next business day after it learns of the violation, and notify the public in accordance with subpart Q.
                                <PRTPAGE P="495"/>
                            </P>
                            <P>(2) A public water system which has failed to comply with a coliform monitoring requirement, including the sanitary survey requirement, must report the monitoring violation to the State within ten days after the system discovers the violation, and notify the public in accordance with subpart Q.</P>
                            <P>
                                (h) The provisions of paragraphs (a) and (d) of this section are applicable until March 31, 2016. The provisions of paragraphs (b), (c), (e), (f), and (g) of this section are applicable until all required repeat monitoring under paragraph (b) of this section and fecal coliform or 
                                <E T="03">E. coli</E>
                                 testing under paragraph (e) of this section that was initiated by a total coliform-positive sample taken before April 1, 2016 is completed, as well as analytical method, reporting, recordkeeping, public notification, and consumer confidence report requirements associated with that monitoring and testing. Beginning April 1, 2016, the provisions of subpart Y of this part are applicable, with systems required to begin regular monitoring at the same frequency as the system-specific frequency required on March 31, 2016.
                            </P>
                            <CITA>[54 FR 27562, June 29, 1989]</CITA>
                            <EDNOTE>
                                <HD SOURCE="HED">Editorial Note:</HD>
                                <P>
                                    For 
                                    <E T="04">Federal Register</E>
                                     citations affecting § 141.21, see the List of CFR Sections Affected, which appears in the Finding Aids section of the printed volume and at 
                                    <E T="03">www.govinfo.gov.</E>
                                </P>
                            </EDNOTE>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 141.22</SECTNO>
                            <SUBJECT>Turbidity sampling and analytical requirements.</SUBJECT>
                            <P>The requirements in this section apply to unfiltered systems until December 30, 1991, unless the State has determined prior to that date, in writing pursuant to section 1412(b)(7)(iii), that filtration is required. The requirements in this section apply to filtered systems until June 29, 1993. The requirements in this section apply to unfiltered systems that the State has determined, in writing pursuant to section 1412(b)(7)(C)(iii), must install filtration, until June 29, 1993, or until filtration is installed, whichever is later.</P>
                            <P>(a) Samples shall be taken by suppliers of water for both community and non-community water systems at a representative entry point(s) to the water distribution system at least once per day, for the purposes of making turbidity measurements to determine compliance with § 141.13. If the State determines that a reduced sampling frequency in a non-community will not pose a risk to public health, it can reduce the required sampling frequency. The option of reducing the turbidity frequency shall be permitted only in those public water systems that practice disinfection and which maintain an active residual disinfectant in the distribution system, and in those cases where the State has indicated in writing that no unreasonable risk to health existed under the circumstances of this option. Turbidity measurements shall be made as directed in § 141.74(a)(1).</P>
                            <P>(b) If the result of a turbidity analysis indicates that the maximum allowable limit has been exceeded, the sampling and measurement shall be confirmed by resampling as soon as practicable and preferably within one hour. If the repeat sample confirms that the maximum allowable limit has been exceeded, the supplier of water shall report to the State within 48 hours. The repeat sample shall be the sample used for the purpose of calculating the monthly average. If the monthly average of the daily samples exceeds the maximum allowable limit, or if the average of two samples taken on consecutive days exceeds 5 TU, the supplier of water shall report to the State and notify the public as directed in § 141.31 and subpart Q.</P>
                            <P>(c) Sampling for non-community water systems shall begin within two years after the effective date of this part.</P>
                            <P>(d) The requirements of this § 141.22 shall apply only to public water systems which use water obtained in whole or in part from surface sources.</P>
                            <P>(e) The State has the authority to determine compliance or initiate enforcement action based upon analytical results or other information compiled by their sanctioned representatives and agencies.</P>
                            <CITA>[40 FR 59570, Dec. 24, 1975, as amended at 45 FR 57344, Aug. 27, 1980; 47 FR 8998, Mar. 3, 1982; 47 FR 10998, Mar. 12, 1982; 54 FR 27527, June 29, 1989; 59 FR 62466, Dec. 5, 1994; 65 FR 26022, May 4, 2000]</CITA>
                        </SECTION>
                        <SECTION>
                            <PRTPAGE P="496"/>
                            <SECTNO>§ 141.23</SECTNO>
                            <SUBJECT>Inorganic chemical sampling and analytical requirements.</SUBJECT>
                            <P>Community water systems shall conduct monitoring to determine compliance with the maximum contaminant levels specified in § 141.62 in accordance with this section. Non-transient, non-community water systems shall conduct monitoring to determine compliance with the maximum contaminant levels specified in § 141.62 in accordance with this section. Transient, non-community water systems shall conduct monitoring to determine compliance with the nitrate and nitrite maximum contaminant levels in §§ 141.11 and 141.62 (as appropriate) in accordance with this section.</P>
                            <P>(a) Monitoring shall be conducted as follows:</P>
                            <P>(1) Groundwater systems shall take a minimum of one sample at every entry point to the distribution system which is representative of each well after treatment (hereafter called a sampling point) beginning in the initial compliance period. The system shall take each sample at the same sampling point unless conditions make another sampling point more representative of each source or treatment plant.</P>
                            <P>(2) Surface water systems shall take a minimum of one sample at every entry point to the distribution system after any application of treatment or in the distribution system at a point which is representative of each source after treatment (hereafter called a sampling point) beginning in the initial compliance period. The system shall take each sample at the same sampling point unless conditions make another sampling point more representative of each source or treatment plant.</P>
                            <NOTE>
                                <HD SOURCE="HED">Note:</HD>
                                <P>For purposes of this paragraph, surface water systems include systems with a combination of surface and ground sources.</P>
                            </NOTE>
                            <P>
                                (3) If a system draws water from more than one source and the sources are combined before distribution, the system must sample at an entry point to the distribution system during periods of normal operating conditions (
                                <E T="03">i.e.</E>
                                , when water is representative of all sources being used).
                            </P>
                            <P>(4) The State may reduce the total number of samples which must be analyzed by allowing the use of compositing. Composite samples from a maximum of five samples are allowed, provided that the detection limit of the method used for analysis is less than one-fifth of the MCL. Compositing of samples must be done in the laboratory.</P>
                            <P>(i) If the concentration in the composite sample is greater than or equal to one-fifth of the MCL of any inorganic chemical, then a follow-up sample must be taken within 14 days at each sampling point included in the composite. These samples must be analyzed for the contaminants which exceeded one-fifth of the MCL in the composite sample. Detection limits for each analytical method and MCLs for each inorganic contaminant are the following:</P>
                            <GPOTABLE COLS="4" OPTS="L2" CDEF="xs75,xs30,r75,xs40">
                                <TTITLE>Detection Limits for Inorganic Contaminants</TTITLE>
                                <BOXHD>
                                    <CHED H="1">Contaminant</CHED>
                                    <CHED H="1">MCL (mg/l)</CHED>
                                    <CHED H="1">Methodology</CHED>
                                    <CHED H="1">Detection limit (mg/l)</CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">Antimony</ENT>
                                    <ENT>0.006</ENT>
                                    <ENT>Atomic Absorption; Furnace</ENT>
                                    <ENT>0.003</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="xl"/>
                                    <ENT>Atomic Absorption; Platform</ENT>
                                    <ENT>
                                        0.0008 
                                        <SU>5</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="xl"/>
                                    <ENT>ICP-Mass Spectrometry</ENT>
                                    <ENT>0.0004</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="xl"/>
                                    <ENT>Hydride-Atomic Absorption</ENT>
                                    <ENT>0.001</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Arsenic</ENT>
                                    <ENT>
                                        0.010 
                                        <SU>6</SU>
                                    </ENT>
                                    <ENT>Atomic Absorption; Furnace</ENT>
                                    <ENT>0.001</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="xl"/>
                                    <ENT>Atomic Absorption; Platform—Stabilized Temperature</ENT>
                                    <ENT>
                                        0.0005 
                                        <SU>7</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="xl"/>
                                    <ENT>Atomic Absorption; Gaseous Hydride</ENT>
                                    <ENT>0.001</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="xl"/>
                                    <ENT>ICP-Mass Spectrometry</ENT>
                                    <ENT>
                                        0.0014 
                                        <SU>8</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Asbestos</ENT>
                                    <ENT>
                                        7 MFL 
                                        <SU>1</SU>
                                    </ENT>
                                    <ENT>Transmission Electron Microscopy</ENT>
                                    <ENT>0.01 MFL</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Barium</ENT>
                                    <ENT>2</ENT>
                                    <ENT>Atomic Absorption; furnace technique</ENT>
                                    <ENT>0.002</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="xl"/>
                                    <ENT>Atomic Absorption; direct aspiration</ENT>
                                    <ENT>0.1</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="xl"/>
                                    <ENT>Inductively Coupled Plasma</ENT>
                                    <ENT>0.002 (0.001)</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Beryllium</ENT>
                                    <ENT>0.004</ENT>
                                    <ENT>Atomic Absorption; Furnace</ENT>
                                    <ENT>0.0002</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="xl"/>
                                    <ENT>Atomic Absorption; Platform</ENT>
                                    <ENT>
                                        0.00002 
                                        <SU>5</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="xl"/>
                                    <ENT>
                                        Inductively Coupled Plasma 
                                        <SU>2</SU>
                                    </ENT>
                                    <ENT>0.0003</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="xl"/>
                                    <ENT>ICP-Mass Spectrometry</ENT>
                                    <ENT>0.0003</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Cadmium</ENT>
                                    <ENT>0.005</ENT>
                                    <ENT>Atomic Absorption; furnace technique</ENT>
                                    <ENT>0.0001</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="xl"/>
                                    <ENT>Inductively Coupled Plasma</ENT>
                                    <ENT>0.001</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Chromium</ENT>
                                    <ENT>0.1</ENT>
                                    <ENT>Atomic Absorption; furnace technique</ENT>
                                    <ENT>0.001</ENT>
                                </ROW>
                                <ROW>
                                    <PRTPAGE P="497"/>
                                    <ENT I="22"> </ENT>
                                    <ENT O="xl"/>
                                    <ENT>Inductively Coupled Plasma</ENT>
                                    <ENT>0.007 (0.001)</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Cyanide</ENT>
                                    <ENT>0.2</ENT>
                                    <ENT>
                                        Distillation, Spectrophotometric 
                                        <SU>3</SU>
                                    </ENT>
                                    <ENT>0.02</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT/>
                                    <ENT>
                                        Distillation, Automated, Spectrophotometric 
                                        <SU>3</SU>
                                    </ENT>
                                    <ENT>0.005</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT/>
                                    <ENT>
                                        Distillation, Amenable, Spectrophotometric 
                                        <SU>4</SU>
                                    </ENT>
                                    <ENT>0.02</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT/>
                                    <ENT>
                                        Distillation, Selective Electrode
                                        <SU>3 4</SU>
                                    </ENT>
                                    <ENT>0.05</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT/>
                                    <ENT>
                                        UV, Distillation, Spectrophotometric 
                                        <SU>9</SU>
                                    </ENT>
                                    <ENT>0.0005</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT/>
                                    <ENT>
                                        Micro Distillation, Flow Injection, Spectrophotometric 
                                        <SU>3</SU>
                                    </ENT>
                                    <ENT>0.0006</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT/>
                                    <ENT>
                                        Ligand Exchange with Amperometry 
                                        <SU>4</SU>
                                    </ENT>
                                    <ENT>0.0005</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Mercury</ENT>
                                    <ENT>0.002</ENT>
                                    <ENT>Manual Cold Vapor Technique</ENT>
                                    <ENT>0.0002</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="xl"/>
                                    <ENT>Automated Cold Vapor Technique</ENT>
                                    <ENT>0.0002</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Nickel</ENT>
                                    <ENT>xl</ENT>
                                    <ENT>Atomic Absorption; Furnace</ENT>
                                    <ENT>0.001</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="xl"/>
                                    <ENT>Atomic Absorption; Platform</ENT>
                                    <ENT>
                                        0.0006 
                                        <SU>5</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="xl"/>
                                    <ENT>
                                        Inductively Coupled Plasma 
                                        <SU>2</SU>
                                    </ENT>
                                    <ENT>0.005</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="xl"/>
                                    <ENT>ICP-Mass Spectrometry</ENT>
                                    <ENT>0.0005</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Nitrate</ENT>
                                    <ENT>10 (as N)</ENT>
                                    <ENT>Manual Cadmium Reduction</ENT>
                                    <ENT>0.01</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="xl"/>
                                    <ENT>Automated Hydrazine Reduction</ENT>
                                    <ENT>0.01</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="xl"/>
                                    <ENT>Automated Cadmium Reduction</ENT>
                                    <ENT>0.05</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="xl"/>
                                    <ENT>Ion Selective Electrode</ENT>
                                    <ENT>1</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="xl"/>
                                    <ENT>Ion Chromatography</ENT>
                                    <ENT>0.01</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="xl"/>
                                    <ENT>Capillary Ion Electrophoresis</ENT>
                                    <ENT>0.076</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Nitrite</ENT>
                                    <ENT>1 (as N)</ENT>
                                    <ENT>Spectrophotometric</ENT>
                                    <ENT>0.01</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="xl"/>
                                    <ENT>Automated Cadmium Reduction</ENT>
                                    <ENT>0.05</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="xl"/>
                                    <ENT>Manual Cadmium Reduction</ENT>
                                    <ENT>0.01</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="xl"/>
                                    <ENT>Ion Chromatography</ENT>
                                    <ENT>0.004</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="xl"/>
                                    <ENT>Capillary Ion Electrophoresis</ENT>
                                    <ENT>0.103</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Selenium</ENT>
                                    <ENT>0.05</ENT>
                                    <ENT>Atomic Absorption; furnace</ENT>
                                    <ENT>0.002</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="xl"/>
                                    <ENT>Atomic Absorption; gaseous hydride</ENT>
                                    <ENT>0.002</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Thallium</ENT>
                                    <ENT>0.002</ENT>
                                    <ENT>Atomic Absorption; Furnace</ENT>
                                    <ENT>0.001</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="xl"/>
                                    <ENT>Atomic Absorption; Platform</ENT>
                                    <ENT>
                                        0.0007 
                                        <SU>5</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="xl"/>
                                    <ENT>ICP-Mass Spectrometry</ENT>
                                    <ENT>0.0003</ENT>
                                </ROW>
                                <TNOTE>
                                    <SU>1</SU>
                                     MFL = million fibers per liter &gt;10 µm.
                                </TNOTE>
                                <TNOTE>
                                    <SU>2</SU>
                                     Using a 2X preconcentration step as noted in Method 200.7. Lower MDLs may be achieved when using a 4X preconcentration.
                                </TNOTE>
                                <TNOTE>
                                    <SU>3</SU>
                                     Screening method for total cyanides.
                                </TNOTE>
                                <TNOTE>
                                    <SU>4</SU>
                                     Measures “free” cyanides when distillation, digestion, or ligand exchange is omitted.
                                </TNOTE>
                                <TNOTE>
                                    <SU>5</SU>
                                     Lower MDLs are reported using stabilized temperature graphite furnace atomic absorption.
                                </TNOTE>
                                <TNOTE>
                                    <SU>6</SU>
                                     The value for arsenic is effective January 23, 2006. Unit then, the MCL is 0.05 mg/L.
                                </TNOTE>
                                <TNOTE>
                                    <SU>7</SU>
                                     The MDL reported for EPA method 200.9 (Atomic Absorption; Platform—Stablized Temperature) was determined using a 2x concentration step during sample digestion. The MDL determined for samples analyzed using direct analyses (
                                    <E T="03">i.e.</E>
                                    , no sample digestion) will be higher. Using multiple depositions, EPA 200.9 is capable of obtaining MDL of 0.0001 mg/L.
                                </TNOTE>
                                <TNOTE>
                                    <SU>8</SU>
                                     Using selective ion monitoring, EPA Method 200.8 (ICP-MS) is capable of obtaining a MDL of 0.0001 mg/L.
                                </TNOTE>
                                <TNOTE>
                                    <SU>9</SU>
                                     Measures total cyanides when UV-digestor is used, and “free” cyanides when UV-digestor is bypassed.
                                </TNOTE>
                            </GPOTABLE>
                            <P>(ii) If the population served by the system is &gt;3,300 persons, then compositing may only be permitted by the State at sampling points within a single system. In systems serving ≤3,300 persons, the State may permit compositing among different systems provided the 5-sample limit is maintained.</P>
                            <P>(iii) If duplicates of the original sample taken from each sampling point used in the composite sample are available, the system may use these instead of resampling. The duplicates must be analyzed and the results reported to the State within 14 days after completing analysis of the composite sample, provided the holding time of the sample is not exceeded.</P>
                            <P>(5) The frequency of monitoring for asbestos shall be in accordance with paragraph (b) of this section: the frequency of monitoring for antimony, arsenic, barium, beryllium, cadmium, chromium, cyanide, fluoride, mercury, nickel, selenium and thallium shall be in accordance with paragraph (c) of this section; the frequency of monitoring for nitrate shall be in accordance with paragraph (d) of this section; and the frequency of monitoring for nitrite shall be in accordance with paragraph (e) of this section.</P>
                            <P>(b) The frequency of monitoring conducted to determine compliance with the maximum contaminant level for asbestos specified in § 141.62(b) shall be conducted as follows:</P>
                            <P>
                                (1) Each community and non-transient, non-community water system is required to monitor for asbestos during the first three-year compliance period 
                                <PRTPAGE P="498"/>
                                of each nine-year compliance cycle beginning in the compliance period starting January 1, 1993.
                            </P>
                            <P>(2) If the system believes it is not vulnerable to either asbestos contamination in its source water or due to corrosion of asbestos-cement pipe, or both, it may apply to the State for a waiver of the monitoring requirement in paragraph (b)(1) of this section. If the State grants the waiver, the system is not required to monitor.</P>
                            <P>(3) The State may grant a waiver based on a consideration of the following factors:</P>
                            <P>(i) Potential asbestos contamination of the water source, and</P>
                            <P>(ii) The use of asbestos-cement pipe for finished water distribution and the corrosive nature of the water.</P>
                            <P>(4) A waiver remains in effect until the completion of the three-year compliance period. Systems not receiving a waiver must monitor in accordance with the provisions of paragraph (b)(1) of this section.</P>
                            <P>(5) A system vulnerable to asbestos contamination due solely to corrosion of asbestos-cement pipe shall take one sample at a tap served by asbestos-cement pipe and under conditions where asbestos contamination is most likely to occur.</P>
                            <P>(6) A system vulnerable to asbestos contamination due solely to source water shall monitor in accordance with the provision of paragraph (a) of this section.</P>
                            <P>(7) A system vulnerable to asbestos contamination due both to its source water supply and corrosion of asbestos-cement pipe shall take one sample at a tap served by asbestos-cement pipe and under conditions where asbestos contamination is most likely to occur.</P>
                            <P>(8) A system which exceeds the maximum contaminant levels as determined in § 141.23(i) of this section shall monitor quarterly beginning in the next quarter after the violation occurred.</P>
                            <P>(9) The State may decrease the quarterly monitoring requirement to the frequency specified in paragraph (b)(1) of this section provided the State has determined that the system is reliably and consistently below the maximum contaminant level. In no case can a State make this determination unless a groundwater system takes a minimum of two quarterly samples and a surface (or combined surface/ground) water system takes a minimum of four quarterly samples.</P>
                            <P>(10) If monitoring data collected after January 1, 1990 are generally consistent with the requirements of § 141.23(b), then the State may allow systems to use that data to satisfy the monitoring requirement for the initial compliance period beginning January 1, 1993.</P>
                            <P>(c) The frequency of monitoring conducted to determine compliance with the maximum contaminant levels in § 141.62 for antimony, arsenic, barium, beryllium, cadmium, chromium, cyanide, fluoride, mercury, nickel, selenium and thallium shall be as follows:</P>
                            <P>(1) Groundwater systems shall take one sample at each sampling point during each compliance period. Surface water systems (or combined surface/ground) shall take one sample annually at each sampling point.</P>
                            <P>(2) The system may apply to the State for a waiver from the monitoring frequencies specified in paragraph (c)(1) of this section. States may grant a public water system a waiver for monitoring of cyanide, provided that the State determines that the system is not vulnerable due to lack of any industrial source of cyanide.</P>
                            <P>
                                (3) A condition of the waiver shall require that a system shall take a minimum of one sample while the waiver is effective. The term during which the waiver is effective shall not exceed one compliance cycle (
                                <E T="03">i.e.</E>
                                , nine years).
                            </P>
                            <P>(4) The State may grant a waiver provided surface water systems have monitored annually for at least three years and groundwater systems have conducted a minimum of three rounds of monitoring. (At least one sample shall have been taken since January 1, 1990). Both surface and groundwater systems shall demonstrate that all previous analytical results were less than the maximum contaminant level. Systems that use a new water source are not eligible for a waiver until three rounds of monitoring from the new source have been completed.</P>
                            <P>
                                (5) In determining the appropriate reduced monitoring frequency, the State shall consider:
                                <PRTPAGE P="499"/>
                            </P>
                            <P>(i) Reported concentrations from all previous monitoring;</P>
                            <P>(ii) The degree of variation in reported concentrations; and</P>
                            <P>(iii) Other factors which may affect contaminant concentrations such as changes in groundwater pumping rates, changes in the system's configuration, changes in the system's operating procedures, or changes in stream flows or characteristics.</P>
                            <P>(6) A decision by the State to grant a waiver shall be made in writing and shall set forth the basis for the determination. The determination may be initiated by the State or upon an application by the public water system. The public water system shall specify the basis for its request. The State shall review and, where appropriate, revise its determination of the appropriate monitoring frequency when the system submits new monitoring data or when other data relevant to the system's appropriate monitoring frequency become available.</P>
                            <P>(7) Systems which exceed the maximum contaminant levels as calculated in § 141.23(i) of this section shall monitor quarterly beginning in the next quarter after the violation occurred.</P>
                            <P>(8) The State may decrease the quarterly monitoring requirement to the frequencies specified in paragraphs (c)(1) and (c)(2) of this section provided it has determined that the system is reliably and consistently below the maximum contaminant level. In no case can a State make this determination unless a groundwater system takes a minimum of two quarterly samples and a surface water system takes a minimum of four quarterly samples.</P>
                            <P>(9) All new systems or systems that use a new source of water that begin operation after January 22, 2004 must demonstrate compliance with the MCL within a period of time specified by the State. The system must also comply with the initial sampling frequencies specified by the State to ensure a system can demonstrate compliance with the MCL. Routine and increased monitoring frequencies shall be conducted in accordance with the requirements in this section.</P>
                            <P>(d) All public water systems (community; non-transient, non-community; and transient, non-community systems) shall monitor to determine compliance with the maximum contaminant level for nitrate in § 141.62.</P>
                            <P>(1) Community and non-transient, non-community water systems served by groundwater systems shall monitor annually beginning January 1, 1993; systems served by surface water shall monitor quarterly beginning January 1, 1993.</P>
                            <P>(2) For community and non-transient, non-community water systems, the repeat monitoring frequency for groundwater systems shall be quarterly for at least one year following any one sample in which the concentration is ≥50 percent of the MCL. The State may allow a groundwater system to reduce the sampling frequency to annually after four consecutive quarterly samples are reliably and consistently less than the MCL.</P>
                            <P>(3) For community and non-transient, non-community water systems, the State may allow a surface water system to reduce the sampling frequency to annually if all analytical results from four consecutive quarters are &lt;50 percent of the MCL. A surface water system shall return to quarterly monitoring if any one sample is ≥50 percent of the MCL.</P>
                            <P>(4) Each transient non-community water system shall monitor annually beginning January 1, 1993.</P>
                            <P>(5) After the initial round of quarterly sampling is completed, each community and non-transient non-community system which is monitoring annually shall take subsequent samples during the quarter(s) which previously resulted in the highest analytical result.</P>
                            <P>(e) All public water systems (community; non-transient, non-community; and transient, non-community systems) shall monitor to determine compliance with the maximum contaminant level for nitrite in § 141.62(b).</P>
                            <P>(1) All public water systems shall take one sample at each sampling point in the compliance period beginning January 1, 1993 and ending December 31, 1995.</P>
                            <P>
                                (2) After the initial sample, systems where an analytical result for nitrite is &lt;50 percent of the MCL shall monitor at the frequency specified by the State.
                                <PRTPAGE P="500"/>
                            </P>
                            <P>(3) For community, non-transient, non-community, and transient non-community water systems, the repeat monitoring frequency for any water system shall be quarterly for at least one year following any one sample in which the concentration is ≥50 percent of the MCL. The State may allow a system to reduce the sampling frequency to annually after determining the system is reliably and consistently less than the MCL.</P>
                            <P>(4) Systems which are monitoring annually shall take each subsequent sample during the quarter(s) which previously resulted in the highest analytical result.</P>
                            <P>(f) Confirmation samples:</P>
                            <P>(1) Where the results of sampling for antimony, arsenic, asbestos, barium, beryllium, cadmium, chromium, cyanide, fluoride, mercury, nickel, selenium or thallium indicate an exceedance of the maximum contaminant level, the State may require that one additional sample be collected as soon as possible after the initial sample was taken (but not to exceed two weeks) at the same sampling point.</P>
                            <P>(2) Where nitrate or nitrite sampling results indicate an exceedance of the maximum contaminant level, the system shall take a confirmation sample within 24 hours of the system's receipt of notification of the analytical results of the first sample. Systems unable to comply with the 24-hour sampling requirement must immediately notify persons served by the public water system in accordance with § 141.202 and meet other Tier 1 public notification requirements under subpart Q of this part. Systems exercising this option must take and analyze a confirmation sample within two weeks of notification of the analytical results of the first sample.</P>
                            <P>(3) If a State-required confirmation sample is taken for any contaminant, then the results of the initial and confirmation sample shall be averaged. The resulting average shall be used to determine the system's compliance in accordance with paragraph (i) of this section. States have the discretion to delete results of obvious sampling errors.</P>
                            <P>(g) The State may require more frequent monitoring than specified in paragraphs (b), (c), (d) and (e) of this section or may require confirmation samples for positive and negative results at its discretion.</P>
                            <P>(h) Systems may apply to the State to conduct more frequent monitoring than the minimum monitoring frequencies specified in this section.</P>
                            <P>(i) Compliance with § 141.11 or § 141.62(b) (as appropriate) shall be determined based on the analytical result(s) obtained at each sampling point.</P>
                            <P>(1) For systems which are conducting monitoring at a frequency greater than annual, compliance with the maximum contaminant levels for antimony, arsenic, asbestos, barium, beryllium, cadmium, chromium, cyanide, fluoride, mercury, nickel, selenium or thallium is determined by a running annual average at any sampling point. If the average at any sampling point is greater than the MCL, then the system is out of compliance. If any one sample would cause the annual average to be exceeded, then the system is out of compliance immediately. Any sample below the method detection limit shall be calculated at zero for the purpose of determining the annual average. If a system fails to collect the required number of samples, compliance (average concentration) will be based on the total number of samples collected.</P>
                            <P>(2) For systems which are monitoring annually, or less frequently, the system is out of compliance with the maximum contaminant levels for antimony, arsenic, asbestos, barium, beryllium, cadmium, chromium, cyanide, fluoride, mercury, nickel, selenium or thallium if the level of a contaminant is greater than the MCL. If confirmation samples are required by the State, the determination of compliance will be based on the annual average of the initial MCL exceedance and any State-required confirmation samples. If a system fails to collect the required number of samples, compliance (average concentration) will be based on the total number of samples collected.</P>
                            <P>
                                (3) Compliance with the maximum contaminant levels for nitrate and nitrate is determined based on one sample if the levels of these contaminants are below the MCLs. If the levels of nitrate and/or nitrite exceed the MCLs in 
                                <PRTPAGE P="501"/>
                                the initial sample, a confirmation sample is required in accordance with paragraph (f)(2) of this section, and compliance shall be determined based on the average of the initial and confirmation samples.
                            </P>
                            <P>(4) Arsenic sampling results will be reported to the nearest 0.001 mg/L.</P>
                            <P>(j) Each public water system shall monitor at the time designated by the State during each compliance period.</P>
                            <P>(k) Inorganic analysis:</P>
                            <P>
                                (1) Analysis for the following contaminants shall be conducted in accordance with the methods in the following table, or the alternative methods listed in appendix A to subpart C of this part, or their equivalent as determined by EPA. Criteria for analyzing arsenic, barium, beryllium, cadmium, calcium, chromium, copper, lead, nickel, selenium, sodium, and thallium with digestion or directly without digestion, and other analytical test procedures are contained in 
                                <E T="03">Technical Notes on Drinking Water Methods,</E>
                                 EPA-600/R-94-173, October 1994. This document is available from the National Service Center for Environmental Publications (NSCEP), P.O. Box 42419, Cincinnati, OH 45242-0419 or 
                                <E T="03">http://www.epa.gov/nscep/.</E>
                                <PRTPAGE P="502"/>
                            </P>
                            <GPOTABLE COLS="8" OPTS="L2,p6,7/8" CDEF="s60,r70,r40,r70,r40,r40,r40,r40">
                                <BOXHD>
                                    <CHED H="1">Contaminant</CHED>
                                    <CHED H="1">
                                        Methodology 
                                        <SU>13</SU>
                                    </CHED>
                                    <CHED H="1">EPA</CHED>
                                    <CHED H="1">
                                        ASTM 
                                        <SU>3</SU>
                                    </CHED>
                                    <CHED H="1">
                                        SM 
                                        <SU>4</SU>
                                         (18th, 19th ed.)
                                    </CHED>
                                    <CHED H="1">
                                        SM 
                                        <SU>4</SU>
                                         (20th ed.)
                                    </CHED>
                                    <CHED H="1">
                                        SM Online 
                                        <SU>22</SU>
                                    </CHED>
                                    <CHED H="1">Other</CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">1. Alkalinity</ENT>
                                    <ENT>Titrimetric</ENT>
                                    <ENT/>
                                    <ENT>D1067-92, 02 B</ENT>
                                    <ENT>2320 B</ENT>
                                    <ENT>2320 B</ENT>
                                    <ENT>2320 B-97</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Electrometric titration</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        I-1030-85 
                                        <SU>5</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">2. Antimony</ENT>
                                    <ENT>Inductively Coupled Plasma (ICP)—Mass Spectrometry</ENT>
                                    <ENT O="xl">
                                        200.8 
                                        <SU>2</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Hydride-Atomic Absorption</ENT>
                                    <ENT/>
                                    <ENT>D3697-92, 02</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Atomic Absorption; Platform</ENT>
                                    <ENT O="xl">
                                        200.9 
                                        <SU>2</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Atomic Absorption; Furnace</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>3113 B</ENT>
                                    <ENT/>
                                    <ENT>3113 B-99</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">
                                        3. Arsenic 
                                        <SU>14</SU>
                                    </ENT>
                                    <ENT>ICP-Mass Spectrometry</ENT>
                                    <ENT>
                                        200.8 
                                        <SU>2</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Atomic Absorption; Platform</ENT>
                                    <ENT>
                                        200.9 
                                        <SU>2</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Atomic Absorption; Furnace</ENT>
                                    <ENT/>
                                    <ENT>D2972-97, 03 C</ENT>
                                    <ENT>3113 B</ENT>
                                    <ENT/>
                                    <ENT>3113 B-99</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Hydride Atomic Absorption</ENT>
                                    <ENT/>
                                    <ENT>D1972-97, 03 B</ENT>
                                    <ENT>3114 B</ENT>
                                    <ENT/>
                                    <ENT>3114 B-97</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">4. Asbestos</ENT>
                                    <ENT>Transmission Electron Microscopy</ENT>
                                    <ENT O="xl">
                                        100.1 
                                        <SU>9</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Transmission Electron Microscopy</ENT>
                                    <ENT O="xl">
                                        100.2 
                                        <SU>10</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">5. Barium</ENT>
                                    <ENT>Inductively Coupled Plasma</ENT>
                                    <ENT>
                                        200.7 
                                        <SU>2</SU>
                                    </ENT>
                                    <ENT/>
                                    <ENT>3120 B</ENT>
                                    <ENT>3120 B</ENT>
                                    <ENT>3120 B-99</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>ICP-Mass Spectrometry</ENT>
                                    <ENT O="xl">
                                        200.8 
                                        <SU>2</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Atomic Absorption; Direct</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>3111D</ENT>
                                    <ENT/>
                                    <ENT>3111 D-99</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Atomic Absorption; Furnace</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>3113 B</ENT>
                                    <ENT/>
                                    <ENT>3113 B-99</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">6. Beryllium</ENT>
                                    <ENT>Inductively Coupled Plasma</ENT>
                                    <ENT>
                                        200.7 
                                        <SU>2</SU>
                                    </ENT>
                                    <ENT/>
                                    <ENT>3120 B</ENT>
                                    <ENT>3120 B</ENT>
                                    <ENT>3120 B-99</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>ICP-Mass Spectrometry</ENT>
                                    <ENT O="xl">
                                        200.8 
                                        <SU>2</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Atomic Absorption; Platform</ENT>
                                    <ENT O="xl">
                                        200.9 
                                        <SU>2</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Atomic Absorption; Furnace</ENT>
                                    <ENT/>
                                    <ENT>D3645-97, 03 B</ENT>
                                    <ENT>3113 B</ENT>
                                    <ENT/>
                                    <ENT>3113 B-99</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">7. Cadmium</ENT>
                                    <ENT>Inductively Coupled Plasma</ENT>
                                    <ENT O="xl">
                                        200.7 
                                        <SU>2</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>ICP-Mass Spectrometry</ENT>
                                    <ENT O="xl">
                                        200.8 
                                        <SU>2</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Atomic Absorption; Platform</ENT>
                                    <ENT O="xl">
                                        200.9 
                                        <SU>2</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <PRTPAGE P="503"/>
                                    <ENT I="22"> </ENT>
                                    <ENT>Atomic Absorption; Furnace</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>3113 B</ENT>
                                    <ENT/>
                                    <ENT>3113 B-99</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">8. Calcium</ENT>
                                    <ENT>EDTA titrimetric</ENT>
                                    <ENT/>
                                    <ENT>D511-93, 03 A</ENT>
                                    <ENT>3500-Ca D</ENT>
                                    <ENT>3500-Ca B</ENT>
                                    <ENT>3500-Ca B-97</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Atomic Absorption; Direct Aspiration</ENT>
                                    <ENT/>
                                    <ENT>D511-93, 03 B</ENT>
                                    <ENT>3111 B</ENT>
                                    <ENT/>
                                    <ENT>3111 B-99</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Inductively Coupled Plasma</ENT>
                                    <ENT>
                                        200.7 
                                        <SU>2</SU>
                                    </ENT>
                                    <ENT/>
                                    <ENT>3120 B</ENT>
                                    <ENT>3120 B</ENT>
                                    <ENT>3120 B-99</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Ion Chromatography</ENT>
                                    <ENT/>
                                    <ENT>D6919-03</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">9. Chromium</ENT>
                                    <ENT>Inductively Coupled Plasma</ENT>
                                    <ENT>
                                        200.7 
                                        <SU>2</SU>
                                    </ENT>
                                    <ENT/>
                                    <ENT>3120 B</ENT>
                                    <ENT>3120 B</ENT>
                                    <ENT>3120 B-99</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>ICP-Mass Spectrometry</ENT>
                                    <ENT O="xl">
                                        200.8 
                                        <SU>2</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Atomic Absorption; Platform</ENT>
                                    <ENT O="xl">
                                        200.9 
                                        <SU>2</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Atomic Absorption; Furnace</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>3113 B</ENT>
                                    <ENT/>
                                    <ENT>3113 B-99</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">10. Copper</ENT>
                                    <ENT>Atomic Absorption; Furnace</ENT>
                                    <ENT/>
                                    <ENT>D1688-95, 02 C</ENT>
                                    <ENT>3113 B</ENT>
                                    <ENT/>
                                    <ENT>3113 B-99</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Atomic Absorption; Direct Aspiration</ENT>
                                    <ENT/>
                                    <ENT>D1688-95, 02 A</ENT>
                                    <ENT>3111 B</ENT>
                                    <ENT/>
                                    <ENT>3111 B-99</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Inductively Coupled Plasma</ENT>
                                    <ENT>
                                        200.7 
                                        <SU>2</SU>
                                    </ENT>
                                    <ENT/>
                                    <ENT>3120 B</ENT>
                                    <ENT>3120 B</ENT>
                                    <ENT>3120 B-99</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>ICP-Mass spectrometry</ENT>
                                    <ENT O="xl">
                                        200.8 
                                        <SU>2</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Atomic Absorption; Platform</ENT>
                                    <ENT O="xl">
                                        200.9 
                                        <SU>2</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">11. Conductivity</ENT>
                                    <ENT>Conductance</ENT>
                                    <ENT/>
                                    <ENT>D1125-95 (Reapproved 1999) A</ENT>
                                    <ENT>2510 B</ENT>
                                    <ENT>2510 B</ENT>
                                    <ENT>2510 B-97</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">12. Cyanide</ENT>
                                    <ENT O="xl">Manual Distillation followed by</ENT>
                                    <ENT/>
                                    <ENT>D2036-98 A</ENT>
                                    <ENT>
                                        4500-CN
                                        <E T="51">−</E>
                                         C
                                    </ENT>
                                    <ENT>
                                        4500-CN
                                        <E T="51">−</E>
                                         C
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="oi3">Spectrophotometric, Amenable</ENT>
                                    <ENT/>
                                    <ENT>D2036-98 B</ENT>
                                    <ENT>
                                        4500-CN
                                        <E T="51">−</E>
                                         G
                                    </ENT>
                                    <ENT>
                                        4500-CN
                                        <E T="51">−</E>
                                         G
                                    </ENT>
                                    <ENT>
                                        4500-CN
                                        <E T="51">−</E>
                                         G-99
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="oi3">Spectro-photometric Manual</ENT>
                                    <ENT/>
                                    <ENT>D2036-98 A</ENT>
                                    <ENT>
                                        4500-CN
                                        <E T="51">−</E>
                                         E
                                    </ENT>
                                    <ENT>
                                        4500-CN
                                        <E T="51">−</E>
                                         E
                                    </ENT>
                                    <ENT>
                                        4500-CN
                                        <E T="51">−</E>
                                         E-99
                                    </ENT>
                                    <ENT>
                                        I-3300-85 
                                        <SU>5</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="oi3">Spectro-photometric Semi-automated</ENT>
                                    <ENT O="xl">
                                        335.4 
                                        <SU>6</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Selective Electrode</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        4500-CN
                                        <E T="51">−</E>
                                         F
                                    </ENT>
                                    <ENT>
                                        4500-CN
                                        <E T="51">−</E>
                                         F
                                    </ENT>
                                    <ENT>
                                        4500-CN
                                        <E T="51">−</E>
                                         F-99
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>UV, Distillation, Spectrophotometric</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        Kelada-01 
                                        <SU>17</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Micro Distillation, Flow Injection, Spectrophotometric</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        QuikChem 10-204-00-1-X 
                                        <SU>18</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>
                                        Ligand Exchange and Amperometry 
                                        <SU>21</SU>
                                    </ENT>
                                    <ENT/>
                                    <ENT>D6888-04</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        OIA-1677, DW 
                                        <SU>20</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <PRTPAGE P="504"/>
                                    <ENT I="01">13. Fluoride</ENT>
                                    <ENT>Ion Chromatography</ENT>
                                    <ENT O="xl">
                                        300.0 
                                        <SU>6</SU>
                                        , 300.1 
                                        <SU>19</SU>
                                    </ENT>
                                    <ENT>D4327-97, 03</ENT>
                                    <ENT>4110 B</ENT>
                                    <ENT>4110 B</ENT>
                                    <ENT>4110 B-00</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Manual Distill.; Color. SPADNS</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        4500-F
                                        <E T="51">−</E>
                                         B, D
                                    </ENT>
                                    <ENT>
                                        4500-F
                                        <E T="51">−</E>
                                         B, D
                                    </ENT>
                                    <ENT>
                                        4500-F
                                        <E T="51">−</E>
                                         B, D-97
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Manual Electrode</ENT>
                                    <ENT/>
                                    <ENT>D1179-93, 99 B</ENT>
                                    <ENT>
                                        4500-F
                                        <E T="51">−</E>
                                         C
                                    </ENT>
                                    <ENT>
                                        4500-F
                                        <E T="51">−</E>
                                         C
                                    </ENT>
                                    <ENT>
                                        4500-F
                                        <E T="51">−</E>
                                         C-97
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Automated Electrode</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        380-75WE 
                                        <SU>11</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Automated Alizarin</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        4500-F
                                        <E T="51">−</E>
                                         E
                                    </ENT>
                                    <ENT>
                                        4500-F
                                        <E T="51">−</E>
                                         E
                                    </ENT>
                                    <ENT>
                                        4500-F
                                        <E T="51">−</E>
                                         E-97
                                    </ENT>
                                    <ENT>
                                        129-71W 
                                        <SU>11</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Capillary Ion Electrophoresis</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        D6508, Rev. 2 
                                        <SU>23</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">14. Lead</ENT>
                                    <ENT>Atomic Absorption; Furnace</ENT>
                                    <ENT/>
                                    <ENT>D3559-96, 03 D</ENT>
                                    <ENT>3113 B</ENT>
                                    <ENT/>
                                    <ENT>3113 B-99</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>ICP-Mass spectrometry</ENT>
                                    <ENT O="xl">
                                        200.8 
                                        <SU>2</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Atomic Absorption; Platform</ENT>
                                    <ENT O="xl">
                                        200.9 
                                        <SU>2</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Differential Pulse Anodic Stripping Voltametry</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        Method 1001 
                                        <SU>16</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">15. Magnesium</ENT>
                                    <ENT>Atomic Absorption</ENT>
                                    <ENT/>
                                    <ENT>D511-93, 03 B</ENT>
                                    <ENT>3111 B</ENT>
                                    <ENT/>
                                    <ENT>3111 B-99</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>ICP</ENT>
                                    <ENT>
                                        200.7 
                                        <SU>2</SU>
                                    </ENT>
                                    <ENT/>
                                    <ENT>3120 B</ENT>
                                    <ENT>3120 B</ENT>
                                    <ENT>3120 B-99</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Complexation Titrimetric Methods</ENT>
                                    <ENT/>
                                    <ENT>D511-93, 03 A</ENT>
                                    <ENT>3500-Mg E</ENT>
                                    <ENT>3500-Mg B</ENT>
                                    <ENT>3500-Mg B-97</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Ion Chromatography</ENT>
                                    <ENT/>
                                    <ENT>D6919-03</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">16. Mercury</ENT>
                                    <ENT>Manual, Cold Vapor</ENT>
                                    <ENT>
                                        245.1 
                                        <SU>2</SU>
                                    </ENT>
                                    <ENT>D3223-97, 02</ENT>
                                    <ENT>3112 B</ENT>
                                    <ENT/>
                                    <ENT>3112 B-99</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Automated, Cold Vapor</ENT>
                                    <ENT O="xl">
                                        245.2 
                                        <SU>1</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>ICP-Mass Spectrometry</ENT>
                                    <ENT O="xl">
                                        200.8 
                                        <SU>2</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">17. Nickel</ENT>
                                    <ENT>Inductively Coupled Plasma</ENT>
                                    <ENT>
                                        200.7 
                                        <SU>2</SU>
                                    </ENT>
                                    <ENT/>
                                    <ENT>3120 B</ENT>
                                    <ENT>3120 B</ENT>
                                    <ENT>3120 B-99</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>ICP-Mass Spectrometry</ENT>
                                    <ENT O="xl">
                                        200.8 
                                        <SU>2</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Atomic Absorption; Platform</ENT>
                                    <ENT O="xl">
                                        200.9 
                                        <SU>2</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Atomic Absorption; Direct</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>3111 B</ENT>
                                    <ENT/>
                                    <ENT>3111 B-99</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Atomic Absorption; Furnace</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>3113 B</ENT>
                                    <ENT/>
                                    <ENT>3113 B-99</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">18. Nitrate</ENT>
                                    <ENT>Ion Chromatography</ENT>
                                    <ENT O="xl">
                                        300.0 
                                        <SU>6</SU>
                                        , 300.1 
                                        <SU>19</SU>
                                    </ENT>
                                    <ENT>D4327-97, 03</ENT>
                                    <ENT>4110 B</ENT>
                                    <ENT>4110 B</ENT>
                                    <ENT>4110 B-00</ENT>
                                    <ENT>
                                        B-1011 
                                        <SU>8</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Automated Cadmium Reduction</ENT>
                                    <ENT>
                                        353.2 
                                        <SU>6</SU>
                                    </ENT>
                                    <ENT>D3867-90 A</ENT>
                                    <ENT>
                                        4500-NO
                                        <E T="52">3</E>
                                        <E T="51">−</E>
                                         F
                                    </ENT>
                                    <ENT>
                                        4500-NO
                                        <E T="52">3</E>
                                        <E T="51">−</E>
                                         F
                                    </ENT>
                                    <ENT O="xl">
                                        4500-NO
                                        <E T="52">3</E>
                                        <E T="51">−</E>
                                         F-00
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"/>
                                    <ENT>Ion Selective Electrode</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        4500-NO
                                        <E T="52">3</E>
                                        <E T="51">−</E>
                                         D
                                    </ENT>
                                    <ENT>
                                        4500-NO
                                        <E T="52">3</E>
                                        <E T="51">−</E>
                                         D
                                    </ENT>
                                    <ENT>
                                        4500-NO
                                        <E T="52">3</E>
                                        <E T="51">−</E>
                                         D-00
                                    </ENT>
                                    <ENT>
                                        601 
                                        <SU>7</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <PRTPAGE P="505"/>
                                    <ENT I="22"> </ENT>
                                    <ENT>Manual Cadmium Reduction</ENT>
                                    <ENT/>
                                    <ENT>D3867-90 B</ENT>
                                    <ENT>
                                        4500-NO
                                        <E T="52">3</E>
                                        <E T="51">−</E>
                                         E
                                    </ENT>
                                    <ENT>
                                        4500-NO
                                        <E T="52">3</E>
                                        <E T="51">−</E>
                                         E
                                    </ENT>
                                    <ENT O="xl">
                                        4500-NO
                                        <E T="52">3</E>
                                        <E T="51">−</E>
                                         E-00
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Capillary Ion Electrophoresis</ENT>
                                    <ENT/>
                                    <ENT O="xl">D6508-00.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">19. Nitrite</ENT>
                                    <ENT>Ion Chromatography</ENT>
                                    <ENT>
                                        300.0 
                                        <SU>6</SU>
                                        , 300.1 
                                        <SU>19</SU>
                                    </ENT>
                                    <ENT>D4327-97, 03</ENT>
                                    <ENT>4110 B</ENT>
                                    <ENT>4110 B</ENT>
                                    <ENT>4110 B-00</ENT>
                                    <ENT>
                                        B-1011 
                                        <SU>8</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Automated Cadmium Reduction</ENT>
                                    <ENT>
                                        353.2 
                                        <SU>6</SU>
                                    </ENT>
                                    <ENT>D3867-90 A</ENT>
                                    <ENT>
                                        4500-NO
                                        <E T="52">3</E>
                                        <E T="51">−</E>
                                         F
                                    </ENT>
                                    <ENT>
                                        4500-NO
                                        <E T="52">3</E>
                                        <E T="51">−</E>
                                         F
                                    </ENT>
                                    <ENT O="xl">
                                        4500-NO
                                        <E T="52">3</E>
                                        <E T="51">−</E>
                                         F-00
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Manual Cadmium Reduction</ENT>
                                    <ENT/>
                                    <ENT>D3867-90 B</ENT>
                                    <ENT>
                                        4500-NO
                                        <E T="52">3</E>
                                        <E T="51">−</E>
                                         E
                                    </ENT>
                                    <ENT>
                                        4500-NO
                                        <E T="52">3</E>
                                        <E T="51">−</E>
                                         E
                                    </ENT>
                                    <ENT O="xl">
                                        4500-NO
                                        <E T="52">3</E>
                                        <E T="51">−</E>
                                         E-00
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Spectrophotometric</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        4500-NO
                                        <E T="52">2</E>
                                        <E T="51">−</E>
                                         B
                                    </ENT>
                                    <ENT>
                                        4500-NO
                                        <E T="52">2</E>
                                        <E T="51">−</E>
                                         B
                                    </ENT>
                                    <ENT O="xl">
                                        4500-NO
                                        <E T="52">2</E>
                                        <E T="51">−</E>
                                         B-00
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"/>
                                    <ENT>Capillary Ion Electrophoresis</ENT>
                                    <ENT/>
                                    <ENT O="xl">D6508-00</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">20. Ortho-phosphate</ENT>
                                    <ENT>Colorimetric, Automated, Ascorbic Acid</ENT>
                                    <ENT>
                                        365.1 
                                        <SU>6</SU>
                                    </ENT>
                                    <ENT/>
                                    <ENT>4500-P F</ENT>
                                    <ENT O="xl">4500-P F</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"/>
                                    <ENT>Colorimetric, ascorbic acid, single reagent</ENT>
                                    <ENT/>
                                    <ENT>D515-88 A</ENT>
                                    <ENT>4500-P E</ENT>
                                    <ENT O="xl">4500-P E</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Colorimetric Phosphomolybdate; Automated-segmented flow; Automated Discrete</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        I-1601-85 
                                        <SU>5</SU>
                                        <LI>
                                            I-2601-90 
                                            <SU>5</SU>
                                        </LI>
                                        <LI>
                                            I-2598-85 
                                            <SU>5</SU>
                                        </LI>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Ion Chromatography</ENT>
                                    <ENT>
                                        300.0 
                                        <SU>6</SU>
                                        , 300.1 
                                        <SU>19</SU>
                                    </ENT>
                                    <ENT>D4327-97, 03</ENT>
                                    <ENT>4110 B</ENT>
                                    <ENT>4110 B</ENT>
                                    <ENT O="xl">4110 B-00</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Capillary Ion Electrophoresis</ENT>
                                    <ENT/>
                                    <ENT O="xl">D6508-00</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">21. pH</ENT>
                                    <ENT>Electrometric</ENT>
                                    <ENT O="xl">
                                        150.1, 150.2 
                                        <SU>1</SU>
                                    </ENT>
                                    <ENT>D1293-95, 99</ENT>
                                    <ENT>
                                        4500-H
                                        <SU>+ </SU>
                                         B
                                    </ENT>
                                    <ENT>
                                        4500-H
                                        <SU>+ </SU>
                                         B
                                    </ENT>
                                    <ENT>
                                        4500-H
                                        <SU>+ </SU>
                                         B-00
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">22. Selenium</ENT>
                                    <ENT>Hydride-Atomic Absorption</ENT>
                                    <ENT/>
                                    <ENT>D3859-98, 03 A</ENT>
                                    <ENT>3114 B</ENT>
                                    <ENT/>
                                    <ENT>3114 B-97</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="21"/>
                                    <ENT>ICP-Mass Spectrometry</ENT>
                                    <ENT O="xl">
                                        200.8 
                                        <SU>2</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Atomic Absorption; Platform</ENT>
                                    <ENT O="xl">
                                        200.9 
                                        <SU>2</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Atomic Absorption; Furnace</ENT>
                                    <ENT/>
                                    <ENT>D3859-98, 03 B</ENT>
                                    <ENT>3113 B</ENT>
                                    <ENT/>
                                    <ENT>3113 B-99</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">23. Silica</ENT>
                                    <ENT>Colorimetric, Molybdate Blue</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        I-1700-85 
                                        <SU>5</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="oi3">Automated-segmented Flow</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        I-2700-85 
                                        <SU>5</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Colorimetric</ENT>
                                    <ENT/>
                                    <ENT>D859-94, 00</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Molybdosilicate</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>4500-Si D</ENT>
                                    <ENT>
                                        4500-SiO
                                        <E T="52">2</E>
                                         C
                                    </ENT>
                                    <ENT>
                                        4500-SiO
                                        <E T="52">2</E>
                                         C-97
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <PRTPAGE P="506"/>
                                    <ENT I="22"> </ENT>
                                    <ENT>Heteropoly blue</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>4500-Si E</ENT>
                                    <ENT>
                                        4500-SiO
                                        <E T="52">2</E>
                                         D
                                    </ENT>
                                    <ENT>
                                        4500-SiO
                                        <E T="52">2</E>
                                         D-97
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Automated for Molybdate-reactive Silica</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>4500-Si F</ENT>
                                    <ENT>
                                        4500-SiO
                                        <E T="52">2</E>
                                         E
                                    </ENT>
                                    <ENT>
                                        4500-SiO
                                        <E T="52">2</E>
                                         E-97
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Inductively Coupled Plasma</ENT>
                                    <ENT>
                                        200.7 
                                        <SU>2</SU>
                                    </ENT>
                                    <ENT/>
                                    <ENT>3120 B</ENT>
                                    <ENT>3120 B</ENT>
                                    <ENT>3120 B-99</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">24. Sodium</ENT>
                                    <ENT>Inductively Coupled Plasma</ENT>
                                    <ENT O="xl">
                                        200.7 
                                        <SU>2</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Atomic Absorption; Direct Aspiration</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>3111 B</ENT>
                                    <ENT/>
                                    <ENT>3111 B-99</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Ion Chromatography</ENT>
                                    <ENT/>
                                    <ENT>D6919-03</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">25. Temperature</ENT>
                                    <ENT>Thermometric</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>2550</ENT>
                                    <ENT>2550</ENT>
                                    <ENT>2550-00</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">26. Thallium</ENT>
                                    <ENT>ICP-Mass Spectrometry</ENT>
                                    <ENT O="xl">
                                        200.8 
                                        <SU>2</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Atomic Absorption; Platform</ENT>
                                    <ENT>
                                        200.9 
                                        <SU>2</SU>
                                    </ENT>
                                </ROW>
                                <TNOTE>
                                    The procedures shall be done in accordance with the documents listed below. The incorporation by reference of the following documents listed in footnotes 1-11, 16-20, and 22-23 was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies of the documents may be obtained from the sources listed below. Information regarding obtaining these documents can be obtained from the Safe Drinking Water Hotline at 800-426-4791. Documents may be inspected at EPA's Drinking Water Docket, EPA West, 1301 Constitution Avenue, NW., Room 3334, Washington, DC 20460 (Telephone: 202-566-2426); or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: 
                                    <E T="03">http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.</E>
                                </TNOTE>
                                <TNOTE>
                                    <SU>1</SU>
                                     “Methods for Chemical Analysis of Water and Wastes,” EPA/600/4-79/020, March 1983. Available at NTIS, PB84-128677.
                                </TNOTE>
                                <TNOTE>
                                    <SU>2</SU>
                                     “Methods for the Determination of Metals in Environmental Samples—Supplement I,” EPA/600/R-94/111, May 1994. Available at NTIS, PB95-125472.
                                </TNOTE>
                                <TNOTE>
                                    <SU>3</SU>
                                     
                                    <E T="03">Annual Book of ASTM Standards,</E>
                                     ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428, 
                                    <E T="03">http://www.astm.org.;</E>
                                     Annual Book of ASTM Standards 1994, Vols. 11.01 and 11.02; Annual Book of ASTM Standards 1996, Vols. 11.01 and 11.02; Annual Book of ASTM Standards 1999, Vols. 11.01 and 11.02; Annual Book of ASTM Standards 2003, Vols. 11.01 and 11.02.
                                </TNOTE>
                                <TNOTE>
                                    <SU>4</SU>
                                     
                                    <E T="03">Standard Methods for the Examination of Water and Wastewater,</E>
                                     American Public Health Association, 800 I Street NW., Washington, DC 20001-3710; 
                                    <E T="03">Standard Methods for the Examination of Water and Wastewater,</E>
                                     18th edition (1992); 
                                    <E T="03">Standard Methods for the Examination of Water and Wastewater,</E>
                                     19th edition (1995); 
                                    <E T="03">Standard Methods for the Examination of Water and Wastewater,</E>
                                     20th edition (1998).The following methods from this edition cannot be used: 3111 B, 3111 D, 3113 B, and 3114 B.
                                </TNOTE>
                                <TNOTE>
                                    <SU>5</SU>
                                     U.S. Geological Survey, Federal Center, Box 25286, Denver, CO 80225-0425; Methods for Analysis by the U.S. Geological Survey National Water Quality Laboratory—Determination of Inorganic and Organic Constituents in Water and Fluvial Sediment, Open File Report 93-125, 1993; Techniques of Water Resources Investigation of the U.S. Geological Survey, Book 5, Chapter A-1, 3rd edition, 1989.
                                </TNOTE>
                                <TNOTE>
                                    <SU>6</SU>
                                     “Methods for the Determination of Inorganic Substances in Environmental Samples,” EPA/600/R-93/100, August 1993. Available as Technical Report PB94-120821 at National Technical Information Service (NTIS), 5301 Shawnee Road, Alexandria, VA 22312. 
                                    <E T="03">http://www.ntis.gov.</E>
                                </TNOTE>
                                <TNOTE>
                                    <SU>7</SU>
                                     The procedure shall be done in accordance with the Technical Bulletin 601 “Standard Method of Test for Nitrate in Drinking Water,” July 1994, PN 221890-001, Analytical Technology, Inc. Copies may be obtained from ATI Orion, 529 Main Street, Boston, MA 02129.
                                </TNOTE>
                                <TNOTE>
                                    <SU>8</SU>
                                     Method B-1011. “Waters Test Method for Determination of Nitrite/Nitrate in Water Using Single Column Ion Chromatography,” August, 1987. Copies may be obtained from Waters Corporation, Technical Services Division, 34 Maple Street, Milford, MA 01757, Telephone: 508/482-2963, Fax: 508/482-4056.
                                </TNOTE>
                                <TNOTE>
                                    <SU>9</SU>
                                     Method 100.1, “Analytical Method For Determination of Asbestos Fibers in Water,” EPA/600/4-83/043, EPA, September 1983. Available at NTIS, PB83-260471.
                                </TNOTE>
                                <TNOTE>
                                    <SU>10</SU>
                                     Method 100.2, “Determination of Asbestos Structure Over 10-μm In Length In Drinking Water,” EPA/600/R-94/134, June 1994. Available at NTIS, PB94-201902.
                                </TNOTE>
                                <TNOTE>
                                    <SU>11</SU>
                                     Industrial Method No. 129-71W, “Fluoride in Water and Wastewater,” December 1972, and Method No. 380-75WE, “Fluoride in Water and Wastewater,” February 1976, Technicon Industrial Systems. Copies may be obtained from Bran &amp; Luebbe, 1025 Busch Parkway, Buffalo Grove, IL 60089.
                                </TNOTE>
                                <TNOTE>
                                    <SU>12</SU>
                                     Unfiltered, no digestion or hydrolysis.
                                </TNOTE>
                                <TNOTE>
                                    <SU>13</SU>
                                     Because MDLs reported in EPA Methods 200.7 and 200.9 were determined using a 2x preconcentration step during sample digestion, MDLs determined when samples are analyzed by direct analysis (
                                    <E T="03">i.e.,</E>
                                     no sample digestion) will be higher. For direct analysis of cadmium and arsenic by Method 200.7, and arsenic by Method 3120 B, sample preconcentration using pneumatic nebulization may be required to achieve lower detection limits. Preconcentration may also be required for direct analysis of antimony, lead, and thallium by Method 200.9; antimony and lead by Method 3113 B; and lead by Method D3559-90D, unless multiple in-furnace depositions are made.
                                </TNOTE>
                                <TNOTE>
                                    <SU>14</SU>
                                     If ultrasonic nebulization is used in the determination of arsenic by Method 200.8, the arsenic must be in the pentavalent state to provide uniform signal response. For direct analysis of arsenic with Method 200.8 using ultrasonic nebulization, samples and standards must contain 1 mg/L of sodium hypochlorite.
                                </TNOTE>
                                <TNOTE>
                                    <SU>15</SU>
                                     [Reserved]
                                    <PRTPAGE P="507"/>
                                </TNOTE>
                                <TNOTE>
                                    <SU>16</SU>
                                     The description for Method Number 1001 for lead is available from Palintest, LTD, 21 Kenton Lands Road, P.O. Box 18395, Erlanger, KY 41018. Or from the Hach Company, P.O. Box 389, Loveland, CO 80539.
                                </TNOTE>
                                <TNOTE>
                                    <SU>17</SU>
                                     The description for the Kelada-01 Method, “Kelada Automated Test Methods for Total Cyanide, Acid Dissociable Cyanide, And Thiocyanate,” Revision 1.2, August 2001, EPA # 821-B-01-009 for cyanide is available from the National Technical Information Service (NTIS), PB 2001-108275, 5285 Port Royal Road, Springfield, VA 22161. The toll free telephone number is 800-553-6847. 
                                    <E T="02">Note:</E>
                                     A 450-W UV lamp may be used in this method instead of the 550-W lamp specified if it provides performance within the quality control (QC) acceptance criteria of the method in a given instrument. Similarly, modified flow cell configurations and flow conditions may be used in the method, provided that the QC acceptance criteria are met.
                                </TNOTE>
                                <TNOTE>
                                    <SU>18</SU>
                                     The description for the QuikChem Method 10-204-00-1-X, “Digestion and distillation of total cyanide in drinking and wastewaters using MICRO DIST and determination of cyanide by flow injection analysis,” Revision 2.1, November 30, 2000, for cyanide is available from Lachat Instruments, 6645 W. Mill Rd., Milwaukee, WI 53218. Telephone: 414-358-4200.
                                </TNOTE>
                                <TNOTE>
                                    <SU>19</SU>
                                     “Methods for the Determination of Organic and Inorganic Compounds in Drinking Water,” Vol. 1, EPA 815-R-00-014, August 2000. Available as Technical Report PB2000-106981 at National Technical Information Service (NTIS), 5301 Shawnee Road, Alexandria, VA 22312. 
                                    <E T="03">http://www.ntis.gov.</E>
                                </TNOTE>
                                <TNOTE>
                                    <SU>20</SU>
                                     Method OIA-1677, DW “Available Cyanide by Flow Injection, Ligand Exchange, and Amperometry,” January 2004. EPA-821-R-04-001, Available from ALPKEM, A Division of OI Analytical, P.O. Box 9010, College Station, TX 77842-9010.
                                </TNOTE>
                                <TNOTE>
                                    <SU>21</SU>
                                     Sulfide levels below those detected using lead acetate paper may produce positive method interferences. Test samples using a more sensitive sulfide method to determine if a sulfide interference is present, and treat samples accordingly.
                                </TNOTE>
                                <TNOTE>
                                    <SU>22</SU>
                                     Standard Methods Online, American Public Health Association, 800 I Street NW., Washington, DC 20001, available at 
                                    <E T="03">http://www.standardmethods.org.</E>
                                     The year in which each method was approved by the Standard Methods Committee is designated by the last two digits in the method number. The methods listed are the only online versions that may be used.
                                </TNOTE>
                            </GPOTABLE>
                            <PRTPAGE P="508"/>
                            <P>(2) Sample collection for antimony, arsenic, asbestos, barium, beryllium, cadmium, chromium, cyanide, fluoride, mercury, nickel, nitrate, nitrite, selenium, and thallium under this section shall be conducted using the sample preservation, container, and maximum holding time procedures specified in the table below:</P>
                            <GPOTABLE COLS="4" OPTS="L2" CDEF="s30,r30,xs28,xs34">
                                <BOXHD>
                                    <CHED H="1">Contaminant</CHED>
                                    <CHED H="1">
                                        Preservative 
                                        <SU>1</SU>
                                    </CHED>
                                    <CHED H="1">
                                        Container 
                                        <SU>2</SU>
                                    </CHED>
                                    <CHED H="1">
                                        Time 
                                        <SU>3</SU>
                                    </CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">Antimony</ENT>
                                    <ENT>
                                        HNO
                                        <SU>3</SU>
                                    </ENT>
                                    <ENT>P or G</ENT>
                                    <ENT>6 months</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Arsenic</ENT>
                                    <ENT>
                                        Conc HNO
                                        <E T="52">3</E>
                                         to pH &lt;2
                                    </ENT>
                                    <ENT>P or G</ENT>
                                    <ENT>6 months</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Asbestos</ENT>
                                    <ENT>4 °C</ENT>
                                    <ENT>P or G</ENT>
                                    <ENT>
                                        48 hours 
                                        <SU>4</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Barium</ENT>
                                    <ENT>
                                        HNO
                                        <SU>3</SU>
                                    </ENT>
                                    <ENT>P or G</ENT>
                                    <ENT>6 months</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Beryllium</ENT>
                                    <ENT>
                                        HNO
                                        <SU>3</SU>
                                    </ENT>
                                    <ENT>P or G</ENT>
                                    <ENT>6 months</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Cadmium</ENT>
                                    <ENT>
                                        HNO
                                        <SU>3</SU>
                                    </ENT>
                                    <ENT>P or G</ENT>
                                    <ENT>6 months</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Chromium</ENT>
                                    <ENT>
                                        HNO
                                        <SU>3</SU>
                                    </ENT>
                                    <ENT>P or G</ENT>
                                    <ENT>6 months</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Cyanide</ENT>
                                    <ENT>4 °C, NaOH</ENT>
                                    <ENT>P or G</ENT>
                                    <ENT>14 days</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Fluoride</ENT>
                                    <ENT>None</ENT>
                                    <ENT>P or G</ENT>
                                    <ENT>1 month</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Mercury</ENT>
                                    <ENT>
                                        HNO
                                        <SU>3</SU>
                                    </ENT>
                                    <ENT>P or G</ENT>
                                    <ENT>28 days</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Nickel</ENT>
                                    <ENT>
                                        HNO
                                        <SU>3</SU>
                                    </ENT>
                                    <ENT>P or G</ENT>
                                    <ENT>6 months</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Nitrate</ENT>
                                    <ENT>4 °C</ENT>
                                    <ENT>P or G</ENT>
                                    <ENT>
                                        48 hours 
                                        <SU>5</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">
                                        Nitrate-Nitrite 
                                        <SU>6</SU>
                                    </ENT>
                                    <ENT>
                                        H
                                        <SU>2</SU>
                                        SO
                                        <SU>4</SU>
                                    </ENT>
                                    <ENT>P or G</ENT>
                                    <ENT>28 days</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Nitrite</ENT>
                                    <ENT>4 °C</ENT>
                                    <ENT>P or G</ENT>
                                    <ENT>48 hours</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Selenium</ENT>
                                    <ENT>
                                        HNO
                                        <SU>3</SU>
                                    </ENT>
                                    <ENT>P or G</ENT>
                                    <ENT>6 months</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Thallium</ENT>
                                    <ENT>
                                        HNO
                                        <SU>3</SU>
                                    </ENT>
                                    <ENT>P or G</ENT>
                                    <ENT>6 months</ENT>
                                </ROW>
                                <TNOTE>
                                    <SU>1</SU>
                                     For cyanide determinations samples must be adjusted with sodium hydroxide to pH 12 at the time off collection. When chilling is indicated the sample must be shipped and stored at 4 °C or less. Acidification of nitrate or metals samples may be with a concentrated acid or a dilute (50% by volume) solution of the applicable concentrated acid. Acidification of samples for metals analysis is encouraged and allowed at the laboratory rather than at the time of sampling provided the shipping time and other instructions in Section 8.3 of EPA Methods 200.7 or 200.8 or 200.9 are followed.
                                </TNOTE>
                                <TNOTE>
                                    <SU>2</SU>
                                     P = plastic, hard or soft; G = glass, hard or soft.
                                </TNOTE>
                                <TNOTE>
                                    <SU>3</SU>
                                     In all cases samples should be analyzed as soon after collection as possible. Follow additional (if any) information on preservation, containers or holding times that is specified in method.
                                </TNOTE>
                                <TNOTE>
                                    <SU>4</SU>
                                     Instructions for containers, preservation procedures and holding times as specified in Method 100.2 must be adhered to for all compliance analyses including those conducted with Method 100.1.
                                </TNOTE>
                                <TNOTE>
                                    <SU>5</SU>
                                     If the sample is chlorinated, the holding time for an unacidified sample kept at 4 °C is extended to 14 days.
                                </TNOTE>
                                <TNOTE>
                                    <SU>6</SU>
                                     Nitrate-Nitrite refers to a measurement of total nitrate.
                                </TNOTE>
                            </GPOTABLE>
                            <P>(3) Analysis under this section shall only be conducted by laboratories that have been certified by EPA or the State. Laboratories may conduct sample analysis under provisional certification until January 1, 1996. To receive certification to conduct analyses for antimony, arsenic, asbestos, barium, beryllium, cadmium, chromium, cyanide, fluoride, mercury, nickel, nitrate, nitrite and selenium and thallium, the laboratory must:</P>
                            <P>(i) Analyze Performance Evaluation (PE) samples provided by EPA, the State or by a third party (with the approval of the State or EPA) at least once a year.</P>
                            <P>(ii) For each contaminant that has been included in the PE sample and for each method for which the laboratory desires certification achieve quantitative results on the analyses that are within the following acceptance limits:</P>
                            <GPOTABLE COLS="2" OPTS="L2" CDEF="s10,xs82">
                                <BOXHD>
                                    <CHED H="1">Contaminant</CHED>
                                    <CHED H="1">Acceptance limit</CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">Antimony</ENT>
                                    <ENT>±30 at ≥0.006 mg/1</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Arsenic</ENT>
                                    <ENT>±30 at ≥0.003 mg/L</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Asbestos</ENT>
                                    <ENT>2 standard deviations based on study statistics.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Barium</ENT>
                                    <ENT>±15% at ≥0.15 mg/1</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Beryllium</ENT>
                                    <ENT>±15% at ≥0.001 mg/1</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Cadmium</ENT>
                                    <ENT>±20% at ≥0.002 mg/1</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Chromium</ENT>
                                    <ENT>±15% at ≥0.01 mg/1</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Cyanide</ENT>
                                    <ENT>±25% at ≥0.1 mg/1</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Fluoride</ENT>
                                    <ENT>±10% at ≥1 to 10 mg/1</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Mercury</ENT>
                                    <ENT>±30% at ≥0.0005 mg/1</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Nickel</ENT>
                                    <ENT>±15% at ≥0.01 mg/1</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Nitrate</ENT>
                                    <ENT>±10% at ≥0.4 mg/1</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Nitrite</ENT>
                                    <ENT>±15% at ≥0.4 mg/1</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Selenium</ENT>
                                    <ENT>±20% at ≥0.01 mg/1</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Thallium</ENT>
                                    <ENT>±30% at ≥0.002 mg/1</ENT>
                                </ROW>
                            </GPOTABLE>
                            <P>(l) Analyses for the purpose of determining compliance with § 141.11 shall be conducted using the requirements specified in paragraphs (l) through (q) of this section.</P>
                            <P>(1) Analyses for all community water systems utilizing surface water sources shall be completed by June 24, 1978. These analyses shall be repeated at yearly intervals.</P>
                            <P>(2) Analyses for all community water systems utilizing only ground water sources shall be completed by June 24, 1979. These analyses shall be repeated at three-year intervals.</P>
                            <P>(3) For non-community water systems, whether supplied by surface or ground sources, analyses for nitrate shall be completed by December 24, 1980. These analyses shall be repeated at intervals determined by the State.</P>
                            <P>(4) The State has the authority to determine compliance or initiate enforcement action based upon analytical results and other information compiled by their sanctioned representatives and agencies.</P>
                            <P>
                                (m) If the result of an analysis made under paragraph (l) of this section indicates that the level of any contaminant listed in § 141.11 exceeds the maximum contaminant level, the supplier of the water shall report to the State within 7 days and initiate three additional analyses at the same sampling point within one month.
                                <PRTPAGE P="509"/>
                            </P>
                            <P>(n) When the average of four analyses made pursuant to paragraph (m) of this section, rounded to the same number of significant figures as the maximum contaminant level for the substance in question, exceeds the maximum contaminant level, the supplier of water shall notify the State pursuant to § 141.31 and give notice to the public pursuant to subpart Q. Monitoring after public notification shall be at a frequency designated by the State and shall continue until the maximum contaminant level has not been exceeded in two successive samples or until a monitoring schedule as a condition to a variance, exemption or enforcement action shall become effective.</P>
                            <P>(o) The provisions of paragraphs (m) and (n) of this section notwithstanding, compliance with the maximum contaminant level for nitrate shall be determined on the basis of the mean of two analyses. When a level exceeding the maximum contaminant level for nitrate is found, a second analysis shall be initiated within 24 hours, and if the mean of the two analyses exceeds the maximum contaminant level, the supplier of water shall report his findings to the State pursuant to § 141.31 and shall notify the public pursuant to subpart Q.</P>
                            <P>(p) For the initial analyses required by paragraph (l) (1), (2) or (3) of this section, data for surface waters acquired within one year prior to the effective date and data for ground waters acquired within 3 years prior to the effective date of this part may be substituted at the discretion of the State.</P>
                            <P>(q) [Reserved]</P>
                            <CITA>[56 FR 3579, Jan. 30, 1991]</CITA>
                            <EDNOTE>
                                <HD SOURCE="HED">Editorial Note:</HD>
                                <P>
                                    For 
                                    <E T="04">Federal Register</E>
                                     citations affecting § 141.23, see the List of CFR Sections Affected, which appears in the Finding Aids section of the printed volume and at 
                                    <E T="03">www.govinfo.gov.</E>
                                </P>
                            </EDNOTE>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 141.24</SECTNO>
                            <SUBJECT>Organic chemicals, sampling and analytical requirements.</SUBJECT>
                            <P>(a)-(d) [Reserved]</P>
                            <P>(e) Analyses for the contaminants in this section shall be conducted using the methods listed in the following table, or the alternative methods listed in appendix A to subpart C of this part, or their equivalent as determined by EPA.</P>
                            <P>
                                (1) The following documents are incorporated by reference. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be inspected at EPA's Drinking Water Docket, 1301 Constitution Avenue, NW., EPA West, Room 3334, Washington, DC 20460 (Telephone: 202-566-2426); or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: 
                                <E T="03">http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.</E>
                                 Method 508A and 515.1 are in 
                                <E T="03">Methods for the Determination of Organic Compounds in Drinking Water,</E>
                                 EPA/600/4-88-039, December 1988, Revised, July 1991. Methods 547, 550 and 550.1 are in 
                                <E T="03">Methods for the Determination of Organic Compounds in Drinking Water—Supplement I,</E>
                                 EPA/600-4-90-020, July 1990. Methods 548.1, 549.1, 552.1 and 555 are in 
                                <E T="03">Methods for the Determination of Organic Compounds in Drinking Water—Supplement II,</E>
                                 EPA/600/R-92-129, August 1992. Methods 502.2, 504.1, 505, 506, 507, 508, 508.1, 515.2, 524.2 525.2, 531.1, 551.1 and 552.2 are in 
                                <E T="03">Methods for the Determination of Organic Compounds in Drinking Water--Supplement III,</E>
                                 EPA/600/R-95-131, August 1995. Method 1613 is titled “Tetra-through Octa-Chlorinated Dioxins and Furans by Isotope-Dilution HRGC/HRMS,” EPA/821-B-94-005, October 1994. These documents are available from the National Technical Information Service, NTIS PB91-231480, PB91-146027, PB92-207703, PB95-261616 and PB95-104774, U.S. Department of Commerce, 5285 Port Royal Road, Springfield, Virginia 22161. The toll free number is: 800-553-6847. Method 6651 shall be followed in accordance with 
                                <E T="03">Standard Methods for the Examination of Water and Wastewater,</E>
                                 18th edition (1992), 19th edition (1995), or 20th edition (1998), American Public Health Association (APHA); any of these three editions may be used. Method 6610 shall be followed in accordance with 
                                <E T="03">Standard Methods for the Examination of Water and Wastewater,</E>
                                 (18th Edition Supplement) (1994), or with the 19th edition (1995) or 20th edition (1998) of 
                                <E T="03">Standard Methods for the Examination of Water and Wastewater;</E>
                                 
                                <PRTPAGE P="510"/>
                                any of these publications may be used. The APHA documents are available from APHA, 1015 Fifteenth Street NW., Washington, DC 20005. Other required analytical test procedures germane to the conduct of these analyses are contained in 
                                <E T="03">Technical Notes on Drinking Water Methods,</E>
                                 EPA/600/R-94-173, October 1994, NTIS PB95-104766. EPA Methods 515.3 and 549.2 are available from U.S. Environmental Protection Agency, National Exposure Research Laboratory (NERL)-Cincinnati, 26 West Martin Luther King Drive, Cincinnati, OH 45268. ASTM Method D 5317-93, 98 (Reapproved 2003) is available in the 
                                <E T="03">Annual Book of ASTM Standards,</E>
                                 (1999), Vol. 11.02, ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428, any edition containing the cited version of the method may be used. EPA Method 515.4, “Determination of Chlorinated Acids in Drinking Water by Liquid-Liquid Microextraction, Derivatization and Fast Gas Chromatography with Electron Capture Detection,” Revision 1.0, April 2000, EPA/815/B-00/001 and EPA Method 552.3, “Determination of Haloacetic Acids and Dalapon in Drinking Water by Liquid-Liquid Microextraction, Derivatization, and Gas Chromatography with Electron Capture Detection,” Revision 1.0, July 2003, EPA 815-B-03-002, can be accessed and downloaded directly online at 
                                <E T="03">http://www.epa.gov/safewater/methods/sourcalt.html.</E>
                                 Syngenta Method AG-625, “Atrazine in Drinking Water by Immunoassay,” February 2001, is available from Syngenta Crop Protection, Inc., 410 Swing Road, P.O. Box 18300, Greensboro, NC 27419. Telephone: 336-632-6000. Method 531.2 “Measurement of N-methylcarbamoyloximes and N-methylcarbamates in Water by Direct Aqueous Injection HPLC with Postcolumn Derivatization,” Revision 1.0, September 2001, EPA 815-B-01-002, can be accessed and downloaded directly online at 
                                <E T="03">http://www.epa.gov/safewater/methods/sourcalt.html.</E>
                            </P>
                            <GPOTABLE COLS="5" OPTS="L2" CDEF="s55,r55,r20,xs30,xs30">
                                <BOXHD>
                                    <CHED H="1">Contaminant</CHED>
                                    <CHED H="1">EPA method</CHED>
                                    <CHED H="1">Standard methods</CHED>
                                    <CHED H="1">ASTM</CHED>
                                    <CHED H="1">Other</CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">1. Benzene</ENT>
                                    <ENT>502.2, 524.2</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">2. Carbon tetrachloride</ENT>
                                    <ENT>502.2, 524.2, 551.1</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">3. Chlorobenzene</ENT>
                                    <ENT>502.2, 524.2</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">4. 1,2-Dichlorobenzene</ENT>
                                    <ENT>502.2, 524.2</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">5. 1,4-Dichlorobenzene</ENT>
                                    <ENT>502.2, 524.2</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">6. 1,2-Dichloroethane</ENT>
                                    <ENT>502.2, 524.2</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">7. cis-Dichloroethylene</ENT>
                                    <ENT>502.2, 524.2</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">8. trans-Dichloroethylene</ENT>
                                    <ENT>502.2, 524.2</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">9. Dichloromethane</ENT>
                                    <ENT>502.2, 524.2</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">10. 1,2-Dichloropropane</ENT>
                                    <ENT>502.2, 524.2</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">11. Ethylbenzene</ENT>
                                    <ENT>502.2, 524.2</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">12. Styrene</ENT>
                                    <ENT>502.2, 524.2</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">13. Tetrachloroethylene</ENT>
                                    <ENT>502.2, 524.2, 551.1</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">14. 1,1,1-Trichloroethane</ENT>
                                    <ENT>502.2, 524.2, 551.1</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">15. Trichloroethylene</ENT>
                                    <ENT>502.2, 524.2, 551.1</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">16. Toluene</ENT>
                                    <ENT>502.2, 524.2</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">17. 1,2,4-Trichlorobenzene</ENT>
                                    <ENT>502.2, 524.2</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">18. 1,1-Dichloroethylene</ENT>
                                    <ENT>502.2, 524.2</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">19. 1,1,2-Trichloroethane</ENT>
                                    <ENT>502.2, 524.2, 551.1</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">20. Vinyl chloride</ENT>
                                    <ENT>502.2, 524.2</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">21. Xylenes (total)</ENT>
                                    <ENT>502.2, 524.2</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">22. 2,3,7,8-TCDD (dioxin)</ENT>
                                    <ENT>1613</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">
                                        23. 2,4-D 
                                        <SU>4</SU>
                                         (as acids, salts, and esters)
                                    </ENT>
                                    <ENT>515.2, 555, 515.1, 515.3, 515.4</ENT>
                                    <ENT/>
                                    <ENT>D5317-93, 98 (Reapproved 2003)</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">
                                        24. 2,4,5-TP 
                                        <SU>4</SU>
                                         (Silvex)
                                    </ENT>
                                    <ENT>515.2, 555, 515.1, 515.3, 515.4</ENT>
                                    <ENT/>
                                    <ENT>D5317-93, 98 (Reapproved 2003)</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">
                                        25. Alachlor 
                                        <SU>2</SU>
                                    </ENT>
                                    <ENT>507, 525.2, 508.1, 505, 551.1</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">
                                        26. Atrazine 
                                        <SU>2</SU>
                                    </ENT>
                                    <ENT>507, 525.2, 508.1, 505, 551.1</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        Syngenta 
                                        <SU>5</SU>
                                         AG-625
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">27. Benzo(a)pyrene</ENT>
                                    <ENT>525.2, 550, 550.1</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">28. Carbofuran</ENT>
                                    <ENT>531.1, 531.2</ENT>
                                    <ENT>6610</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">29. Chlordane</ENT>
                                    <ENT>508, 525.2, 508.1, 505</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">30. Dalapon</ENT>
                                    <ENT>552.1 515.1, 552.2, 515.3, 515.4, 552.3</ENT>
                                </ROW>
                                <ROW>
                                    <PRTPAGE P="511"/>
                                    <ENT I="01">31. Di(2-ethylhexyl)adipate</ENT>
                                    <ENT>506, 525.2</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">32. Di(2-ethylhexyl)phthalate</ENT>
                                    <ENT>506, 525.2</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">33. Dibromochloropropane (DBCP)</ENT>
                                    <ENT>504.1, 551.1</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">
                                        34. Dinoseb 
                                        <SU>4</SU>
                                    </ENT>
                                    <ENT>515.2, 555, 515.1, 515.3, 515.4</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">35. Diquat</ENT>
                                    <ENT>549.2</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">36. Endothall</ENT>
                                    <ENT>548.1</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">37. Endrin</ENT>
                                    <ENT>508, 525.2, 508.1, 505, 551.1</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">38. Ethylene dibromide (EDB)</ENT>
                                    <ENT>504.1, 551.1</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">39. Glyphosate</ENT>
                                    <ENT>547</ENT>
                                    <ENT>6651</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">40. Heptachlor</ENT>
                                    <ENT>508, 525.2, 508.1, 505, 551.1</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">41. Heptachlor Epoxide</ENT>
                                    <ENT>508, 525.2, 508.1, 505, 551.1</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">42. Hexachlorobenzene</ENT>
                                    <ENT>508, 525.2, 508.1, 505, 551.1</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">43. Hexachlorocyclopentadiene</ENT>
                                    <ENT>508, 525.2, 508.1, 505, 551.1</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">44. Lindane</ENT>
                                    <ENT>508, 525.2, 508.1, 505, 551.1</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">45. Methoxychlor</ENT>
                                    <ENT>508, 525.2, 508.1, 505, 551.1</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">46. Oxamyl</ENT>
                                    <ENT>531.1, 531.2</ENT>
                                    <ENT>6610</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">
                                        47. PCBs 
                                        <SU>3</SU>
                                         (as decachlorobiphenyl)
                                    </ENT>
                                    <ENT>508A</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">
                                        48. PCBs 
                                        <SU>3</SU>
                                         (as Aroclors)
                                    </ENT>
                                    <ENT>508.1, 508, 525.2, 505</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">49. Pentachlorophenol</ENT>
                                    <ENT>515.2, 525.2, 555, 515.1, 515.3, 515.4</ENT>
                                    <ENT/>
                                    <ENT>D5317-93, 98 (Reapproved 2003)</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">
                                        50. Picloram 
                                        <SU>4</SU>
                                    </ENT>
                                    <ENT>515.2, 555, 515.1, 515.3, 515.4</ENT>
                                    <ENT/>
                                    <ENT>D5317-93, 98 (Reapproved 2003)</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">
                                        51. Simazine 
                                        <SU>2</SU>
                                    </ENT>
                                    <ENT>507, 525.2, 508.1, 505, 551.1</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">52. Toxaphene</ENT>
                                    <ENT>508, 508.1, 525.2, 505</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">53. Total Trihalomethanes</ENT>
                                    <ENT>502.2, 524.2, 551.1</ENT>
                                </ROW>
                                <TNOTE>
                                    <SU>1</SU>
                                     [Reserved]
                                </TNOTE>
                                <TNOTE>
                                    <SU>2</SU>
                                     Substitution of the detector specified in Method 505, 507, 508 or 508.1 for the purpose of achieving lower detection limits is allowed as follows. Either an electron capture or nitrogen phosphorous detector may be used provided all regulatory requirements and quality control criteria are met.
                                </TNOTE>
                                <TNOTE>
                                    <SU>3</SU>
                                     PCBs are qualitatively identified as Aroclors and measured for compliance purposes as decachlorobiphenyl. Users of Method 505 may have more difficulty in achieving the required detection limits than users of Methods 508.1, 525.2 or 508.
                                </TNOTE>
                                <TNOTE>
                                    <SU>4</SU>
                                     Accurate determination of the chlorinated esters requires hydrolysis of the sample as described in EPA Methods 515.1, 515.2, 515.3, 515.4 and 555 and ASTM Method D5317-93.
                                </TNOTE>
                                <TNOTE>
                                    <SU>5</SU>
                                     This method may not be used for the analysis of atrazine in any system where chlorine dioxide is used for drinking water treatment. In samples from all other systems, any result for atrazine generated by Method AG-625 that is greater than one-half the maximum contaminant level (MCL) (in other words, greater than 0.0015mg/L or 1.5 μg/L) must be confirmed using another approved method for this contaminant and should use additional volume of the original sample collected for compliance monitoring. In instances where a result from Method AG-625 triggers such confirmatory testing, the confirmatory result is to be used to determine compliance.
                                </TNOTE>
                            </GPOTABLE>
                            <P>(2) [Reserved]</P>
                            <P>(f) Beginning with the initial compliance period, analysis of the contaminants listed in § 141.61(a) (1) through (21) for the purpose of determining compliance with the maximum contaminant level shall be conducted as follows:</P>
                            <P>(1) Groundwater systems shall take a minimum of one sample at every entry point to the distribution system which is representative of each well after treatment (hereafter called a sampling point). Each sample must be taken at the same sampling point unless conditions make another sampling point more representative of each source, treatment plant, or within the distribution system.</P>
                            <P>(2) Surface water systems (or combined surface/ground) shall take a minimum of one sample at points in the distribution system that are representative of each source or at each entry point to the distribution system after treatment (hereafter called a sampling point). Each sample must be taken at the same sampling point unless conditions make another sampling point more representative of each source, treatment plant, or within the distribution system.</P>
                            <P>
                                (3) If the system draws water from more than one source and the sources are combined before distribution, the system must sample at an entry point to the distribution system during periods of normal operating conditions 
                                <PRTPAGE P="512"/>
                                (
                                <E T="03">i.e.</E>
                                , when water representative of all sources is being used).
                            </P>
                            <P>(4) Each community and non-transient non-community water system shall take four consecutive quarterly samples for each contaminant listed in § 141.61(a) (2) through (21) during each compliance period, beginning in the initial compliance period.</P>
                            <P>(5) If the initial monitoring for contaminants listed in § 141.61(a) (1) through (8) and the monitoring for the contaminants listed in § 141.61(a) (9) through (21) as allowed in paragraph (f)(18) has been completed by December 31, 1992, and the system did not detect any contaminant listed in § 141.61(a) (1) through (21), then each ground and surface water system shall take one sample annually beginning with the initial compliance period.</P>
                            <P>(6) After a minimum of three years of annual sampling, the State may allow groundwater systems with no previous detection of any contaiminant listed in § 141.61(a) to take one sample during each compliance period.</P>
                            <P>(7) Each community and non-transient non-community ground water system which does not detect a contaminant listed in § 141.61(a) (1) through (21) may apply to the State for a waiver from the requirements of paragraphs (f)(5) and (f)(6) of this section after completing the initial monitoring. (For purposes of this section, detection is defined as ≥0.0005 mg/l.) A waiver shall be effective for no more than six years (two compliance periods). States may also issue waivers to small systems for the initial round of monitoring for 1,2,4-trichlorobenzene.</P>
                            <P>(8) A State may grant a waiver after evaluating the following factor(s):</P>
                            <P>(i) Knowledge of previous use (including transport, storage, or disposal) of the contaminant within the watershed or zone of influence of the system. If a determination by the State reveals no previous use of the contaminant within the watershed or zone of influence, a waiver may be granted.</P>
                            <P>(ii) If previous use of the contaminant is unknown or it has been used previously, then the following factors shall be used to determine whether a waiver is granted.</P>
                            <P>(A) Previous analytical results.</P>
                            <P>(B) The proximity of the system to a potential point or non-point source of contamination. Point sources include spills and leaks of chemicals at or near a water treatment facility or at manufacturing, distribution, or storage facilities, or from hazardous and municipal waste landfills and other waste handling or treatment facilities.</P>
                            <P>(C) The environmental persistence and transport of the contaminants.</P>
                            <P>(D) The number of persons served by the public water system and the proximity of a smaller system to a larger system.</P>
                            <P>(E) How well the water source is protected against contamination, such as whether it is a surface or groundwater system. Groundwater systems must consider factors such as depth of the well, the type of soil, and wellhead protection. Surface water systems must consider watershed protection.</P>
                            <P>
                                (9) As a condition of the waiver a groundwater system must take one sample at each sampling point during the time the waiver is effective (
                                <E T="03">i.e.</E>
                                , one sample during two compliance periods or six years) and update its vulnerability assessment considering the factors listed in paragraph (f)(8) of this section. Based on this vulnerability assessment the State must reconfirm that the system is non-vulnerable. If the State does not make this reconfirmation within three years of the initial determination, then the waiver is invalidated and the system is required to sample annually as specified in paragraph (5) of this section.
                            </P>
                            <P>
                                (10) Each community and non-transient non-community surface water system which does not detect a contaminant listed in § 141.61(a) (1) through (21) may apply to the State for a waiver from the requirements of (f)(5) of this section after completing the initial monitoring. Composite samples from a maximum of five sampling points are allowed, provided that the detection limit of the method used for analysis is less than one-fifth of the MCL. Systems meeting this criterion must be determined by the State to be non-vulnerable based on a vulnerability assessment during each compliance period. Each system receiving a waiver shall sample at the frequency specified by the State (if any).
                                <PRTPAGE P="513"/>
                            </P>
                            <P>(11) If a contaminant listed in § 141.61(a) (2) through (21) is detected at a level exceeding 0.0005 mg/l in any sample, then:</P>
                            <P>(i) The system must monitor quarterly at each sampling point which resulted in a detection.</P>
                            <P>(ii) The State may decrease the quarterly monitoring requirement speci fied in paragraph (f)(11)(i) of this section provided it has determined that the system is reliably and consistently below the maximum contaminant level. In no case shall the State make this determination unless a groundwater system takes a minimum of two quarterly samples and a surface water system takes a minimum of four quarterly samples.</P>
                            <P>(iii) If the State determines that the system is reliably and consistently below the MCL, the State may allow the system to monitor annually. Systems which monitor annually must monitor during the quarter(s) which previously yielded the highest analytical result.</P>
                            <P>(iv) Systems which have three consecutive annual samples with no detection of a contaminant may apply to the State for a waiver as specified in paragraph (f)(7) of this section.</P>
                            <P>(v) Groundwater systems which have detected one or more of the following two-carbon organic compounds: trichloroethylene, tetrachloroethylene, 1,2-dichloroethane, 1,1,1-trichloroethane, cis-1,2-dichloroethylene, trans-1,2-dichloroethylene, or 1,1-dichloroethylene shall monitor quarterly for vinyl chloride. A vinyl chloride sample shall be taken at each sampling point at which one or more of the two-carbon organic compounds was detected. If the results of the first analysis do not detect vinyl chloride, the State may reduce the quarterly monitoring frequency of vinyl chloride monitoring to one sample during each compliance period. Surface water systems are required to monitor for vinyl chloride as specified by the State.</P>
                            <P>(12) Systems which violate the requirements of § 141.61(a) (1) through (21), as determined by paragraph (f)(15) of this section, must monitor quarterly. After a minimum of four consecutive quarterly samples which show the system is in compliance as specified in paragraph (f)(15) of this section the system and the State determines that the system is reliably and consistently below the maximum contaminant level, the system may monitor at the frequency and times specified in paragraph (f)(11)(iii) of this section.</P>
                            <P>(13) The State may require a confirmation sample for positive or negative results. If a confirmation sample is required by the State, the result must be averaged with the first sampling result and the average is used for the compliance determination as specified by paragraph (f)(15). States have discretion to delete results of obvious sampling errors from this calculation.</P>
                            <P>(14) The State may reduce the total number of samples a system must analyze by allowing the use of compositing. Composite samples from a maximum of five sampling points are allowed, provided that the detection limit of the method used for analysis is less than one-fifth of the MCL. Compositing of samples must be done in the laboratory and analyzed within 14 days of sample collection.</P>
                            <P>(i) If the concentration in the composite sample is greater than or equal to 0.0005 mg/l for any contaminant listed in § 141.61(a), then a follow-up sample must be taken within 14 days at each sampling point included in the composite, and be analyzed for that contaminant.</P>
                            <P>(ii) If duplicates of the original sample taken from each sampling point used in the composite sample are available, the system may use these instead of resampling. The duplicates must be analyzed and the results reported to the State within 14 days after completing analysis of the composite sample, provided the holding time of the sample is not exceeded.</P>
                            <P>(iii) If the population served by the system is &gt;3,300 persons, then compositing may only be permitted by the State at sampling points within a single system. In systems serving ≤3,300 persons, the State may permit compositing among different systems provided the 5-sample limit is maintained.</P>
                            <P>
                                (iv) Compositing samples prior to GC analysis.
                                <PRTPAGE P="514"/>
                            </P>
                            <P>(A) Add 5 ml or equal larger amounts of each sample (up to 5 samples are allowed) to a 25 ml glass syringe. Special precautions must be made to maintain zero headspace in the syringe.</P>
                            <P>(B) The samples must be cooled at 4 °C during this step to minimize volatilization losses.</P>
                            <P>(C) Mix well and draw out a 5-ml aliquot for analysis.</P>
                            <P>(D) Follow sample introduction, purging, and desorption steps described in the method.</P>
                            <P>(E) If less than five samples are used for compositing, a proportionately small syringe may be used.</P>
                            <P>(v) Compositing samples prior to GC/MS analysis.</P>
                            <P>(A) Inject 5-ml or equal larger amounts of each aqueous sample (up to 5 samples are allowed) into a 25-ml purging device using the sample introduction technique described in the method.</P>
                            <P>(B) The total volume of the sample in the purging device must be 25 ml.</P>
                            <P>(C) Purge and desorb as described in the method.</P>
                            <P>(15) Compliance with § 141.61(a) (1) through (21) shall be determined based on the analytical results obtained at each sampling point. If one sampling point is in violation of an MCL, the system is in violation of the MCL.</P>
                            <P>(i) For systems monitoring more than once per year, compliance with the MCL is determined by a running annual average at each sampling point.</P>
                            <P>(ii) Systems monitoring annually or less frequently whose sample result exceeds the MCL must begin quarterly sampling. The system will not be considered in violation of the MCL until it has completed one year of quarterly sampling.</P>
                            <P>(iii) If any sample result will cause the running annual average to exceed the MCL at any sampling point, the system is out of compliance with the MCL immediately.</P>
                            <P>(iv) If a system fails to collect the required number of samples, compliance will be based on the total number of samples collected.</P>
                            <P>(v) If a sample result is less than the detection limit, zero will be used to calculate the annual average.</P>
                            <P>(16) [Reserved]</P>
                            <P>(17) Analysis under this section shall only be conducted by laboratories that are certified by EPA or the State according to the following conditions (laboratories may conduct sample analysis under provisional certification until January 1, 1996):</P>
                            <P>(i) To receive certification to conduct analyses for the contaminants in § 141.61(a) (2) through (21) the laboratory must:</P>
                            <P>(A) Analyze Performance Evaluation (PE) samples provided by EPA, the State, or by a third party (with the approval of the State or EPA) at least once a year by each method for which the laboratory desires certification.</P>
                            <P>(B) Achieve the quantitative acceptance limits under paragraphs (f)(17)(i)(C) and (D) of this section for at least 80 percent of the regulated organic contaminants included in the PE sample.</P>
                            <P>(C) Achieve quantitative results on the analyses performed under paragraph (f)(17)(i)(A) of this section that are within ±20% of the actual amount of the substances in the Performance Evaluation sample when the actual amount is greater than or equal to 0.010 mg/l.</P>
                            <P>(D) Achieve quantitative results on the analyses performed under paragraph (f)(17)(i)(A) of this section that are within ±40 percent of the actual amount of the substances in the Performance Evaluation sample when the actual amount is less than 0.010 mg/l.</P>
                            <P>(E) Achieve a method detection limit of 0.0005 mg/l, according to the procedures in appendix B of part 136.</P>
                            <P>(ii) To receive certification to conduct analyses for vinyl chloride, the laboratory must:</P>
                            <P>(A) Analyze Performance Evaluation (PE) samples provided by EPA, the State, or by a third party (with the approval of the State or EPA) at least once a year by each method for which the laboratory desires certification.</P>
                            <P>(B) Achieve quantitative results on the analyses performed under paragraph (f)(17)(ii)(A) of this section that are within ±40 percent of the actual amount of vinyl chloride in the Performance Evaluation sample.</P>
                            <P>
                                (C) Achieve a method detection limit of 0.0005 mg/l, according to the procedures in appendix B of part 136.
                                <PRTPAGE P="515"/>
                            </P>
                            <P>(D) Obtain certification for the contaminants listed in § 141.61(a)(2) through (21).</P>
                            <P>
                                (18) States may allow the use of monitoring data collected after January 1, 1988, required under section 1445 of the Act for purposes of initial monitoring compliance. If the data are generally consistent with the other requirements of this section, the State may use these data (
                                <E T="03">i.e.</E>
                                , a single sample rather than four quarterly samples) to satisfy the initial monitoring requirement of paragraph (f)(4) of this section. Systems which use grandfathered samples and did not detect any contaminant listed § 141.61(a)(2) through (21) shall begin monitoring annually in accordance with paragraph (f)(5) of this section beginning with the initial compliance period.
                            </P>
                            <P>(19) States may increase required monitoring where necessary to detect variations within the system.</P>
                            <P>(20) Each certified laboratory must determine the method detection limit (MDL), as defined in appendix B to part 136, at which it is capable of detecting VOCs. The acceptable MDL is 0.0005 mg/l. This concentration is the detection concentration for purposes of this section.</P>
                            <P>(21) Each public water system shall monitor at the time designated by the State within each compliance period.</P>
                            <P>(22) All new systems or systems that use a new source of water that begin operation after January 22, 2004 must demonstrate compliance with the MCL within a period of time specified by the State. The system must also comply with the initial sampling frequencies specified by the State to ensure a system can demonstrate compliance with the MCL. Routine and increased monitoring frequencies shall be conducted in accordance with the requirements in this section.</P>
                            <P>(g) [Reserved]</P>
                            <P>(h) Analysis of the contaminants listed in § 141.61(c) for the purposes of determining compliance with the maximum contaminant level shall be conducted as follows, with the exceptions that this paragraph (h) does not apply to regulated PFAS (see § 141.902) and no monitoring is required for aldicarb, aldicarb sulfoxide, or aldicarb sulfone:</P>
                            <P>(1) Groundwater systems shall take a minimum of one sample at every entry point to the distribution system which is representative of each well after treatment (hereafter called a sampling point). Each sample must be taken at the same sampling point unless conditions make another sampling point more representative of each source or treatment plant.</P>
                            <P>(2) Surface water systems shall take a minimum of one sample at points in the distribution system that are representative of each source or at each entry point to the distribution system after treatment (hereafter called a sampling point). Each sample must be taken at the same sampling point unless conditions make another sampling point more representative of each source or treatment plant.</P>
                            <NOTE>
                                <HD SOURCE="HED">Note:</HD>
                                <P>For purposes of this paragraph, surface water systems include systems with a combination of surface and ground sources.</P>
                            </NOTE>
                            <P>
                                (3) If the system draws water from more than one source and the sources are combined before distribution, the system must sample at an entry point to the distribution system during periods of normal operating conditions (
                                <E T="03">i.e.</E>
                                , when water representative of all sources is being used).
                            </P>
                            <P>
                                (4) 
                                <E T="03">Monitoring frequency:</E>
                                 (i) Each community and non-transient non-community water system shall take four consecutive quarterly samples for each contaminant listed in § 141.61(c) during each compliance period beginning with the initial compliance period.
                            </P>
                            <P>(ii) Systems serving more than 3,300 persons which do not detect a contaminant in the initial compliance period may reduce the sampling frequency to a minimum of two quarterly samples in one year during each repeat compliance period.</P>
                            <P>(iii) Systems serving less than or equal to 3,300 persons which do not detect a contaminant in the initial compliance period may reduce the sampling frequency to a minimum of one sample during each repeat compliance period.</P>
                            <P>
                                (5) Each community and non-transient water system may apply to the 
                                <PRTPAGE P="516"/>
                                State for a waiver from the requirement of paragraph (h)(4) of this section. A system must reapply for a waiver for each compliance period.
                            </P>
                            <P>(6) A State may grant a waiver after evaluating the following factor(s): Knowledge of previous use (including transport, storage, or disposal) of the contaminant within the watershed or zone of influence of the system. If a determination by the State reveals no previous use of the contaminant within the watershed or zone of influence, a waiver may be granted. If previous use of the contaminant is unknown or it has been used previously, then the following factors shall be used to determine whether a waiver is granted.</P>
                            <P>(i) Previous analytical results.</P>
                            <P>(ii) The proximity of the system to a potential point or non-point source of contamination. Point sources include spills and leaks of chemicals at or near a water treatment facility or at manufacturing, distribution, or storage facilities, or from hazardous and municipal waste landfills and other waste handling or treatment facilities. Non-point sources include the use of pesticides to control insect and weed pests on agricultural areas, forest lands, home and gardens, and other land application uses.</P>
                            <P>(iii) The environmental persistence and transport of the pesticide or PCBs.</P>
                            <P>(iv) How well the water source is protected against contamination due to such factors as depth of the well and the type of soil and the integrity of the well casing.</P>
                            <P>(v) Elevated nitrate levels at the water supply source.</P>
                            <P>
                                (vi) Use of PCBs in equipment used in the production, storage, or distribution of water (
                                <E T="03">i.e.</E>
                                , PCBs used in pumps, transformers, etc.).
                            </P>
                            <P>(7) If an organic contaminant listed in § 141.61(c) is detected (as defined by paragraph (h)(18) of this section) in any sample, then:</P>
                            <P>(i) Each system must monitor quarterly at each sampling point which resulted in a detection.</P>
                            <P>(ii) The State may decrease the quarterly monitoring requirement specified in paragraph (h)(7)(i) of this section provided it has determined that the system is reliably and consistently below the maximum contaminant level. In no case shall the State make this determination unless a groundwater system takes a minimum of two quarterly samples and a surface water system takes a minimum of four quarterly samples.</P>
                            <P>(iii) After the State determines the system is reliably and consistently below the maximum contaminant level the State may allow the system to monitor annually. Systems which monitor annually must monitor during the quarter that previously yielded the highest analytical result.</P>
                            <P>(iv) Systems which have 3 consecutive annual samples with no detection of a contaminant may apply to the State for a waiver as specified in paragraph (h)(6) of this section.</P>
                            <P>(v) If the monitoring results in detection of one or more of certain related contaminants (heptachlor and heptachlor epoxide), then subsequent monitoring shall analyze for all related contaminants.</P>
                            <P>(8) Systems which violate the requirements of § 141.61(c) as determined by paragraph (h)(11) of this section must monitor quarterly. After a minimum of four quarterly samples show the system is in compliance and the State determines the system is reliably and consistently below the MCL, as specified in paragraph (h)(11) of this section, the system shall monitor at the frequency specified in paragraph (h)(7)(iii) of this section.</P>
                            <P>(9) The State may require a confirmation sample for positive or negative results. If a confirmation sample is required by the State, the result must be averaged with the first sampling result and the average used for the compliance determination as specified by paragraph (h)(11) of this section. States have discretion to delete results of obvious sampling errors from this calculation.</P>
                            <P>
                                (10) The State may reduce the total number of samples a system must analyze by allowing the use of compositing. Composite samples from a maximum of five sampling points are allowed, provided that the detection limit of the method used for analysis is less than one-fifth of the MCL. Compositing of samples must be done in the laboratory and analyzed within 14 days of sample collection.
                                <PRTPAGE P="517"/>
                            </P>
                            <P>(i) If the concentration in the composite sample detects one or more contaminants listed in § 141.61(c), then a follow-up sample must be taken within 14 days at each sampling point included in the composite, and be analyzed for that contaminant.</P>
                            <P>(ii) If duplicates of the original sample taken from each sampling point used in the composite sample are available, the system may use these instead of resampling. The duplicates must be analyzed and the results reported to the State within 14 days after completion of the composite analysis or before the holding time for the initial sample is exceeded whichever is sooner.</P>
                            <P>(iii) If the population served by the system is &gt;3,300 persons, then compositing may only be permitted by the State at sampling points within a single system. In systems serving ≤3,300 persons, the State may permit compositing among different systems provided the 5-sample limit is maintained.</P>
                            <P>(11) Compliance with § 141.61(c) shall be determined based on the analytical results obtained at each sampling point. If one sampling point is in violation of an MCL, the system is in violation of the MCL.</P>
                            <P>(i) For systems monitoring more than once per year, compliance with the MCL is determined by a running annual average at each sampling point.</P>
                            <P>(ii) Systems monitoring annually or less frequently whose sample result exceeds the regulatory detection level as defined by paragraph (h)(18) of this section must begin quarterly sampling. The system will not be considered in violation of the MCL until it has completed one year of quarterly sampling.</P>
                            <P>(iii) If any sample result will cause the running annual average to exceed the MCL at any sampling point, the system is out of compliance with the MCL immediately.</P>
                            <P>(iv) If a system fails to collect the required number of samples, compliance will be based on the total number of samples collected.</P>
                            <P>(v) If a sample result is less than the detection limit, zero will be used to calculate the annual average.</P>
                            <P>(12) [Reserved]</P>
                            <P>(13) Analysis for PCBs shall be conducted as follows using the methods in paragraph (e) of this section:</P>
                            <P>(i) Each system which monitors for PCBs shall analyze each sample using either Method 508.1, 525.2, 508 or 505. Users of Method 505 may have more difficulty in achieving the required Aroclor detection limits than users of Methods 508.1, 525.2 or 508.</P>
                            <P>(ii) If PCBs (as one of seven Aroclors) are detected (as designated in this paragraph) in any sample analyzed using Method 505 or 508, the system shall reanalyze the sample using Method 508A to quantitate PCBs (as decachlorobiphenyl).</P>
                            <GPOTABLE COLS="2" OPTS="L2" CDEF="s10,6.9">
                                <BOXHD>
                                    <CHED H="1">Aroclor</CHED>
                                    <CHED H="1">Detection limit (mg/l)</CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">1016</ENT>
                                    <ENT>0.00008</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">1221</ENT>
                                    <ENT>0.02</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">1232</ENT>
                                    <ENT>0.0005</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">1242</ENT>
                                    <ENT>0.0003</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">1248</ENT>
                                    <ENT>0.0001</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">1254</ENT>
                                    <ENT>0.0001</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">1260</ENT>
                                    <ENT>0.0002</ENT>
                                </ROW>
                            </GPOTABLE>
                            <P>(iii) Compliance with the PCB MCL shall be determined based upon the quantitative results of analyses using Method 508A.</P>
                            <P>(14) If monitoring data collected after January 1, 1990, are generally consistent with the requirements of § 141.24(h), then the State may allow systems to use that data to satisfy the monitoring requirement for the initial compliance period beginning January 1, 1993.</P>
                            <P>(15) The State may increase the required monitoring frequency, where necessary, to detect variations within the system (e.g., fluctuations in concentration due to seasonal use, changes in water source).</P>
                            <P>(16) The State has the authority to determine compliance or initiate enforcement action based upon analytical results and other information compiled by their sanctioned representatives and agencies.</P>
                            <P>(17) Each public water system shall monitor at the time designated by the State within each compliance period.</P>
                            <P>
                                (18) Detection as used in this paragraph shall be defined as greater than or equal to the following concentrations for each contaminant.
                                <PRTPAGE P="518"/>
                            </P>
                            <GPOTABLE COLS="2" OPTS="L2" CDEF="s25,1.9">
                                <BOXHD>
                                    <CHED H="1">Contaminant</CHED>
                                    <CHED H="1">Detection limit (mg/l)</CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">Alachlor</ENT>
                                    <ENT>.0002</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Aldicarb</ENT>
                                    <ENT>.0005</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Aldicarb sulfoxide</ENT>
                                    <ENT>.0005</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Aldicarb sulfone</ENT>
                                    <ENT>.0008</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Atrazine</ENT>
                                    <ENT>.0001</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Benzo[a]pyrene</ENT>
                                    <ENT>.00002</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Carbofuran</ENT>
                                    <ENT>.0009</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Chlordane</ENT>
                                    <ENT>.0002</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Dalapon</ENT>
                                    <ENT>.001</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">1,2-Dibromo-3-chloropropane (DBCP)</ENT>
                                    <ENT>.00002</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Di (2-ethylhexyl) adipate</ENT>
                                    <ENT>.0006</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Di (2-ethylhexyl) phthalate</ENT>
                                    <ENT>.0006</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Dinoseb</ENT>
                                    <ENT>.0002</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Diquat</ENT>
                                    <ENT>.0004</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">2,4-D</ENT>
                                    <ENT>.0001</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Endothall</ENT>
                                    <ENT>.009</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Endrin</ENT>
                                    <ENT>.00001</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Ethylene dibromide (EDB)</ENT>
                                    <ENT>.00001</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Glyphosate</ENT>
                                    <ENT>.006</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Heptachlor</ENT>
                                    <ENT>.00004</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Heptachlor epoxide</ENT>
                                    <ENT>.00002</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Hexachlorobenzene</ENT>
                                    <ENT>.0001</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Hexachlorocyclopentadiene</ENT>
                                    <ENT>.0001</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Lindane</ENT>
                                    <ENT>.00002</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Methoxychlor</ENT>
                                    <ENT>.0001</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Oxamyl</ENT>
                                    <ENT>.002</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Picloram</ENT>
                                    <ENT>.0001</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Polychlorinated biphenyls (PCBs) (as decachlorobiphenyl)</ENT>
                                    <ENT>.0001</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Pentachlorophenol</ENT>
                                    <ENT>.00004</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Simazine</ENT>
                                    <ENT>.00007</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Toxaphene</ENT>
                                    <ENT>.001</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">2,3,7,8-TCDD (Dioxin)</ENT>
                                    <ENT>.000000005</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">2,4,5-TP (Silvex)</ENT>
                                    <ENT>.0002</ENT>
                                </ROW>
                            </GPOTABLE>
                            <P>(19) Anaylsis under this section shall only be conducted by laboratories that have received certification by EPA or the State and have met the following conditions:</P>
                            <P>(i) To receive certification to conduct analyses for the contaminants in § 141.61(c) the laboratory must:</P>
                            <P>(A) Analyze Performance Evaluation (PE) samples provided by EPA, the State, or by a third party (with the approval of the State or EPA) at least once a year by each method for which the laboratory desires certification.</P>
                            <P>(B) For each contaminant that has been included in the PE sample achieve quantitative results on the analyses that are within the following acceptance limits:</P>
                            <GPOTABLE COLS="2" OPTS="L2" CDEF="s25,r25">
                                <BOXHD>
                                    <CHED H="1">Contaminant</CHED>
                                    <CHED H="1">Acceptance limits (percent)</CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">DBCP</ENT>
                                    <ENT>±40</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">EDB</ENT>
                                    <ENT>±40.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Alachlor</ENT>
                                    <ENT>±45.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Atrazine</ENT>
                                    <ENT>±45.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Benzo[a]pyrene</ENT>
                                    <ENT>2 standard deviations.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Carbofuran</ENT>
                                    <ENT>±45.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Chlordane</ENT>
                                    <ENT>±45.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Dalapon</ENT>
                                    <ENT>2 standard deviations.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Di(2-ethylhexyl)adipate</ENT>
                                    <ENT>2 standard deviations.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Di(2-ethylhexyl)phthalate</ENT>
                                    <ENT>2 standard deviations.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Dinoseb</ENT>
                                    <ENT>2 standard deviations.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Diquat</ENT>
                                    <ENT>2 standard deviations.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Endothall</ENT>
                                    <ENT>2 standard deviations.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Endrin</ENT>
                                    <ENT>±30.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Glyphosate</ENT>
                                    <ENT>2 standard deviations.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Heptachlor</ENT>
                                    <ENT>±45.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Heptachlor epoxide</ENT>
                                    <ENT>±45.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Hexachlorobenzene</ENT>
                                    <ENT>2 standard deviations.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01" O="xl">Hexachloro- cyclopentadiene</ENT>
                                    <ENT>2 standard deviations.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Lindane</ENT>
                                    <ENT>±45.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Methoxychlor</ENT>
                                    <ENT>±45.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Oxamyl</ENT>
                                    <ENT>2 standard deviations.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01" O="xl">PCBs (as Decachlorobiphenyl)</ENT>
                                    <ENT>0-200.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Picloram</ENT>
                                    <ENT>2 standard deviations.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Simazine</ENT>
                                    <ENT>2 standard deviations.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Toxaphene</ENT>
                                    <ENT>±45.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Aldicarb</ENT>
                                    <ENT>2 standard deviations.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Aldicarb sulfoxide</ENT>
                                    <ENT>2 standard deviations.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Aldicarb sulfone</ENT>
                                    <ENT>2 standard deviations.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Pentachlorophenol</ENT>
                                    <ENT>±50.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">2,3,7,8-TCDD (Dioxin)</ENT>
                                    <ENT>2 standard deviations.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">2,4-D</ENT>
                                    <ENT>±50.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">2,4,5-TP (Silvex)</ENT>
                                    <ENT>±50.</ENT>
                                </ROW>
                            </GPOTABLE>
                            <P>(ii) [Reserved]</P>
                            <P>(20) All new systems or systems that use a new source of water that begin operation after January 22, 2004 must demonstrate compliance with the MCL within a period of time specified by the State. The system must also comply with the initial sampling frequencies specified by the State to ensure a system can demonstrate compliance with the MCL. Routine and increased monitoring frequencies shall be conducted in accordance with the requirements in this section.</P>
                            <APPRO>(Approved by the Office of Management and Budget under control number 2040-0090)</APPRO>
                            <CITA>[40 FR 59570, Dec. 24, 1975]</CITA>
                            <EDNOTE>
                                <HD SOURCE="HED">Editorial Note:</HD>
                                <P>
                                    For 
                                    <E T="04">Federal Register</E>
                                     citations affecting § 141.24, see the List of CFR Sections Affected, which appears in the Finding Aids section of the printed volume and at 
                                    <E T="03">www.govinfo.gov.</E>
                                </P>
                            </EDNOTE>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 141.25</SECTNO>
                            <SUBJECT>Analytical methods for radioactivity.</SUBJECT>
                            <P>
                                (a) Analysis for the following contaminants shall be conducted to determine compliance with § 141.66 (radioactivity) in accordance with the methods in the following table, or the alternative methods listed in appendix A to subpart C this part, or their equivalent determined by EPA in accordance with § 141.27.
                                <PRTPAGE P="519"/>
                            </P>
                            <GPOTABLE COLS="11" OPTS="L2,p6,7/8" CDEF="s48,r30,8,xs20,xs24,xs30,xs44,xs32,xs40,xs32,xs24">
                                <BOXHD>
                                    <CHED H="1">Contaminant</CHED>
                                    <CHED H="1">Methodology</CHED>
                                    <CHED H="1">Reference (Method of Page Number)</CHED>
                                    <CHED H="2">
                                        EPA 
                                        <SU>1</SU>
                                    </CHED>
                                    <CHED H="2">
                                        EPA 
                                        <SU>2</SU>
                                    </CHED>
                                    <CHED H="2">
                                        EPA 
                                        <SU>3</SU>
                                    </CHED>
                                    <CHED H="2">
                                        EPA 
                                        <SU>4</SU>
                                    </CHED>
                                    <CHED H="2">
                                        SM 
                                        <SU>5</SU>
                                    </CHED>
                                    <CHED H="2">
                                        ASTM 
                                        <SU>6</SU>
                                    </CHED>
                                    <CHED H="2">
                                        USGS 
                                        <SU>7</SU>
                                    </CHED>
                                    <CHED H="2">
                                        DOE 
                                        <SU>8</SU>
                                    </CHED>
                                    <CHED H="2">Other</CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="22">Naturally Occurring:</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="03">
                                        Gross alpha 
                                        <SU>11</SU>
                                         and beta
                                    </ENT>
                                    <ENT>Evaporation</ENT>
                                    <ENT>900.0</ENT>
                                    <ENT>p. 1</ENT>
                                    <ENT>00-01</ENT>
                                    <ENT>p. 1</ENT>
                                    <ENT>302, 7110 B, 7110 B-00</ENT>
                                    <ENT/>
                                    <ENT>R-1120-76</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="03">
                                        Gross alpha 
                                        <SU>11</SU>
                                    </ENT>
                                    <ENT>Coprecipitation</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>00-02</ENT>
                                    <ENT/>
                                    <ENT>7110 C, 7110 C-00</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="03">Radium 226</ENT>
                                    <ENT>Radon emanation</ENT>
                                    <ENT>903.1</ENT>
                                    <ENT>p. 16</ENT>
                                    <ENT>Ra-04</ENT>
                                    <ENT>p. 19</ENT>
                                    <ENT>305, 7500-Ra C, 7500-Ra C-01</ENT>
                                    <ENT>D3454-97</ENT>
                                    <ENT>R-1141-76</ENT>
                                    <ENT>Ra-04</ENT>
                                    <ENT>
                                        NY 
                                        <SU>9</SU>
                                        ,
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Radiochemical</ENT>
                                    <ENT>903.0</ENT>
                                    <ENT>p. 13</ENT>
                                    <ENT>Ra-03</ENT>
                                    <ENT/>
                                    <ENT>304, 7500-Ra B, 7500-Ra B-01</ENT>
                                    <ENT>D2460-97</ENT>
                                    <ENT>R-1140-76</ENT>
                                    <ENT/>
                                    <ENT>
                                        GA 
                                        <SU>14</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="03">Radium 228</ENT>
                                    <ENT>Radiochemical</ENT>
                                    <ENT>904.0</ENT>
                                    <ENT>p. 24</ENT>
                                    <ENT>Ra-05</ENT>
                                    <ENT>p. 19</ENT>
                                    <ENT>7500-Ra D, 7500-Ra D-01</ENT>
                                    <ENT/>
                                    <ENT>R-1142-76</ENT>
                                    <ENT/>
                                    <ENT>
                                        NY 
                                        <SU>9</SU>
                                        ,
                                        <LI>
                                            NJ 
                                            <SU>10</SU>
                                            ,
                                        </LI>
                                        <LI>
                                            GA 
                                            <SU>14</SU>
                                        </LI>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="03">
                                        Uranium 
                                        <SU>12</SU>
                                    </ENT>
                                    <ENT>Radiochemical</ENT>
                                    <ENT>908.0</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>7500-U B, 7500-U B-00</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Fluorometric</ENT>
                                    <ENT>908.1</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>7500-U C (17th Ed.)</ENT>
                                    <ENT>D2907-97</ENT>
                                    <ENT>R-1180-76, R-1181-76</ENT>
                                    <ENT>U-04</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>ICP-MS</ENT>
                                    <ENT>
                                        200.8 
                                        <SU>13</SU>
                                    </ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>3125</ENT>
                                    <ENT>D5673-03</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Alpha Spectrometry</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>00-07</ENT>
                                    <ENT>p. 33</ENT>
                                    <ENT>7500-U C (18th, 19th, or 20th Ed.), 7500-U C-00</ENT>
                                    <ENT>D3972-97, 02</ENT>
                                    <ENT>R-1182-76</ENT>
                                    <ENT>U-02</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Laser Phosphorimetry</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>D5174-97, 02</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22">Man-Made:</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="03">Radioactive Cesium</ENT>
                                    <ENT>Radiochemical</ENT>
                                    <ENT>901.0</ENT>
                                    <ENT>p. 4</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>7500-Cs B, 7500-Cs B-00</ENT>
                                    <ENT>D2459-72</ENT>
                                    <ENT>R-1111-76</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Gamma Ray Spectrometry</ENT>
                                    <ENT>901.1</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>p. 92</ENT>
                                    <ENT>7120, 7120-97</ENT>
                                    <ENT>D3649-91, 98a</ENT>
                                    <ENT>R-1110-76</ENT>
                                    <ENT>4.5.2.3</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="03">Radioactive Iodine</ENT>
                                    <ENT>Radiochemical</ENT>
                                    <ENT>902.0</ENT>
                                    <ENT>p. 6</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>7500-I B, 7500-I B-00</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="xl"/>
                                    <ENT O="xl"/>
                                    <ENT>p. 9</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>7500-I C, 7500-I C-00</ENT>
                                </ROW>
                                <ROW>
                                    <PRTPAGE P="520"/>
                                    <ENT I="22"> </ENT>
                                    <ENT O="xl"/>
                                    <ENT O="xl"/>
                                    <ENT O="xl"/>
                                    <ENT O="xl"/>
                                    <ENT O="xl"/>
                                    <ENT>7500-I D, 7500-I D-00</ENT>
                                    <ENT>D3649-91, 98a</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Gamma Ray Spectrometry</ENT>
                                    <ENT>901.1</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>p. 92</ENT>
                                    <ENT>7120, 7120-97</ENT>
                                    <ENT>D4785-93, 00a</ENT>
                                    <ENT/>
                                    <ENT>4.5.2.3</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="03">Radioactive Strontium 89, 90</ENT>
                                    <ENT>Radiochemical</ENT>
                                    <ENT>905.0</ENT>
                                    <ENT>p. 29</ENT>
                                    <ENT>Sr-04</ENT>
                                    <ENT>p. 65</ENT>
                                    <ENT>303, 7500-Sr B, 7500-Sr B-01</ENT>
                                    <ENT/>
                                    <ENT>R-1160-76</ENT>
                                    <ENT>Sr-01, Sr-02</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="03">Tritium</ENT>
                                    <ENT>Liquid Scintillation</ENT>
                                    <ENT>906.0</ENT>
                                    <ENT>p. 34</ENT>
                                    <ENT>H-02</ENT>
                                    <ENT>p. 87</ENT>
                                    <ENT>
                                        306, 7500-
                                        <SU>3</SU>
                                         H B, 7500-
                                        <SU>3</SU>
                                         H B-00
                                    </ENT>
                                    <ENT>D4107-91, 98 (Reapproved 2002)</ENT>
                                    <ENT>R-1171-76</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="03">Gamma Emitters</ENT>
                                    <ENT>Gamma Ray Spectrometry</ENT>
                                    <ENT>901.1</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>p. 92</ENT>
                                    <ENT>7120, 7120-97</ENT>
                                    <ENT>D3649-91, 98a</ENT>
                                    <ENT>R-1110-76</ENT>
                                    <ENT>Ga-01-R</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="xl"/>
                                    <ENT>902.0</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>7500-Cs B, 7500-Cs B-00</ENT>
                                    <ENT>D4785-93, 00a</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="xl"/>
                                    <ENT>901.0</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>7500-I B, 7500-I B-00</ENT>
                                </ROW>
                                <TNOTE>
                                    The procedures shall be done in accordance with the documents listed below. The incorporation by reference of documents 1 through 10 and 13 through 14 was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies of the documents may be obtained from the sources listed below. Information regarding obtaining these documents can be obtained from the Safe Drinking Water Hotline at 800-426-4791. Documents may be inspected at EPA's Drinking Water Docket, EPA West, 1301 Constitution Avenue, NW., Room 3334 , Washington, DC 20460 (Telephone: 202-566-2426); or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: 
                                    <E T="03">http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.</E>
                                </TNOTE>
                                <TNOTE>
                                    <SU>1</SU>
                                     “Prescribed Procedures for the Measurement of Radioactivity in Drinking Water,” EPA 600/4-80-032, August 1980. Available at the U.S. Department of Commerce, National Technical Information Service (NTIS), 5285 Port Royal Road, Springfield, VA 22161 (Telephone 800-553-6847), PB 80-224744.
                                </TNOTE>
                                <TNOTE>
                                    <SU>2</SU>
                                     “Interim Radiochemical Methodology for Drinking Water,” EPA 600/4-75-008 (revised), March 1976. Available NTIS, ibid.
                                </TNOTE>
                                <TNOTE>
                                    <SU>3</SU>
                                     “Radiochemistry Procedures Manual,” EPA 520/5-84-006, December 1987. Available NTIS, ibid.
                                </TNOTE>
                                <TNOTE>
                                    <SU>4</SU>
                                     “Radiochemical Analytical Procedures for Analysis of Environmental Samples,” March 1979. Available at NTIS, ibid. EMSL LV 053917.
                                </TNOTE>
                                <TNOTE>
                                    <SU>5</SU>
                                     “Standard Methods for the Examination of Water and Wastewater,” 13th, 17th, 18th, 19th or 20th edition, 1971, 1989, 1992, 1995, 1998. Available at American Public Health Association, 1015 Fifteenth Street, NW., Washington, DC 20005. Methods 302, 303, 304, 305 and 306 are only in the 13th edition. Methods 7110B, 7500-Ra B, 7500-Ra C, 7500-Ra D, 7500-U B, 7500-Cs B, 7500-I B, 7500-I C, 7500-I D, 7500-Sr B, and 7500-
                                    <SU>3</SU>
                                    H B are in the 17th, 18th, 19th and 20th editions. Method 7110 C is in the 18th, 19th and 20th editions. Method 7500-U C Fluorometric Uranium is only in the 17th Edition, and 7500-U C Alpha spectrometry is only in the 18th, 19th and 20th editions. Method 7120 is only in the 19th and 20th editions. Method 3125 is only in the 20th edition. Methods 7110 B-00, 7110 C-00, 7500-Ra B-01, 7500-Ra C-01, 7500-Ra D-01, 7500-U B-00, 7500-U C-00, 7500-I B-00, 7500-I C-00, 7500-I D-00, 7120-97, 7500-Sr B-01, and 7500-
                                    <SU>3</SU>
                                    H B-00 are available online at 
                                    <E T="03">http://www.standardmethods.org.</E>
                                     The year in which each method was approved by the Standard Methods Committee is designated by the last two digits in the method number. The methods listed are the only online versions that may be used.
                                </TNOTE>
                                <TNOTE>
                                    <SU>6</SU>
                                     
                                    <E T="03">Annual Book of ASTM Standards,</E>
                                     Vol. 11.01 and 11.02, 2002; ASTM International; any year containing the cited version of the method may be used. Copies of these two volumes and the 2003 version of D 5673-03 may be obtained from ASTM International, 100 Barr Harbor Drive, P.O. Box C700, West Conshohocken, PA 19428-2959.
                                </TNOTE>
                                <TNOTE>
                                    <SU>7</SU>
                                     “Methods for Determination of Radioactive Substances in Water and Fluvial Sediments,” Chapter A5 in Book 5 of 
                                    <E T="03">Techniques of Water-Resources Investigations of the United States Geological Survey,</E>
                                     1977. Available at U.S. Geological Survey (USGS) Information Services, Box 25286, Federal Center, Denver, CO 80225-0425.
                                </TNOTE>
                                <TNOTE>
                                    <SU>8</SU>
                                     “EML Procedures Manual,” 28th (1997) or 27th (1990) Editions, Volumes 1 and 2; either edition may be used. In the 27th Edition Method Ra-04 is listed as Ra-05 and Method Ga-01-R is listed as Sect. 4.5.2.3. Available at the Environmental Measurements Laboratory, U.S. Department of Energy (DOE), 376 Hudson Street, New York, NY 10014-3621.
                                    <PRTPAGE P="521"/>
                                </TNOTE>
                                <TNOTE>
                                    <SU>9</SU>
                                     “Determination of Ra-226 and Ra-228 (Ra-02),” January 1980, Revised June 1982. Available at Radiological Sciences Institute for Laboratories and Research, New York State Department of Health, Empire State Plaza, Albany, NY 12201.
                                </TNOTE>
                                <TNOTE>
                                    <SU>10</SU>
                                     “Determination of Radium 228 in Drinking Water,” August 1980. Available at State of New Jersey, Department of Environmental Protection, Division of Environmental Quality, Bureau of Radiation and Inorganic Analytical Services, 9 Ewing Street, Trenton, NJ 08625.
                                </TNOTE>
                                <TNOTE>
                                    <SU>11</SU>
                                     Natural uranium and thorium-230 are approved as gross alpha calibration standards for gross alpha with co-precipitation and evaporation methods; americium-241 is approved with co-precipitation methods.
                                </TNOTE>
                                <TNOTE>
                                    <SU>12</SU>
                                     If uranium (U) is determined by mass, a 0.67 pCi/μg of uranium conversion factor must be used. This conversion factor is based on the 1:1 activity ratio of U-234 and U-238 that is characteristic of naturally occurring uranium.
                                </TNOTE>
                                <TNOTE>
                                    <SU>13</SU>
                                     “Determination of Trace Elements in Waters and Wastes by Inductively Coupled Plasma-Mass Spectrometry,” Revision 5.4, which is published in “Methods for the Determination of Metals in Environmental Samples—Supplement I,” ' EPA 600-R-94-111, May 1994. Available at NTIS, PB 95-125472.
                                </TNOTE>
                                <TNOTE>
                                    <SU>14</SU>
                                     “The Determination of Radium-226 and Radium-228 in Drinking Water by Gamma-ray Spectrometry Using HPGE or Ge(Li) Detectors,” Revision 1.2, December 2004. Available from the Environmental Resources Center, Georgia Institute of Technology, 620 Cherry Street, Atlanta, GA 30332-0335, USA, Telephone: 404-894-3776. This method may be used to analyze for radium-226 and radium-228 in samples collected after January 1, 2005 to satisfy the radium-226 and radium-228 monitoring requirements specified at 40 CFR 141.26.
                                </TNOTE>
                            </GPOTABLE>
                            <PRTPAGE P="522"/>
                            <P>(b) When the identification and measurement of radionuclides other than those listed in paragraph (a) of this section is required, the following references are to be used, except in cases where alternative methods have been approved in accordance with § 141.27.</P>
                            <P>
                                (1) 
                                <E T="03">Procedures for Radiochemical Analysis of Nuclear Reactor Aqueous Solutions,</E>
                                 H. L. Krieger and S. Gold, EPA-R4-73-014. USEPA, Cincinnati, Ohio, May 1973.
                            </P>
                            <P>
                                (2) 
                                <E T="03">HASL Procedure Manual,</E>
                                 Edited by John H. Harley. HASL 300, ERDA Health and Safety Laboratory, New York, NY., 1973.
                            </P>
                            <P>(c) For the purpose of monitoring radioactivity concentrations in drinking water, the required sensitivity of the radioanalysis is defined in terms of a detection limit. The detection limit shall be that concentration which can be counted with a precision of plus or minus 100 percent at the 95 percent confidence level (1.96σ where σ is the standard deviation of the net counting rate of the sample).</P>
                            <P>(1) To determine compliance with § 141.66(b), (c), and (e) the detection limit shall not exceed the concentrations in Table B to this paragraph.</P>
                            <GPOTABLE COLS="2" OPTS="L2" CDEF="s25,xs40">
                                <TTITLE>Table B—Detection Limits for Gross Alpha Particle Activity, Radium 226, Radium 228, and Uranium</TTITLE>
                                <BOXHD>
                                    <CHED H="1">Contaminant</CHED>
                                    <CHED H="1">
                                        Detection
                                        <LI>limit</LI>
                                    </CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">Gross alpha particle activity</ENT>
                                    <ENT>3 pCi/L.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Radium 226</ENT>
                                    <ENT>1 pCi/L.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Radium 228</ENT>
                                    <ENT>1 pCi/L.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Uranium</ENT>
                                    <ENT>1 µg/L</ENT>
                                </ROW>
                            </GPOTABLE>
                            <P>(2) To determine compliance with § 141.66(d) the detection limits shall not exceed the concentrations listed in Table C to this paragraph.</P>
                            <GPOTABLE COLS="2" OPTS="L2" CDEF="s50,r50">
                                <TTITLE>Table C—Detection Limits for Man-made Beta Particle and Photon Emitters</TTITLE>
                                <BOXHD>
                                    <CHED H="1">Radionuclide</CHED>
                                    <CHED H="1">Detection limit</CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">Tritium</ENT>
                                    <ENT>1,000 pCi/1.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Strontium-89</ENT>
                                    <ENT>10 pCi/1.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Strontium-90</ENT>
                                    <ENT>2 pCi/1.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Iodine-131</ENT>
                                    <ENT>1 pCi/1.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Cesium-134</ENT>
                                    <ENT>10 pCi/1.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Gross beta</ENT>
                                    <ENT>4 pCi/1.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Other radionuclides</ENT>
                                    <ENT>
                                        <FR>1/10</FR>
                                         of the applicable limit.
                                    </ENT>
                                </ROW>
                            </GPOTABLE>
                            <P>(d) To judge compliance with the maximum contaminant levels listed in § 141.66, averages of data shall be used and shall be rounded to the same number of significant figures as the maximum contaminant level for the substance in question.</P>
                            <P>(e) The State has the authority to determine compliance or initiate enforcement action based upon analytical results or other information compiled by their sanctioned representatives and agencies.</P>
                            <CITA>[41 FR 28404, July 9, 1976, as amended at 45 FR 57345, Aug. 27, 1980; 62 FR 10173, Mar. 5, 1997; 65 FR 76745, Dec. 7, 2000; 67 FR 65250, Oct. 23, 2002; 69 FR 38855, June 29, 2004; 69 FR 52180, Aug. 25, 2004; 72 FR 11245, Mar. 12, 2007; 74 FR 30958, June 29, 2009]</CITA>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 141.26</SECTNO>
                            <SUBJECT>Monitoring frequency and compliance requirements for radionuclides in community water systems.</SUBJECT>
                            <P>
                                (a) 
                                <E T="03">Monitoring and compliance requirements for gross alpha particle activity, radium-226, radium-228, and uranium.</E>
                                 (1) Community water systems (CWSs) must conduct initial monitoring to determine compliance with § 141.66(b), (c), and (e) by December 31, 2007. For the purposes of monitoring for gross alpha particle activity, radium-226, radium-228, uranium, and beta particle and photon radioactivity in drinking water, “detection limit” is defined as in § 141.25(c).
                            </P>
                            <P>
                                (i) 
                                <E T="03">Applicability and sampling location for existing community water systems or sources.</E>
                                 All existing CWSs using ground water, surface water or systems using both ground and surface water (for the purpose of this section hereafter referred to as systems) must sample at every entry point to the distribution system that is representative of all sources being used (hereafter called a sampling point) under normal operating conditions. The system must take each sample at the same sampling point unless conditions make another sampling point more representative of each source or the State has designated a distribution system location, in accordance with paragraph (a)(2)(ii)(C) of this section.
                            </P>
                            <P>
                                (ii) 
                                <E T="03">Applicability and sampling location for new community water systems or sources.</E>
                                 All new CWSs or CWSs that use a new source of water must begin to conduct initial monitoring for the new source within the first quarter after 
                                <PRTPAGE P="523"/>
                                initiating use of the source. CWSs must conduct more frequent monitoring when ordered by the State in the event of possible contamination or when changes in the distribution system or treatment processes occur which may increase the concentration of radioactivity in finished water.
                            </P>
                            <P>
                                (2) 
                                <E T="03">Initial monitoring:</E>
                                 Systems must conduct initial monitoring for gross alpha particle activity, radium-226, radium-228, and uranium as follows:
                            </P>
                            <P>(i) Systems without acceptable historical data, as defined below, must collect four consecutive quarterly samples at all sampling points before December 31, 2007.</P>
                            <P>
                                (ii) 
                                <E T="03">Grandfathering of data:</E>
                                 States may allow historical monitoring data collected at a sampling point to satisfy the initial monitoring requirements for that sampling point, for the following situations.
                            </P>
                            <P>(A) To satisfy initial monitoring requirements, a community water system having only one entry point to the distribution system may use the monitoring data from the last compliance monitoring period that began between June 2000 and December 8, 2003.</P>
                            <P>(B) To satisfy initial monitoring requirements, a community water system with multiple entry points and having appropriate historical monitoring data for each entry point to the distribution system may use the monitoring data from the last compliance monitoring period that began between June 2000 and December 8, 2003.</P>
                            <P>(C) To satisfy initial monitoring requirements, a community water system with appropriate historical data for a representative point in the distribution system may use the monitoring data from the last compliance monitoring period that began between June 2000 and December 8, 2003, provided that the State finds that the historical data satisfactorily demonstrate that each entry point to the distribution system is expected to be in compliance based upon the historical data and reasonable assumptions about the variability of contaminant levels between entry points. The State must make a written finding indicating how the data conforms to the these requirements.</P>
                            <P>(iii) For gross alpha particle activity, uranium, radium-226, and radium-228 monitoring, the State may waive the final two quarters of initial monitoring for a sampling point if the results of the samples from the previous two quarters are below the detection limit.</P>
                            <P>(iv) If the average of the initial monitoring results for a sampling point is above the MCL, the system must collect and analyze quarterly samples at that sampling point until the system has results from four consecutive quarters that are at or below the MCL, unless the system enters into another schedule as part of a formal compliance agreement with the State.</P>
                            <P>
                                (3) 
                                <E T="03">Reduced monitoring:</E>
                                 States may allow community water systems to reduce the future frequency of monitoring from once every three years to once every six or nine years at each sampling point, based on the following criteria.
                            </P>
                            <P>
                                (i) If the average of the initial monitoring results for each contaminant (
                                <E T="03">i.e.,</E>
                                 gross alpha particle activity, uranium, radium-226, or radium-228) is below the detection limit specified in Table B, in § 141.25(c)(1), the system must collect and analyze for that contaminant using at least one sample at that sampling point every nine years.
                            </P>
                            <P>
                                (ii) For gross alpha particle activity and uranium, if the average of the initial monitoring results for each contaminant is at or above the detection limit but at or below 
                                <FR>1/2</FR>
                                 the MCL, the system must collect and analyze for that contaminant using at least one sample at that sampling point every six years. For combined radium-226 and radium-228, the analytical results must be combined. If the average of the combined initial monitoring results for radium-226 and radium-228 is at or above the detection limit but at or below 
                                <FR>1/2</FR>
                                 the MCL, the system must collect and analyze for that contaminant using at least one sample at that sampling point every six years.
                            </P>
                            <P>
                                (iii) For gross alpha particle activity and uranium, if the average of the initial monitoring results for each contaminant is above 
                                <FR>1/2</FR>
                                 the MCL but at or below the MCL, the system must collect and analyze at least one sample at that sampling point every three years. For combined radium-226 and radium-
                                <PRTPAGE P="524"/>
                                228, the analytical results must be combined. If the average of the combined initial monitoring results for radium-226 and radium-228 is above 
                                <FR>1/2</FR>
                                 the MCL but at or below the MCL, the system must collect and analyze at least one sample at that sampling point every three years.
                            </P>
                            <P>
                                (iv) Systems must use the samples collected during the reduced monitoring period to determine the monitoring frequency for subsequent monitoring periods (e.g., if a system's sampling point is on a nine year monitoring period, and the sample result is above 
                                <FR>1/2</FR>
                                 MCL, then the next monitoring period for that sampling point is three years).
                            </P>
                            <P>(v) If a system has a monitoring result that exceeds the MCL while on reduced monitoring, the system must collect and analyze quarterly samples at that sampling point until the system has results from four consecutive quarters that are below the MCL, unless the system enters into another schedule as part of a formal compliance agreement with the State.</P>
                            <P>
                                (4) 
                                <E T="03">Compositing:</E>
                                 To fulfill quarterly monitoring requirements for gross alpha particle activity, radium-226, radium-228, or uranium, a system may composite up to four consecutive quarterly samples from a single entry point if analysis is done within a year of the first sample. States will treat analytical results from the composited as the average analytical result to determine compliance with the MCLs and the future monitoring frequency. If the analytical result from the composited sample is greater than 
                                <FR>1/2</FR>
                                 MCL, the State may direct the system to take additional quarterly samples before allowing the system to sample under a reduced monitoring schedule.
                            </P>
                            <P>
                                (5) A gross alpha particle activity measurement may be substituted for the required radium-226 measurement provided that the measured gross alpha particle activity does not exceed 5 pCi/l. A gross alpha particle activity measurement may be substituted for the required uranium measurement provided that the measured gross alpha particle activity does not exceed 15 pCi/l. The gross alpha measurement shall have a confidence interval of 95% (1.65σ, where σ is the standard deviation of the net counting rate of the sample) for radium-226 and uranium. When a system uses a gross alpha particle activity measurement in lieu of a radium-226 and/or uranium measurement, the gross alpha particle activity analytical result will be used to determine the future monitoring frequency for radium-226 and/or uranium. If the gross alpha particle activity result is less than detection, 
                                <FR>1/2</FR>
                                 the detection limit will be used to determine compliance and the future monitoring frequency.
                            </P>
                            <P>
                                (b) 
                                <E T="03">Monitoring and compliance requirements for beta particle and photon radioactivity.</E>
                                 To determine compliance with the maximum contaminant levels in § 141.66(d) for beta particle and photon radioactivity, a system must monitor at a frequency as follows:
                            </P>
                            <P>(1) Community water systems (both surface and ground water) designated by the State as vulnerable must sample for beta particle and photon radioactivity. Systems must collect quarterly samples for beta emitters and annual samples for tritium and strontium-90 at each entry point to the distribution system (hereafter called a sampling point), beginning within one quarter after being notified by the State. Systems already designated by the State must continue to sample until the State reviews and either reaffirms or removes the designation.</P>
                            <P>(i) If the gross beta particle activity minus the naturally occurring potassium-40 beta particle activity at a sampling point has a running annual average (computed quarterly) less than or equal to 50 pCi/L (screening level), the State may reduce the frequency of monitoring at that sampling point to once every 3 years. Systems must collect all samples required in paragraph (b)(1) of this section during the reduced monitoring period.</P>
                            <P>
                                (ii) For systems in the vicinity of a nuclear facility, the State may allow the CWS to utilize environmental surveillance data collected by the nuclear facility in lieu of monitoring at the system's entry point(s), where the State determines if such data is applicable to a particular water system. In the event that there is a release from a nuclear facility, systems which are using surveillance data must begin monitoring at the community water 
                                <PRTPAGE P="525"/>
                                system's entry point(s) in accordance with paragraph (b)(1) of this section.
                            </P>
                            <P>(2) Community water systems (both surface and ground water) designated by the State as utilizing waters contaminated by effluents from nuclear facilities must sample for beta particle and photon radioactivity. Systems must collect quarterly samples for beta emitters and iodine-131 and annual samples for tritium and strontium-90 at each entry point to the distribution system (hereafter called a sampling point), beginning within one quarter after being notified by the State. Systems already designated by the State as systems using waters contaminated by effluents from nuclear facilities must continue to sample until the State reviews and either reaffirms or removes the designation.</P>
                            <P>(i) Quarterly monitoring for gross beta particle activity shall be based on the analysis of monthly samples or the analysis of a composite of three monthly samples. The former is recommended.</P>
                            <P>(ii) For iodine-131, a composite of five consecutive daily samples shall be analyzed once each quarter. As ordered by the State, more frequent monitoring shall be conducted when iodine-131 is identified in the finished water.</P>
                            <P>(iii) Annual monitoring for strontium-90 and tritium shall be conducted by means of the analysis of a composite of four consecutive quarterly samples or analysis of four quarterly samples. The latter procedure is recommended.</P>
                            <P>(iv) If the gross beta particle activity minus the naturally occurring potassium-40 beta particle activity at a sampling point has a running annual average (computed quarterly) less than or equal to 15 pCi/L (screening level), the State may reduce the frequency of monitoring at that sampling point to every 3 years. Systems must collect the same type of samples required in paragraph (b)(2) of this section during the reduced monitoring period.</P>
                            <P>(v) For systems in the vicinity of a nuclear facility, the State may allow the CWS to utilize environmental surveillance data collected by the nuclear facility in lieu of monitoring at the system's entry point(s), where the State determines if such data is applicable to a particular water system. In the event that there is a release from a nuclear facility, systems which are using surveillance data must begin monitoring at the community water system's entry point(s) in accordance with paragraph (b)(2) of this section.</P>
                            <P>(3) Community water systems designated by the State to monitor for beta particle and photon radioactivity can not apply to the State for a waiver from the monitoring frequencies specified in paragraph (b)(1) or (b)(2) of this section.</P>
                            <P>(4) Community water systems may analyze for naturally occurring potassium-40 beta particle activity from the same or equivalent sample used for the gross beta particle activity analysis. Systems are allowed to subtract the potassium-40 beta particle activity value from the total gross beta particle activity value to determine if the screening level is exceeded. The potassium-40 beta particle activity must be calculated by multiplying elemental potassium concentrations (in mg/L) by a factor of 0.82.</P>
                            <P>(5) If the gross beta particle activity minus the naturally occurring potassium-40 beta particle activity exceeds the appropriate screening level, an analysis of the sample must be performed to identify the major radioactive constituents present in the sample and the appropriate doses must be calculated and summed to determine compliance with § 141.66(d)(1), using the formula in § 141.66(d)(2). Doses must also be calculated and combined for measured levels of tritium and strontium to determine compliance.</P>
                            <P>(6) Systems must monitor monthly at the sampling point(s) which exceed the maximum contaminant level in § 141.66(d) beginning the month after the exceedance occurs. Systems must continue monthly monitoring until the system has established, by a rolling average of 3 monthly samples, that the MCL is being met. Systems who establish that the MCL is being met must return to quarterly monitoring until they meet the requirements set forth in paragraph (b)(1)(i) or (b)(2)(iv) of this section.</P>
                            <P>
                                (c) 
                                <E T="03">General monitoring and compliance requirements for radionuclides.</E>
                                 (1) The 
                                <PRTPAGE P="526"/>
                                State may require more frequent monitoring than specified in paragraphs (a) and (b) of this section, or may require confirmation samples at its discretion. The results of the initial and confirmation samples will be averaged for use in compliance determinations.
                            </P>
                            <P>(2) Each public water systems shall monitor at the time designated by the State during each compliance period.</P>
                            <P>
                                (3) 
                                <E T="03">Compliance:</E>
                                 Compliance with § 141.66 (b) through (e) will be determined based on the analytical result(s) obtained at each sampling point. If one sampling point is in violation of an MCL, the system is in violation of the MCL.
                            </P>
                            <P>(i) For systems monitoring more than once per year, compliance with the MCL is determined by a running annual average at each sampling point. If the average of any sampling point is greater than the MCL, then the system is out of compliance with the MCL.</P>
                            <P>(ii) For systems monitoring more than once per year, if any sample result will cause the running average to exceed the MCL at any sample point, the system is out of compliance with the MCL immediately.</P>
                            <P>(iii) Systems must include all samples taken and analyzed under the provisions of this section in determining compliance, even if that number is greater than the minimum required.</P>
                            <P>(iv) If a system does not collect all required samples when compliance is based on a running annual average of quarterly samples, compliance will be based on the running average of the samples collected.</P>
                            <P>
                                (v) If a sample result is less than the detection limit, zero will be used to calculate the annual average, unless a gross alpha particle activity is being used in lieu of radium-226 and/or uranium. If the gross alpha particle activity result is less than detection, 
                                <FR>1/2</FR>
                                 the detection limit will be used to calculate the annual average.
                            </P>
                            <P>(4) States have the discretion to delete results of obvious sampling or analytic errors.</P>
                            <P>(5) If the MCL for radioactivity set forth in § 141.66 (b) through (e) is exceeded, the operator of a community water system must give notice to the State pursuant to § 141.31 and to the public as required by subpart Q of this part.</P>
                            <CITA>[65 FR 76745, Dec. 7, 2000, as amended at 69 FR 38855, June 29, 2004]</CITA>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 141.27</SECTNO>
                            <SUBJECT>Alternate analytical techniques.</SUBJECT>
                            <P>(a) With the written permission of the State, concurred in by the Administrator of the U.S. EPA, an alternate analytical technique may be employed. An alternate technique shall be accepted only if it is substantially equivalent to the prescribed test in both precision and accuracy as it relates to the determination of compliance with any MCL. The use of the alternate analytical technique shall not decrease the frequency of monitoring required by this part.</P>
                            <CITA>[45 FR 57345, Aug. 27, 1980]</CITA>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 141.28</SECTNO>
                            <SUBJECT>Certified laboratories.</SUBJECT>
                            <P>(a) For the purpose of determining compliance with §§ 141.21 through 141.27, 141.40, 141.74, 141.89, 141.402, 141.901, and 141.902, samples may be considered only if they have been analyzed by a laboratory certified by EPA or the State except that measurements of alkalinity, disinfectant residual, orthophosphate, pH, silica, temperature, and turbidity may be performed by any person acceptable to the State.</P>
                            <P>(b) Nothing in this part shall be construed to preclude the State or any duly designated representative of the State from taking samples or from using the results from such samples to determine compliance by a supplier of water with the applicable requirements of this part.</P>
                            <CITA>[45 FR 57345, Aug. 27, 1980; 47 FR 10999, Mar. 12, 1982, as amended at 59 FR 34323, July 1, 1994; 64 FR 67465, Dec. 1, 1999; 71 FR 65651, Nov. 8, 2006; 86 FR 4282, Jan. 15, 2021; 89 FR 32744, Apr. 26, 2024]</CITA>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 141.29</SECTNO>
                            <SUBJECT>Monitoring of consecutive public water systems.</SUBJECT>
                            <P>
                                When a public water system supplies water to one or more other public water systems, the State may modify the monitoring requirements imposed by this part to the extent that the interconnection of the systems justifies treating them as a single system for monitoring purposes. Any modified 
                                <PRTPAGE P="527"/>
                                monitoring shall be conducted pursuant to a schedule specified by the State and concurred in by the Administrator of the U.S. Environmental Protection Agency.
                            </P>
                        </SECTION>
                        <APPENDIX>
                            <EAR>Pt. 141, Subpt. C, App. A</EAR>
                            <HD SOURCE="HED">Appendix A to Subpart C of Part 141—Alternative Testing Methods Approved for Analyses Under the Safe Drinking Water Act</HD>
                            <P>Only the editions stated in the following table are approved.</P>
                            <GPOTABLE COLS="6" OPTS="L2" CDEF="s50,r50,r50,r50,r50,xs60">
                                <TTITLE>
                                    Alternative Testing Methods for Contaminants Listed at 40 CFR 141.21(
                                    <E T="01">f</E>
                                    )(3)
                                </TTITLE>
                                <BOXHD>
                                    <CHED H="1">Organism</CHED>
                                    <CHED H="1">Methodology</CHED>
                                    <CHED H="1">
                                        SM 21st Edition 
                                        <SU>1</SU>
                                    </CHED>
                                    <CHED H="1">
                                        SM 22nd Edition 
                                        <SU>28</SU>
                                    </CHED>
                                    <CHED H="1">
                                        SM Online 
                                        <SU>3</SU>
                                    </CHED>
                                    <CHED H="1">Other</CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">Total Coliforms</ENT>
                                    <ENT>Total Coliform Fermentation Technique</ENT>
                                    <ENT>9221 A, B</ENT>
                                    <ENT>9221 A, B</ENT>
                                    <ENT>9221 A,B-06</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Total Coliform Membrane Filter Technique</ENT>
                                    <ENT>9222 A, B, C</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Presence-Absence (P-A) Coliform Test</ENT>
                                    <ENT>9221 D</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>ONPG-MUG Test</ENT>
                                    <ENT>9223</ENT>
                                    <ENT>9223 B</ENT>
                                    <ENT>9223 B-04</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>
                                        Colitag 
                                        <SU>TM</SU>
                                    </ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        Modified Colitag 
                                        <SU>TM</SU>
                                         
                                        <SU>13</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>
                                        Tecta EC/TC 
                                        <SU>33</SU>
                                    </ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                </ROW>
                            </GPOTABLE>
                            <GPOTABLE COLS="4" OPTS="L2" CDEF="s50,r50,r50,12C">
                                <TTITLE>
                                    Alternative Testing Methods for Contaminants Listed at 40 CFR 141.21(
                                    <E T="01">f</E>
                                    )(5)
                                </TTITLE>
                                <BOXHD>
                                    <CHED H="1">Organism</CHED>
                                    <CHED H="1">Methodology</CHED>
                                    <CHED H="1">
                                        SM 22nd Edition 
                                        <SU>28</SU>
                                    </CHED>
                                    <CHED H="1">
                                        SM Online 
                                        <SU>3</SU>
                                    </CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">Fecal Coliforms</ENT>
                                    <ENT>Fecal Coliform Procedure</ENT>
                                    <ENT>9221 E</ENT>
                                    <ENT>9221 E-06</ENT>
                                </ROW>
                            </GPOTABLE>
                            <PRTPAGE P="528"/>
                            <GPOTABLE COLS="7" OPTS="L2" CDEF="s50,r50,12C,12C,12C,18C,xs88">
                                <TTITLE>
                                    Alternative Testing Methods for Contaminants Listed at 40 CFR 141.21(
                                    <E T="01">f</E>
                                    )(6)
                                </TTITLE>
                                <BOXHD>
                                    <CHED H="1">Organism</CHED>
                                    <CHED H="1">Methodology</CHED>
                                    <CHED H="1">
                                        SM 20th
                                        <LI>
                                            Edition 
                                            <SU>6</SU>
                                        </LI>
                                    </CHED>
                                    <CHED H="1">
                                        SM 21st
                                        <LI>
                                            Edition 
                                            <SU>1</SU>
                                        </LI>
                                    </CHED>
                                    <CHED H="1">
                                        SM 22nd
                                        <LI>
                                            Edition 
                                            <SU>28</SU>
                                        </LI>
                                    </CHED>
                                    <CHED H="1">
                                        SM Online 
                                        <SU>3</SU>
                                    </CHED>
                                    <CHED H="1">Other</CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">
                                        <E T="03">E.coli</E>
                                    </ENT>
                                    <ENT>ONPG-MUG Test</ENT>
                                    <ENT>9223 B</ENT>
                                    <ENT>9223 B</ENT>
                                    <ENT>9223 B</ENT>
                                    <ENT>9223 B-97, B-04</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>
                                        Colitag 
                                        <SU>TM</SU>
                                    </ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        Modified Colitag 
                                        <SU>TM</SU>
                                         
                                        <SU>13</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>
                                        Tecta EC/TC 
                                        <SU>33</SU>
                                    </ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                </ROW>
                            </GPOTABLE>
                            <GPOTABLE COLS="9" OPTS="L2,p7,7/8" CDEF="s50,r50,r30,r30,r30,r30,r30,r30,r30">
                                <TTITLE>
                                    Alternative Testing Methods for Contaminants Listed at 40 CFR 141.23(
                                    <E T="01">k</E>
                                    )(1)
                                </TTITLE>
                                <BOXHD>
                                    <CHED H="1">Contaminant</CHED>
                                    <CHED H="1">Methodology</CHED>
                                    <CHED H="1">EPA method</CHED>
                                    <CHED H="1">
                                        SM 21st
                                        <LI>
                                            edition 
                                            <SU>1</SU>
                                        </LI>
                                    </CHED>
                                    <CHED H="1">
                                        SM 22nd
                                        <LI>
                                            edition 
                                            <SU>28</SU>
                                        </LI>
                                    </CHED>
                                    <CHED H="1">
                                        SM 23rd
                                        <LI>
                                            edition,
                                            <SU>49</SU>
                                             SM
                                        </LI>
                                        <LI>
                                            24th edition 
                                            <SU>66</SU>
                                        </LI>
                                    </CHED>
                                    <CHED H="1">
                                        SM online 
                                        <SU>3</SU>
                                    </CHED>
                                    <CHED H="1">
                                        ASTM 
                                        <SU>4</SU>
                                    </CHED>
                                    <CHED H="1">Other</CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">Alkalinity</ENT>
                                    <ENT>Titrimetric</ENT>
                                    <ENT/>
                                    <ENT>2320 B</ENT>
                                    <ENT>2320 B</ENT>
                                    <ENT>2320 B</ENT>
                                    <ENT/>
                                    <ENT>D1067-06 B, 11 B, 16 B</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Antimony</ENT>
                                    <ENT>Hydride—Atomic Absorption</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>D 3697-07, -12, -17</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Atomic Absorption; Furnace</ENT>
                                    <ENT/>
                                    <ENT>3113 B</ENT>
                                    <ENT>3113 B</ENT>
                                    <ENT>3113 B</ENT>
                                    <ENT>3113 B-04, B-10</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)</ENT>
                                    <ENT>
                                        200.5, Revision 4.2 
                                        <SU>2</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Arsenic</ENT>
                                    <ENT>Atomic Absorption; Furnace</ENT>
                                    <ENT/>
                                    <ENT>3113 B</ENT>
                                    <ENT>3113 B</ENT>
                                    <ENT>3113 B</ENT>
                                    <ENT>3113 B-04, B-10</ENT>
                                    <ENT>D 2972-08 C, -15 C</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Hydride Atomic Absorption</ENT>
                                    <ENT/>
                                    <ENT>3114 B</ENT>
                                    <ENT>3114 B</ENT>
                                    <ENT>3114 B</ENT>
                                    <ENT>3114 B-09</ENT>
                                    <ENT>D 2972-08 B, -15 B</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)</ENT>
                                    <ENT>
                                        200.5, Revision 4.2 
                                        <SU>2</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Barium</ENT>
                                    <ENT>Inductively Coupled Plasma</ENT>
                                    <ENT/>
                                    <ENT>3120 B</ENT>
                                    <ENT>3120 B</ENT>
                                    <ENT>3120 B</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Atomic Absorption; Direct</ENT>
                                    <ENT/>
                                    <ENT>3111 D</ENT>
                                    <ENT>3111 D</ENT>
                                    <ENT>3111 D</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Atomic Absorption; Furnace</ENT>
                                    <ENT/>
                                    <ENT>3113 B</ENT>
                                    <ENT>3113 B</ENT>
                                    <ENT>3113 B</ENT>
                                    <ENT>3113 B-04, B-10</ENT>
                                </ROW>
                                <ROW>
                                    <PRTPAGE P="529"/>
                                    <ENT I="22"> </ENT>
                                    <ENT>Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)</ENT>
                                    <ENT>
                                        200.5, Revision 4.2 
                                        <SU>2</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Beryllium</ENT>
                                    <ENT>Inductively Coupled Plasma</ENT>
                                    <ENT/>
                                    <ENT>3120 B</ENT>
                                    <ENT>3120 B</ENT>
                                    <ENT>3120 B</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Atomic Absorption; Furnace</ENT>
                                    <ENT/>
                                    <ENT>3113 B</ENT>
                                    <ENT>3113 B</ENT>
                                    <ENT>3113 B</ENT>
                                    <ENT>3113 B-04, B-10</ENT>
                                    <ENT>D 3645-08 B, -15 B</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)</ENT>
                                    <ENT>
                                        200.5, Revision 4.2 
                                        <SU>2</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Cadmium</ENT>
                                    <ENT>Atomic Absorption; Furnace</ENT>
                                    <ENT/>
                                    <ENT>3113 B</ENT>
                                    <ENT>3113 B</ENT>
                                    <ENT>3113 B</ENT>
                                    <ENT>3113 B-04, B-10</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)</ENT>
                                    <ENT>
                                        200.5, Revision 4.2 
                                        <SU>2</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Calcium</ENT>
                                    <ENT>EDTA titrimetric</ENT>
                                    <ENT/>
                                    <ENT>3500-Ca B</ENT>
                                    <ENT>3500-Ca B</ENT>
                                    <ENT>3500-Ca B</ENT>
                                    <ENT/>
                                    <ENT>D 511-09, -14 A</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Atomic Absorption; Direct Aspiration</ENT>
                                    <ENT/>
                                    <ENT>3111 B</ENT>
                                    <ENT>3111 B</ENT>
                                    <ENT>3111 B</ENT>
                                    <ENT/>
                                    <ENT>D 511-09, -14 B</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Inductively Coupled Plasma</ENT>
                                    <ENT/>
                                    <ENT>3120 B</ENT>
                                    <ENT>3120 B</ENT>
                                    <ENT>3120 B</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)</ENT>
                                    <ENT>
                                        200.5, Revision 4.2 
                                        <SU>2</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Ion Chromatography</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>D 6919-09, -17</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Chromium</ENT>
                                    <ENT>Inductively Coupled Plasma</ENT>
                                    <ENT/>
                                    <ENT>3120 B</ENT>
                                    <ENT>3120 B</ENT>
                                    <ENT>3120 B</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Atomic Absorption; Furnace</ENT>
                                    <ENT/>
                                    <ENT>3113 B</ENT>
                                    <ENT>3113 B</ENT>
                                    <ENT>3113 B</ENT>
                                    <ENT>3113 B-04, B-10</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)</ENT>
                                    <ENT>
                                        200.5, Revision 4.2 
                                        <SU>2</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <PRTPAGE P="530"/>
                                    <ENT I="01">Copper</ENT>
                                    <ENT>Atomic Absorption; Furnace</ENT>
                                    <ENT/>
                                    <ENT>3113 B</ENT>
                                    <ENT>3113 B</ENT>
                                    <ENT>3113 B</ENT>
                                    <ENT>3113 B-04, B-10</ENT>
                                    <ENT>D 1688-07, -12 C, 17 C</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Atomic Absorption; Direct Aspiration</ENT>
                                    <ENT/>
                                    <ENT>3111 B</ENT>
                                    <ENT>3111 B</ENT>
                                    <ENT>3111 B</ENT>
                                    <ENT/>
                                    <ENT>D 1688-07, -12 A, 17 A</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Inductively Coupled Plasma</ENT>
                                    <ENT/>
                                    <ENT>3120 B</ENT>
                                    <ENT>3120 B</ENT>
                                    <ENT>3120 B</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)</ENT>
                                    <ENT>
                                        200.5, Revision 4.2 
                                        <SU>2</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Colorimetry</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        Hach Method 8026,
                                        <SU>35</SU>
                                         Hach Method 10272.
                                        <SU>36</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Conductivity</ENT>
                                    <ENT>Conductance</ENT>
                                    <ENT/>
                                    <ENT>2510 B</ENT>
                                    <ENT>2510 B</ENT>
                                    <ENT>2510 B</ENT>
                                    <ENT/>
                                    <ENT>D 1125-14 A</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Cyanide</ENT>
                                    <ENT>
                                        Manual Distillation with MgCl
                                        <E T="0732">2</E>
                                         followed by:
                                    </ENT>
                                    <ENT/>
                                    <ENT>
                                        4500-CN
                                        <E T="0731">−</E>
                                        C
                                    </ENT>
                                    <ENT>
                                        4500-CN
                                        <E T="0731">−</E>
                                        C
                                    </ENT>
                                    <ENT>
                                        4500-CN
                                        <E T="0731">−</E>
                                        C
                                    </ENT>
                                    <ENT>
                                        4500-CN
                                        <E T="0731">−</E>
                                        C-99
                                    </ENT>
                                    <ENT>D 2036-06 A</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Spectrophotometric, Amenable</ENT>
                                    <ENT/>
                                    <ENT>
                                        4500-CN
                                        <E T="0731">−</E>
                                        G
                                    </ENT>
                                    <ENT>
                                        4500-CN
                                        <E T="0731">−</E>
                                        G
                                    </ENT>
                                    <ENT>
                                        4500-CN
                                        <E T="0731">−</E>
                                        G
                                    </ENT>
                                    <ENT/>
                                    <ENT>D 2036-06 B</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Spectrophotometric Manual</ENT>
                                    <ENT/>
                                    <ENT>
                                        4500-CN
                                        <E T="0731">−</E>
                                        E
                                    </ENT>
                                    <ENT>
                                        4500-CN
                                        <E T="0731">−</E>
                                        E
                                    </ENT>
                                    <ENT>
                                        4500-CN
                                        <E T="0731">−</E>
                                        E
                                    </ENT>
                                    <ENT/>
                                    <ENT>D2036-06 A</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Selective Electrode</ENT>
                                    <ENT/>
                                    <ENT>
                                        4500-CN
                                        <E T="0731">−</E>
                                        F
                                    </ENT>
                                    <ENT>
                                        4500-CN
                                        <E T="0731">−</E>
                                        F
                                    </ENT>
                                    <ENT>
                                        4500-CN
                                        <E T="0731">−</E>
                                        F
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Gas Chromatography/Mass Spectrometry Headspace</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        ME355.01.
                                        <SU>7</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Fluoride</ENT>
                                    <ENT>Ion Chromatography</ENT>
                                    <ENT/>
                                    <ENT>4110 B</ENT>
                                    <ENT>4110 B</ENT>
                                    <ENT>4110 B</ENT>
                                    <ENT/>
                                    <ENT>D 4327-11, -17</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Manual Distillation; Colorimetric SPADNS</ENT>
                                    <ENT/>
                                    <ENT>
                                        4500-F
                                        <E T="0731">−</E>
                                        B, D
                                    </ENT>
                                    <ENT>
                                        4500-F
                                        <E T="0731">−</E>
                                        B, D
                                    </ENT>
                                    <ENT>
                                        4500-F
                                        <E T="0731">−</E>
                                        B, D
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Manual Electrode</ENT>
                                    <ENT/>
                                    <ENT>
                                        4500-F
                                        <E T="0731">−</E>
                                        C
                                    </ENT>
                                    <ENT>
                                        4500-F
                                        <E T="0731">−</E>
                                        C
                                    </ENT>
                                    <ENT>
                                        4500-F
                                        <E T="0731">−</E>
                                        C
                                    </ENT>
                                    <ENT/>
                                    <ENT>D 1179-04, 10 B, 16 B</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Automated Alizarin</ENT>
                                    <ENT/>
                                    <ENT>
                                        4500-F
                                        <E T="0731">−</E>
                                        E
                                    </ENT>
                                    <ENT>
                                        4500-F
                                        <E T="0731">−</E>
                                        E
                                    </ENT>
                                    <ENT>
                                        4500-F
                                        <E T="0731">−</E>
                                        E
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <PRTPAGE P="531"/>
                                    <ENT I="22"> </ENT>
                                    <ENT>Arsenite-Free Colorimetric SPADNS</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        Hach SPADNS 2 Method 10225,
                                        <SU>22</SU>
                                         Hach Method 10312.
                                        <SU>67</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Lead</ENT>
                                    <ENT>Atomic Absorption; Furnace</ENT>
                                    <ENT/>
                                    <ENT>3113 B</ENT>
                                    <ENT>3113 B</ENT>
                                    <ENT>3113 B</ENT>
                                    <ENT>3113 B-04, B-10</ENT>
                                    <ENT>D 3559-08 D, 15 D</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)</ENT>
                                    <ENT>
                                        200.5, Revision 4.2 
                                        <SU>2</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Differential Pulse Anodic Stripping Voltametry</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        Method 1001, Rev. 1.1.
                                        <SU>57</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Magnesium</ENT>
                                    <ENT>Atomic Absorption</ENT>
                                    <ENT/>
                                    <ENT>3111 B</ENT>
                                    <ENT>3111 B</ENT>
                                    <ENT>3111 B</ENT>
                                    <ENT/>
                                    <ENT>D 511-09, -14 B</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Inductively Coupled Plasma</ENT>
                                    <ENT/>
                                    <ENT>3120 B</ENT>
                                    <ENT>3120 B</ENT>
                                    <ENT>3120 B</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Complexation Titrimetric Methods</ENT>
                                    <ENT/>
                                    <ENT>3500-Mg B</ENT>
                                    <ENT>3500-Mg B</ENT>
                                    <ENT>3500-Mg B</ENT>
                                    <ENT/>
                                    <ENT>D 511-09, -14 A</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)</ENT>
                                    <ENT>
                                        200.5, Revision 4.2 
                                        <SU>2</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Ion Chromatography</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>D 6919-09, -17</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Mercury</ENT>
                                    <ENT>Manual, Cold Vapor</ENT>
                                    <ENT/>
                                    <ENT>3112 B</ENT>
                                    <ENT>3112 B</ENT>
                                    <ENT>3112 B</ENT>
                                    <ENT>3112 B-09</ENT>
                                    <ENT>D 3223-12, -17</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Nickel</ENT>
                                    <ENT>Inductively Coupled Plasma</ENT>
                                    <ENT/>
                                    <ENT>3120 B</ENT>
                                    <ENT>3120 B</ENT>
                                    <ENT>3120 B</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Atomic Absorption; Direct</ENT>
                                    <ENT/>
                                    <ENT>3111 B</ENT>
                                    <ENT>3111 B</ENT>
                                    <ENT>3111 B</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Atomic Absorption; Furnace</ENT>
                                    <ENT/>
                                    <ENT>3113 B</ENT>
                                    <ENT>3113 B</ENT>
                                    <ENT>3113 B</ENT>
                                    <ENT>3113 B-04, B-10</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)</ENT>
                                    <ENT>
                                        200.5, Revision 4.2 
                                        <SU>2</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <PRTPAGE P="532"/>
                                    <ENT I="01">Nitrate</ENT>
                                    <ENT>Ion Chromatography</ENT>
                                    <ENT/>
                                    <ENT>4110 B</ENT>
                                    <ENT>4110 B</ENT>
                                    <ENT>4110 B</ENT>
                                    <ENT/>
                                    <ENT>D 4327-11, -17</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Automated Cadmium Reduction</ENT>
                                    <ENT/>
                                    <ENT>
                                        4500-NO
                                        <E T="0732">3</E>
                                        <E T="0731">−</E>
                                        F
                                    </ENT>
                                    <ENT>
                                        4500-NO
                                        <E T="0732">3</E>
                                        <E T="0731">−</E>
                                        F
                                    </ENT>
                                    <ENT>
                                        4500-NO
                                        <E T="0732">3</E>
                                        <E T="0731">−</E>
                                        F
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Manual Cadmium Reduction</ENT>
                                    <ENT/>
                                    <ENT>
                                        4500-NO
                                        <E T="0732">3</E>
                                        <E T="0731">−</E>
                                         E
                                    </ENT>
                                    <ENT>
                                        4500-NO
                                        <E T="0732">3</E>
                                        <E T="0731">−</E>
                                         E
                                    </ENT>
                                    <ENT>
                                        4500-NO
                                        <E T="0732">3</E>
                                        <E T="0731">−</E>
                                         E
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Ion Selective Electrode</ENT>
                                    <ENT/>
                                    <ENT>
                                        4500-NO
                                        <E T="0732">3</E>
                                        <E T="0731">−</E>
                                         D
                                    </ENT>
                                    <ENT>
                                        4500-NO
                                        <E T="0732">3</E>
                                        <E T="0731">−</E>
                                         D
                                    </ENT>
                                    <ENT>
                                        4500-NO
                                        <E T="0732">3</E>
                                        <E T="0731">−</E>
                                         D
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Reduction/Colorimetric</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        Systea Easy (1-Reagent),
                                        <SU>8</SU>
                                         NECi Nitrate-Reductase.
                                        <SU>40</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Colorimetric; Direct</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        Hach TNTplus
                                        <SU>TM</SU>
                                         835/836 Method 10206.
                                        <SU>23</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Capillary Ion Electrophoresis</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>D 6508-15</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Nitrite</ENT>
                                    <ENT>Ion Chromatography</ENT>
                                    <ENT/>
                                    <ENT>4110 B</ENT>
                                    <ENT>4110 B</ENT>
                                    <ENT>4110 B</ENT>
                                    <ENT/>
                                    <ENT>D 4327-11, -17</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Automated Cadmium Reduction</ENT>
                                    <ENT/>
                                    <ENT>
                                        4500-NO
                                        <E T="0732">3</E>
                                        <E T="0731">−</E>
                                        F
                                    </ENT>
                                    <ENT>
                                        4500-NO
                                        <E T="0732">3</E>
                                        <E T="0731">−</E>
                                        F
                                    </ENT>
                                    <ENT>
                                        4500-NO
                                        <E T="0732">3</E>
                                        <E T="0731">−</E>
                                        F
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Manual Cadmium Reduction</ENT>
                                    <ENT/>
                                    <ENT>
                                        4500-NO
                                        <E T="0732">3</E>
                                        <E T="0731">−</E>
                                        E
                                    </ENT>
                                    <ENT>
                                        4500-NO
                                        <E T="0732">3</E>
                                        <E T="0731">−</E>
                                        E
                                    </ENT>
                                    <ENT>
                                        4500-NO
                                        <E T="0732">3</E>
                                        <E T="0731">−</E>
                                        E
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Spectrophotometric</ENT>
                                    <ENT/>
                                    <ENT>
                                        4500-NO
                                        <E T="0732">2</E>
                                        <E T="0731">−</E>
                                        B
                                    </ENT>
                                    <ENT>
                                        4500-NO
                                        <E T="0732">2</E>
                                        <E T="0731">−</E>
                                        B
                                    </ENT>
                                    <ENT>
                                        4500-NO
                                        <E T="0732">2</E>
                                        <E T="0731">−</E>
                                        B
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Reduction/Colorimetric</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        Systea Easy (1-Reagent),
                                        <SU>8</SU>
                                         NECi Nitrate-Reductase.
                                        <SU>40</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Capillary Ion Electrophoresis</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>D 6508-15</ENT>
                                </ROW>
                                <ROW>
                                    <PRTPAGE P="533"/>
                                    <ENT I="01">Ortho-phosphate</ENT>
                                    <ENT>Ion Chromatography</ENT>
                                    <ENT/>
                                    <ENT>4110 B</ENT>
                                    <ENT>4110 B</ENT>
                                    <ENT>4110 B</ENT>
                                    <ENT/>
                                    <ENT>D 4327-11, -17</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Colorimetric, ascorbic acid, single reagent</ENT>
                                    <ENT/>
                                    <ENT>4500-P E</ENT>
                                    <ENT>4500-P E</ENT>
                                    <ENT>4500-P E</ENT>
                                    <ENT>4500-P E-99</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Colorimetric, Automated, Ascorbic Acid</ENT>
                                    <ENT/>
                                    <ENT>4500-P F</ENT>
                                    <ENT>4500-P F</ENT>
                                    <ENT>4500-P F</ENT>
                                    <ENT>4500-P F-99</ENT>
                                    <ENT/>
                                    <ENT>
                                        Thermo Fisher Discrete Analyzer.
                                        <SU>41</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Capillary Ion Electrophoresis</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>D 6508-15</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">pH</ENT>
                                    <ENT>Electrometric</ENT>
                                    <ENT>
                                        150.3 
                                        <SU>48</SU>
                                    </ENT>
                                    <ENT>
                                        4500-H
                                        <SU>+</SU>
                                         B
                                    </ENT>
                                    <ENT>
                                        4500-H
                                        <SU>+</SU>
                                         B
                                    </ENT>
                                    <ENT>
                                        4500-H
                                        <SU>+</SU>
                                         B
                                    </ENT>
                                    <ENT/>
                                    <ENT>D 1293-12, -18</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Selenium</ENT>
                                    <ENT>Hydride-Atomic Absorption</ENT>
                                    <ENT/>
                                    <ENT>3114 B</ENT>
                                    <ENT>3114 B</ENT>
                                    <ENT>3114 B</ENT>
                                    <ENT>3114 B-09</ENT>
                                    <ENT>D 3859-08 A, -15 A</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Atomic Absorption; Furnace</ENT>
                                    <ENT/>
                                    <ENT>3113 B</ENT>
                                    <ENT>3113 B</ENT>
                                    <ENT>3113 B</ENT>
                                    <ENT>3113 B-04, B-10</ENT>
                                    <ENT>D 3859-08 B, -15 B</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)</ENT>
                                    <ENT>
                                        200.5, Revision 4.2 
                                        <SU>2</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Silica</ENT>
                                    <ENT>Colorimetric</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>D859-05, 10, 16</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Molybdosilicate</ENT>
                                    <ENT/>
                                    <ENT>
                                        4500-SiO
                                        <E T="0732">2</E>
                                         C
                                    </ENT>
                                    <ENT>
                                        4500-SiO
                                        <E T="0732">2</E>
                                         C
                                    </ENT>
                                    <ENT>
                                        4500-SiO
                                        <E T="0732">2</E>
                                         C
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Heteropoly blue</ENT>
                                    <ENT/>
                                    <ENT>
                                        4500-SiO
                                        <E T="0732">2</E>
                                         D
                                    </ENT>
                                    <ENT>
                                        4500-SiO
                                        <E T="0732">2</E>
                                         D
                                    </ENT>
                                    <ENT>
                                        4500-SiO
                                        <E T="0732">2</E>
                                         D
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Automated for Molybdate-reactive Silica</ENT>
                                    <ENT/>
                                    <ENT>
                                        4500-SiO
                                        <E T="0732">2</E>
                                         E
                                    </ENT>
                                    <ENT>
                                        4500-SiO
                                        <E T="0732">2</E>
                                         E
                                    </ENT>
                                    <ENT>
                                        4500-SiO
                                        <E T="0732">2</E>
                                         E
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)</ENT>
                                    <ENT>
                                        200.5, Revision 4.2 
                                        <SU>2</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Inductively Coupled Plasma</ENT>
                                    <ENT/>
                                    <ENT>3120 B</ENT>
                                    <ENT>3120 B</ENT>
                                    <ENT>3120 B</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Sodium</ENT>
                                    <ENT>Atomic Absorption; Direct Aspiration</ENT>
                                    <ENT/>
                                    <ENT>3111 B</ENT>
                                    <ENT>3111 B</ENT>
                                    <ENT>3111 B</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)</ENT>
                                    <ENT>
                                        200.5, Revision 4.2 
                                        <SU>2</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Ion Chromatography</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>D 6919-09, -17</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Temperature</ENT>
                                    <ENT>Thermometric</ENT>
                                    <ENT/>
                                    <ENT>2550</ENT>
                                    <ENT>2550</ENT>
                                    <ENT>2550</ENT>
                                    <ENT>2550-10</ENT>
                                </ROW>
                            </GPOTABLE>
                            <PRTPAGE P="534"/>
                            <GPOTABLE COLS="8" OPTS="L2,p7,7/8" CDEF="s50,r50,r50,r30,r30,r30,r30,r30">
                                <TTITLE>
                                    Alternative Testing Methods for Contaminants Listed at 40 CFR 141.24(
                                    <E T="01">e</E>
                                    )(1)
                                </TTITLE>
                                <BOXHD>
                                    <CHED H="1">Contaminant</CHED>
                                    <CHED H="1">Methodology</CHED>
                                    <CHED H="1">EPA method</CHED>
                                    <CHED H="1">
                                        SM 21st edition 
                                        <SU>1</SU>
                                    </CHED>
                                    <CHED H="1">
                                        SM 22nd
                                        <LI>
                                            edition,
                                            <SU>28</SU>
                                             SM
                                        </LI>
                                        <LI>
                                            23rd edition,
                                            <SU>49</SU>
                                             SM
                                        </LI>
                                        <LI>
                                            24th edition 
                                            <SU>66</SU>
                                        </LI>
                                    </CHED>
                                    <CHED H="1">
                                        SM online 
                                        <SU>3</SU>
                                    </CHED>
                                    <CHED H="1">
                                        ASTM 
                                        <SU>4</SU>
                                    </CHED>
                                    <CHED H="1">Other</CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">Benzene</ENT>
                                    <ENT>Purge &amp;Trap/Gas Chromatography/Mass Spectrometry</ENT>
                                    <ENT O="xl">
                                        524.3,
                                        <SU>9</SU>
                                         524.4.
                                        <SU>29</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Carbon tetrachloride</ENT>
                                    <ENT>Purge &amp;Trap/Gas Chromatography/Mass Spectrometry</ENT>
                                    <ENT O="xl">
                                        524.3,
                                        <SU>9</SU>
                                         524.4.
                                        <SU>29</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Chlorobenzene</ENT>
                                    <ENT>Purge &amp;Trap/Gas Chromatography/Mass Spectrometry</ENT>
                                    <ENT O="xl">
                                        524.3,
                                        <SU>9</SU>
                                         524.4.
                                        <SU>29</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">1,2-Dichlorobenzene</ENT>
                                    <ENT>Purge &amp;Trap/Gas Chromatography/Mass Spectrometry</ENT>
                                    <ENT O="xl">
                                        524.3,
                                        <SU>9</SU>
                                         524.4.
                                        <SU>29</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">1,4-Dichlorobenzene</ENT>
                                    <ENT>Purge &amp;Trap/Gas Chromatography/Mass Spectrometry</ENT>
                                    <ENT O="xl">
                                        524.3,
                                        <SU>9</SU>
                                         524.4.
                                        <SU>29</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">1,2-Dichloroethane</ENT>
                                    <ENT>Purge &amp;Trap/Gas Chromatography/Mass Spectrometry</ENT>
                                    <ENT O="xl">
                                        524.3,
                                        <SU>9</SU>
                                         524.4.
                                        <SU>29</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">cis-Dichloroethylene</ENT>
                                    <ENT>Purge &amp;Trap/Gas Chromatography/Mass Spectrometry</ENT>
                                    <ENT O="xl">
                                        524.3,
                                        <SU>9</SU>
                                         524.4.
                                        <SU>29</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">trans-Dichloroethylene</ENT>
                                    <ENT>Purge &amp;Trap/Gas Chromatography/Mass Spectrometry</ENT>
                                    <ENT O="xl">
                                        524.3,
                                        <SU>9</SU>
                                         524.4.
                                        <SU>29</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Dichloromethane</ENT>
                                    <ENT>Purge &amp;Trap/Gas Chromatography/Mass Spectrometry</ENT>
                                    <ENT O="xl">
                                        524.3,
                                        <SU>9</SU>
                                         524.4.
                                        <SU>29</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">1,2-Dichloropropane</ENT>
                                    <ENT>Purge &amp;Trap/Gas Chromatography/Mass Spectrometry</ENT>
                                    <ENT O="xl">
                                        524.3,
                                        <SU>9</SU>
                                         524.4.
                                        <SU>29</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Ethylbenzene</ENT>
                                    <ENT>Purge &amp;Trap/Gas Chromatography/Mass Spectrometry</ENT>
                                    <ENT O="xl">
                                        524.3,
                                        <SU>9</SU>
                                         524.4.
                                        <SU>29</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Styrene</ENT>
                                    <ENT>Purge &amp;Trap/Gas Chromatography/Mass Spectrometry</ENT>
                                    <ENT>
                                        524.3,
                                        <SU>9</SU>
                                         524.4 
                                        <SU>29</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <PRTPAGE P="535"/>
                                    <ENT I="01">Tetrachloroethylene</ENT>
                                    <ENT>Purge &amp;Trap/Gas Chromatography/Mass Spectrometry</ENT>
                                    <ENT O="xl">
                                        524.3,
                                        <SU>9</SU>
                                         524.4.
                                        <SU>29</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">1,1,1-Trichloroethane</ENT>
                                    <ENT>Purge &amp;Trap/Gas Chromatography/Mass Spectrometry</ENT>
                                    <ENT O="xl">
                                        524.3,
                                        <SU>9</SU>
                                         524.4.
                                        <SU>29</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Trichloroethylene</ENT>
                                    <ENT>Purge &amp;Trap/Gas Chromatography/Mass Spectrometry</ENT>
                                    <ENT O="xl">
                                        524.3,
                                        <SU>9</SU>
                                         524.4.
                                        <SU>29</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Toluene</ENT>
                                    <ENT>Purge &amp;Trap/Gas Chromatography/Mass Spectrometry</ENT>
                                    <ENT O="xl">
                                        524.3,
                                        <SU>9</SU>
                                         524.4.
                                        <SU>29</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">1,2,4-Trichlorobenzene</ENT>
                                    <ENT>Purge &amp;Trap/Gas Chromatography/Mass Spectrometry</ENT>
                                    <ENT O="xl">
                                        524.3,
                                        <SU>9</SU>
                                         524.4.
                                        <SU>29</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">1,1-Dichloroethylene</ENT>
                                    <ENT>Purge &amp;Trap/Gas Chromatography/Mass Spectrometry</ENT>
                                    <ENT>
                                        524.3,
                                        <SU>9</SU>
                                         524.4 
                                        <SU>29</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">1,1,2-Trichlorethane</ENT>
                                    <ENT>Purge &amp;Trap/Gas Chromatography/Mass Spectrometry</ENT>
                                    <ENT O="xl">
                                        524.3,
                                        <SU>9</SU>
                                         524.4.
                                        <SU>29</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Vinyl chloride</ENT>
                                    <ENT>Purge &amp;Trap/Gas Chromatography/Mass Spectrometry</ENT>
                                    <ENT O="xl">
                                        524.3,
                                        <SU>9</SU>
                                         524.4.
                                        <SU>29</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Xylenes (total)</ENT>
                                    <ENT>Purge &amp;Trap/Gas Chromatography/Mass Spectrometry</ENT>
                                    <ENT O="xl">
                                        524.3,
                                        <SU>9</SU>
                                         524.4.
                                        <SU>29</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">2,4-D</ENT>
                                    <ENT>Gas Chromatography/Electron Capture Detection (GC/ECD)</ENT>
                                    <ENT/>
                                    <ENT>6640 B</ENT>
                                    <ENT>6640 B</ENT>
                                    <ENT>6640 B-01, B-06</ENT>
                                    <ENT>D 5317-20</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">2,4,5-TP (Silvex)</ENT>
                                    <ENT>Gas Chromatography/Electron Capture Detection (GC/ECD)</ENT>
                                    <ENT/>
                                    <ENT>6640 B</ENT>
                                    <ENT>6640 B</ENT>
                                    <ENT>6640 B-01, B-06</ENT>
                                    <ENT>D 5317-20</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Alachlor</ENT>
                                    <ENT>Solid Phase Extraction/Gas Chromatography/Mass Spectrometry (GC/MS)</ENT>
                                    <ENT O="xl">
                                        525.3.
                                        <SU>24</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Atrazine</ENT>
                                    <ENT>Liquid Chromatography Electrospray Ionization Tandem Mass Spectrometry (LC/ESI-MS/MS)</ENT>
                                    <ENT O="xl">
                                        536.
                                        <SU>25</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <PRTPAGE P="536"/>
                                    <ENT I="22"> </ENT>
                                    <ENT>Solid Phase Extraction/Gas Chromatography/Mass Spectrometry (GC/MS)</ENT>
                                    <ENT O="xl">
                                        525.3,
                                        <SU>24</SU>
                                         523.
                                        <SU>26</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Benzo(a)pyrene</ENT>
                                    <ENT>Solid Phase Extraction/Gas Chromatography/Mass Spectrometry (GC/MS)</ENT>
                                    <ENT O="xl">
                                        525.3.
                                        <SU>24</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Carbofuran</ENT>
                                    <ENT>High-performance liquid chromatography (HPLC) with post-column derivatization and fluorescence detection</ENT>
                                    <ENT/>
                                    <ENT>6610 B</ENT>
                                    <ENT>6610 B</ENT>
                                    <ENT>6610 B-04</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Liquid Chromatography/Mass Spectrometry</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        ME 531.
                                        <SU>58</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Chlordane</ENT>
                                    <ENT>Solid Phase Extraction/Gas Chromatography/Mass Spectrometry (GC/MS)</ENT>
                                    <ENT O="xl">
                                        525.3.
                                        <SU>24</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Dalapon</ENT>
                                    <ENT>Ion Chromatography Electrospray Ionization Tandem Mass Spectrometry (IC-ESI-MS/MS)</ENT>
                                    <ENT O="xl">
                                        557.
                                        <SU>14</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Gas Chromatography/Electron Capture Detection (GC/ECD)</ENT>
                                    <ENT/>
                                    <ENT>6640 B</ENT>
                                    <ENT>6640 B</ENT>
                                    <ENT>6640 B-01, B-06</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Di(2-ethylhexyl)adipate</ENT>
                                    <ENT>Solid Phase Extraction/Gas Chromatography/Mass Spectrometry (GC/MS)</ENT>
                                    <ENT O="xl">
                                        525.3.
                                        <SU>24</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Di(2-ethylhexyl)phthalate</ENT>
                                    <ENT>Solid Phase Extraction/Gas Chromatography/Mass Spectrometry (GC/MS)</ENT>
                                    <ENT O="xl">
                                        525.3.
                                        <SU>24</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <PRTPAGE P="537"/>
                                    <ENT I="01">Dibromochloropropane (DBCP)</ENT>
                                    <ENT>Purge &amp;Trap/Gas Chromatography/Mass Spectrometry</ENT>
                                    <ENT O="xl">
                                        524.3.
                                        <SU>9</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Dinoseb</ENT>
                                    <ENT>Gas Chromatography/Electron Capture Detection (GC/ECD)</ENT>
                                    <ENT/>
                                    <ENT>6640 B</ENT>
                                    <ENT>6640 B</ENT>
                                    <ENT>6640 B-01, B-06</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Endrin</ENT>
                                    <ENT>Solid Phase Extraction/Gas Chromatography/Mass Spectrometry (GC/MS)</ENT>
                                    <ENT O="xl">
                                        525.3.
                                        <SU>24</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Ethyl dibromide (EDB)</ENT>
                                    <ENT>Purge &amp;Trap/Gas Chromatography/Mass Spectrometry</ENT>
                                    <ENT O="xl">
                                        524.3.
                                        <SU>9</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Glyphosate</ENT>
                                    <ENT>High-Performance Liquid Chromatography (HPLC) with Post-Column Derivatization and Fluorescence Detection</ENT>
                                    <ENT/>
                                    <ENT>6651 B</ENT>
                                    <ENT>6651 B</ENT>
                                    <ENT>6651 B-00, B-05</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Heptachlor</ENT>
                                    <ENT>Solid Phase Extraction/Gas Chromatography/Mass Spectrometry (GC/MS)</ENT>
                                    <ENT O="xl">
                                        525.3.
                                        <SU>24</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Heptachlor Epoxide</ENT>
                                    <ENT>Solid Phase Extraction/Gas Chromatography/Mass Spectrometry (GC/MS)</ENT>
                                    <ENT O="xl">
                                        525.3.
                                        <SU>24</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Hexachlorobenzene</ENT>
                                    <ENT>Solid Phase Extraction/Gas Chromatography/Mass Spectrometry (GC/MS)</ENT>
                                    <ENT O="xl">
                                        525.3.
                                        <SU>24</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Hexachlorocyclo-pentadiene</ENT>
                                    <ENT>Solid Phase Extraction/Gas Chromatography/Mass Spectrometry (GC/MS)</ENT>
                                    <ENT O="xl">
                                        525.3.
                                        <SU>24</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Lindane</ENT>
                                    <ENT>Solid Phase Extraction/Gas Chromatography/Mass Spectrometry (GC/MS)</ENT>
                                    <ENT O="xl">
                                        525.3.
                                        <SU>24</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <PRTPAGE P="538"/>
                                    <ENT I="01">Methoxychlor</ENT>
                                    <ENT>Solid Phase Extraction/Gas Chromatography/Mass Spectrometry (GC/MS)</ENT>
                                    <ENT O="xl">
                                        525.3.
                                        <SU>24</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Oxamyl</ENT>
                                    <ENT>High-performance liquid chromatography (HPLC) with post-column derivatization and fluorescence detection</ENT>
                                    <ENT/>
                                    <ENT>6610 B</ENT>
                                    <ENT>6610 B</ENT>
                                    <ENT>6610 B-04</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Liquid Chromatography/Mass Spectrometry</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        ME 531.
                                        <SU>58</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">PCBs (as Aroclors)</ENT>
                                    <ENT>Solid Phase Extraction/Gas Chromatography/Mass Spectrometry (GC/MS)</ENT>
                                    <ENT O="xl">
                                        525.3.
                                        <SU>24</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Pentachlorophenol</ENT>
                                    <ENT>Gas Chromatography/Electron Capture Detection (GC/ECD)</ENT>
                                    <ENT/>
                                    <ENT>6640 B</ENT>
                                    <ENT>6640 B</ENT>
                                    <ENT>6640 B-01, B-06</ENT>
                                    <ENT>D 5317-20</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Solid Phase Extraction/Gas Chromatography/Mass Spectrometry (GC/MS)</ENT>
                                    <ENT O="xl">
                                        525.3.
                                        <SU>24</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Picloram</ENT>
                                    <ENT>Gas Chromatography/Electron Capture Detection (GC/ECD)</ENT>
                                    <ENT/>
                                    <ENT>6640 B</ENT>
                                    <ENT>6640 B</ENT>
                                    <ENT>6640 B-01, B-06</ENT>
                                    <ENT>D 5317-20</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Simazine</ENT>
                                    <ENT>Liquid Chromatography Electrospray Ionization Tandem Mass Spectrometry (LC/ESI-MS/MS)</ENT>
                                    <ENT O="xl">
                                        536.
                                        <SU>25</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Solid Phase Extraction/Gas Chromatography/Mass Spectrometry (GC/MS)</ENT>
                                    <ENT O="xl">
                                        525.3,
                                        <SU>24</SU>
                                         523.
                                        <SU>26</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <PRTPAGE P="539"/>
                                    <ENT I="01">Toxaphene</ENT>
                                    <ENT>Solid Phase Extraction/Gas Chromatography/Mass Spectrometry (GC/MS)</ENT>
                                    <ENT O="xl">
                                        525.3.
                                        <SU>24</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Total Trihalomethanes</ENT>
                                    <ENT>Purge &amp;Trap/Gas Chromatography/Mass Spectrometry</ENT>
                                    <ENT O="xl">
                                        524.3,
                                        <SU>9</SU>
                                         524.4.
                                        <SU>29</SU>
                                    </ENT>
                                </ROW>
                            </GPOTABLE>
                            <PRTPAGE P="540"/>
                            <GPOTABLE COLS="7" OPTS="L2,nj,p7,7/8" CDEF="s50,r50,r30,r30,r30,r30,r30">
                                <TTITLE>
                                    Alternative Testing Methods for Contaminants Listed at 40 CFR 141.25(
                                    <E T="01">a</E>
                                    )
                                </TTITLE>
                                <BOXHD>
                                    <CHED H="1">Contaminant</CHED>
                                    <CHED H="1">Methodology</CHED>
                                    <CHED H="1">EPA method</CHED>
                                    <CHED H="1">
                                        SM 21st edition 
                                        <SU>1</SU>
                                    </CHED>
                                    <CHED H="1">
                                        SM 22nd edition,
                                        <SU>28</SU>
                                         SM 23rd edition,
                                        <SU>49</SU>
                                         SM 24th edition 
                                        <SU>66</SU>
                                    </CHED>
                                    <CHED H="1">
                                        ASTM 
                                        <SU>4</SU>
                                    </CHED>
                                    <CHED H="1">
                                        SM online 
                                        <SU>3</SU>
                                    </CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="22">Naturally Occurring:</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="03">Gross alpha and beta</ENT>
                                    <ENT>Evaporation</ENT>
                                    <ENT>
                                        900.0, Rev. 1.0 
                                        <SU>50</SU>
                                    </ENT>
                                    <ENT>7110 B</ENT>
                                    <ENT>7110 B</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Liquid Scintillation</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>7110 D</ENT>
                                    <ENT>D 7283-17</ENT>
                                    <ENT>7110 D-17.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="03">Gross alpha</ENT>
                                    <ENT>Coprecipitation</ENT>
                                    <ENT/>
                                    <ENT>7110 C</ENT>
                                    <ENT>7110 C</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="03">Radium 226</ENT>
                                    <ENT>Radon emanation</ENT>
                                    <ENT>
                                        903.1, Rev. 1.0 
                                        <SU>53</SU>
                                    </ENT>
                                    <ENT>7500-Ra C</ENT>
                                    <ENT>7500-Ra C</ENT>
                                    <ENT>D 3454-05, -18, D 3454-21</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Radiochemical</ENT>
                                    <ENT>
                                        903.0, Rev. 1.0 
                                        <SU>54</SU>
                                    </ENT>
                                    <ENT>7500-Ra B</ENT>
                                    <ENT>7500-Ra B</ENT>
                                    <ENT>D 2460-07</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Gamma Spectrometry</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>7500-Ra E</ENT>
                                    <ENT/>
                                    <ENT>7500-Ra E-07.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="03">Radium 228</ENT>
                                    <ENT>Radiochemical</ENT>
                                    <ENT>
                                        904.0, Rev. 1.0 
                                        <SU>62</SU>
                                    </ENT>
                                    <ENT>7500-Ra D</ENT>
                                    <ENT>7500-Ra D</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Gamma Spectrometry</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>7500-Ra E</ENT>
                                    <ENT/>
                                    <ENT>7500-Ra E-07.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="03">Uranium</ENT>
                                    <ENT>Radiochemical</ENT>
                                    <ENT/>
                                    <ENT>7500-U B</ENT>
                                    <ENT>7500-U B</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>ICP-MS</ENT>
                                    <ENT/>
                                    <ENT>3125</ENT>
                                    <ENT/>
                                    <ENT>D 5673-05, 10, 16</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Alpha spectrometry</ENT>
                                    <ENT/>
                                    <ENT>7500-U C</ENT>
                                    <ENT>7500-U C</ENT>
                                    <ENT>D 3972-09</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Laser Phosphorimetry</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>D 5174-07</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Alpha Liquid Scintillation Spectrometry</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>D 6239-09</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22">Man-Made:</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="03">Radioactive Cesium</ENT>
                                    <ENT>Radiochemical</ENT>
                                    <ENT/>
                                    <ENT>7500-Cs B</ENT>
                                    <ENT>7500-Cs B</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Gamma Ray Spectrometry</ENT>
                                    <ENT/>
                                    <ENT>7120</ENT>
                                    <ENT>7120</ENT>
                                    <ENT>D 3649-06</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="03">Radioactive Iodine</ENT>
                                    <ENT>Radiochemical</ENT>
                                    <ENT/>
                                    <ENT>7500-I B, 7500-I C, 7500-I D</ENT>
                                    <ENT>7500-I B, 7500-I C, 7500-I D</ENT>
                                    <ENT>D 3649-06</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Gamma Ray Spectrometry</ENT>
                                    <ENT/>
                                    <ENT>7120</ENT>
                                    <ENT>7120</ENT>
                                    <ENT>D 4785-08, -20</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="03">Radioactive Strontium 89, 90</ENT>
                                    <ENT>Radiochemical</ENT>
                                    <ENT/>
                                    <ENT>7500-Sr B</ENT>
                                    <ENT>7500-Sr B</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="03">Tritium</ENT>
                                    <ENT>Liquid Scintillation</ENT>
                                    <ENT/>
                                    <ENT>
                                        7500-
                                        <SU>3</SU>
                                        H B
                                    </ENT>
                                    <ENT>
                                        7500-
                                        <SU>3</SU>
                                        H B
                                    </ENT>
                                    <ENT>D 4107-08, -20</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="03">Gamma Emitters</ENT>
                                    <ENT>Gamma Ray Spectrometry</ENT>
                                    <ENT/>
                                    <ENT>7120, 7500-Cs B, 7500-I B</ENT>
                                    <ENT>7120, 7500-Cs B, 7500-I B</ENT>
                                    <ENT>D 3649-06, D 4785-08, -20</ENT>
                                </ROW>
                            </GPOTABLE>
                            <PRTPAGE P="541"/>
                            <GPOTABLE COLS="8" OPTS="L2,nj,p7,7/8" CDEF="s50,r50,r30,r30,r30,r30,r30,r50">
                                <TTITLE>
                                    Alternative Testing Methods for Contaminants Listed at 40 CFR 141.74(
                                    <E T="01">a</E>
                                    )(1)
                                </TTITLE>
                                <BOXHD>
                                    <CHED H="1">Organism</CHED>
                                    <CHED H="1">Methodology</CHED>
                                    <CHED H="1">
                                        SM 21st edition 
                                        <SU>1</SU>
                                    </CHED>
                                    <CHED H="1">
                                        SM 22nd
                                        <LI>
                                            edition 
                                            <SU>28</SU>
                                        </LI>
                                    </CHED>
                                    <CHED H="1">
                                        SM 23rd edition 
                                        <SU>49</SU>
                                    </CHED>
                                    <CHED H="1">
                                        SM 24th edition 
                                        <SU>66</SU>
                                    </CHED>
                                    <CHED H="1">
                                        SM online 
                                        <SU>3</SU>
                                    </CHED>
                                    <CHED H="1">Other</CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">Total Coliform</ENT>
                                    <ENT>Total Coliform Fermentation Technique</ENT>
                                    <ENT>9221 A, B, C</ENT>
                                    <ENT>9221 A, B, C</ENT>
                                    <ENT>9221 A, B, C</ENT>
                                    <ENT>9221 A, B, C</ENT>
                                    <ENT>9221 A, B, C-06</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Total Coliform Membrane Filter Technique</ENT>
                                    <ENT>9222 A, B, C</ENT>
                                    <ENT/>
                                    <ENT>9222 A, B, C</ENT>
                                    <ENT>9222 A, B, C</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>ONPG-MUG Test</ENT>
                                    <ENT>9223</ENT>
                                    <ENT>9223 B</ENT>
                                    <ENT>9223 B</ENT>
                                    <ENT>9223 B</ENT>
                                    <ENT>9223 B-04</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Fecal Coliforms</ENT>
                                    <ENT>Fecal Coliform Procedure</ENT>
                                    <ENT>9221 E</ENT>
                                    <ENT>9221 E</ENT>
                                    <ENT>9221 E</ENT>
                                    <ENT>9221 E</ENT>
                                    <ENT>9221 E-06</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Fecal Coliform Filter Procedure</ENT>
                                    <ENT>9222 D</ENT>
                                    <ENT>9222 D</ENT>
                                    <ENT>9222 D</ENT>
                                    <ENT>9222 D</ENT>
                                    <ENT>9222 D-06</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Heterotrophic bacteria</ENT>
                                    <ENT>Pour Plate Method</ENT>
                                    <ENT>9215 B</ENT>
                                    <ENT>9215 B</ENT>
                                    <ENT>9215 B</ENT>
                                    <ENT/>
                                    <ENT>9215 B-04</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Turbidity</ENT>
                                    <ENT>Nephelometric Method</ENT>
                                    <ENT>2130 B</ENT>
                                    <ENT>2130 B</ENT>
                                    <ENT>2130 B</ENT>
                                    <ENT>2130 B</ENT>
                                    <ENT/>
                                    <ENT>
                                        Hach Method 8195, Rev. 3.0.
                                        <SU>52</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Laser Nephelometry (on-line)</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        Mitchell M5271,
                                        <SU>10</SU>
                                         Mitchell M5331, Rev. 1.2,
                                        <SU>42</SU>
                                         Lovibond PTV 6000.
                                        <SU>46</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>LED Nephelometry (on-line)</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        Mitchell M5331,
                                        <SU>11</SU>
                                         Mitchell M5331, Rev. 1.2,
                                        <SU>42</SU>
                                         Lovibond PTV 2000,
                                        <SU>45</SU>
                                         Yokogawa 820.
                                        <SU>68</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>LED Nephelometry (on-line)</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        AMI Turbiwell,
                                        <SU>15</SU>
                                         Lovibond PTV 1000.
                                        <SU>44</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>LED Nephelometry (portable)</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        Orion AQ4500,
                                        <SU>12</SU>
                                         Lovibond TB 3500,
                                        <SU>64</SU>
                                         Lovibond TB 5000.
                                        <SU>65</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Laser Nephelometry (portable)</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        Lovibond TB 6000.
                                        <SU>63</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>360° Nephelometry</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        Hach Method 10258, Rev. 1.0,
                                        <SU>39</SU>
                                         Hach Method 10258, Rev. 2.0.
                                        <SU>51</SU>
                                    </ENT>
                                </ROW>
                            </GPOTABLE>
                            <PRTPAGE P="542"/>
                            <GPOTABLE COLS="7" OPTS="L2,nj,p7,7/8" CDEF="s50,r50,r30,r30,r30,r30,r30">
                                <TTITLE>
                                    Alternative Testing Methods for Disinfectant Residuals Listed at 40 CFR 141.74(
                                    <E T="01">a</E>
                                    )(2)
                                </TTITLE>
                                <BOXHD>
                                    <CHED H="1">Residual</CHED>
                                    <CHED H="1">Methodology</CHED>
                                    <CHED H="1">EPA methods</CHED>
                                    <CHED H="1">
                                        SM 21st edition 
                                        <SU>1</SU>
                                    </CHED>
                                    <CHED H="1">
                                        SM 22nd edition,
                                        <SU>28</SU>
                                         SM 23rd edition,
                                        <SU>49</SU>
                                         SM 24th edition 
                                        <SU>66</SU>
                                    </CHED>
                                    <CHED H="1">
                                        ASTM 
                                        <SU>4</SU>
                                    </CHED>
                                    <CHED H="1">Other</CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">Free Chlorine</ENT>
                                    <ENT>Amperometric Titration</ENT>
                                    <ENT/>
                                    <ENT>4500-Cl D</ENT>
                                    <ENT>4500-Cl D</ENT>
                                    <ENT>D 1253-08, -14</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>DPD Ferrous Titrimetric</ENT>
                                    <ENT/>
                                    <ENT>4500-Cl F</ENT>
                                    <ENT>4500-Cl F</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>DPD Colorimetric</ENT>
                                    <ENT/>
                                    <ENT>4500-Cl G</ENT>
                                    <ENT>4500-Cl G</ENT>
                                    <ENT/>
                                    <ENT>
                                        Hach Method 10260.
                                        <SU>31</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Indophenol Colorimetric</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        Hach Method 10241.
                                        <SU>34</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Syringaldazine (FACTS)</ENT>
                                    <ENT/>
                                    <ENT>4500-Cl H</ENT>
                                    <ENT>4500-Cl H</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>On-line Chlorine Analyzer</ENT>
                                    <ENT O="xl">
                                        EPA 334.0.
                                        <SU>16</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Amperometric Sensor</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        ChloroSense,
                                        <SU>17</SU>
                                         ChloroSense, Rev. 1.1.
                                        <SU>59</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Total Chlorine</ENT>
                                    <ENT>Amperometric Titration</ENT>
                                    <ENT/>
                                    <ENT>4500-Cl D</ENT>
                                    <ENT>4500-Cl D</ENT>
                                    <ENT>D 1253-08, -14</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Amperometric Titration (Low level measurement)</ENT>
                                    <ENT/>
                                    <ENT>4500-Cl E</ENT>
                                    <ENT>4500-Cl E</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>DPD Ferrous Titrimetric</ENT>
                                    <ENT/>
                                    <ENT>4500-Cl F</ENT>
                                    <ENT>4500-Cl F</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>DPD Colorimetric</ENT>
                                    <ENT/>
                                    <ENT>4500-Cl G</ENT>
                                    <ENT>4500-Cl G</ENT>
                                    <ENT/>
                                    <ENT>
                                        Hach Method 10260.
                                        <SU>31</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Indophenol Colorimetric</ENT>
                                    <ENT O="xl">
                                        127.
                                        <SU>55</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Iodometric Electrode</ENT>
                                    <ENT/>
                                    <ENT>4500-Cl I</ENT>
                                    <ENT>4500-Cl I</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>On-line Chlorine Analyzer</ENT>
                                    <ENT O="xl">
                                        EPA 334.0.
                                        <SU>16</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Amperometric Sensor</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        ChloroSense,
                                        <SU>17</SU>
                                         ChloroSense, Rev. 1.1.
                                        <SU>59</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Chlorine Dioxide</ENT>
                                    <ENT>Amperometric Titration</ENT>
                                    <ENT/>
                                    <ENT>
                                        4500-ClO
                                        <E T="0732">2</E>
                                         C
                                    </ENT>
                                    <ENT>
                                        4500-ClO
                                        <E T="0732">2</E>
                                         C
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Amperometric Titration</ENT>
                                    <ENT/>
                                    <ENT>
                                        4500-ClO
                                        <E T="0732">2</E>
                                         E
                                    </ENT>
                                    <ENT>
                                        4500-ClO
                                        <E T="0732">2</E>
                                         E
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Amperometric Sensor</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        ChlordioX Plus,
                                        <SU>32</SU>
                                         ChlordioX Plus, Rev. 1.1.
                                        <SU>60</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Ozone</ENT>
                                    <ENT>Indigo Method</ENT>
                                    <ENT/>
                                    <ENT>
                                        4500-O
                                        <E T="0732">3</E>
                                         B
                                    </ENT>
                                    <ENT>
                                        4500-O
                                        <E T="0732">3</E>
                                         B
                                    </ENT>
                                </ROW>
                            </GPOTABLE>
                            <PRTPAGE P="543"/>
                            <GPOTABLE COLS="8" OPTS="L2,nj,p7,7/8" CDEF="s50,r50,r50,r30,r30,r30,r30,r30">
                                <TTITLE>
                                    Alternative Testing Methods for Contaminants Listed at 40 CFR 141.131(
                                    <E T="01">b</E>
                                    )(1)
                                </TTITLE>
                                <BOXHD>
                                    <CHED H="1">Contaminant</CHED>
                                    <CHED H="1">Methodology</CHED>
                                    <CHED H="1">EPA method</CHED>
                                    <CHED H="1">
                                        ASTM 
                                        <SU>4</SU>
                                    </CHED>
                                    <CHED H="1">
                                        SM online 
                                        <SU>3</SU>
                                    </CHED>
                                    <CHED H="1">
                                        SM 21st edition 
                                        <SU>1</SU>
                                    </CHED>
                                    <CHED H="1">
                                        SM 22nd
                                        <LI>
                                            edition,
                                            <SU>28</SU>
                                             SM
                                        </LI>
                                        <LI>
                                            23rd edition,
                                            <SU>49</SU>
                                        </LI>
                                        <LI>SM 24th</LI>
                                        <LI>
                                            Edition 
                                            <SU>66</SU>
                                        </LI>
                                    </CHED>
                                    <CHED H="1">Other</CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">TTHM</ENT>
                                    <ENT>P&amp;T/GC/MS</ENT>
                                    <ENT O="xl">
                                        524.3,
                                        <SU>9</SU>
                                         524.4.
                                        <SU>29</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">HAA5</ENT>
                                    <ENT>LLE (diazomethane)/GC/ECD</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>6251 B-07</ENT>
                                    <ENT>6251 B</ENT>
                                    <ENT>6251 B</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Ion Chromatography Electrospray Ionization Tandem Mass Spectrometry (IC-ESI-MS/MS)</ENT>
                                    <ENT O="xl">
                                        557.
                                        <SU>14</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Two-Dimensional Ion Chromatography (IC) with Suppressed Conductivity Detection</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        Thermo Fisher 557.1.
                                        <SU>47</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Bromate</ENT>
                                    <ENT>Two-Dimensional Ion Chromatography (IC)</ENT>
                                    <ENT O="xl">
                                        302.0
                                        <SU>18</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Ion Chromatography Electrospray Ionization Tandem Mass Spectrometry (IC-ESI-MS/MS)</ENT>
                                    <ENT O="xl">
                                        557.
                                        <SU>14</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Chemically Suppressed Ion Chromatography</ENT>
                                    <ENT/>
                                    <ENT>D 6581-08 A</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Electrolytically Suppressed Ion Chromatography</ENT>
                                    <ENT/>
                                    <ENT>D 6581-08 B</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Chlorite</ENT>
                                    <ENT>Chemically Suppressed Ion Chromatography</ENT>
                                    <ENT/>
                                    <ENT>D 6581-08 A</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Electrolytically Suppressed Ion Chromatography</ENT>
                                    <ENT/>
                                    <ENT>D 6581-08 B</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Chlorite—daily monitoring as prescribed in 40 CFR 141.132(b)(2)(i)(A)</ENT>
                                    <ENT>Amperometric Titration</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        4500-ClO
                                        <E T="0732">2</E>
                                         E
                                    </ENT>
                                    <ENT>
                                        4500-ClO
                                        <E T="0732">2</E>
                                         E
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <PRTPAGE P="544"/>
                                    <ENT I="22"> </ENT>
                                    <ENT>Amperometric Sensor</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        ChlordioX Plus,
                                        <SU>32</SU>
                                         ChlordioX Plus, Rev. 1.1.
                                        <SU>60</SU>
                                    </ENT>
                                </ROW>
                            </GPOTABLE>
                            <PRTPAGE P="545"/>
                            <GPOTABLE COLS="06" OPTS="L2,p1,7/8" CDEF="s50,r50,r30,r30,r30,r30">
                                <TTITLE>
                                    Alternative Testing Methods for Disinfectant Residuals Listed at 40 CFR 141.131(
                                    <E T="01">c</E>
                                    )(1)
                                </TTITLE>
                                <BOXHD>
                                    <CHED H="1">Residual</CHED>
                                    <CHED H="1">Methodology</CHED>
                                    <CHED H="1">
                                        SM 21
                                        <SU>st</SU>
                                         edition 
                                        <SU>1</SU>
                                    </CHED>
                                    <CHED H="1">
                                        SM 22
                                        <SU>nd</SU>
                                         edition,
                                        <SU>28</SU>
                                         SM 23
                                        <SU>rd</SU>
                                         edition,
                                        <SU>49</SU>
                                         SM 24
                                        <SU>th</SU>
                                         edition 
                                        <SU>66</SU>
                                    </CHED>
                                    <CHED H="1">
                                        ASTM 
                                        <SU>4</SU>
                                    </CHED>
                                    <CHED H="1">Other</CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">Free Chlorine</ENT>
                                    <ENT>Amperometric Titration</ENT>
                                    <ENT>4500-Cl D</ENT>
                                    <ENT>4500-Cl D</ENT>
                                    <ENT>D 1253-08, -14</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>DPD Ferrous Titrimetric</ENT>
                                    <ENT>4500-Cl F</ENT>
                                    <ENT>4500-Cl F</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>DPD Colorimetric</ENT>
                                    <ENT>4500-Cl G</ENT>
                                    <ENT>4500-Cl G</ENT>
                                    <ENT/>
                                    <ENT>
                                        Hach Method 10260.
                                        <SU>31</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Indophenol Colorimetric</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        Hach Method 10241.
                                        <SU>34</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Syringaldazine (FACTS)</ENT>
                                    <ENT>4500-Cl H</ENT>
                                    <ENT>4500-Cl H</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Amperometric Sensor</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        ChloroSense,
                                        <SU>17</SU>
                                         ChloroSense, Rev. 1.1.
                                        <SU>59</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>On-line Chlorine Analyzer</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        EPA 334.0.
                                        <SU>16</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Combined Chlorine</ENT>
                                    <ENT>Amperometric Titration</ENT>
                                    <ENT>4500-Cl D</ENT>
                                    <ENT>4500-Cl D</ENT>
                                    <ENT>D 1253-08, -14.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>DPD Ferrous Titrimetric</ENT>
                                    <ENT>4500-Cl F</ENT>
                                    <ENT>4500-Cl F</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>DPD Colorimetric</ENT>
                                    <ENT>4500-Cl G</ENT>
                                    <ENT>4500-Cl G</ENT>
                                    <ENT/>
                                    <ENT>
                                        Hach Method 10260.
                                        <SU>31</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Total Chlorine</ENT>
                                    <ENT>Amperometric Titration</ENT>
                                    <ENT>4500-Cl D</ENT>
                                    <ENT>4500-Cl D</ENT>
                                    <ENT>D 1253-08, -14</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Low level Amperometric Titration</ENT>
                                    <ENT>4500-Cl E</ENT>
                                    <ENT>4500-Cl E</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>DPD Ferrous Titrimetric</ENT>
                                    <ENT>4500-Cl F</ENT>
                                    <ENT>4500-Cl F</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>DPD Colorimetric</ENT>
                                    <ENT>4500-Cl G</ENT>
                                    <ENT>4500-Cl G</ENT>
                                    <ENT/>
                                    <ENT>
                                        Hach Method 10260.
                                        <SU>31</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Iodometric Electrode</ENT>
                                    <ENT>4500-Cl I</ENT>
                                    <ENT>4500-Cl I</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Amperometric Sensor</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        ChloroSense,
                                        <SU>17</SU>
                                         ChloroSense, Rev. 1.1.
                                        <SU>59</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>On-line Chlorine Analyzer</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        EPA 334.0.
                                        <SU>16</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Chlorine Dioxide</ENT>
                                    <ENT>Amperometric Method II</ENT>
                                    <ENT>
                                        4500-ClO
                                        <E T="0732">2</E>
                                         E
                                    </ENT>
                                    <ENT>
                                        4500-ClO
                                        <E T="0732">2</E>
                                         E
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Amperometric Sensor</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        ChlordioX Plus,
                                        <SU>32</SU>
                                         ChlordioX Plus, Rev. 1.1.
                                        <SU>60</SU>
                                    </ENT>
                                </ROW>
                            </GPOTABLE>
                            <GPOTABLE COLS="3" OPTS="L2" CDEF="s25,r75,xls68">
                                <TTITLE>
                                    Alternative Testing Methods for Disinfectant Residuals Listed at 40 CFR 141.131(
                                    <E T="01">c</E>
                                    )(2), If Approved by the State
                                </TTITLE>
                                <BOXHD>
                                    <CHED H="1">Residual</CHED>
                                    <CHED H="1">Methodology</CHED>
                                    <CHED H="1">Method</CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">Free Chlorine</ENT>
                                    <ENT>Test Strips</ENT>
                                    <ENT>
                                        Method D99-003 
                                        <SU>5</SU>
                                    </ENT>
                                </ROW>
                            </GPOTABLE>
                            <PRTPAGE P="546"/>
                            <GPOTABLE COLS="08" OPTS="L2,p1,7/8" CDEF="s50,r50,r30,r30,r30,r30,r30,r50">
                                <TTITLE>
                                    Alternative Testing Methods for Parameters Listed at 40 CFR 141.131(
                                    <E T="01">d</E>
                                    )
                                </TTITLE>
                                <BOXHD>
                                    <CHED H="1">Parameter</CHED>
                                    <CHED H="1">Methodology</CHED>
                                    <CHED H="1">
                                        SM 21
                                        <SU>st</SU>
                                         edition 
                                        <SU>1</SU>
                                    </CHED>
                                    <CHED H="1">
                                        SM 22
                                        <SU>nd</SU>
                                         edition 
                                        <SU>28</SU>
                                    </CHED>
                                    <CHED H="1">
                                        SM 23
                                        <SU>rd</SU>
                                         edition 
                                        <SU>49</SU>
                                        , SM 24
                                        <SU>th</SU>
                                         edition 
                                        <SU>66</SU>
                                    </CHED>
                                    <CHED H="1">
                                        SM online 
                                        <SU>3</SU>
                                    </CHED>
                                    <CHED H="1">EPA</CHED>
                                    <CHED H="1">Other</CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">Total Organic Carbon (TOC)</ENT>
                                    <ENT>High Temperature Combustion</ENT>
                                    <ENT>5310 B</ENT>
                                    <ENT>5310 B</ENT>
                                    <ENT>5310 B</ENT>
                                    <ENT/>
                                    <ENT>
                                        415.3, Rev 1.2 
                                        <SU>19</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Persulfate-Ultraviolet or Heated Persulfate Oxidation</ENT>
                                    <ENT>5310 C</ENT>
                                    <ENT>5310 C</ENT>
                                    <ENT>5310 C</ENT>
                                    <ENT/>
                                    <ENT>
                                        415.3, Rev 1.2 
                                        <SU>19</SU>
                                    </ENT>
                                    <ENT>
                                        Hach Method 10267 
                                        <SU>38</SU>
                                        .
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Wet Oxidation</ENT>
                                    <ENT>5310 D</ENT>
                                    <ENT>5310 D</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        415.3, Rev 1.2 
                                        <SU>19</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Ozone Oxidation</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        Hach Method 10261 
                                        <SU>37</SU>
                                        .
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Specific Ultraviolet Absorbance (SUVA)</ENT>
                                    <ENT>
                                        Calculation using DOC and UV
                                        <E T="0732">254</E>
                                         data
                                    </ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        415.3, Rev 1.2 
                                        <SU>19</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Dissolved Organic Carbon (DOC)</ENT>
                                    <ENT>High Temperature Combustion</ENT>
                                    <ENT>5310 B</ENT>
                                    <ENT>5310 B</ENT>
                                    <ENT>5310 B</ENT>
                                    <ENT/>
                                    <ENT>
                                        415.3, Rev 1.2 
                                        <SU>19</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Persulfate-Ultraviolet or Heated Persulfate Oxidation</ENT>
                                    <ENT>5310 C</ENT>
                                    <ENT>5310 C</ENT>
                                    <ENT>5310 C</ENT>
                                    <ENT/>
                                    <ENT>
                                        415.3, Rev 1.2 
                                        <SU>19</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Wet Oxidation</ENT>
                                    <ENT>5310 D</ENT>
                                    <ENT>5310 D</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        415.3, Rev 1.2 
                                        <SU>19</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">
                                        Ultraviolet absorption at 254 nm (UV
                                        <E T="0732">254</E>
                                        )
                                    </ENT>
                                    <ENT>Spectrophotometry</ENT>
                                    <ENT>5910 B</ENT>
                                    <ENT>5910 B</ENT>
                                    <ENT>5910 B</ENT>
                                    <ENT>5910 B-11</ENT>
                                    <ENT>
                                        415.3, Rev 1.2 
                                        <SU>19</SU>
                                    </ENT>
                                    <ENT/>
                                </ROW>
                            </GPOTABLE>
                            <PRTPAGE P="547"/>
                            <GPOTABLE COLS="3" OPTS="L2" CDEF="xs60,r100,xs60">
                                <TTITLE>
                                    Alternative Testing Methods With MRL ≤0.0010 mg/L for Monitoring Listed at 
                                    <E T="01">40 CFR 141.132(b)(3)(ii)(B)</E>
                                </TTITLE>
                                <BOXHD>
                                    <CHED H="1">Contaminant</CHED>
                                    <CHED H="1">Methodology</CHED>
                                    <CHED H="1">EPA method</CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">Bromate</ENT>
                                    <ENT>Two-Dimensional Ion Chromatography (IC)</ENT>
                                    <ENT>
                                        302.0 
                                        <SU>18</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Ion Chromatography Electrospray Ionization Tandem Mass Spectrometry (IC-ESI-MS/MS)</ENT>
                                    <ENT>
                                        557 
                                        <SU>14</SU>
                                    </ENT>
                                </ROW>
                            </GPOTABLE>
                            <PRTPAGE P="548"/>
                            <GPOTABLE COLS="08" OPTS="L2,p1,7/8" CDEF="s50,r50,r30,r30,r30,r30,r30,r50">
                                <TTITLE>
                                    Alternative Testing Methods for Contaminants Listed at 40 CFR 141.402(
                                    <E T="01">c</E>
                                    )(2)
                                </TTITLE>
                                <BOXHD>
                                    <CHED H="1">Organism</CHED>
                                    <CHED H="1">Methodology</CHED>
                                    <CHED H="1">
                                        SM 20
                                        <SU>th</SU>
                                         edition 
                                        <SU>6</SU>
                                    </CHED>
                                    <CHED H="1">
                                        SM 21
                                        <SU>st</SU>
                                         edition 
                                        <SU>1</SU>
                                    </CHED>
                                    <CHED H="1">
                                        SM 22
                                        <SU>nd</SU>
                                         edition 
                                        <SU>28</SU>
                                    </CHED>
                                    <CHED H="1">
                                        SM 23
                                        <SU>rd</SU>
                                         edition 
                                        <SU>49</SU>
                                        , SM 24
                                        <SU>th</SU>
                                         edition 
                                        <SU>66</SU>
                                    </CHED>
                                    <CHED H="1">
                                        SM online 
                                        <SU>3</SU>
                                    </CHED>
                                    <CHED H="1">Other</CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">
                                        <E T="03">E. coli</E>
                                    </ENT>
                                    <ENT>Colilert</ENT>
                                    <ENT/>
                                    <ENT>9223 B</ENT>
                                    <ENT>9223 B</ENT>
                                    <ENT>9223 B</ENT>
                                    <ENT>9223 B-97, B-04</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Colisure</ENT>
                                    <ENT/>
                                    <ENT>9223 B</ENT>
                                    <ENT>9223 B</ENT>
                                    <ENT>9223 B</ENT>
                                    <ENT>9223 B-97, B-04</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Colilert-18</ENT>
                                    <ENT>9223 B</ENT>
                                    <ENT>9223 B</ENT>
                                    <ENT>9223 B</ENT>
                                    <ENT>9223 B</ENT>
                                    <ENT>9223 B-97, B-04</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Readycult®</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        Readycult®.
                                        <SU>20</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Colitag</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        Modified Colitag
                                        <E T="0731">TM</E>
                                         
                                        <SU>13</SU>
                                        , Modified Colitag 
                                        <E T="0731">TM</E>
                                        , Version 2.0.
                                        <SU>61</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Chromocult®</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        Chromocult®.
                                        <SU>21</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>EC-MUG</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>9221 F</ENT>
                                    <ENT>9221 F</ENT>
                                    <ENT>9221 F-06</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>NA-MUG</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>9222 I</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>mColiBlue24 Test</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>9222 J</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>
                                        Tecta EC/TC 
                                        <SU>33</SU>
                                         
                                        <SU>43</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>
                                        RAPID'E.coli 2 
                                        <SU>56</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Enterococci</ENT>
                                    <ENT>Multiple-Tube Technique</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>9230 B</ENT>
                                    <ENT>9230 B-04</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Membrane Filter Techniques</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>9230 C</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Fluorogenic Substrate Enterococcus Test (using Enterolert)</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>9230 D</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Coliphage</ENT>
                                    <ENT>Two-Step Enrichment Presence-Absence Procedure</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        Fast Phage.
                                        <SU>30</SU>
                                    </ENT>
                                </ROW>
                            </GPOTABLE>
                            <PRTPAGE P="549"/>
                            <GPOTABLE COLS="3" OPTS="L2" CDEF="s50,r150,xls60">
                                <TTITLE>
                                    Alternative Testing Methods for Contaminants Listed at 40 CFR 141.704(
                                    <E T="01">a</E>
                                    )
                                </TTITLE>
                                <BOXHD>
                                    <CHED H="1">Organism</CHED>
                                    <CHED H="1">Methodology</CHED>
                                    <CHED H="1">EPA Method</CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">
                                        <E T="03">Cryptosporidium</E>
                                    </ENT>
                                    <ENT>
                                        <E T="03">Filtration/Immunomagnetic Separation/Immunofluorescence Assay Microscopy</E>
                                    </ENT>
                                    <ENT>
                                        <E T="03">1623.1</E>
                                         
                                        <SU>27</SU>
                                    </ENT>
                                </ROW>
                            </GPOTABLE>
                            <GPOTABLE COLS="3" OPTS="L2" CDEF="s25,r100,xs68">
                                <TTITLE>
                                    Alternative Testing Methods for Contaminants Listed at 40 CFR 141.704(
                                    <E T="01">b</E>
                                    )
                                </TTITLE>
                                <BOXHD>
                                    <CHED H="1">Organism</CHED>
                                    <CHED H="1">Methodology</CHED>
                                    <CHED H="1">
                                        SM 20th edition 
                                        <SU>6</SU>
                                    </CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">
                                        <E T="03">E. coli</E>
                                    </ENT>
                                    <ENT>Membrane Filtration, Two Step</ENT>
                                    <ENT>9222 D/9222 G</ENT>
                                </ROW>
                            </GPOTABLE>
                            <GPOTABLE COLS="07" OPTS="L2,p1,7/8" CDEF="s50,r50,r50,r30,r30,r30,r30">
                                <TTITLE>
                                    Alternative Testing Methods for Contaminants Listed at 40 CFR 141.852(
                                    <E T="01">a</E>
                                    )(5)
                                </TTITLE>
                                <BOXHD>
                                    <CHED H="1">Organism</CHED>
                                    <CHED H="1">Methodology category</CHED>
                                    <CHED H="1">Method</CHED>
                                    <CHED H="1">
                                        SM 20
                                        <SU>th</SU>
                                        , 21
                                        <SU>st</SU>
                                         editions 
                                        <SU>1</SU>
                                         
                                        <SU>6</SU>
                                    </CHED>
                                    <CHED H="1">
                                        SM 22
                                        <SU>nd</SU>
                                         edition 
                                        <SU>28</SU>
                                    </CHED>
                                    <CHED H="1">
                                        SM 23
                                        <SU>rd</SU>
                                         edition 
                                        <SU>49</SU>
                                        , SM 24
                                        <SU>th</SU>
                                         edition 
                                        <SU>66</SU>
                                    </CHED>
                                    <CHED H="1">
                                        SM online 
                                        <SU>3</SU>
                                    </CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">Total Coliforms</ENT>
                                    <ENT>Lactose Fermentation Methods</ENT>
                                    <ENT>Standard Total Coliform Fermentation Technique</ENT>
                                    <ENT/>
                                    <ENT>9221 B.1, B.2</ENT>
                                    <ENT>9221 B.1, B.2, B.3, B.4</ENT>
                                    <ENT>9221 B.1, B.2-06.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="xl"/>
                                    <ENT>Presence-Absence (P-A) Coliform Test</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>9221 D.1, D.2, D.3</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Membrane Filtration Methods</ENT>
                                    <ENT>Standard Total Coliform Membrane Filter Procedure using Endo Media</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>9222 B, C</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="xl"/>
                                    <ENT>
                                        Simultaneous Detection of Total Coliforms and 
                                        <E T="03">E. coli</E>
                                         by Dual Chromogen Membrane Filter Procedure (using mColiBlue24 medium)
                                    </ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>9222 J</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="xl"/>
                                    <ENT>
                                        Simultaneous Detection of Total Coliform Bacteria and 
                                        <E T="03">Escherichia coli</E>
                                         Using RAPID'
                                        <E T="03">E.coli</E>
                                         (REC2) in Drinking Water 
                                        <SU>56</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Enzyme Substrate Methods</ENT>
                                    <ENT>Colilert®</ENT>
                                    <ENT/>
                                    <ENT>9223 B</ENT>
                                    <ENT>9223 B</ENT>
                                    <ENT>9223 B-04.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="xl"/>
                                    <ENT>Colisure®</ENT>
                                    <ENT/>
                                    <ENT>9223 B</ENT>
                                    <ENT>9223 B</ENT>
                                    <ENT>9223 B-04.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="xl"/>
                                    <ENT>Colilert-18</ENT>
                                    <ENT>9223 B</ENT>
                                    <ENT>9223 B</ENT>
                                    <ENT>9223 B</ENT>
                                    <ENT>9223 B-04.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="xl"/>
                                    <ENT>
                                        Tecta EC/TC 
                                        <SU>33</SU>
                                         
                                        <SU>43</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="xl"/>
                                    <ENT>
                                        Modified Colitag
                                        <E T="0731">TM</E>
                                        , Version 2.0 
                                        <SU>61</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">
                                        <E T="03">Escherichia coli</E>
                                    </ENT>
                                    <ENT>
                                        <E T="03">Escherichia coli</E>
                                         Procedure (following Lactose Fermentation Methods)
                                    </ENT>
                                    <ENT>EC-MUG medium</ENT>
                                    <ENT/>
                                    <ENT>9221 F.1</ENT>
                                    <ENT>9221 F.1</ENT>
                                    <ENT>9221 F.1-06.</ENT>
                                </ROW>
                                <ROW>
                                    <PRTPAGE P="550"/>
                                    <ENT I="22"> </ENT>
                                    <ENT>
                                        <E T="03">Escherichia coli</E>
                                         Partitioning Methods (following Membrane Filtration Methods)
                                    </ENT>
                                    <ENT>EC broth with MUG (EC-MUG)</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>9222 H</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="xl"/>
                                    <ENT>NA-MUG medium</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>9222 I</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>
                                        Simultaneous Detection of Total Coliforms and 
                                        <E T="03">E. coli</E>
                                         by Dual Chromogen Membrane Filter Procedure
                                    </ENT>
                                    <ENT>mColiBlue24 medium</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>9222 J</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Membrane Filtration Method</ENT>
                                    <ENT>
                                        Simultaneous Detection of Total Coliform Bacteria and 
                                        <E T="03">Escherichia coli</E>
                                         Using RAPID'
                                        <E T="03">E.coli</E>
                                         (REC2) in Drinking Water 
                                        <SU>56</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Enzyme Substrate Methods</ENT>
                                    <ENT>Colilert®</ENT>
                                    <ENT/>
                                    <ENT>9223 B</ENT>
                                    <ENT>9223 B</ENT>
                                    <ENT>9223 B-04.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="xl"/>
                                    <ENT>Colisure®</ENT>
                                    <ENT/>
                                    <ENT>9223 B</ENT>
                                    <ENT>9223 B</ENT>
                                    <ENT>9223 B-04.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="xl"/>
                                    <ENT>Colilert-18</ENT>
                                    <ENT>9223 B</ENT>
                                    <ENT>9223 B</ENT>
                                    <ENT>9223 B</ENT>
                                    <ENT>9223 B-04.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="xl"/>
                                    <ENT>
                                        Tecta EC/TC 
                                        <SU>33</SU>
                                         
                                        <SU>43</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="xl"/>
                                    <ENT>
                                        Modified Colitag
                                        <E T="0731">TM</E>
                                        , Version 2.0 
                                        <SU>61</SU>
                                    </ENT>
                                </ROW>
                            </GPOTABLE>
                            <PRTPAGE P="551"/>
                            <GPOTABLE COLS="07" OPTS="L2,p7,7/8" CDEF="s50,r50,r30,r30,r50,r50,r50">
                                <TTITLE>
                                    Alternative Testing Methods for Contaminants Listed at 40 CFR 143.4(
                                    <E T="01">b</E>
                                    )
                                </TTITLE>
                                <BOXHD>
                                    <CHED H="1">Contaminant</CHED>
                                    <CHED H="1">Methodology</CHED>
                                    <CHED H="1">EPA method</CHED>
                                    <CHED H="1">
                                        ASTM 
                                        <SU>4</SU>
                                    </CHED>
                                    <CHED H="1">
                                        SM 21
                                        <SU>st</SU>
                                         edition 
                                        <SU>1</SU>
                                    </CHED>
                                    <CHED H="1">
                                        SM 22
                                        <SU>nd</SU>
                                         edition,
                                        <SU>28</SU>
                                         SM 23
                                        <SU>rd</SU>
                                         edition,
                                        <SU>49</SU>
                                         SM 24
                                        <SU>th</SU>
                                         edition 
                                        <SU>66</SU>
                                    </CHED>
                                    <CHED H="1">
                                        SM online 
                                        <SU>3</SU>
                                    </CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">Aluminum</ENT>
                                    <ENT>Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)</ENT>
                                    <ENT>
                                        200.5, Revision 4.2 
                                        <SU>2</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Atomic Absorption; Direct</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>3111 D</ENT>
                                    <ENT>3111 D</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Atomic Absorption; Furnace</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>3113 B</ENT>
                                    <ENT>3113 B</ENT>
                                    <ENT>3113 B-04, B-10.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Inductively Coupled Plasma</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>3120 B</ENT>
                                    <ENT>3120 B</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Chloride</ENT>
                                    <ENT>Silver Nitrate Titration</ENT>
                                    <ENT/>
                                    <ENT>D 512-04 B, 12 B</ENT>
                                    <ENT>
                                        4500-Cl
                                        <SU>−</SU>
                                        B
                                    </ENT>
                                    <ENT>
                                        4500-Cl
                                        <SU>−</SU>
                                        B
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Ion Chromatography</ENT>
                                    <ENT/>
                                    <ENT>D 4327-11, -17</ENT>
                                    <ENT>4110 B</ENT>
                                    <ENT>4110 B</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Potentiometric Titration</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        4500-Cl
                                        <SU>−</SU>
                                        D
                                    </ENT>
                                    <ENT>
                                        4500-Cl
                                        <SU>−</SU>
                                        D
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Color</ENT>
                                    <ENT>Visual Comparison</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>2120 B</ENT>
                                    <ENT>2120 B</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Foaming Agents</ENT>
                                    <ENT>Methylene Blue Active Substances (MBAS)</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>5540 C</ENT>
                                    <ENT>5540 C</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Iron</ENT>
                                    <ENT>Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)</ENT>
                                    <ENT>
                                        200.5, Revision 4.2 
                                        <SU>2</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Atomic Absorption; Direct</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>3111 B</ENT>
                                    <ENT>3111 B</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Atomic Absorption; Furnace</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>3113 B</ENT>
                                    <ENT>3113 B</ENT>
                                    <ENT>3113 B-04, B-10</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Inductively Coupled Plasma</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>3120 B</ENT>
                                    <ENT>3120 B</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Manganese</ENT>
                                    <ENT>Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)</ENT>
                                    <ENT>
                                        200.5, Revision 4.2 
                                        <SU>2</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Atomic Absorption; Direct</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>3111 B</ENT>
                                    <ENT>3111 B</ENT>
                                </ROW>
                                <ROW>
                                    <PRTPAGE P="552"/>
                                    <ENT I="22"> </ENT>
                                    <ENT>Atomic Absorption; Furnace</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>3113 B</ENT>
                                    <ENT>3113 B</ENT>
                                    <ENT>3113 B-04, B-10.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Inductively Coupled Plasma</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>3120 B</ENT>
                                    <ENT>3120 B</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Odor</ENT>
                                    <ENT>Threshold Odor Test</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>2150 B</ENT>
                                    <ENT>2150 B</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Silver</ENT>
                                    <ENT>Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)</ENT>
                                    <ENT>
                                        200.5, Revision 4.2 
                                        <SU>2</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Atomic Absorption; Direct</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>3111 B</ENT>
                                    <ENT>3111 B</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Atomic Absorption; Furnace</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>3113 B</ENT>
                                    <ENT>3113 B</ENT>
                                    <ENT>3113 B-04, B-10.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Inductively Coupled Plasma</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>3120 B</ENT>
                                    <ENT>3120 B</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Sulfate</ENT>
                                    <ENT>Ion Chromatography</ENT>
                                    <ENT/>
                                    <ENT>D 4327-11, -17</ENT>
                                    <ENT>4110 B</ENT>
                                    <ENT>4110 B</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Gravimetric with ignition of residue</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        4500-SO
                                        <E T="0732">4</E>
                                         
                                        <SU>2</SU>
                                        <SU>−</SU>
                                        C
                                    </ENT>
                                    <ENT>
                                        4500-SO
                                        <E T="0732">4</E>
                                         
                                        <SU>2</SU>
                                        <SU>−</SU>
                                        C
                                    </ENT>
                                    <ENT>
                                        4500-SO
                                        <E T="0732">4</E>
                                         
                                        <SU>2</SU>
                                        <SU>−</SU>
                                        C-97.
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Gravimetric with drying of residue</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        4500-SO
                                        <E T="0732">4</E>
                                         
                                        <SU>2</SU>
                                        <SU>−</SU>
                                        D
                                    </ENT>
                                    <ENT>
                                        4500-SO
                                        <E T="0732">4</E>
                                         
                                        <SU>2</SU>
                                        <SU>−</SU>
                                        D
                                    </ENT>
                                    <ENT>
                                        4500-SO
                                        <E T="0732">4</E>
                                         
                                        <SU>2</SU>
                                        <SU>−</SU>
                                        D-97.
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Turbidimetric method</ENT>
                                    <ENT/>
                                    <ENT>D 516-07, 11, 16</ENT>
                                    <ENT>
                                        4500-SO
                                        <E T="0732">4</E>
                                         
                                        <SU>2</SU>
                                        <SU>−</SU>
                                        E
                                    </ENT>
                                    <ENT>
                                        4500-SO
                                        <E T="0732">4</E>
                                         
                                        <SU>2</SU>
                                        <SU>−</SU>
                                        E
                                    </ENT>
                                    <ENT>
                                        4500-SO
                                        <E T="0732">4</E>
                                         
                                        <SU>2</SU>
                                        <SU>−</SU>
                                        E-97.
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Automated methylthymol blue method</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        4500-SO
                                        <E T="0732">4</E>
                                         
                                        <SU>2</SU>
                                        <SU>−</SU>
                                        F
                                    </ENT>
                                    <ENT>
                                        4500-SO
                                        <E T="0732">4</E>
                                         
                                        <SU>2</SU>
                                        <SU>−</SU>
                                        F
                                    </ENT>
                                    <ENT>
                                        4500-SO
                                        <E T="0732">4</E>
                                         
                                        <SU>2</SU>
                                        <SU>−</SU>
                                        F-97.
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Total Dissolved Solids</ENT>
                                    <ENT>Total Dissolved Solids Dried at 180 deg C</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>2540 C</ENT>
                                    <ENT>2540 C</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Zinc</ENT>
                                    <ENT>Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)</ENT>
                                    <ENT>
                                        200.5, Revision 4.2 
                                        <SU>2</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Atomic Absorption; Direct Aspiration</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>3111 B</ENT>
                                    <ENT>3111 B</ENT>
                                </ROW>
                                <ROW>
                                    <PRTPAGE P="553"/>
                                    <ENT I="22"> </ENT>
                                    <ENT>Inductively Coupled Plasma</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>3120 B</ENT>
                                    <ENT>3120 B</ENT>
                                </ROW>
                                <TNOTE>
                                    <SU>1</SU>
                                     
                                    <E T="03">Standard Methods for the Examination of Water and Wastewater,</E>
                                     21st edition (2005). Available from American Public Health Association, 800 I Street NW, Washington, DC 20001-3710.
                                </TNOTE>
                                <TNOTE>
                                    <SU>2</SU>
                                     EPA Method 200.5, Revision 4.2. “Determination of Trace Elements in Drinking Water by Axially Viewed Inductively Coupled Plasma-Atomic Emission Spectrometry.” 2003. EPA/600/R-06/115. (Available at 
                                    <E T="03">http://www.epa.gov/water-research/epa-drinking-water-research-methods</E>
                                    .)
                                </TNOTE>
                                <TNOTE>
                                    <SU>3</SU>
                                     Standard Methods Online are available at 
                                    <E T="03">http://www.standardmethods.org</E>
                                    . The year in which each method was approved by the Standard Methods Committee is designated by the last two digits in the method number. The methods listed are the only online versions that may be used.
                                </TNOTE>
                                <TNOTE>
                                    <SU>4</SU>
                                     Available from ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959 or 
                                    <E T="03">http://astm.org</E>
                                    . The methods listed are the only alternative versions that may be used.
                                </TNOTE>
                                <TNOTE>
                                    <SU>5</SU>
                                     Method D99-003, Revision 3.0. “Free Chlorine Species (HOCl
                                    <E T="51">−</E>
                                     and OCl
                                    <E T="51">−</E>
                                    ) by Test Strip,” November 21, 2003. Available from Industrial Test Systems, Inc., 1875 Langston St., Rock Hill, SC 29730.
                                </TNOTE>
                                <TNOTE>
                                    <SU>6</SU>
                                     
                                    <E T="03">Standard Methods for the Examination of Water and Wastewater,</E>
                                     20th edition (1998). Available from American Public Health Association, 800 I Street NW, Washington, DC 20001-3710.
                                </TNOTE>
                                <TNOTE>
                                    <SU>7</SU>
                                     Method ME355.01, Revision 1.0. “Determination of Cyanide in Drinking Water by GC/MS Headspace,” May 26, 2009. Available at 
                                    <E T="03">https://www.nemi.gov</E>
                                     or from James Eaton, H &amp; E Testing Laboratory, 221 State Street, Augusta, ME 04333. (207) 287-2727.
                                </TNOTE>
                                <TNOTE>
                                    <SU>8</SU>
                                     Systea Easy (1-Reagent). “Systea Easy (1-Reagent) Nitrate Method,” February 4, 2009. Available at 
                                    <E T="03">https://www.nemi.gov</E>
                                     or from Systea Scientific, LLC., 900 Jorie Blvd., Suite 35, Oak Brook, IL 60523.
                                </TNOTE>
                                <TNOTE>
                                    <SU>9</SU>
                                     EPA Method 524.3, Version 1.0. “Measurement of Purgeable Organic Compounds in Water by Capillary Column Gas Chromatography/Mass Spectrometry,” June 2009. EPA 815-B-09-009. Available at 
                                    <E T="03">https://www.nemi.gov</E>
                                    .
                                </TNOTE>
                                <TNOTE>
                                    <SU>10</SU>
                                     Mitchell Method M5271, Revision 1.1. “Determination of Turbidity by Laser Nephelometry,” March 5, 2009. Available at 
                                    <E T="03">https://www.nemi.gov</E>
                                     or from Leck Mitchell, Ph.D., PE, 656 Independence Valley Dr., Grand Junction, CO 81507.
                                </TNOTE>
                                <TNOTE>
                                    <SU>11</SU>
                                     Mitchell Method M5331, Revision 1.1. “Determination of Turbidity by LED Nephelometry,” March 5, 2009. Available at 
                                    <E T="03">https://www.nemi.gov</E>
                                     or from Leck Mitchell, Ph.D., PE, 656 Independence Valley Dr., Grand Junction, CO 81507.
                                </TNOTE>
                                <TNOTE>
                                    <SU>12</SU>
                                     Orion Method AQ4500, Revision 1.0. “Determination of Turbidity by LED Nephelometry,” May 8, 2009. Available at 
                                    <E T="03">https://www.nemi.gov</E>
                                     or from Thermo Scientific, 166 Cummings Center, Beverly, MA 01915, 
                                    <E T="03">http://www.thermo.com</E>
                                    .
                                </TNOTE>
                                <TNOTE>
                                    <SU>13</SU>
                                     Modified Colitag
                                    <E T="0731">TM</E>
                                     Method. “Modified Colitag
                                    <E T="0731">TM</E>
                                     Test Method for the Simultaneous Detection of 
                                    <E T="03">E. coli</E>
                                     and other Total Coliforms in Water (ATP D05-0035),” August 28, 2009. Available at 
                                    <E T="03">https://www.nemi.gov</E>
                                     or from CPI International, 5580 Skylane Boulevard, Santa Rosa, CA 95403.
                                </TNOTE>
                                <TNOTE>
                                    <SU>14</SU>
                                     EPA Method 557. “Determination of Haloacetic Acids, Bromate, and Dalapon in Drinking Water by Ion Chromatography Electrospray Ionization Tandem Mass Spectrometry (IC-ESI-MS/MS),” September 2009. EPA 815-B-09-012. Available at 
                                    <E T="03">https://www.nemi.gov</E>
                                    .
                                </TNOTE>
                                <TNOTE>
                                    <SU>15</SU>
                                     AMI Turbiwell, “Continuous Measurement of Turbidity Using a SWAN AMI Turbiwell Turbidimeter,” August 2009. Available at 
                                    <E T="03">https://www.nemi.gov</E>
                                     or from Markus Bernasconi, SWAN Analytische Instrumente AG, Studbachstrasse 13, CH-8340 Hinwil, Switzerland.
                                </TNOTE>
                                <TNOTE>
                                    <SU>16</SU>
                                     EPA Method 334.0. “Determination of Residual Chlorine in Drinking Water Using an On-line Chlorine Analyzer,” September 2009. EPA 815-B-09-013. Available at 
                                    <E T="03">https://www.nemi.gov</E>
                                    .
                                </TNOTE>
                                <TNOTE>
                                    <SU>17</SU>
                                     ChloroSense. “Measurement of Free and Total Chlorine in Drinking Water by Palintest ChloroSense,” August 2009. Available at 
                                    <E T="03">https://www.nemi.gov</E>
                                     or from Palintest Ltd, 1455 Jamike Avenue (Suite 100), Erlanger, KY 41018.
                                </TNOTE>
                                <TNOTE>
                                    <SU>18</SU>
                                     EPA Method 302.0. “Determination of Bromate in Drinking Water using Two-Dimensional Ion Chromatography with Suppressed Conductivity Detection,” September 2009. EPA 815-B-09-014. Available at 
                                    <E T="03">https://www.nemi.gov</E>
                                    .
                                </TNOTE>
                                <TNOTE>
                                    <SU>19</SU>
                                     EPA 415.3, Revision 1.2. “Determination of Total Organic Carbon and Specific UV Absorbance at 254 nm in Source Water and Drinking Water,” September 2009. EPA/600/R-09/122. Available at 
                                    <E T="03">http://www.epa.gov/water-research/epa-drinking-water-research-methods</E>
                                    .
                                </TNOTE>
                                <TNOTE>
                                    <SU>20</SU>
                                     Readycult® Method, “Readycult® Coliforms 100 Presence/Absence Test for Detection and Identification of Coliform Bacteria and 
                                    <E T="03">Escherichia coli</E>
                                     in Finished Waters,” January, 2007. Version 1.1. Available from EMD Millipore (division of Merck KGaA, Darmstadt, Germany), 290 Concord Road, Billerica, MA 01821.
                                </TNOTE>
                                <TNOTE>
                                    <SU>21</SU>
                                     Chromocult® Method, “Chromocult® Coliform Agar Presence/Absence Membrane Filter Test Method for Detection and Identification of Coliform Bacteria and 
                                    <E T="03">Escherichia coli</E>
                                     in Finished Waters,” November, 2000. Version 1.0. EMD Millipore (division of Merck KGaA, Darmstadt, Germany), 290 Concord Road, Billerica, MA 01821.
                                </TNOTE>
                                <TNOTE>
                                    <SU>22</SU>
                                     Hach Company. “Hach Company SPADNS 2 (Arsenite-Free) Fluoride Method 10225-Spectrophotometric Measurement of Fluoride in Water and Wastewater,” January 2011. 5600 Lindbergh Drive, P.O. Box 389, Loveland, Colorado 80539.
                                </TNOTE>
                                <TNOTE>
                                    <SU>23</SU>
                                     Hach Company. “Hach Company TNTplus
                                    <SU>TM</SU>
                                     835/836 Nitrate Method 10206-Spectrophotometric Measurement of Nitrate in Water and Wastewater,” January 2011. 5600 Lindbergh Drive, P.O. Box 389, Loveland, Colorado 80539.
                                    <PRTPAGE P="554"/>
                                </TNOTE>
                                <TNOTE>
                                    <SU>24</SU>
                                     EPA Method 525.3. “Determination of Semivolatile Organic Chemicals in Drinking Water by Solid Phase Extraction and Capillary Column Gas Chromatography/Mass Spectrometry (GC/MS),” February 2012. EPA/600/R-12/010. Available at 
                                    <E T="03">http://www.epa.gov/water-research/epa-drinking-water-research-methods</E>
                                    .
                                </TNOTE>
                                <TNOTE>
                                    <SU>25</SU>
                                     EPA Method 536. “Determination of Triazine Pesticides and their Degradates in Drinking Water by Liquid Chromatography Electrospray Ionization Tandem Mass Spectrometry (LC/ESI-MS/MS),” October 2007. EPA 815-B-07-002. Available at the National Service Center for Environmental Publications at 
                                    <E T="03">https://www.epa.gov/nscep</E>
                                    .
                                </TNOTE>
                                <TNOTE>
                                    <SU>26</SU>
                                     EPA Method 523. “Determination of Triazine Pesticides and their Degradates in Drinking Water by Gas Chromatography/Mass Spectrometry (GC/MS),” February 2011. EPA 815-R-11-002. Available at the National Service Center for Environmental Publications at 
                                    <E T="03">https://www.epa.gov/nscep</E>
                                    .
                                </TNOTE>
                                <TNOTE>
                                    <SU>27</SU>
                                     EPA Method 1623.1. “
                                    <E T="03">Cryptosporidium</E>
                                     and 
                                    <E T="03">Giardia</E>
                                     in Water by Filtration/IMS/FA,” 2012. EPA-816-R-12-001. Available at the National Service Center for Environmental Publications at 
                                    <E T="03">https://www.epa.gov/nscep.</E>
                                </TNOTE>
                                <TNOTE>
                                    <SU>28</SU>
                                     
                                    <E T="03">Standard Methods for the Examination of Water and Wastewater,</E>
                                     22nd edition (2012). Available from American Public Health Association, 800 I Street NW, Washington, DC 20001-3710.
                                </TNOTE>
                                <TNOTE>
                                    <SU>29</SU>
                                     EPA Method 524.4, Version 1.0. “Measurement of Purgeable Organic Compounds in Water by Gas Chromatography/Mass Spectrometry using Nitrogen Purge Gas.” May 2013. EPA 815-R-13-002. Available at the National Service Center for Environmental Publications at 
                                    <E T="03">https://www.epa.gov/nscep</E>
                                    .
                                </TNOTE>
                                <TNOTE>
                                    <SU>30</SU>
                                     Charm Sciences Inc. “Fast Phage Test Procedure. Presence/Absence for Coliphage in Ground Water with Same Day Positive Prediction”. Version 009. November 2012. 659 Andover Street, Lawrence, MA 01843. Available at 
                                    <E T="03">www.charmsciences.com</E>
                                    .
                                </TNOTE>
                                <TNOTE>
                                    <SU>31</SU>
                                     Hach Company. “Hach Method 10260-Determination of Chlorinated Oxidants (Free and Total) in Water Using Disposable Planar Reagent-filled Cuvettes and Mesofluidic Channel Colorimetry,” April 2013. 5600 Lindbergh Drive, P.O. Box 389, Loveland, CO 80539.
                                </TNOTE>
                                <TNOTE>
                                    <SU>32</SU>
                                     ChlordioX Plus. “Chlorine Dioxide and Chlorite in Drinking Water by Amperometry using Disposable Sensors,” November 2013.
                                </TNOTE>
                                <TNOTE>Available from Palintest Ltd, 1455 Jamike Avenue (Suite 100), Erlanger, KY 41018.</TNOTE>
                                <TNOTE>
                                    <SU>33</SU>
                                     Tecta EC/TC. “Techta
                                    <E T="0731">TM</E>
                                     EC/TC Medium and Techta
                                    <E T="0731">TM</E>
                                     Instrument: A Presence/Absence Method for the Simultaneous Detection of Total Coliforms and Escherichia coli (
                                    <E T="03">E. coli</E>
                                    ) in Drinking Water,” version 1.0, May 2014. Available from Pathogen Detection Systems, Inc., 382 King Street East, Kingston, Ontario, Canada, K7K 2Y2.
                                </TNOTE>
                                <TNOTE>
                                    <SU>34</SU>
                                     Hach Company. “Hach Method 10241-Spectrophotometric Measurement of Free Chlorine (Cl
                                    <E T="0732">2</E>
                                    ) in Drinking Water,” November 2015. Revision 1.2. 5600 Lindbergh Drive, P.O. Box 389, Loveland, CO 80539.
                                </TNOTE>
                                <TNOTE>
                                    <SU>35</SU>
                                     Hach Company. “Hach Method 8026-Spectrophotometric Measurement of Copper in Finished Drinking Water,” December 2015. Revision 1.2. 5600 Lindbergh Drive, P.O. Box 389, Loveland, CO 80539.
                                </TNOTE>
                                <TNOTE>
                                    <SU>36</SU>
                                     Hach Company. “Hach Method 10272-Spectrophotometric Measurement of Copper in Finished Drinking Water,” December 2015. Revision 1.2. 5600 Lindbergh Drive, P.O. Box 389, Loveland, CO 80539.
                                </TNOTE>
                                <TNOTE>
                                    <SU>37</SU>
                                     Hach Company. “Hach Method 10261-Total Organic Carbon in Finished Drinking Water by Catalyzed Ozone Hydroxyl Radical Oxidation Infrared Analysis,” December 2015. Revision 1.2. 5600 Lindbergh Drive, P.O. Box 389, Loveland, CO 80539.
                                </TNOTE>
                                <TNOTE>
                                    <SU>38</SU>
                                     Hach Company. “Hach Method 10267-Spectrophotometric Measurement of Total Organic Carbon (TOC) in Finished Drinking Water,” December 2015. Revision 1.2. 5600 Lindbergh Drive, P.O. Box 389, Loveland, CO 80539.
                                </TNOTE>
                                <TNOTE>
                                    <SU>39</SU>
                                     Hach Company. “Hach Method 10258-Determination of Turbidity by 360° Nephelometry,” January 2016. Revision 1.0. 5600 Lindbergh Drive, P.O. Box 389, Loveland, CO 80539.
                                </TNOTE>
                                <TNOTE>
                                    <SU>40</SU>
                                     Nitrate Elimination Company Inc. (NECi). “Method for Nitrate Reductase Nitrate-Nitrogen Analysis of Drinking Water,” February 2016. Superior Enzymes Inc., 334 Hecla Street, Lake Linden, Michigan 49945.
                                </TNOTE>
                                <TNOTE>
                                    <SU>41</SU>
                                     Thermo Fisher. “Thermo Fisher Scientific Drinking Water Orthophosphate Method for Thermo Scientific Gallery Discrete Analyzer,” February 2016. Revision 5. Thermo Fisher Scientific, Ratastie 2, 01620 Vantaa, Finland.
                                </TNOTE>
                                <TNOTE>
                                    <SU>42</SU>
                                     Mitchell Method M5331, Revision 1.2. “Determination of Turbidity by LED or Laser Nephelometry,” February 2016. Available from Leck Mitchell, Ph.D., PE, 656 Independence Valley Dr., Grand Junction, CO 81507.
                                </TNOTE>
                                <TNOTE>
                                    <SU>43</SU>
                                     Tecta EC/TC. “Tecta
                                    <E T="0731">TM</E>
                                     EC/TC Medium and the Tecta
                                    <E T="0731">TM</E>
                                     Instrument: A Presence/Absence Method for the Simultaneous Detection of Total Coliforms and 
                                    <E T="03">Escherichia coli</E>
                                     (
                                    <E T="03">E. coli</E>
                                    ) in Drinking Water,” version 2.0, March 2017. Available from Pathogen Detection Systems, Inc., 382 King Street East, Kingston, Ontario, Canada, K7K 2Y2.
                                </TNOTE>
                                <TNOTE>
                                    <SU>44</SU>
                                     Lovibond PTV 1000. “Continuous Measurement of Drinking Water Turbidity using a Lovibond PTV 1000 White Light LED Turbidimeter,” December 2016. Revision 1.0. Available from Tintometer, Inc., 6456 Parkland Drive, Sarasota, FL 34243.
                                </TNOTE>
                                <TNOTE>
                                    <SU>45</SU>
                                     Lovibond PTV 2000. “Continuous Measurement of Drinking Water Turbidity Using a Lovibond PTV 2000 660-nm LED Turbidimeter,” December 2016. Revision 1.0. Available from Tintometer, Inc., 6456 Parkland Drive, Sarasota, FL 34243.
                                </TNOTE>
                                <TNOTE>
                                    <SU>46</SU>
                                     Lovibond PTV 6000. “Continuous Measurement of Drinking Water Turbidity Using a Lovibond PTV 6000 Laser Turbidimeter,” December 2016. Revision 1.0. Available from Tintometer, Inc., 6456 Parkland Drive, Sarasota, FL 34243.
                                    <PRTPAGE P="555"/>
                                </TNOTE>
                                <TNOTE>
                                    <SU>47</SU>
                                     Thermo Fisher. “Thermo Fisher method 557.1: Determination of Haloacetic Acids in Drinking Water using Two-Dimensional Ion Chromatography with Suppressed Conductivity Detection,” January 2017. Version 1.0. Available from Thermo Fisher Scientific, 490 Lakeside Dr., Sunnyvale, CA 94085 (
                                    <E T="03">Richard.jack@thermofisher.com</E>
                                    ).
                                </TNOTE>
                                <TNOTE>
                                    <SU>48</SU>
                                     EPA Method 150.3. “Determination of pH in Drinking Water,” February 2017. EPA 815-B-17-001. Available at the National Service Center for Environmental Publications at 
                                    <E T="03">https://www.epa.gov/nscep</E>
                                    .
                                </TNOTE>
                                <TNOTE>
                                    <SU>49</SU>
                                     
                                    <E T="03">Standard Methods for the Examination of Water and Wastewater,</E>
                                     23rd edition (2017). Available from American Public Health Association, 800 I Street NW, Washington, DC 20001-3710.
                                </TNOTE>
                                <TNOTE>
                                    <SU>50</SU>
                                     EPA Method 900.0, Rev. 1.0. “Determination of Gross Alpha and Gross Beta in Drinking Water,” February 2018. EPA 815-B-18-002. Available at the National Service Center for Environmental Publications at 
                                    <E T="03">https://www.epa.gov/nscep</E>
                                    .
                                </TNOTE>
                                <TNOTE>
                                    <SU>51</SU>
                                     Hach Company. “Hach Method 10258—Determination of Turbidity by 360° Nephelometry.” March 2018. Revision 2.0. 5600 Lindbergh Drive, P.O. Box 389, Loveland, CO 80539.
                                </TNOTE>
                                <TNOTE>
                                    <SU>52</SU>
                                     Hach Company. “Hach Method 8195-Determination of Turbidity by Nephelometry.” March 2018. Revision 3.0. 5600 Lindbergh Drive, P.O. Box 389, Loveland, CO 80539.
                                </TNOTE>
                                <TNOTE>
                                    <SU>53</SU>
                                     EPA Method 903.1, Rev. 1.0. “Radium-226 in Drinking Water Radon Emanation Technique.” January 2021. EPA 815-B-21-003. Available at the National Service Center for Environmental Publications at 
                                    <E T="03">https://www.epa.gov/nscep</E>
                                    .
                                </TNOTE>
                                <TNOTE>
                                    <SU>54</SU>
                                     EPA Method 903.0, Rev. 1.0. “Alpha-Emitting Radium Isotopes in Drinking Water.” January 2021. EPA 815-B-21-002. Available at the National Service Center for Environmental Publications at 
                                    <E T="03">https://www.epa.gov/nscep</E>
                                    .
                                </TNOTE>
                                <TNOTE>
                                    <SU>55</SU>
                                     EPA Method 127. “Determination of Monochloramine Concentration in Drinking Water.” January 2021. EPA 815-B-21-004. Available at the National Service Center for Environmental Publications at 
                                    <E T="03">https://www.epa.gov/nscep</E>
                                    .
                                </TNOTE>
                                <TNOTE>
                                    <SU>56</SU>
                                     Bio-Rad. “Simultaneous Detection of Total Coliform Bacteria and 
                                    <E T="03">Escherichia coli</E>
                                     using RAPID'
                                    <E T="03">E. coli</E>
                                     2 (REC2) in Drinking Water.” May 2020. Bio-Rad Laboratories, 2000 Nobel Drive, Hercules, California 94547.
                                </TNOTE>
                                <TNOTE>
                                    <SU>57</SU>
                                     Method 1001, Rev. 1.1. “Lead in Drinking Water by Differential Pulse Anodic Stripping Voltammetry.” May 2020. Palintest Ltd, 400 Corporate Circle, Suite J, Golden, CO 80401.
                                </TNOTE>
                                <TNOTE>
                                    <SU>58</SU>
                                     ME 531, Version 1.0. “Measurement of N-Methylcarbamoyloximes and N-Methylcarbamates in Drinking Water by LC-MS/MS. September 2019. Maine Health Environmental Testing Laboratory, 221 State Street, Augusta, ME 04330.
                                </TNOTE>
                                <TNOTE>
                                    <SU>59</SU>
                                     ChloroSense, Rev. 1.1. “Free and Total Chlorine in Drinking Water by Amperometry using Disposable Sensors.” February 2020. Palintest Ltd, 400 Corporate Circle, Suite J, Golden, CO 80401.
                                </TNOTE>
                                <TNOTE>
                                    <SU>60</SU>
                                     ChlordioX Plus, Rev. 1.1. “Chlorine Dioxide and Chlorite in Drinking Water by Amperometry using Disposable Sensors.” February 2020. Palintest Ltd, 400 Corporate Circle, Suite J, Golden, CO 80401.
                                </TNOTE>
                                <TNOTE>
                                    <SU>61</SU>
                                     Modified Colitag
                                    <E T="0731">TM</E>
                                    , Version 2.0. “Modified Colitag
                                    <E T="0731">TM</E>
                                     Test Method for the Simultaneous Determination of Total Coliforms and 
                                    <E T="03">E. coli</E>
                                     in Water.” June 2020. Neogen Corporation, 620 Lesher Place, Lansing, MI 48912.
                                </TNOTE>
                                <TNOTE>
                                    <SU>62</SU>
                                     EPA Method 904.0, Rev. 1.0. “Radium-228 in Drinking Water.” March 2022. EPA 815-B-22-003. Available at the National Service Center for Environmental Publications at 
                                    <E T="03">https://www.epa.gov/nscep</E>
                                    .
                                </TNOTE>
                                <TNOTE>
                                    <SU>63</SU>
                                     Lovibond TB 6000. “Measurement of Drinking Water Turbidity of a Captured Sample using a Lovibond Portable Laser Turbidimeter.” May 2021. Revision 1.0. Available from Tintometer, Inc., 6456 Parkland Drive, Sarasota, FL 34243.
                                </TNOTE>
                                <TNOTE>
                                    <SU>64</SU>
                                     Lovibond TB 3500. “Measurement of Drinking Water Turbidity of a Captured Sample using a Lovibond White Light LED Portable Turbidimeter.” May 2021. Revision 1.0. Available from Tintometer, Inc., 6456 Parkland Drive, Sarasota, FL 34243.
                                </TNOTE>
                                <TNOTE>
                                    <SU>65</SU>
                                     Lovibond TB 5000. “Measurement of Drinking Water Turbidity of a Captured Sample using a Lovibond 660-nm LED Portable Turbidimeter.” May 2021. Revision 1.0. Available from Tintometer, Inc., 6456 Parkland Drive, Sarasota, FL 34243.
                                </TNOTE>
                                <TNOTE>
                                    <SU>66</SU>
                                     
                                    <E T="03">Standard Methods for the Examination of Water and Wastewater,</E>
                                     24th edition (2023). Available from American Public Health Association, 800 I Street NW, Washington, DC 20001-3710.
                                </TNOTE>
                                <TNOTE>
                                    <SU>67</SU>
                                     Hach Company. “Hach Method 10312—Spectrophotometric Measurement of Fluoride in Finished Drinking Water Aluminum-Chromeazurol S complex (AL-CAS) Using Planar Reagent-filled Cuvettes”. August 2022. Revision 1.0. 5600 Lindbergh Drive, Loveland, Colorado 80539.
                                </TNOTE>
                                <TNOTE>
                                    <SU>68</SU>
                                     Yokogawa Electric Corporation. “Yokogawa Method 820—Measurement of Turbidity in Drinking Water by Right Angle Scattered Light Turbidity Analyzer”. November 2022. Revision 1.0. 2-9-32 Nakamachi, Musashino-shi, Tokyo, Japan 180-8750.
                                </TNOTE>
                                <TNOTE>
                                    <SU>69</SU>
                                     e-sens, Inc. “e-sens, Inc. Automated Micro Chlorine Detection (AMCD) Method for the Determination of Residual Free and Total Chlorine in Water.” December 2023. Available from e-sens, Inc., 630 Komas Dr., Ste 235, Salt Lake City, Utah 84108.
                                    <PRTPAGE P="556"/>
                                </TNOTE>
                                <TNOTE>
                                    <SU>70</SU>
                                     EPA Method 537.1, Version 1.0. “Determination of Selected Per- and Polyfluorinated Alkyl Substances (PFAS) in Drinking Water by Solid Phase Extraction and Liquid Chromatography/Tandem Mass Spectrometry (LC/MS/MS).” November 2018. EPA/600/R-18/352. Approved as alternative testing method to support initial PFAS monitoring (for monitoring-frequency determinations) until April 26, 2027 as described at 40 CFR 141.902(b)(1) [Monitoring requirements for PFAS—Initial monitoring]. Available at the National Service Center for Environmental Publications at 
                                    <E T="03">https://www.epa.gov/nscep.</E>
                                </TNOTE>
                            </GPOTABLE>
                            <CITA>[74 FR 38353, Aug. 3, 2009, as amended at 74 FR 57914, Nov. 10, 2009; 74 FR 63069, Dec. 2, 2009; 75 FR 32299, June 8, 2010; 76 FR 37018, June 24, 2011; 77 FR 38527, June 28, 2012; 78 FR 32565, May 31, 2013; 78 FR 37463, June 21, 2013; 79 FR 35086, June 19, 2014; 79 FR 36428, June 27, 2014; 81 FR 46844, July 19, 2016; 82 FR 34867, July 27, 2017; 83 FR 51644, Oct. 12, 2018; 83 FR 54676, Oct. 31, 2018; 86 FR 28284, May 26, 2021; 86 FR 29526, June 2, 2021; 87 FR 50579, Aug. 17, 2022; 89 FR 5780, Jan. 30, 2024; 89 FR 7624, Feb. 5, 2024; 90 FR 4660, Jan. 16, 2025]</CITA>
                            <EDNOTE>
                                <PRTPAGE P="557"/>
                                <HD SOURCE="HED">Editorial Note:</HD>
                                <P>At 90 FR 4660, Jan. 16, 2025, appendix A to subpart C of part 141 was amended in part by revising the entries for “Free Chlorine” and “Total Chlorine” in the table entitled “Alternative Testing Methods for Contaminants Listed at 40 CFR 141.74(a)(2)”, revising the entries for “Free Chlorine” and “Total Chlorine” in the table entitled “Alternative Testing Methods for Contaminants Listed at 40 CFR 141.131(c)(1)”, and adding the table entitled “Alternative Testing Methods for Contaminants Listed at 40 CFR 141.901(b)(1)”.However, the amendments could not be incorporated due to errors in the amendatory instruction that misidentified the tables.</P>
                            </EDNOTE>
                        </APPENDIX>
                    </SUBPART>
                    <SUBPART>
                        <HD SOURCE="HED">Subpart D—Reporting and Recordkeeping</HD>
                        <SECTION>
                            <SECTNO>§ 141.31</SECTNO>
                            <SUBJECT>Reporting requirements.</SUBJECT>
                            <P>(a) Except where a shorter period is specified in this part, the supplier of water shall report to the State the results of any test measurement or analysis required by this part within (1) The first ten days following the month in which the result is received, or (2) the first ten days following the end of the required monitoring period as stipulated by the State, whichever of these is shortest.</P>
                            <P>(b) Except where a different reporting period is specified in this part, the supplier of water must report to the State within 48 hours the failure to comply with any national primary drinking water regulation (including failure to comply with monitoring requirements) set forth in this part.</P>
                            <P>(c) The supplier of water is not required to report analytical results to the State in cases where a State laboratory performs the analysis and reports the results to the State office which would normally receive such notification from the supplier.</P>
                            <P>(d)(1) The public water system, within 10 days of completing the public notification requirements under subpart Q of this part for the initial public notice and any repeat notices, must submit to the primary agency a certification that it has fully complied with the public notification regulations under subpart Q. The public water system must include with this certification a representative copy of each type of notice distributed, published, posted, and made available to the persons served by the system and to the media.</P>
                            <P>(2) For Tier 1 notices for a lead action level exceedance, public water systems must provide a copy of the Tier 1 notice to the Administrator and the head of the primacy agency as soon as practicable, but not later than 24 hours after the public water system learns of the exceedance.</P>
                            <P>(e) The water supply system shall submit to the State within the time stated in the request copies of any records required to be maintained under § 141.33 hereof or copies of any documents then in existence which the State or the Administrator is entitled to inspect pursuant to the authority of section 1445 of the Safe Drinking Water Act or the equivalent provisions of State law.</P>
                            <CITA>[40 FR 59570, Dec. 24, 1975, as amended at 45 FR 57345, Aug. 27, 1980; 65 FR 26022, May 4, 2000; 86 FR 4282, Jan. 15, 2021; 89 FR 86626, Oct. 30, 2024]</CITA>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 141.32</SECTNO>
                            <RESERVED>[Reserved]</RESERVED>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 141.33</SECTNO>
                            <SUBJECT>Record maintenance.</SUBJECT>
                            <P>Any owner or operator of a public water system subject to the provisions of this part shall retain on its premises or at a convenient location near its premises the following records:</P>
                            <P>(a) Records of microbiological analyses and turbidity analyses made pursuant to this part shall be kept for not less than 5 years. Records of chemical analyses made pursuant to this part shall be kept for not less than 10 years. Actual laboratory reports may be kept, or data may be transferred to tabular summaries, provided that the following information is included:</P>
                            <P>(1) The date, place, and time of sampling, and the name of the person who collected the sample;</P>
                            <P>(2) Identification of the sample as to whether it was a routine distribution system sample, check sample, raw or process water sample or other special purpose sample;</P>
                            <P>(3) Date of analysis;</P>
                            <P>(4) Laboratory and person responsible for performing analysis;</P>
                            <P>(5) The analytical technique/method used; and</P>
                            <P>
                                (6) The results of the analysis.
                                <PRTPAGE P="558"/>
                            </P>
                            <P>(b) Records of action taken by the system to correct violations of primary drinking water regulations shall be kept for a period not less than 3 years after the last action taken with respect to the particular violation involved.</P>
                            <P>(c) Copies of any written reports, summaries or communications relating to sanitary surveys of the system conducted by the system itself, by a private consultant, or by any local, State or Federal agency, shall be kept for a period not less than 10 years after completion of the sanitary survey involved.</P>
                            <P>(d) Records concerning a variance or exemption granted to the system shall be kept for a period ending not less than 5 years following the expiration of such variance or exemption.</P>
                            <P>(e) Copies of public notices issued pursuant to subpart Q of this part and certifications made to the primacy agency pursuant to § 141.31 must be kept for three years after issuance.</P>
                            <P>(f) Copies of monitoring plans developed pursuant to this part shall be kept for the same period of time as the records of analyses taken under the plan are required to be kept under paragraph (a) of this section, except as specified elsewhere in this part.</P>
                            <CITA>[40 FR 59570, Dec. 24, 1975, as amended at 65 FR 26022, May 4, 2000; 71 FR 478, Jan. 4, 2006]</CITA>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 141.34</SECTNO>
                            <RESERVED>[Reserved]</RESERVED>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 141.35</SECTNO>
                            <SUBJECT>Reporting for unregulated contaminant monitoring results.</SUBJECT>
                            <P>
                                (a) 
                                <E T="03">General applicability.</E>
                                 This section applies to any owner or operator of a public water system (PWS) required to monitor for unregulated contaminants under § 141.40(a); such owner or operator is referred to as “you.” This section specifies the information that must be reported to EPA prior to the commencement of monitoring and describes the process for reporting monitoring results to EPA. For the purposes of this section, PWS “population served” is the retail population served directly by the PWS as reported to the Federal Safe Drinking Water Information System (SDWIS/Fed). For purposes of this section, the term “finished” means water that is introduced into the distribution system of a PWS and is intended for distribution and consumption without further treatment, except the treatment necessary to maintain water quality in the distribution system (e.g., booster disinfection, addition of corrosion control chemicals). For purposes of this section, the term “State” refers to the State or Tribal government entity that has jurisdiction over your PWS even if that government does not have primary enforcement responsibility for PWSs under the Safe Drinking Water Act. For purposes of this section, the term “PWS Official” refers to the person at your PWS who is able to function as the official spokesperson for the system's Unregulated Contaminant Monitoring Regulation (UCMR) activities; and the term “PWS Technical Contact” refers to the person at your PWS who is responsible for the technical aspects of your UCMR activities, such as details concerning sampling and reporting.
                            </P>
                            <P>
                                (b) 
                                <E T="03">Reporting by all systems.</E>
                                 You must meet the reporting requirements of this paragraph if you meet the applicability criteria in § 141.40(a)(1) and (2).
                            </P>
                            <P>
                                (1) 
                                <E T="03">Where to submit UCMR reporting requirement information.</E>
                                 Some of your reporting requirements are to be fulfilled electronically and others by mail. Information that must be submitted using EPA's electronic data reporting system must be submitted through: 
                                <E T="03">https://www.epa.gov/dwucmr.</E>
                                 Documentation that is required to be mailed can be submitted either: To UCMR Sampling Coordinator, USEPA, Technical Support Center, 26 West Martin Luther King Drive (MS 140), Cincinnati, OH 45268; or by email at 
                                <E T="03">UCMR_Sampling_Coordinator@epa.gov.</E>
                                 In addition, you must notify the public of the availability of unregulated contaminant monitoring data as provided in subpart Q (Public Notification) of this part (40 CFR 141.207). Community Water Systems that detect unregulated contaminants under this monitoring must also address such detections as part of their Consumer Confidence Reports, as provided in subpart O of this part (40 CFR 141.151).
                            </P>
                            <P>
                                (2) 
                                <E T="03">Contacting EPA if your system does not meet applicability criteria or has a status change.</E>
                                 If you have received a letter from EPA or your State concerning your required monitoring and 
                                <PRTPAGE P="559"/>
                                your system does not meet the applicability criteria for UCMR established in § 141.40(a)(1) or (2), or if a change occurs at your system that may affect your requirements under UCMR as defined in § 141.40(a)(3) through (5), you must mail or email a letter to EPA, as specified in paragraph (b)(1) of this section. The letter must be from your PWS Official and must include your PWS Identification (PWSID) Code along with an explanation as to why the UCMR requirements are not applicable to your PWS, or have changed for your PWS, along with the appropriate contact information. EPA will make an applicability determination based on your letter and in consultation with the State when necessary. You are subject to UCMR requirements unless and until you receive a letter from EPA agreeing that you do not meet the applicability criteria.
                            </P>
                            <P>
                                (c) 
                                <E T="03">Reporting by large systems.</E>
                                 If you serve a population of more than 10,000 people, and meet the applicability criteria in § 141.40(a)(2)(i), you must meet the reporting requirements in paragraphs (c)(1) through (8) of this section.
                            </P>
                            <P>
                                (1) 
                                <E T="03">Contact and zip code information.</E>
                                 You must provide contact information by December 31, 2022, and provide updates within 30 days if this information changes. The contact information must be submitted using EPA's electronic data reporting system, as specified in paragraph (b)(1) of this section, and include the name, affiliation, mailing address, phone number, and email address for your PWS Technical Contact and your PWS Official. In addition, as a one-time reporting requirement, you must report the U.S. Postal Service Zip Code(s) for all areas being served water by your PWS.
                            </P>
                            <P>
                                (2) 
                                <E T="03">Sampling location inventory information.</E>
                                 You must provide your inventory information by December 31, 2022, using EPA's electronic data reporting system, as specified in paragraph (b)(1) of this section. You must submit, verify, or update data elements 1-9 (as defined in Table 1 of paragraph (e) of this section) for each sampling location, or for each approved representative sampling location (as specified in paragraph (c)(3) of this section) regarding representative sampling locations. If this information changes, you must report updates, including new sources, and sampling locations that are put in use before or during the UCMR sampling period, to EPA's electronic data reporting system within 30 days of the change.
                            </P>
                            <P>
                                (3) 
                                <E T="03">Proposed ground water representative sampling locations.</E>
                                 Some systems that use ground water as a source and have multiple entry points to the distribution system (EPTDSs) may propose monitoring at representative entry point(s), rather than monitor at every EPTDS, as follows:
                            </P>
                            <P>
                                (i) 
                                <E T="03">Qualifications.</E>
                                 Large PWSs that have EPA- or State-approved representative EPTDS sampling locations from a previous UCMR cycle, or as provided for under 40 CFR 141.23(a)(1), 40 CFR 141.24(f)(1), or 40 CFR 141.24(h)(1), may submit a copy of documentation from your State or EPA that approves your representative sampling plan. PWSs that do not have an approved representative EPTDS sampling plan may submit a proposal to sample at representative EPTDS(s) rather than at each individual EPTDS if: You use ground water as a source; all of your well sources have either the same treatment or no treatment; and you have multiple EPTDSs from the same source (
                                <E T="03">i.e.,</E>
                                 same aquifer). You must submit a copy of the existing or proposed representative EPTDS sampling plan, as appropriate, at least six months prior to your scheduled sample collection, as specified in paragraph (b)(1) of this section. If changes to your inventory that impact your representative plan occur before or during the UCMR sampling period, you must report updates within 30 days of the change.
                            </P>
                            <P>
                                (ii) 
                                <E T="03">Demonstration.</E>
                                 If you are submitting a proposal to sample at representative EPTDS(s) rather than at each individual EPTDS, you must demonstrate that any EPTDS that you propose as representative of multiple wells is associated with a well that draws from the same aquifer as the wells it will represent. The proposed well must be representative of the highest annual volume and most consistently active wells in the representative array. If that representative well is not in use at the scheduled sampling time, you must select and sample an alternative 
                                <PRTPAGE P="560"/>
                                representative well. You must submit the information defined in Table 1, paragraph (e) of this section for each proposed representative sampling location. You must also include documentation to support your proposal that the specified wells are representative of other wells. This documentation can include system-maintained well logs or construction drawings indicating that the representative well(s) is/are at a representative depth, and details of well casings and grouting; data demonstrating relative homogeneity of water quality constituents (e.g., pH, dissolved oxygen, conductivity, iron, manganese) in samples drawn from each well; and data showing that your wells are located in a limited geographic area (e.g., all wells within a 0.5 mile radius) and/or, if available, the hydrogeologic data indicating the ground water travel time between the representative well and each of the individual wells it represents (e.g., all wells within a five-year time of travel delineation). Your proposal must be sent in writing to EPA, as specified in paragraph (b)(1) of this section.
                            </P>
                            <P>
                                (iii) 
                                <E T="03">Approval.</E>
                                 EPA or the State (as specified in the Partnership Agreement reached between the State and EPA) will review your proposal and coordinate any necessary changes with you. Your plan will not be final until you receive written approval from EPA, identifying the final list of EPTDSs where you will be required to monitor.
                            </P>
                            <P>
                                (4) 
                                <E T="03">Contacting EPA if your PWS has not been notified of requirements.</E>
                                 If you believe you are subject to UCMR requirements, as defined in 40 CFR 141.40(a)(1) and (a)(2)(i), and you have not been contacted by either EPA or your State by April 26, 2022, you must send a letter to EPA, as specified in paragraph (b)(1) of this section. The letter must be from your PWS Official and must include an explanation as to why the UCMR requirements are applicable to your system along with the appropriate contact information. A copy of the letter must also be submitted to the State as directed by the State. EPA will make an applicability determination based on your letter, and in consultation with the State when necessary and will notify you regarding your applicability status and required sampling schedule. However, if your PWS meets the applicability criteria specified in 40 CFR 141.40(a)(2)(i), you are subject to the UCMR monitoring and reporting requirements, regardless of whether you have been contacted by the State or EPA.
                            </P>
                            <P>
                                (5) 
                                <E T="03">Notifying EPA if your PWS cannot sample according to schedule</E>
                                —(i) 
                                <E T="03">General rescheduling notification requirements.</E>
                                 Large systems may independently change their monitoring schedules up to December 31, 2022, using EPA's electronic data reporting system, as specified in paragraph (b)(1) of this section. After this date has passed, if your PWS cannot sample according to your assigned sampling schedule (e.g., because of budget constraints, or if a sampling location will be closed during the scheduled month of monitoring), you must mail or email a letter to EPA, as specified in paragraph (b)(1) of this section, prior to the scheduled sampling date. You must include an explanation of why the samples cannot be taken according to the assigned schedule, and you must provide the alternative schedule you are requesting. You must not reschedule monitoring specifically to avoid sample collection during a suspected vulnerable period. You are subject to your assigned UCMR sampling schedule or the schedule that you revised on or before December 31, 2022, unless and until you receive a letter from EPA specifying a new schedule.
                            </P>
                            <P>
                                (ii) 
                                <E T="03">Exceptions to the rescheduling notification requirements.</E>
                                 For ground water sampling, if the second round of sampling will be completed five to seven months after the first sampling event, as specified in Table 2 of § 141.40(a)(4)(i)(B), no notification to EPA is required. If any ground water sampling location will be non-operational for more than one month before and one month after the month in which the second sampling event is scheduled (
                                <E T="03">i.e.</E>
                                , it is not possible for you to sample within the five to seven month window), you must notify EPA, as specified in paragraph (b)(1) of this section, explaining why the schedule cannot be met. You must comply with any modified schedule provided by EPA.
                            </P>
                            <P>
                                (6) 
                                <E T="03">Reporting monitoring results.</E>
                                 For UCMR samples, you must report all 
                                <PRTPAGE P="561"/>
                                data elements specified in Table 1 of paragraph (e) of this section, using EPA's electronic data reporting system. You also must report any changes, relative to what is currently posted, made to data elements 1 through 9 to EPA in writing, explaining the nature and purpose of the proposed change, as specified in paragraph (b)(1) of this section.
                            </P>
                            <P>
                                (i) 
                                <E T="03">Electronic reporting system.</E>
                                 You are responsible for ensuring that the laboratory conducting the analysis of your unregulated contaminant monitoring samples (your laboratory) posts the analytical results to EPA's electronic reporting system. You are also responsible for reviewing, approving, and submitting those results to EPA.
                            </P>
                            <P>
                                (ii) 
                                <E T="03">Reporting schedule.</E>
                                 You must require your laboratory, on your behalf, to post and approve the data in EPA's electronic data reporting system, accessible at 
                                <E T="03">https://www.epa.gov/dwucmr,</E>
                                 for your review within 90 days from the sample collection date (sample collection must occur as specified in 40 CFR 141.40(a)(4)). You then have 30 days from when the laboratory posts and approves your data to review, approve, and submit the data to the State and EPA via the agency's electronic data reporting system. If you do not electronically approve and submit the laboratory data to EPA within 30 days of the laboratory posting approved data, the data will be considered approved by you and available for State and EPA review.
                            </P>
                            <P>
                                (7) 
                                <E T="03">Only one set of results accepted.</E>
                                 If you report more than one set of valid results for the same sampling location and the same sampling event (for example, because you have had more than one laboratory analyze replicate samples collected under § 141.40(a)(5), or because you have collected multiple samples during a single monitoring event at the same sampling location), EPA will use the highest of the reported values as the official result.
                            </P>
                            <P>
                                (8) 
                                <E T="03">No reporting of previously collected data.</E>
                                 You cannot report previously collected data to meet the testing and reporting requirements for the contaminants listed in § 141.40(a)(3). All analyses must be performed by laboratories approved by EPA to perform UCMR analyses using the analytical methods specified in Table 1 of § 141.40(a)(3) and using samples collected according to § 141.40(a)(4). Such requirements preclude the possibility of “grandfathering” previously collected data.
                            </P>
                            <P>
                                (d) 
                                <E T="03">Reporting by small systems.</E>
                                 If you serve a population of 10,000 or fewer people, and you are notified that you have been selected for UCMR monitoring, your reporting requirements will be specified within the materials that EPA sends you, including a request for contact information, and a request for information associated with the sampling kit.
                            </P>
                            <P>
                                (1) 
                                <E T="03">Contact and zip code information.</E>
                                 EPA will send you a notice requesting contact information for key individuals at your system, including name, affiliation, mailing address, phone number and email address. These individuals include your PWS Technical Contact and your PWS Official. You are required to provide this contact information within 90 days of receiving the notice from EPA as specified in paragraph (b)(1) of this section. If this contact information changes, you also must provide updates within 30 days of the change, as specified in paragraph (b)(1) of this section. In addition, as a one-time reporting requirement, you must report the U.S. Postal Service Zip Code(s) for all areas being served water by your PWS.
                            </P>
                            <P>
                                (2) 
                                <E T="03">Sampling location inventory information.</E>
                                 You must provide your inventory information by December 31, 2022, using EPA's electronic data reporting system, as specified in paragraph (b)(1) of this section. If this information changes, you must report updates, including new sources, and sampling locations that are put in use before or during the UCMR sampling period, to EPA's electronic data reporting system within 30 days of the change, as specified in paragraph (b)(1) of this section. You must record all data elements listed in Table 1 of paragraph (e) of this section on each sample form and sample bottle, as appropriate, provided to you by the UCMR Sampling Coordinator. You must send this information as specified in the instructions of your sampling kit, which will include the due date and return address. You must 
                                <PRTPAGE P="562"/>
                                report any changes made in data elements 1 through 9 by emailing an explanation of the nature and purpose of the proposed change to EPA, as specified in paragraph (b)(1) of this section.
                            </P>
                            <P>
                                (e) 
                                <E T="03">Data elements.</E>
                                 Table 1 defines the data elements that must be provided for UCMR monitoring.
                            </P>
                            <GPOTABLE COLS="2" OPTS="L2,nj" CDEF="s50,r150">
                                <TTITLE>
                                    Table 1 to Paragraph 
                                    <E T="01">(e)</E>
                                    —Unregulated Contaminant Monitoring Reporting Requirements
                                </TTITLE>
                                <BOXHD>
                                    <CHED H="1">Data element</CHED>
                                    <CHED H="1">Definition</CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">1. Public Water System Identification (PWSID) Code</ENT>
                                    <ENT>The code used to identify each PWS. The code begins with the standard 2-character postal State abbreviation or Region code; the remaining 7 numbers are unique to each PWS in the State. The same identification code must be used to represent the PWS identification for all current and future UCMR monitoring.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">2. Public Water System Name</ENT>
                                    <ENT>Unique name, assigned once by the PWS.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">3. Public Water System Facility Identification Code</ENT>
                                    <ENT>An identification code established by the State or, at the State's discretion, by the PWS, following the format of a 5-digit number unique within each PWS for each applicable facility (i.e., for each source of water, treatment plant, distribution system, or any other facility associated with water treatment or delivery). The same identification code must be used to represent the facility for all current and future UCMR monitoring.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">4. Public Water System Facility Name</ENT>
                                    <ENT>Unique name, assigned once by the PWS, for every facility ID (e.g., Treatment Plant).</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">5. Public Water System Facility Type</ENT>
                                    <ENT>
                                        That code that identifies that type of facility as either:
                                        <LI>CC = Consecutive connection.</LI>
                                        <LI>SS = Sampling station.</LI>
                                        <LI>TP = Treatment plant.</LI>
                                        <LI>OT = Other.</LI>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">6. Water Source Type</ENT>
                                    <ENT>The type of source water that supplies a water system facility. Systems must report one of the following codes for each sampling location:</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>SW = Surface water (to be reported for water facilities that are served entirely by a surface water source during the 12-month period).</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>GU = Ground water under the direct influence of surface water (to be reported for water facilities that are served all or in part by ground water under the direct influence of surface water at any time during the 12-month sampling period), and are not served at all by surface water during this period.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>MX = Mixed water (to be reported for water facilities that are served by a mix of surface water, ground water, and/or ground water under the direct influence of surface water during the 12-month period).</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>GW = Ground water (to be reported for water facilities that are served entirely by a ground water source during the 12-month period).</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">7. Sampling Point Identification Code</ENT>
                                    <ENT>
                                        An identification code established by the State, or at the State's discretion, by the PWS, that uniquely identifies each sampling point. Each sampling code must be unique within each applicable facility, for each applicable sampling location (i.e
                                        <E T="03">.,</E>
                                         entry point to the distribution system). The same identification code must be used to represent the sampling location for all current and future UCMR monitoring.
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">8. Sampling Point Name</ENT>
                                    <ENT>Unique sample point name, assigned once by the PWS, for every sample point ID (e.g., Entry Point).</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">9. Sampling Point Type Code</ENT>
                                    <ENT>
                                        A code that identifies the location of the sampling point as:
                                        <LI>EP = Entry point to the distribution system.</LI>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">10. Disinfectant Type</ENT>
                                    <ENT>All of the disinfectants/oxidants that have been added prior to and at the entry point to the distribution system. Please select all that apply:</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>PEMB = Permanganate.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>HPXB = Hydrogen peroxide.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>CLGA = Gaseous chlorine.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>CLOF = Offsite generated hypochlorite (stored as a liquid form).</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>CLON = Onsite generated hypochlorite.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>CAGC = Chloramine (formed with gaseous chlorine).</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>CAOF = Chloramine (formed with offsite hypochlorite).</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>CAON = Chloramine (formed with onsite hypochlorite).</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>CLDB = Chlorine dioxide.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>OZON = Ozone.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>ULVL = Ultraviolet light.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>OTHD = All other types of disinfectant/oxidant.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>NODU = No disinfectant/oxidant used.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">11. Treatment Information</ENT>
                                    <ENT>Treatment information associated with the sample point. Please select all that apply.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>CON = Conventional (non-softening, consisting of at least coagulation/sedimentation basins and filtration).</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>SFN = Softening.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>RBF = River bank filtration.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>PSD = Pre-sedimentation.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>INF = In-line filtration.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>DFL = Direct filtration.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>SSF = Slow sand filtration.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>BIO = Biological filtration (operated with an intention of maintaining biological activity within filter).</ENT>
                                </ROW>
                                <ROW>
                                    <PRTPAGE P="563"/>
                                    <ENT I="22"> </ENT>
                                    <ENT>UTR = Unfiltered treatment for surface water source.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>GWD = Groundwater system with disinfection only.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>PAC = Application of powder activated carbon.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>GAC = Granular activated carbon adsorption (not part of filters in CON, SFN, INF, DFL, or SSF).</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>AIR = Air stripping (packed towers, diffused gas contactors).</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>POB = Pre-oxidation with chlorine (applied before coagulation for CON or SFN plants or before filtration for other filtration plants).</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>MFL = Membrane filtration.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>IEX = Ionic exchange.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>DAF = Dissolved air floatation.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>CWL = Clear well/finished water storage without aeration.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>CWA = Clear well/finished water storage with aeration.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>ADS = Aeration in distribution system (localized treatment).</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>OTH = All other types of treatment.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>NTU = No treatment used.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>DKN = Do not know.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">12. Sample Collection Date</ENT>
                                    <ENT>The date the sample is collected, reported as 4-digit year, 2-digit month, and 2-digit day (YYYYMMDD).</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">13. Sample Identification Code</ENT>
                                    <ENT>An alphanumeric value up to 30 characters assigned by the laboratory to uniquely identify containers, or groups of containers, containing water samples collected at the same sampling location for the same sampling date.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">14. Contaminant</ENT>
                                    <ENT>The unregulated contaminant for which the sample is being analyzed.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">15. Analytical Method Code</ENT>
                                    <ENT>The identification code of the analytical method used.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">16. Extraction Batch Identification Code</ENT>
                                    <ENT>Laboratory assigned extraction batch ID. Must be unique for each extraction batch within the laboratory for each method. For CCC samples report the Analysis Batch Identification Code as the value for this field. For methods without an extraction batch, leave this field null.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">17. Extraction Date</ENT>
                                    <ENT>Date for the start of the extraction batch (YYYYMMDD). For methods without an extraction batch, leave this field null.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">18. Analysis Batch Identification Code</ENT>
                                    <ENT>Laboratory assigned analysis batch ID. Must be unique for each analysis batch within the laboratory for each method.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">19. Analysis Date</ENT>
                                    <ENT>Date for the start of the analysis batch (YYYYMMDD).</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">20. Sample Analysis Type</ENT>
                                    <ENT>
                                        The type of sample collected and/or prepared, as well as the fortification level. Permitted values include:
                                        <LI>CCCL = MRL level continuing calibration check; a calibration standard containing the contaminant, the internal standard, and surrogate analyzed to verify the existing calibration for those contaminants.</LI>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>CCCM = Medium level continuing calibration check; a calibration standard containing the contaminant, the internal standard, and surrogate analyzed to verify the existing calibration for those contaminants.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>CCCH = High level continuing calibration check; a calibration standard containing the contaminant, the internal standard, and surrogate analyzed to verify the existing calibration for those contaminants.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>FS = Field sample; sample collected and submitted for analysis under this final rule.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>LFB = Laboratory fortified blank; an aliquot of reagent water fortified with known quantities of the contaminants and all preservation compounds.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>LRB = Laboratory reagent blank; an aliquot of reagent water treated exactly as a field sample, including the addition of preservatives, internal standards, and surrogates to determine if interferences are present in the laboratory, reagents, or other equipment.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>LFSM = Laboratory fortified sample matrix; a UCMR field sample with a known amount of the contaminant of interest and all preservation compounds added.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>LFSMD = Laboratory fortified sample matrix duplicate; duplicate of the laboratory fortified sample matrix.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>QCS = Quality control sample; a sample prepared with a source external to the one used for initial calibration and CCC. The QCS is used to check calibration standard integrity.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>FRB = Field reagent blank; an aliquot of reagent water treated as a sample including exposure to sampling conditions to determine if interferences or contamination are present from sample collection through analysis.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">21. Analytical Result—Sign</ENT>
                                    <ENT>
                                        A value indicating whether the sample analysis result was:
                                        <LI>(&lt;) “less than” means the contaminant was not detected, or was detected at a level below the Minimum Reporting Level.</LI>
                                        <LI>(=) “equal to” means the contaminant was detected at the level reported in “Analytical Result— Measured Value.”</LI>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">22. Analytical Result—Measured Value</ENT>
                                    <ENT>The actual numeric value of the analytical results for: Field samples; laboratory fortified matrix samples; laboratory fortified sample matrix duplicates; and concentration fortified.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">23. Additional Value</ENT>
                                    <ENT>Represents the true value or the fortified concentration for spiked samples for QC Sample Analysis Types (CCCL, CCCM, CCCH, QCS, LFB, LFSM, and LFSMD).</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">24. Laboratory Identification Code</ENT>
                                    <ENT>The code, assigned by EPA, used to identify each laboratory. The code begins with the standard two-character State postal abbreviation; the remaining five numbers are unique to each laboratory in the State.</ENT>
                                </ROW>
                                <ROW>
                                    <PRTPAGE P="564"/>
                                    <ENT I="01">25. Sample Event Code</ENT>
                                    <ENT>A code assigned by the PWS for each sample event. This will associate samples with the PWS monitoring plan to allow EPA to track compliance and completeness. Systems must assign the following codes:</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>SE1, SE2, SE3, and SE4—Represent samples collected to meet UCMR Assessment Monitoring requirements; where “SE1” and “SE2” represent the first and second sampling period for all water types; and “SE3” and “SE4” represent the third and fourth sampling period for SW, GU, and MX sources only.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">26. Historical Information for Contaminant Detections and Treatment</ENT>
                                    <ENT>
                                        A yes or no answer provided by the PWS for each entry point to the distribution system.
                                        <LI>Question: Have you tested for the contaminant in your drinking water in the past?</LI>
                                        <LI>YES = If yes, did you modify your treatment and if so, what types of treatment did you implement? Select all that apply.</LI>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="oi3">PAC = Application of powder activated carbon.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="oi3">GAC = Granular activated carbon adsorption (not part of filters in CON, SFN, INF, DFL, or SSF).</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="oi3">IEX = Ionic exchange.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="oi3">NRO = Nanofiltration and reverse osmosis.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="oi3">OZN = Ozone.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="oi3">BAC = Biologically active carbon.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="oi3">MFL = Membrane filtration.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="oi3">UVL = Ultraviolet light.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="oi3">OTH = Other.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="oi3">NMT = Not modified after testing.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="oi3">NO = Have never tested for the contaminant.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="oi3">DK = Do not know.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">27. Potential PFAS Sources</ENT>
                                    <ENT>
                                        A yes or no answer provided by the PWS for each entry point to the distribution system.
                                        <LI>Question: Are you aware of any potential current and/or historical sources of PFAS that may have impacted the drinking water sources at your water system?</LI>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="oi3">YES = If yes, select all that apply:</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="oi3">MB = Military base.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="oi3">FT = Firefighting training school.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="oi3">AO = Airport operations.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="oi3">CW = Car wash or industrial launderers.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="oi3">PS = Public safety activities (e.g., fire and rescue services).</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="oi3">WM = Waste management.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="oi3">HW = Hazardous waste collection, treatment, and disposal.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="oi3">UW = Underground injection well.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="oi3">SC = Solid waste collection, combustors, incinerators.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="oi3">MF = Manufacturing.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="oi3">FP = Food packaging.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="oi3">TA = Textile and apparel (e.g., stain- and water-resistant, fiber/thread, carpet, house furnishings, leather).</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="oi3">PP = Paper.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="oi3">CC = Chemical.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="oi3">PR = Plastics and rubber products.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="oi3">MM = Machinery.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="oi3">CE = Computer and electronic products.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="oi3">FM = Fabricated metal products (e.g., nonstick cookware).</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="oi3">PC = Petroleum and coal products.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="oi3">FF = Furniture.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="oi3">OG = Oil and gas production.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="oi3">
                                        UT = Utilities (e.g
                                        <E T="03">.,</E>
                                         sewage treatment facilities).
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="oi3">
                                        CT = Construction (e.g
                                        <E T="03">.,</E>
                                         wood floor finishing, electrostatic painting).
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="oi3">OT = Other.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="oi3">NO = Not aware of any potential current and/or historical sources.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT O="oi3">DK = Do not know.</ENT>
                                </ROW>
                            </GPOTABLE>
                            <CITA>[72 FR 389, Jan. 4, 2007, as amended at 77 FR 26096, May 2, 2012; 81 FR 92684, Dec. 20, 2016; 86 FR 73151, Dec. 27, 2021; 87 FR 3679, Jan. 25, 2022]</CITA>
                        </SECTION>
                    </SUBPART>
                    <SUBPART>
                        <PRTPAGE P="565"/>
                        <HD SOURCE="HED">Subpart E—Special Regulations, Including Monitoring</HD>
                        <SECTION>
                            <SECTNO>§ 141.40</SECTNO>
                            <SUBJECT>Monitoring requirements for unregulated contaminants.</SUBJECT>
                            <P>
                                (a) 
                                <E T="03">General applicability.</E>
                                 This section specifies the monitoring and quality control requirements that must be followed if you own or operate a public water system (PWS) that is subject to the Unregulated Contaminant Monitoring Regulation (UCMR), as specified in paragraphs (a)(1) and (2) of this section. In addition, this section specifies the UCMR requirements for State and Tribal participation. For the purposes of this section, PWS “population served,” “State,” ” PWS Official,” “PWS Technical Contact,” and “finished water” apply as defined in § 141.35(a). The determination of whether a PWS is required to monitor under this rule is based on the type of system (e.g., community water system, non-transient non-community water system, etc.), and its retail population, as indicated by SDWIS/Fed on February 1, 2021 or subsequent corrections from the State.
                            </P>
                            <P>
                                (1) 
                                <E T="03">Applicability to transient non-community systems.</E>
                                 If you own or operate a transient non-community water system, you are not subject to monitoring requirements in this section.
                            </P>
                            <P>
                                (2) 
                                <E T="03">Applicability to community water systems and non-transient non-community water systems</E>
                                —(i) 
                                <E T="03">Large systems.</E>
                                 If you own or operate a retail PWS (other than a transient non-community system) that serves more than 10,000 people, you must monitor according to the specifications in this paragraph (a)(2)(i). If you believe that your applicability status is different than EPA has specified in the notification letter that you received, or if you are subject to UCMR requirements and you have not been notified by either EPA or your State, you must report to EPA, as specified in § 141.35(b)(2) or (c)(4).
                            </P>
                            <P>
                                (A) 
                                <E T="03">Assessment monitoring.</E>
                                 You must monitor for the contaminants on List 1, per Table 1, UCMR Contaminant List, in paragraph (a)(3) of this section. If you serve a retail population of more than 10,000 people, you are required to perform this monitoring regardless of whether you have been notified by the State or EPA.
                            </P>
                            <P>
                                (B) 
                                <E T="03">Screening Survey.</E>
                                 You must monitor for the unregulated contaminants on List 2 (Screening Survey) of Table 1, as specified in paragraph (a)(3) of this section, if your system serves 10,001 to 100,000 people and you are notified by EPA or your State that you are part of the State Monitoring Plan for Screening Survey testing. If your system serves more than 100,000 people, you are required to conduct this Screening Survey testing regardless of whether you have been notified by the State or EPA.
                            </P>
                            <P>
                                (C) 
                                <E T="03">Pre-Screen Testing.</E>
                                 You must monitor for the unregulated contaminants on List 3 of Table 1, in paragraph (a)(3) of this section, if notified by your State or EPA that you are part of the Pre-Screen Testing.
                            </P>
                            <P>
                                (ii) 
                                <E T="03">Small systems.</E>
                                 EPA will provide sample containers, provide pre-paid air bills for shipping the sampling materials, conduct the laboratory analysis, and report and review monitoring results for all small systems selected to conduct monitoring under paragraphs (a)(2)(ii)(A) through (C) of this section. If you own or operate a PWS (other than a transient non-community water system) that serves a retail population of 10,000 or fewer people and you are notified of monitoring requirements by the State or EPA, you must monitor as follows:
                            </P>
                            <P>
                                (A) 
                                <E T="03">Assessment Monitoring.</E>
                                 You must monitor for the contaminants on List 1 per table 1 to paragraph (a)(3) if you are notified by your State or EPA that you are part of the State Monitoring Plan for Assessment Monitoring.
                            </P>
                            <P>
                                (B) 
                                <E T="03">Screening Survey.</E>
                                 You must monitor for the unregulated contaminants on List 2 of Table 1, in paragraph (a)(3) of this section, if notified by your State or EPA that you are part of the State Monitoring Plan for the Screening Survey.
                            </P>
                            <P>
                                (C) 
                                <E T="03">Pre-screen testing.</E>
                                 You must monitor for the contaminants on List 3 of Table 1, in paragraph (a)(3) of this section if you are notified by your State or EPA that you are part of the State Monitoring Plan for Pre-Screen Testing.
                            </P>
                            <P>
                                (3) 
                                <E T="03">Analytes to be monitored.</E>
                                 Lists 1, 2, and 3 contaminants are provided in table 1 to paragraph (a)(3):
                                <PRTPAGE P="566"/>
                            </P>
                            <GPOTABLE COLS="6" OPTS="L2,nj,p7,7/8" CDEF="s100,r50,r50,xs68,xs50,xs76">
                                <TTITLE>
                                    Table 1 to Paragraph 
                                    <E T="01">(a)(3)</E>
                                    —UCMR Contaminant List
                                </TTITLE>
                                <BOXHD>
                                    <CHED H="1">1—Contaminant</CHED>
                                    <CHED H="1">2—CASRN</CHED>
                                    <CHED H="1">
                                        3—Analytical
                                        <LI>
                                            methods 
                                            <SU>a</SU>
                                        </LI>
                                    </CHED>
                                    <CHED H="1">
                                        4—Minimum
                                        <LI>
                                            reporting level 
                                            <SU>b</SU>
                                        </LI>
                                    </CHED>
                                    <CHED H="1">
                                        5—Sampling
                                        <LI>
                                            location 
                                            <SU>c</SU>
                                        </LI>
                                    </CHED>
                                    <CHED H="1">
                                        6—Period during
                                        <LI>which sample</LI>
                                        <LI>collection</LI>
                                        <LI>to be completed</LI>
                                    </CHED>
                                </BOXHD>
                                <ROW EXPSTB="05" RUL="s">
                                    <ENT I="21">
                                        <E T="02">List 1: Assessment Monitoring</E>
                                    </ENT>
                                </ROW>
                                <ROW RUL="s">
                                    <ENT I="21">
                                        <E T="02">Per- and Polyfluoroalkyl Substances (PFAS)</E>
                                    </ENT>
                                </ROW>
                                <ROW EXPSTB="00">
                                    <ENT I="01">11-chloroeicosafluoro-3-oxaundecane-1-sulfonic acid (11Cl-PF3OUdS)</ENT>
                                    <ENT>763051-92-9</ENT>
                                    <ENT>EPA 533</ENT>
                                    <ENT>0.005 µg/L</ENT>
                                    <ENT>EPTDS</ENT>
                                    <ENT>1/1/2023-12/31/2025</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">1H, 1H, 2H, 2H-perfluorodecane sulfonic acid (8:2 FTS)</ENT>
                                    <ENT>39108-34-4</ENT>
                                    <ENT>EPA 533</ENT>
                                    <ENT>0.005 µg/L</ENT>
                                    <ENT>EPTDS</ENT>
                                    <ENT>1/1/2023-12/31/2025</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">1H, 1H, 2H, 2H-perfluorohexane sulfonic acid (4:2 FTS)</ENT>
                                    <ENT>757124-72-4</ENT>
                                    <ENT>EPA 533</ENT>
                                    <ENT>0.003 µg/L</ENT>
                                    <ENT>EPTDS</ENT>
                                    <ENT>1/1/2023-12/31/2025</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">1H, 1H, 2H, 2H-perfluorooctane sulfonic acid (6:2 FTS)</ENT>
                                    <ENT>27619-97-2</ENT>
                                    <ENT>EPA 533</ENT>
                                    <ENT>0.005 µg/L</ENT>
                                    <ENT>EPTDS</ENT>
                                    <ENT>1/1/2023-12/31/2025</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">4,8-dioxa-3H-perfluorononanoic acid (ADONA)</ENT>
                                    <ENT>919005-14-4</ENT>
                                    <ENT>EPA 533</ENT>
                                    <ENT>0.003 µg/L</ENT>
                                    <ENT>EPTDS</ENT>
                                    <ENT>1/1/2023-12/31/2025</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">9-chlorohexadecafluoro-3-oxanone-1-sulfonic acid (9Cl-PF3ONS)</ENT>
                                    <ENT>756426-58-1</ENT>
                                    <ENT>EPA 533</ENT>
                                    <ENT>0.002 µg/L</ENT>
                                    <ENT>EPTDS</ENT>
                                    <ENT>1/1/2023-12/31/2025</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">hexafluoropropylene oxide dimer acid (HFPO-DA) (GenX)</ENT>
                                    <ENT>13252-13-6</ENT>
                                    <ENT>EPA 533</ENT>
                                    <ENT>0.005 µg/L</ENT>
                                    <ENT>EPTDS</ENT>
                                    <ENT>1/1/2023-12/31/2025</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">nonafluoro-3,6-dioxaheptanoic acid (NFDHA)</ENT>
                                    <ENT>151772-58-6</ENT>
                                    <ENT>EPA 533</ENT>
                                    <ENT>0.02 µg/L</ENT>
                                    <ENT>EPTDS</ENT>
                                    <ENT>1/1/2023-12/31/2025</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">perfluoro (2-ethoxyethane) sulfonic acid (PFEESA)</ENT>
                                    <ENT>113507-82-7</ENT>
                                    <ENT>EPA 533</ENT>
                                    <ENT>0.003 µg/L</ENT>
                                    <ENT>EPTDS</ENT>
                                    <ENT>1/1/2023-12/31/2025</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">perfluoro-3-methoxypropanoic acid (PFMPA)</ENT>
                                    <ENT>377-73-1</ENT>
                                    <ENT>EPA 533</ENT>
                                    <ENT>0.004 µg/L</ENT>
                                    <ENT>EPTDS</ENT>
                                    <ENT>1/1/2023-12/31/2025</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">perfluoro-4-methoxybutanoic acid (PFMBA)</ENT>
                                    <ENT>863090-89-5</ENT>
                                    <ENT>EPA 533</ENT>
                                    <ENT>0.003 µg/L</ENT>
                                    <ENT>EPTDS</ENT>
                                    <ENT>1/1/2023-12/31/2025</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">perfluorobutanesulfonic acid (PFBS)</ENT>
                                    <ENT>375-73-5</ENT>
                                    <ENT>EPA 533</ENT>
                                    <ENT>0.003 µg/L</ENT>
                                    <ENT>EPTDS</ENT>
                                    <ENT>1/1/2023-12/31/2025</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">perfluorobutanoic acid (PFBA)</ENT>
                                    <ENT>375-22-4</ENT>
                                    <ENT>EPA 533</ENT>
                                    <ENT>0.005 µg/L</ENT>
                                    <ENT>EPTDS</ENT>
                                    <ENT>1/1/2023-12/31/2025</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">perfluorodecanoic acid (PFDA)</ENT>
                                    <ENT>335-76-2</ENT>
                                    <ENT>EPA 533</ENT>
                                    <ENT>0.003 µg/L</ENT>
                                    <ENT>EPTDS</ENT>
                                    <ENT>1/1/2023-12/31/2025</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">perfluorododecanoic acid (PFDoA)</ENT>
                                    <ENT>307-55-1</ENT>
                                    <ENT>EPA 533</ENT>
                                    <ENT>0.003 µg/L</ENT>
                                    <ENT>EPTDS</ENT>
                                    <ENT>1/1/2023-12/31/2025</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">perfluoroheptanesulfonic acid (PFHpS)</ENT>
                                    <ENT>375-92-8</ENT>
                                    <ENT>EPA 533</ENT>
                                    <ENT>0.003 µg/L</ENT>
                                    <ENT>EPTDS</ENT>
                                    <ENT>1/1/2023-12/31/2025</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">perfluoroheptanoic acid (PFHpA)</ENT>
                                    <ENT>375-85-9</ENT>
                                    <ENT>EPA 533</ENT>
                                    <ENT>0.003 µg/L</ENT>
                                    <ENT>EPTDS</ENT>
                                    <ENT>1/1/2023-12/31/2025</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">perfluorohexanesulfonic acid (PFHxS)</ENT>
                                    <ENT>355-46-4</ENT>
                                    <ENT>EPA 533</ENT>
                                    <ENT>0.003 µg/L</ENT>
                                    <ENT>EPTDS</ENT>
                                    <ENT>1/1/2023-12/31/2025</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">perfluorohexanoic acid (PFHxA)</ENT>
                                    <ENT>307-24-4</ENT>
                                    <ENT>EPA 533</ENT>
                                    <ENT>0.003 µg/L</ENT>
                                    <ENT>EPTDS</ENT>
                                    <ENT>1/1/2023-12/31/2025</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">perfluorononanoic acid (PFNA)</ENT>
                                    <ENT>375-95-1</ENT>
                                    <ENT>EPA 533</ENT>
                                    <ENT>0.004 µg/L</ENT>
                                    <ENT>EPTDS</ENT>
                                    <ENT>1/1/2023-12/31/2025</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">perfluorooctanesulfonic acid (PFOS)</ENT>
                                    <ENT>1763-23-1</ENT>
                                    <ENT>EPA 533</ENT>
                                    <ENT>0.004 µg/L</ENT>
                                    <ENT>EPTDS</ENT>
                                    <ENT>1/1/2023-12/31/2025</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">perfluorooctanoic acid (PFOA)</ENT>
                                    <ENT>335-67-1</ENT>
                                    <ENT>EPA 533</ENT>
                                    <ENT>0.004 µg/L</ENT>
                                    <ENT>EPTDS</ENT>
                                    <ENT>1/1/2023-12/31/2025</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">perfluoropentanesulfonic acid (PFPeS)</ENT>
                                    <ENT>2706-91-4</ENT>
                                    <ENT>EPA 533</ENT>
                                    <ENT>0.004 µg/L</ENT>
                                    <ENT>EPTDS</ENT>
                                    <ENT>1/1/2023-12/31/2025</ENT>
                                </ROW>
                                <ROW>
                                    <PRTPAGE P="567"/>
                                    <ENT I="01">perfluoropentanoic acid (PFPeA)</ENT>
                                    <ENT>2706-90-3</ENT>
                                    <ENT>EPA 533</ENT>
                                    <ENT>0.003 µg/L</ENT>
                                    <ENT>EPTDS</ENT>
                                    <ENT>1/1/2023-12/31/2025</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">perfluoroundecanoic acid (PFUnA)</ENT>
                                    <ENT>2058-94-8</ENT>
                                    <ENT>EPA 533</ENT>
                                    <ENT>0.002 µg/L</ENT>
                                    <ENT>EPTDS</ENT>
                                    <ENT>1/1/2023-12/31/2025</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">n-ethyl perfluorooctanesulfonamidoacetic acid (NEtFOSAA)</ENT>
                                    <ENT>2991-50-6</ENT>
                                    <ENT>EPA 537.1</ENT>
                                    <ENT>0.005 µg/L</ENT>
                                    <ENT>EPTDS</ENT>
                                    <ENT>1/1/2023-12/31/2025</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">n-methyl perfluorooctanesulfonamidoacetic acid (NMeFOSAA)</ENT>
                                    <ENT>2355-31-9</ENT>
                                    <ENT>EPA 537.1</ENT>
                                    <ENT>0.006 µg/L</ENT>
                                    <ENT>EPTDS</ENT>
                                    <ENT>1/1/2023-12/31/2025</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">perfluorotetradecanoic acid (PFTA)</ENT>
                                    <ENT>376-06-7</ENT>
                                    <ENT>EPA 537.1</ENT>
                                    <ENT>0.008 µg/L</ENT>
                                    <ENT>EPTDS</ENT>
                                    <ENT>1/1/2023-12/31/2025</ENT>
                                </ROW>
                                <ROW RUL="s">
                                    <ENT I="01">perfluorotridecanoic acid (PFTrDA)</ENT>
                                    <ENT>72629-94-8</ENT>
                                    <ENT>EPA 537.1</ENT>
                                    <ENT>0.007 µg/L</ENT>
                                    <ENT>EPTDS</ENT>
                                    <ENT>1/1/2023-12/31/2025</ENT>
                                </ROW>
                                <ROW EXPSTB="05" RUL="s">
                                    <ENT I="21">
                                        <E T="02">Metal/Pharmaceutical</E>
                                    </ENT>
                                </ROW>
                                <ROW EXPSTB="00" RUL="s">
                                    <ENT I="01">Lithium</ENT>
                                    <ENT>7439-93-2</ENT>
                                    <ENT>EPA 200.7, SM 3120 B, ASTM D1976-20</ENT>
                                    <ENT>9 µg/L</ENT>
                                    <ENT>EPTDS</ENT>
                                    <ENT>1/1/2023-12/31/2025</ENT>
                                </ROW>
                                <ROW EXPSTB="05" RUL="s">
                                    <ENT I="21">
                                        <E T="02">List 2: Screening Survey</E>
                                    </ENT>
                                </ROW>
                                <ROW EXPSTB="00" RUL="s">
                                    <ENT I="01">Reserved</ENT>
                                    <ENT>Reserved</ENT>
                                    <ENT>Reserved</ENT>
                                    <ENT>Reserved</ENT>
                                    <ENT>Reserved</ENT>
                                    <ENT>Reserved</ENT>
                                </ROW>
                                <ROW EXPSTB="05" RUL="s">
                                    <ENT I="21">
                                        <E T="02">List 3: Pre-Screen Testing</E>
                                    </ENT>
                                </ROW>
                                <ROW EXPSTB="00">
                                    <ENT I="01">Reserved</ENT>
                                    <ENT>Reserved</ENT>
                                    <ENT>Reserved</ENT>
                                    <ENT>Reserved</ENT>
                                    <ENT>Reserved</ENT>
                                    <ENT>Reserved</ENT>
                                </ROW>
                                <TNOTE>Column headings are:</TNOTE>
                                <TNOTE>
                                    <E T="03">1—Contaminant:</E>
                                     The name of the contaminant to be analyzed.
                                </TNOTE>
                                <TNOTE>
                                    <E T="03">2—CASRN (Chemical Abstracts Service Registry Number) or Identification Number:</E>
                                     A unique number identifying the chemical contaminants.
                                </TNOTE>
                                <TNOTE>
                                    <E T="03">3—Analytical Methods:</E>
                                     Method numbers identifying the methods that must be used to test the contaminants.
                                </TNOTE>
                                <TNOTE>
                                    <E T="03">4—Minimum Reporting Level (MRL):</E>
                                     The value and unit of measure at or above which the concentration of the contaminant must be measured using the approved analytical methods. If EPA determines, after the first six months of monitoring that the specified MRLs result in excessive resampling, EPA will establish alternate MRLs and will notify affected PWSs and laboratories of the new MRLs. N/A is defined as non-applicable.
                                </TNOTE>
                                <TNOTE>
                                    <E T="03">5—Sampling Location:</E>
                                     The locations within a PWS at which samples must be collected.
                                </TNOTE>
                                <TNOTE>
                                    <E T="03">6—Period During Which Sample Collection to be Completed:</E>
                                     The time period during which the sampling and testing will occur for the indicated contaminant.
                                </TNOTE>
                                <TNOTE>
                                    <SU>a</SU>
                                     The analytical procedures shall be performed in accordance with the documents associated with each method, see paragraph (c) of this section.
                                </TNOTE>
                                <TNOTE>
                                    <SU>b</SU>
                                     The MRL is the minimum concentration of each analyte that must be reported to EPA.
                                </TNOTE>
                                <TNOTE>
                                    <SU>c</SU>
                                     Sampling must occur at your PWS's entry points to the distribution system (EPTDSs), after treatment is applied, that represent each non-emergency water source in routine use over the 12-month period of monitoring. Systems that purchase water with multiple connections from the same wholesaler may select one representative connection from that wholesaler. The representative EPTDS must be a location within the purchaser's water system. This EPTDS sampling location must be representative of the highest annual volume connections. If the connection selected as the representative EPTDS is not available for sampling, an alternate highest volume representative connection must be sampled. See 40 CFR 141.35(c)(3) for an explanation of the requirements related to the use of representative GW EPTDSs.
                                </TNOTE>
                            </GPOTABLE>
                            <PRTPAGE P="568"/>
                            <P>
                                (4) 
                                <E T="03">Sampling requirements</E>
                                —(i) 
                                <E T="03">Large systems.</E>
                                 If you serve more than 10,000 people and meet the UCMR applicability criteria specified in paragraph (a)(2)(i) of this section, you must comply with the requirements specified in paragraphs (a)(4)(i)(A) through (I) of this section. Your samples must be collected according to the schedule that you are assigned by EPA or your State, or the schedule that you revised using EPA's electronic data reporting system on or before December 31, 2022. Your schedule must follow both the timing and frequency of monitoring specified in Tables 1 and 2 of this section.
                            </P>
                            <P>
                                (A) 
                                <E T="03">Sample collection period.</E>
                                 You must collect the samples in one continuous 12-month period for List 1 Assessment Monitoring, and, if applicable, for List 2 Screening Survey, or List 3 Pre-Screen Testing, during the timeframe indicated in column 6 of table 1 to paragraph (a)(3) of this section. EPA or your State will specify the month(s) and year(s) in which your monitoring must occur. As specified in 40 CFR 141.35(c)(5), you must contact EPA if you believe you cannot collect samples according to your schedule.
                            </P>
                            <P>
                                (B) 
                                <E T="03">Frequency.</E>
                                 You must collect the samples within the timeframe and according to the frequency specified by contaminant type and water source type for each sampling location, as specified in table 2 to this paragraph (a)(4)(i)(B). For the second or subsequent round of sampling, if a sample location is non-operational for more than one month before and one month after the scheduled sampling month (
                                <E T="03">i.e.,</E>
                                 it is not possible for you to sample within the window specified in table 2), you must notify EPA as specified in 40 CFR 141.35(c)(5) to reschedule your sampling.
                            </P>
                            <GPOTABLE COLS="4" OPTS="L2,p7,7/8" CDEF="xs76,r25,xs54,r100">
                                <TTITLE>
                                    Table 2 to Paragraph (
                                    <E T="01">a</E>
                                    )(4)(
                                    <E T="01">i</E>
                                    )(B)—Monitoring Frequency by Contaminant and Water Source Types
                                </TTITLE>
                                <BOXHD>
                                    <CHED H="1">Contaminant type</CHED>
                                    <CHED H="1">Water source type</CHED>
                                    <CHED H="1">Timeframe</CHED>
                                    <CHED H="1">
                                        Frequency 
                                        <SU>1</SU>
                                    </CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">List 1 Contaminants</ENT>
                                    <ENT>Surface water, Mixed, or GWUDI</ENT>
                                    <ENT>12 months</ENT>
                                    <ENT>You must monitor for four consecutive quarters. Sample events must occur three months apart. (Example: If first monitoring is in January, the second monitoring must occur any time in April, the third any time in July, and the fourth any time in October).</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Ground water</ENT>
                                    <ENT>12 months</ENT>
                                    <ENT>You must monitor twice in a consecutive 12-month period. Sample events must occur 5-7 months apart. (Example: If the first monitoring event is in April, the second monitoring event must occur any time in September, October, or November.)</ENT>
                                </ROW>
                                <TNOTE>
                                    <SU>1</SU>
                                     Systems must assign a sample event code for each contaminant listed in Table 1. Sample event codes must be assigned by the PWS for each sample event. For more information on sample event codes see 40 CFR 141.35(e) Table 1.
                                </TNOTE>
                            </GPOTABLE>
                            <P>
                                (C) 
                                <E T="03">Location.</E>
                                 You must collect samples for each List 1 Assessment Monitoring contaminant, and, if applicable, for each List 2 Screening Survey, or List 3 Pre-Screen Testing contaminant, as specified in table 1 to paragraph (a)(3) of this section. Samples must be collected at each sample point that is specified in column 5 and footnote c of table 1 to paragraph (a)(3) of this section. If you are a GW system with multiple EPTDSs, and you request and receive approval from EPA or the State for sampling at representative EPTDS(s), as specified in 40 CFR 141.35(c)(3), you must collect your samples from the approved representative sampling location(s).
                            </P>
                            <P>
                                (D) 
                                <E T="03">Sampling instructions.</E>
                                 For each List 1 Assessment Monitoring contaminant, and, if applicable, for each List 2 Screening Survey, or List 3 Pre-Screen Testing contaminant, you must follow the sampling procedure for the method specified in column 3 of Table 1, in paragraph (a)(3) of this section. In addition, you must not composite (that is, combine, mix, or blend) the samples; 
                                <PRTPAGE P="569"/>
                                you must collect and preserve each sample separately.
                            </P>
                            <P>
                                (E) 
                                <E T="03">Sample collection and shipping time.</E>
                                 If you must ship the samples for analysis, you must collect the samples early enough in the day to allow adequate time to send the samples for overnight delivery to the laboratory. You should not collect samples on Friday, Saturday, or Sunday because sampling on these days may not allow samples to be shipped and received at the laboratory at the required temperature, unless you have made special arrangements with your laboratory to receive the samples.
                            </P>
                            <P>
                                (F) 
                                <E T="03">Analytical methods.</E>
                                 For each contaminant, you must use the respective analytical methods for List 1, and, if applicable, for List 2, or List 3 that are specified in column 3 of Table 1, in paragraph (a)(3) of this section; report values at or above the minimum reporting levels for List 1, and, if applicable, for List 2 Screening Survey, or List 3 Pre-Screen Testing, that are specified in column 4 of Table 1, in paragraph (a)(3) of this section; and conduct the quality control procedures specified in paragraph (a)(5) of this section.
                            </P>
                            <P>
                                (G) 
                                <E T="03">Laboratory errors or sampling deviations.</E>
                                 If the laboratory data do not meet the required QC criteria, as specified in paragraph (a)(5) of this section, or you do not follow the required sampling procedures, as specified in paragraphs (a)(4) of this section, you must resample within 30 days of being informed or becoming aware of these facts. This resampling is not for the purpose of confirming previous results, but to correct the sampling or laboratory error. All systems must report the results obtained from the first sampling for each sampling period, except for cases of sampling or laboratory errors. For the purposes of this rule, no samples are to be recollected for the purposes of confirming the results observed in a previous sampling.
                            </P>
                            <P>
                                (H) 
                                <E T="03">Analysis.</E>
                                 For the List 1 contaminants, and, if applicable, List 2 Screening Survey, or List 3 Pre-Screen Testing contaminants, identified in Table 1, paragraph (a)(3) of this section, you must arrange for testing by a laboratory that has been approved by EPA according to requirements in paragraph (a)(5)(ii) of this section.
                            </P>
                            <P>
                                (I) 
                                <E T="03">Review and reporting of results.</E>
                                 After you have received the laboratory results, you must review, approve, and submit the system information, and sample collection data and test results. You must report the results as provided in § 141.35(c)(6).
                            </P>
                            <P>
                                (ii) 
                                <E T="03">Small systems.</E>
                                 If you serve a population of 10,000 or fewer people and are notified that you are part of the State Monitoring Plan, you must comply with the requirements specified in paragraphs (a)(4)(ii)(A) through (H) of this section. If EPA or the State informs you that they will be collecting your UCMR samples, you must assist them in identifying the appropriate sampling locations and in collecting the samples.
                            </P>
                            <P>
                                (A) 
                                <E T="03">Sample collection and frequency.</E>
                                 You must collect samples at the times specified for you by the State or EPA. Your schedule must follow both the timing of monitoring specified in table 1 to paragraph (a)(3) of this section, List 1, and, if applicable, List 2, or List 3, and the frequency of monitoring in table 2 to paragraph (a)(4)(i)(B) of this section.
                            </P>
                            <P>
                                (B) 
                                <E T="03">Location.</E>
                                 You must collect samples at the locations specified for you by the State or EPA.
                            </P>
                            <P>
                                (C) 
                                <E T="03">Sample kits.</E>
                                 You must store and maintain the sample collection kits sent to you by the UCMR Sampling Coordinator in accordance with the kit's instructions. The sample kit will include all necessary containers, packing materials and cold packs, instructions for collecting the sample and sample treatment (such as dechlorination or preservation), report forms for each sample, contact name and telephone number for the laboratory, and a prepaid return shipping docket and return address label. If any of the materials listed in the kit's instructions are not included in the kit or arrive damaged, you must notify the UCMR Sampling Coordinator who sent you the sample collection kits.
                            </P>
                            <P>
                                (D) 
                                <E T="03">Sampling instructions.</E>
                                 You must comply with the instructions sent to you by the State or EPA concerning the use of containers, collection (how to fill the sample bottle), dechlorination and/or preservation, and 
                                <PRTPAGE P="570"/>
                                sealing and preparation of sample and shipping containers for shipment. You must not composite (that is, combine, mix, or blend) the samples. You also must collect, preserve, and test each sample separately. You must also comply with the instructions sent to you by the UCMR Sampling Coordinator concerning the handling of sample containers for specific contaminants.
                            </P>
                            <P>
                                (E) 
                                <E T="03">Sampling deviations.</E>
                                 If you do not collect a sample according to the instructions provided to you for a listed contaminant, you must report the deviation within 7 days of the scheduled monitoring on the sample reporting form, as specified in § 141.35(d)(2). You must resample following instructions that you will be sent from the UCMR Sampling Coordinator or State. A copy of the form must be sent to the laboratory with the recollected samples, and to the UCMR Sampling Coordinator.
                            </P>
                            <P>(F) [Reserved]</P>
                            <P>
                                (G) 
                                <E T="03">Sampling forms.</E>
                                 You must completely fill out each of the sampling forms and bottles sent to you by the UCMR Sampling Coordinator, including data elements listed in § 141.35(e) for each sample, as specified in § 141.35(d)(2). You must sign and date the sampling forms.
                            </P>
                            <P>
                                (H) 
                                <E T="03">Sample collection and shipping.</E>
                                 You must collect the samples early enough in the day to allow adequate time to send the samples for overnight delivery to the laboratory. You should not collect samples on Friday, Saturday, or Sunday because sampling on these days may not allow samples to be shipped and received at the laboratory at the required temperature unless you have made special arrangements with EPA for the laboratory to receive the samples. Once you have collected the samples and completely filled in the sampling forms, you must send the samples and the sampling forms to the laboratory designated on the air bill.
                            </P>
                            <P>
                                (5) 
                                <E T="03">Quality control requirements.</E>
                                 If your system serves more than 10,000 people, you must ensure that the quality control requirements listed below are met during your sampling procedures and by the laboratory conducting your analyses. You must also ensure that all method quality control procedures and all UCMR quality control procedures are followed.
                            </P>
                            <P>
                                (i) 
                                <E T="03">Sample collection/preservation.</E>
                                 You must follow the sample collection and preservation requirements for the specified method for each of the contaminants in Table 1, in paragraph (a)(3) of this section. These requirements specify sample containers, collection, dechlorination, preservation, storage, sample holding time, and extract storage and/or holding time that you must assure that the laboratory follow.
                            </P>
                            <P>
                                (ii) 
                                <E T="03">Laboratory approval for Lists 1, List 2 and List 3.</E>
                                 To be approved to conduct UCMR testing, the laboratory must be certified under § 141.28 for one or more compliance analyses; demonstrate for each analytical method it plans to use for UCMR testing that it can meet the Initial Demonstration of Capability (IDC) requirements detailed in the analytical methods specified in column 3 of Table 1, in paragraph (a)(3) of this section; and successfully participate in the UCMR Proficiency Testing (PT) Program administered by EPA for each analytical method it plans to use for UCMR testing. UCMR laboratory approval decisions will be granted on an individual method basis for the methods listed in column 3 of Table 1 in paragraph (a)(3) of this section for List 1, List 2, and List 3 contaminants. Laboratory approval is contingent upon the capability of the laboratory to post monitoring data to the EPA electronic data reporting system. To participate in the UCMR Laboratory Approval Program, the laboratory must register and complete the necessary application materials by August 1, 2022. Correspondence must be addressed to: UCMR Laboratory Approval Coordinator, USEPA, Technical Support Center, 26 West Martin Luther King Drive, (MS 140), Cincinnati, Ohio 45268; or emailed to EPA at: 
                                <E T="03">UCMR_Lab_Approval@epa.gov.</E>
                            </P>
                            <P>
                                (iii) 
                                <E T="03">Minimum Reporting Level.</E>
                                 The MRL is defined by EPA as the quantitation limit achievable, with 95 percent confidence, by 75 percent of laboratories nationwide, assuming the use of good instrumentation and experienced analysts.
                            </P>
                            <P>
                                (A) Validation of laboratory performance. Your laboratory must be capable of quantifying each contaminant listed 
                                <PRTPAGE P="571"/>
                                in Table 1, at or below the MRL specified in column 4 of Table 1, in paragraph (a)(3) of this section. You must ensure that the laboratory completes and has on file and available for your inspection, records of two distinct procedures. First, your laboratory must have conducted an IDC involving replicate analyses at or below the MRL as described in this paragraph. Second, for each day that UCMR analyses are conducted by your laboratory, a validation of its ability to quantify each contaminant, at or below the MRL specified in column 4 of Table 1, in paragraph (a)(3) of this section, following the procedure listed in paragraph (a)(5)(iii)(B) of this section, must be performed. The procedure for initial validation of laboratory performance at or below the MRL is as follows:
                            </P>
                            <P>
                                (
                                <E T="03">1</E>
                                ) All laboratories performing analysis under UCMR must demonstrate that they are capable of meeting data quality objectives at or below the MRL listed in Table 1, column 4, in paragraph (a)(3) of this section.
                            </P>
                            <P>
                                (
                                <E T="03">2</E>
                                ) The MRL, or any concentration below the MRL, at which performance is being evaluated, must be contained within the range of calibration. The calibration curve regression model and the range of calibration levels that are used in these performance validation steps must be used in all routine sample analyses used to comply with this regulation. Only straight line or quadratic regression models are allowed. The use of either weighted or unweighted models is permitted. The use of cubic regression models is not permitted.
                            </P>
                            <P>
                                (
                                <E T="03">3</E>
                                ) Replicate analyses of at least seven (7) fortified samples in reagent water must be performed at or below the MRL for each analyte, and must be processed through the entire method procedure (
                                <E T="03">i.e.</E>
                                , including extraction, where applicable, and with all preservatives).
                            </P>
                            <P>
                                (
                                <E T="03">4</E>
                                ) A prediction interval of results (PIR), which is based on the estimated arithmetic mean of analytical results and the estimated sample standard deviation of measurement results, must be determined by Equation 1:
                            </P>
                            <MATH SPAN="2" DEEP="30">
                                <MID>ER04JA07.000</MID>
                            </MATH>
                            <EXTRACT>
                                <FP>Where:</FP>
                                <FP SOURCE="FP-2">
                                    <E T="03">t</E>
                                     is the Student's 
                                    <E T="03">t</E>
                                     value with 
                                    <E T="03">df</E>
                                     degrees of freedom and confidence level (1-α),
                                </FP>
                                <FP SOURCE="FP-2">
                                    <E T="03">s</E>
                                     is the sample standard deviation of 
                                    <E T="03">n</E>
                                     replicate samples fortified at the MRL,
                                </FP>
                                <FP SOURCE="FP-2">
                                    <E T="03">n</E>
                                     is the number of replicates.
                                </FP>
                            </EXTRACT>
                            <P>
                                (
                                <E T="03">5</E>
                                ) The values needed to calculate the PIR using Equation 1 are: Number of replicates (
                                <E T="03">n</E>
                                ); Student's 
                                <E T="03">t</E>
                                 value with a two-sided 99% confidence level for 
                                <E T="03">n</E>
                                 number of replicates; the average (mean) of at least seven replicates; and the sample standard deviation. Factor 1 is referred to as the Half Range PIR (HR
                                <E T="52">PIR</E>
                                ).
                            </P>
                            <MATH SPAN="1" DEEP="30">
                                <MID>ER04JA07.001</MID>
                            </MATH>
                            <FP>
                                For a certain number of replicates and for a certain confidence level in Student's 
                                <E T="03">t</E>
                                , this factor
                            </FP>
                            <MATH SPAN="1" DEEP="30">
                                <MID>ER04JA07.002</MID>
                            </MATH>
                            <FP>
                                is constant, and can be tabulated according to replicate number and confidence level for the Student's 
                                <E T="03">t.</E>
                                 Table 3 in this paragraph lists the constant factor (
                                <E T="03">C</E>
                                ) for replicate sample numbers 7 through 10 with a confidence level of 99% for Student's 
                                <E T="03">t.</E>
                            </FP>
                            <P>
                                (
                                <E T="03">6</E>
                                ) The HRPIR is calculated by Equation 2:
                            </P>
                            <MATH SPAN="1" DEEP="15">
                                <MID>ER04JA07.003</MID>
                            </MATH>
                            <P>
                                (
                                <E T="03">7</E>
                                ) The PIR is calculated by Equation 3:
                            </P>
                            <MATH SPAN="1" DEEP="15">
                                <MID>ER04JA07.004</MID>
                            </MATH>
                            <PRTPAGE P="572"/>
                            <GPOTABLE COLS="3" OPTS="L2" CDEF="25C,25C,25C">
                                <TTITLE>
                                    Table 3—The Constant Factor (C) to be Multiplied by the Standard Deviation to Determine the Half Range Interval of the PIR (Student's 
                                    <E T="01">t</E>
                                     99% Confidence Level) 
                                    <E T="01">
                                        <SU>a</SU>
                                    </E>
                                </TTITLE>
                                <BOXHD>
                                    <CHED H="1">Replicates</CHED>
                                    <CHED H="1">Degrees of freedom</CHED>
                                    <CHED H="1">
                                        Constant factor (C) to be multiplied by the standard
                                        <LI>deviation</LI>
                                    </CHED>
                                </BOXHD>
                                <ROW RUL="s">
                                    <ENT I="01">7</ENT>
                                    <ENT>6</ENT>
                                    <ENT>3.963</ENT>
                                </ROW>
                                <ROW RUL="s">
                                    <ENT I="01">8</ENT>
                                    <ENT>7</ENT>
                                    <ENT>3.711</ENT>
                                </ROW>
                                <ROW RUL="s">
                                    <ENT I="01">9</ENT>
                                    <ENT>8</ENT>
                                    <ENT>3.536</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">10</ENT>
                                    <ENT>9</ENT>
                                    <ENT>3.409</ENT>
                                </ROW>
                                <TNOTE>
                                    <SU>a</SU>
                                     The critical 
                                    <E T="03">t</E>
                                    -value for a two-sided 99% confidence interval is equivalent to the critical 
                                    <E T="03">t</E>
                                    -value for a one-sided 99.5% confidence interval, due to the symmetry of the 
                                    <E T="03">t</E>
                                    -distribution. PIR = Prediction Interval of Results.
                                </TNOTE>
                            </GPOTABLE>
                            <P>
                                (
                                <E T="03">8</E>
                                ) The lower and upper result limits of the PIR must be converted to percent recovery of the concentration being tested. To pass criteria at a certain level, the PIR lower recovery limits cannot be lower than the lower recovery limits of the QC interval (50%), and the PIR upper recovery limits cannot be greater than the upper recovery limits of the QC interval (150%). When either of the PIR recovery limits falls outside of either bound of the QC interval of recovery (higher than 150% or less than 50%), laboratory performance is not validated at the concentration evaluated. If the PIR limits are contained within both bounds of the QC interval, laboratory performance is validated for that analyte.
                            </P>
                            <P>(B) Quality control requirements for validation of laboratory performance at or below the MRL.</P>
                            <P>
                                (
                                <E T="03">1</E>
                                ) You must ensure that the calibration curve regression model and that the range of calibration levels that are used in these performance validation steps are used in future routine sample analysis. Only straight line or quadratic regression models are allowed. The use of either weighted or unweighted models is permitted. The use of cubic regression models is not permitted.
                            </P>
                            <P>
                                (
                                <E T="03">2</E>
                                ) You must ensure, once your laboratory has performed an IDC as specified in each analytical method (demonstrating that DQOs are met at or below an MRL), that a daily performance check is performed for each analyte and method. A single laboratory blank, fortified at or below the MRL for each analyte, must be processed through the entire method procedure. The measured concentration for each analyte must be converted to a percent recovery, and if the recovery is within 50%-150% (inclusive), the daily performance of the laboratory has been validated. The results for any analyte for which 50%-150% recovery cannot be demonstrated during the daily check are not valid. Laboratories may elect to re-run the daily performance check sample if the performance for any analyte or analytes cannot be validated. If performance is validated for these analytes, the laboratory performance is considered validated. Alternatively, the laboratory may re-calibrate and repeat the performance validation process for all analytes.
                            </P>
                            <P>(iv) [Reserved]</P>
                            <P>
                                (v) 
                                <E T="03">Method defined quality control.</E>
                                 You must ensure that your laboratory analyzes Laboratory Fortified Blanks and conducts Laboratory Performance Checks, as appropriate to the method's requirements, for those methods listed in column 3 in table 1 to paragraph (a)(3) of this section. Each method specifies acceptance criteria for these QC checks.
                            </P>
                            <P>
                                (vi) 
                                <E T="03">Reporting.</E>
                                 You must require your laboratory, on your behalf, to post and approve these data in EPA's electronic data reporting system, accessible at 
                                <E T="03">https://www.epa.gov/dwucmr,</E>
                                 for your review within 90 days from the sample collection date. You then have 30 days from when the laboratory posts and approves your data to review, approve, and submit the data to the State and EPA, via the agency's electronic data reporting system. If you do not electronically approve and submit the laboratory data to EPA within 30 days of the laboratory posting approved data, the data will be considered approved by 
                                <PRTPAGE P="573"/>
                                you and available for State and EPA review.
                            </P>
                            <P>
                                (6) 
                                <E T="03">Violation of this rule</E>
                                —(i) 
                                <E T="03">Monitoring violations.</E>
                                 Any failure to monitor in accordance with § 141.40(a)(3)-(5) is a monitoring violation.
                            </P>
                            <P>
                                (ii) 
                                <E T="03">Reporting violations.</E>
                                 Any failure to report in accordance with § 141.35 is a reporting violation.
                            </P>
                            <P>
                                (b) 
                                <E T="03">Petitions and waivers by States</E>
                                —(1) 
                                <E T="03">Governors' petition for additional contaminants.</E>
                                 The Safe Drinking Water Act allows Governors of seven (7) or more States to petition the EPA Administrator to add one or more contaminants to the UCMR Contaminant List in paragraph (a)(3) of this section. The petition must clearly identify the reason(s) for adding the contaminant(s) to the monitoring list, including the potential risk to public health, particularly any information that might be available regarding disproportional risks to the health and safety of children, the expected occurrence documented by any available data, any analytical methods known or proposed to be used to test for the contaminant(s), and any other information that could assist the Administrator in determining which contaminants present the greatest public health concern and should, therefore, be included on the UCMR Contaminant List in paragraph (a)(3) of this section.
                            </P>
                            <P>
                                (2) 
                                <E T="03">State-wide waivers.</E>
                                 A State can waive monitoring requirements only with EPA approval and under very limited conditions. Conditions and procedures for obtaining a waiver are as follows:
                            </P>
                            <P>
                                (i) 
                                <E T="03">Application.</E>
                                 A State may apply to EPA for a State-wide waiver from the unregulated contaminant monitoring requirements for PWSs serving more than 10,000 people. To apply for such a waiver, the State must submit an application to EPA that includes the following information: The list of contaminants on the UCMR Contaminant List for which a waiver is requested, along with documentation for each contaminant in the request demonstrating that the contaminants or their parent compounds do not occur naturally in the State, and certifying that during the past 15 years they have not been used, applied, stored, disposed of, released, or detected in the source waters or distribution systems in the State.
                            </P>
                            <P>
                                (ii) 
                                <E T="03">Approval.</E>
                                 EPA will review State applications and notify the State whether it accepts or rejects the request. The State must receive written approval from EPA before issuing a State-wide waiver.
                            </P>
                            <P>
                                (c) 
                                <E T="03">Incorporation by reference.</E>
                                 The standards required in this section are incorporated by reference into this section with the approval of the Director of the Federal Register under 5 U.S.C. 552(a) and 1 CFR part 51. All approved material is available for inspection at U.S. Environmental Protection Agency, Water Docket, EPA/DC, EPA West, Room 3334, 1301 Constitution Ave. NW, Washington, DC 20004, (202) 566-1744, email 
                                <E T="03">Docket-customerservice@epa.gov,</E>
                                 or go to 
                                <E T="03">https://www.epa.gov/dockets/epa-docket-center-reading-room,</E>
                                 and is available from the sources indicated elsewhere in this paragraph. The material is also available for inspection at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, email 
                                <E T="03">fr.inspection@nara.gov,</E>
                                 or go to 
                                <E T="03">www.archives.gov/federal-register/cfr/ibr-locations.html.</E>
                            </P>
                            <P>(1) U.S. Environmental Protection Agency, EPA West, Room 3334, 1301 Constitution Ave. NW, Washington, DC 20004; telephone: (202) 566-1744.</P>
                            <P>
                                (i) Method 200.7, “Determination of Metals and Trace Elements in Water and Wastes by Inductively Coupled Plasma-Atomic Emission Spectrometry,” Revision 4.4, EMMC Version, 1994. Available at 
                                <E T="03">https://www.epa.gov/esam/method-2007-determination-metals-and-trace-elements-water-and-wastes-inductively-coupled-plasma.</E>
                            </P>
                            <P>
                                (ii) Method 537.1, “Determination of Selected Per- and Polyfluorinated Alkyl Substances in Drinking Water by Solid Phase Extraction and Liquid Chromatography/Tandem Mass Spectrometry,” Version 2.0, 2020. Available at 
                                <E T="03">https://www.epa.gov/water-research/epa-drinking-water-research-methods.</E>
                            </P>
                            <P>
                                (iii) Method 533, “Determination of Per- and Polyfluoroalkyl Substances in Drinking Water by Isotope Dilution Anion Exchange Solid Phase Extraction and Liquid Chromatography/Tandem Mass Spectrometry,” November 2019, EPA 815-B-19-020. Available at 
                                <PRTPAGE P="574"/>
                                <E T="03">https://www.epa.gov/dwanalyticalmethods.</E>
                            </P>
                            <P>
                                (2) American Public Health Association, 800 I Street NW, Washington, DC 20001-3710; telephone: (202) 777-2742; email: 
                                <E T="03">comments@apha.org; www.apha.org.</E>
                            </P>
                            <P>(i) “Standard Methods for the Examination of Water &amp; Wastewater,” 23rd edition (2017).</P>
                            <P>(A) SM 3120 B, “Metals by Plasma Emission Spectroscopy (2017): Inductively Coupled Plasma (ICP) Method.”</P>
                            <P>(B) [Reserved]</P>
                            <P>
                                (ii) “Standard Methods Online,” approved 1999; 
                                <E T="03">https://www.standardmethods.org.</E>
                            </P>
                            <P>(A) SM 3120 B, “Metals by Plasma Emission Spectroscopy: Inductively Coupled Plasma (ICP) Method,” revised December 14, 2020.</P>
                            <P>(B) [Reserved]</P>
                            <P>
                                (3) ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959; telephone: (610) 832-9500; email: 
                                <E T="03">service@astm.org; www.astm.org.</E>
                            </P>
                            <P>(i) ASTM D1976-20, “Standard Test Method for Elements in Water by Inductively-Coupled Plasma Atomic Emission Spectroscopy,” approved May 1, 2020.</P>
                            <P>(ii) [Reserved]</P>
                            <CITA>[72 FR 393, Jan. 4, 2007; 72 FR 3916, Jan. 26, 2007, as amended at 77 FR 26098, May 2, 2012; 81 FR 92688, Dec. 20, 2016; 86 FR 73155, Dec. 27, 2021; 87 FR 3679, Jan. 25, 2022]</CITA>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 141.41</SECTNO>
                            <SUBJECT>Special monitoring for sodium.</SUBJECT>
                            <P>(a) Suppliers of water for community public water systems shall collect and analyze one sample per plant at the entry point of the distribution system for the determination of sodium concentration levels; samples must be collected and analyzed annually for systems utilizing surface water sources in whole or in part, and at least every three years for systems utilizing solely ground water sources. The minimum number of samples required to be taken by the system shall be based on the number of treatment plants used by the system, except that multiple wells drawing raw water from a single aquifer may, with the State approval, be considered one treatment plant for determining the minimum number of samples. The supplier of water may be required by the State to collect and analyze water samples for sodium more frequently in locations where the sodium content is variable.</P>
                            <P>(b) The supplier of water shall report to EPA and/or the State the results of the analyses for sodium within the first 10 days of the month following the month in which the sample results were received or within the first 10 days following the end of the required monitoring period as stipulated by the State, whichever of these is first. If more than annual sampling is required the supplier shall report the average sodium concentration within 10 days of the month following the month in which the analytical results of the last sample used for the annual average was received. The supplier of water shall not be required to report the results to EPA where the State has adopted this regulation and results are reported to the State. The supplier shall report the results to EPA where the State has not adopted this regulation.</P>
                            <P>(c) The supplier of water shall notify appropriate local and State public health officials of the sodium levels by written notice by direct mail within three months. A copy of each notice required to be provided by this paragraph shall be sent to EPA and/or the State within 10 days of its issuance. The supplier of water is not required to notify appropriate local and State public health officials of the sodium levels where the State provides such notices in lieu of the supplier.</P>
                            <P>(d) Analyses for sodium shall be conducted as directed in § 141.23(k)(1).</P>
                            <CITA>[45 FR 57345, Aug. 27, 1980, as amended at 59 FR 62470, Dec. 5, 1994]</CITA>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 141.42</SECTNO>
                            <SUBJECT>Special monitoring for corrosivity characteristics.</SUBJECT>
                            <P>(a)-(c) [Reserved]</P>
                            <P>(d) Community water supply systems shall identify whether the following construction materials are present in their distribution system and report to the State:</P>
                            <EXTRACT>
                                <FP SOURCE="FP-1">Lead from piping, solder, caulking, interior lining of distribution mains, alloys and home plumbing.</FP>
                                <FP SOURCE="FP-1">Copper from piping and alloys, service lines, and home plumbing.</FP>
                                <FP SOURCE="FP-1">
                                    Galvanized piping, service lines, and home plumbing.
                                    <PRTPAGE P="575"/>
                                </FP>
                                <FP SOURCE="FP-1">Ferrous piping materials such as cast iron and steel.</FP>
                                <FP SOURCE="FP-1">Asbestos cement pipe.</FP>
                            </EXTRACT>
                            <FP>In addition, States may require identification and reporting of other materials of construction present in distribution systems that may contribute contaminants to the drinking water, such as:</FP>
                            <EXTRACT>
                                <FP SOURCE="FP-1">Vinyl lined asbestos cement pipe.</FP>
                                <FP SOURCE="FP-1">Coal tar lined pipes and tanks.</FP>
                            </EXTRACT>
                            <CITA>[45 FR 57346, Aug. 27, 1980; 47 FR 10999, Mar. 12, 1982, as amended at 59 FR 62470, Dec. 5, 1994]</CITA>
                        </SECTION>
                    </SUBPART>
                    <SUBPART>
                        <HD SOURCE="HED">Subpart F—Maximum Contaminant Level Goals and Maximum Residual Disinfectant Level Goals</HD>
                        <SECTION>
                            <SECTNO>§ 141.50</SECTNO>
                            <SUBJECT>Maximum contaminant level goals for organic contaminants.</SUBJECT>
                            <P>(a) MCLGs are zero for the following contaminants:</P>
                            <P>(1) Benzene.</P>
                            <P>(2) Vinyl chloride.</P>
                            <P>(3) Carbon tetrachloride.</P>
                            <P>(4) 1,2-dichloroethane.</P>
                            <P>(5) Trichloroethylene.</P>
                            <P>(6) Acrylamide.</P>
                            <P>(7) Alachlor.</P>
                            <P>(8) Chlordane.</P>
                            <P>(9) Dibromochloropropane.</P>
                            <P>(10) 1,2-Dichloropropane.</P>
                            <P>(11) Epichlorohydrin.</P>
                            <P>(12) Ethylene dibromide.</P>
                            <P>(13) Heptachlor.</P>
                            <P>(14) Heptachlor epoxide.</P>
                            <P>(15) Pentachlorophenol.</P>
                            <P>(16) Polychlorinated biphenyls (PCBs).</P>
                            <P>(17) Tetrachloroethylene.</P>
                            <P>(18) Toxaphene.</P>
                            <P>(19) Benzo[a]pyrene.</P>
                            <P>(20) Dichloromethane (methylene chloride).</P>
                            <P>(21) Di(2-ethylhexyl)phthalate.</P>
                            <P>(22) Hexachlorobenzene.</P>
                            <P>(23) 2,3,7,8-TCDD (Dioxin).</P>
                            <P>(24) PFOA.</P>
                            <P>(25) PFOS.</P>
                            <P>(b) MCLGs for the following contaminants are as indicated:</P>
                            <GPOTABLE COLS="2" OPTS="L0" CDEF="s100,xs60">
                                <BOXHD>
                                    <CHED H="1">Contaminant</CHED>
                                    <CHED H="1">
                                        MCLG in mg/l
                                        <LI>(unless otherwise noted)</LI>
                                    </CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">(1) 1,1-Dichloroethylene</ENT>
                                    <ENT>0.007</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(2) 1,1,1-Trichloroethane</ENT>
                                    <ENT>0.20</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(3) para-Dichlorobenzene</ENT>
                                    <ENT>0.075</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(4) Aldicarb</ENT>
                                    <ENT>0.001</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(5) Aldicarb sulfoxide</ENT>
                                    <ENT>0.001</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(6) Aldicarb sulfone</ENT>
                                    <ENT>0.001</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(7) Atrazine</ENT>
                                    <ENT>0.003</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(8) Carbofuran</ENT>
                                    <ENT>0.04</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(9) o-Dichlorobenzene</ENT>
                                    <ENT>0.6</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(10) cis-1,2-Dichloroethylene</ENT>
                                    <ENT>0.07</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(11) trans-1,2-Dichloroethylene</ENT>
                                    <ENT>0.1</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(12) 2,4-D</ENT>
                                    <ENT>0.07</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(13) Ethylbenzene</ENT>
                                    <ENT>0.7</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(14) Lindane</ENT>
                                    <ENT>0.0002</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(15) Methoxychlor</ENT>
                                    <ENT>0.04</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(16) Monochlorobenzene</ENT>
                                    <ENT>0.1</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(17) Styrene</ENT>
                                    <ENT>0.1</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(18) Toluene</ENT>
                                    <ENT>1</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(19) 2,4,5-TP</ENT>
                                    <ENT>0.05</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(20) Xylenes (total)</ENT>
                                    <ENT>10</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(21) Dalapon</ENT>
                                    <ENT>0.2</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(22) Di(2-ethylhexyl)adipate</ENT>
                                    <ENT>.4</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(23) Dinoseb</ENT>
                                    <ENT>.007</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(24) Diquat</ENT>
                                    <ENT>.02</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(25) Endothall</ENT>
                                    <ENT>.1</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(26) Endrin</ENT>
                                    <ENT>.002</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(27) Glyphosate</ENT>
                                    <ENT>.7</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(28) Hexachlorocyclopentadiene</ENT>
                                    <ENT>.05</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(29) Oxamyl (Vydate)</ENT>
                                    <ENT>.2</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(30) Picloram</ENT>
                                    <ENT>.5</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(31) Simazine</ENT>
                                    <ENT>.004</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(32) 1,2,4-Trichlorobenzene</ENT>
                                    <ENT>.07</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(33) 1,1,2-Trichloroethane</ENT>
                                    <ENT>.003</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(34) Hazard Index PFAS (HFPO-DA, PFBS, PFHxS, and PFNA)</ENT>
                                    <ENT>
                                        1 (unitless).
                                        <SU>1</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(35) HFPO-DA</ENT>
                                    <ENT>0.00001.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(36) PFHxS</ENT>
                                    <ENT>0.00001.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(37) PFNA</ENT>
                                    <ENT>0.00001.</ENT>
                                </ROW>
                                <TNOTE>
                                    <SU>1</SU>
                                     The PFAS Mixture Hazard Index (HI) is the sum of component hazard quotients (HQs), which are calculated by dividing the measured component PFAS concentration in water by the corresponding contaminant's health-based water concentration (HBWC) when expressed in the same units (shown in ng/l). The HBWC for PFHxS is 10 ng/l; the HBWC for HFPO-DA is 10 ng/l; the HBWC for PFNA is 10 ng/l; and the HBWC for PFBS is 2000 ng/l. A PFAS Mixture Hazard Index greater than 1 (unitless) indicates an exceedance of the health protective level and indicates potential human health risk from the PFAS mixture in drinking water.
                                </TNOTE>
                            </GPOTABLE>
                            <FP SOURCE="FP-2">
                                Hazard Index = ([HFPO-DA
                                <E T="52">water</E>
                                 ng/l]/[10 ng/l]) + ([PFBS
                                <E T="52">water</E>
                                 ng/l]/[2000 ng/l]) + ([PFNA
                                <E T="52">water</E>
                                 ng/l]/[10 ng/l]]) + ([PFHxS
                                <E T="52">water</E>
                                 ng/l]/[10 ng/l])
                            </FP>
                            <EXTRACT>
                                <FP SOURCE="FP-2">HBWC = health-based water concentration</FP>
                                <FP SOURCE="FP-2">HQ = hazard quotient</FP>
                                <FP SOURCE="FP-2">ng/l = nanograms per liter</FP>
                                <FP SOURCE="FP-2">
                                    PFAS
                                    <E T="52">water</E>
                                     = the concentration of a specific PFAS in water
                                </FP>
                            </EXTRACT>
                            <CITA>[50 FR 46901, Nov. 13, 1985, as amended at 52 FR 20674, June 2, 1987; 52 FR 25716, July 8, 1987; 56 FR 3592, Jan. 30, 1991; 56 FR 30280, July 1, 1991; 57 FR 31846, July 17, 1992; 89 FR 32744, April 25, 2024]</CITA>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 141.51</SECTNO>
                            <SUBJECT>Maximum contaminant level goals for inorganic contaminants.</SUBJECT>
                            <P>(a) [Reserved]</P>
                            <P>
                                (b) MCLGs for the following contaminants are as indicated:
                                <PRTPAGE P="576"/>
                            </P>
                            <GPOTABLE COLS="2" OPTS="L2" CDEF="s35,21">
                                <BOXHD>
                                    <CHED H="1">Contaminant</CHED>
                                    <CHED H="1">MCLG (mg/l)</CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">Antimony</ENT>
                                    <ENT>0.006</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Arsenic</ENT>
                                    <ENT>
                                        zero 
                                        <SU>1</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Asbestos</ENT>
                                    <ENT>7 Million fibers/liter (longer than 10 µm).</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Barium</ENT>
                                    <ENT>2</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Beryllium</ENT>
                                    <ENT>.004</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Cadmium</ENT>
                                    <ENT>0.005</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Chromium</ENT>
                                    <ENT>0.1</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Copper</ENT>
                                    <ENT>1.3</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Cyanide (as free Cyanide)</ENT>
                                    <ENT>.2</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Fluoride</ENT>
                                    <ENT>4.0</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Lead</ENT>
                                    <ENT>zero</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Mercury</ENT>
                                    <ENT>0.002</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Nitrate</ENT>
                                    <ENT>10 (as Nitrogen).</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Nitrite</ENT>
                                    <ENT>1 (as Nitrogen).</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Total Nitrate + Nitrite</ENT>
                                    <ENT>10 (as Nitrogen).</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Selenium</ENT>
                                    <ENT>0.05</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Thallium</ENT>
                                    <ENT>.0005</ENT>
                                </ROW>
                                <TNOTE>
                                    <SU>1</SU>
                                     This value for arsenic is effective January 23, 2006. Until then, there is no MCLG.
                                </TNOTE>
                            </GPOTABLE>
                            <CITA>[50 FR 47155, Nov. 14, 1985, as amended at 52 FR 20674, June 2, 1987; 56 FR 3593, Jan. 30, 1991; 56 FR 26548, June 7, 1991; 56 FR 30280, July 1, 1991; 57 FR 31846, July 17, 1992; 60 FR 33932, June 29, 1995; 66 FR 7063, Jan. 22, 2001]</CITA>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 141.52</SECTNO>
                            <SUBJECT>Maximum contaminant level goals for microbiological contaminants.</SUBJECT>
                            <P>(a) MCLGs for the following contaminants are as indicated:</P>
                            <GPOTABLE COLS="2" OPTS="L2" CDEF="s20,r5">
                                <BOXHD>
                                    <CHED H="1">Contaminant</CHED>
                                    <CHED H="1">MCLG</CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">
                                        (1) 
                                        <E T="03">Giardia lamblia</E>
                                    </ENT>
                                    <ENT>zero</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(2) Viruses</ENT>
                                    <ENT>zero</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">
                                        (3) 
                                        <E T="03">Legionella</E>
                                    </ENT>
                                    <ENT>zero</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(4) Total coliforms (including fecal)</ENT>
                                    <ENT>zero</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">
                                        coliforms and 
                                        <E T="03">Escherichia coli</E>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">
                                        (5) 
                                        <E T="03">Cryptosporidium</E>
                                    </ENT>
                                    <ENT>zero</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">
                                        (6) 
                                        <E T="03">Escherichia coli (E. coli)</E>
                                    </ENT>
                                    <ENT>zero</ENT>
                                </ROW>
                            </GPOTABLE>
                            <P>(b) The MCLG identified in paragraph (a)(4) of this section is applicable until March 31, 2016. The MCLG identified in paragraph (a)(6) of this section is applicable beginning April 1, 2016.</P>
                            <CITA>[78 FR 10347, Feb. 13, 2013]</CITA>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 141.53</SECTNO>
                            <SUBJECT>Maximum contaminant level goals for disinfection byproducts.</SUBJECT>
                            <P>MCLGs for the following disinfection byproducts are as indicated:</P>
                            <GPOTABLE COLS="2" OPTS="L2" CDEF="s25,4.2">
                                <BOXHD>
                                    <CHED H="1">Disinfection byproduct</CHED>
                                    <CHED H="1">
                                        MCLG
                                        <LI>(mg/L)</LI>
                                    </CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">Bromodichloromethane</ENT>
                                    <ENT>zero</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Bromoform</ENT>
                                    <ENT>zero</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Bromate</ENT>
                                    <ENT>zero</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Chlorite</ENT>
                                    <ENT>0.8</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Chloroform</ENT>
                                    <ENT>0.07</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Dibromochloromethane</ENT>
                                    <ENT>0.06</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Dichloroacetic acid</ENT>
                                    <ENT>zero</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Monochloroacetic acid</ENT>
                                    <ENT>0.07</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Trichloroacetic acid</ENT>
                                    <ENT>0.02</ENT>
                                </ROW>
                            </GPOTABLE>
                            <CITA>[63 FR 69465, Dec. 16, 1998, as amended at 65 FR 34405, May 30, 2000; 71 FR 478, Jan. 4, 2006]</CITA>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 141.54</SECTNO>
                            <SUBJECT>Maximum residual disinfectant level goals for disinfectants.</SUBJECT>
                            <P>MRDLGs for disinfectants are as follows:</P>
                            <GPOTABLE COLS="2" OPTS="L2" CDEF="s25,xs56">
                                <BOXHD>
                                    <CHED H="1">Disinfectant residual</CHED>
                                    <CHED H="1">MRDLG(mg/L)</CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">Chlorine</ENT>
                                    <ENT>
                                        4 (as Cl 
                                        <E T="52">2</E>
                                        ).
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Chloramines</ENT>
                                    <ENT>
                                        4 (as Cl 
                                        <E T="52">2</E>
                                        ).
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Chlorine dioxide</ENT>
                                    <ENT>
                                        0.8 (as ClO
                                        <E T="52">2</E>
                                        )
                                    </ENT>
                                </ROW>
                            </GPOTABLE>
                            <CITA>[63 FR 69465, Dec. 16, 1998]</CITA>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 141.55</SECTNO>
                            <SUBJECT>Maximum contaminant level goals for radionuclides.</SUBJECT>
                            <P>MCLGs for radionuclides are as indicated in the following table:</P>
                            <GPOTABLE COLS="2" OPTS="L2" CDEF="s25,xs24">
                                <BOXHD>
                                    <CHED H="1">Contaminant</CHED>
                                    <CHED H="1">MCLG</CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">1. Combined radium-226 and radium-228</ENT>
                                    <ENT>Zero.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">2. Gross alpha particle activity (excluding radon and uranium)</ENT>
                                    <ENT>Zero.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">3. Beta particle and photon radioactivity</ENT>
                                    <ENT>Zero.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">4. Uranium</ENT>
                                    <ENT>Zero.</ENT>
                                </ROW>
                            </GPOTABLE>
                            <CITA>[65 FR 76748, Dec. 7, 2000]</CITA>
                        </SECTION>
                    </SUBPART>
                    <SUBPART>
                        <HD SOURCE="HED">Subpart G—National Primary Drinking Water Regulations: Maximum Contaminant Levels and Maximum Residual Disinfectant Levels</HD>
                        <SECTION>
                            <SECTNO>§ 141.60</SECTNO>
                            <SUBJECT>Effective dates.</SUBJECT>
                            <P>(a) The effective dates for § 141.61 are as follows:</P>
                            <P>(1) The effective date for paragraphs (a)(1) through (a)(8) of § 141.61 is January 9, 1989.</P>
                            <P>(2) The effective date for paragraphs (a)(9) through (a)(18) and (c)(1) through (c)(18) of § 141.61 is July 30, 1992.</P>
                            <P>(3) The effective date for paragraphs (a)(19) through (a)(21), (c)(19) through (c)(25), and (c)(27) through (c)(33) of § 141.61 is January 17, 1994. The effective date of § 141.61(c)(26) is August 17, 1992.</P>
                            <P>(4) The effective date for § 141.61(c)(2)(i) through (vii) is April 26, 2029.</P>
                            <P>(b) The effective dates for § 141.62 are as follows:</P>
                            <P>(1) The effective date of paragraph (b)(1) of § 141.62 is October 2, 1987.</P>
                            <P>
                                (2) The effective date for paragraphs (b)(2) and (b)(4) through (b)(10) of § 141.62 is July 30, 1992.
                                <PRTPAGE P="577"/>
                            </P>
                            <P>(3) The effective date for paragraphs (b)(11) through (b)(15) of § 141.62 is January 17, 1994.</P>
                            <P>(4) The effective date for § 141.62(b)(16) is January 23, 2006.</P>
                            <CITA>[56 FR 3593, Jan. 30, 1991, as amended at 57 FR 31846, July 17, 1992; 59 FR 34324, July 1, 1994; 66 FR 7063, Jan. 22, 2001; 89 FR 32744, Apr. 26, 2024; 89 FR 49102, June 11, 2024]</CITA>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 141.61</SECTNO>
                            <SUBJECT>Maximum contaminant levels for organic contaminants.</SUBJECT>
                            <P>(a) The following maximum contaminant levels for volatile organic contaminants apply to community and non-transient, non-community water systems.</P>
                            <GPOTABLE COLS="3" OPTS="L2" CDEF="s100,r100,7.8">
                                <TTITLE>
                                    Table 1 to Paragraph (
                                    <E T="01">a</E>
                                    )—Maximum Contaminant Levels for Volatile Organic Contaminants
                                </TTITLE>
                                <BOXHD>
                                    <CHED H="1">CAS No.</CHED>
                                    <CHED H="1">Contaminant</CHED>
                                    <CHED H="1">MCL (mg/l)</CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01"> (1) 75-01-4</ENT>
                                    <ENT>Vinyl chloride</ENT>
                                    <ENT>0.002</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01"> (2) 71-43-2</ENT>
                                    <ENT>Benzene</ENT>
                                    <ENT>0.005</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01"> (3) 56-23-5</ENT>
                                    <ENT>Carbon tetrachloride</ENT>
                                    <ENT>0.005</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01"> (4) 107-06-2</ENT>
                                    <ENT>1,2-Dichloroethane</ENT>
                                    <ENT>0.005</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01"> (5) 79-01-6</ENT>
                                    <ENT>Trichloroethylene</ENT>
                                    <ENT>0.005</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01"> (6) 106-46-7</ENT>
                                    <ENT>para-Dichlorobenzene</ENT>
                                    <ENT>0.075</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01"> (7) 75-35-4</ENT>
                                    <ENT>1,1-Dichloroethylene</ENT>
                                    <ENT>0.007</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01"> (8) 71-55-6</ENT>
                                    <ENT>1,1,1-Trichloroethane</ENT>
                                    <ENT>0.2</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01"> (9) 156-59-2</ENT>
                                    <ENT>cis-1,2-Dichloroethylene</ENT>
                                    <ENT>0.07</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01"> (10) 78-87-5</ENT>
                                    <ENT>1,2-Dichloropropane</ENT>
                                    <ENT>0.005</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01"> (11) 100-41-4</ENT>
                                    <ENT>Ethylbenzene</ENT>
                                    <ENT>0.7</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01"> (12) 108-90-7</ENT>
                                    <ENT>Monochlorobenzene</ENT>
                                    <ENT>0.1</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01"> (13) 95-50-1</ENT>
                                    <ENT>o-Dichlorobenzene</ENT>
                                    <ENT>0.6</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01"> (14) 100-42-5</ENT>
                                    <ENT>Styrene</ENT>
                                    <ENT>0.1</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01"> (15) 127-18-4</ENT>
                                    <ENT>Tetrachloroethylene</ENT>
                                    <ENT>0.005</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01"> (16) 108-88-3</ENT>
                                    <ENT>Toluene</ENT>
                                    <ENT>1</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01"> (17) 156-60-5</ENT>
                                    <ENT>trans-1,2-Dichloroethylene</ENT>
                                    <ENT>0.1</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01"> (18) 1330-20-7</ENT>
                                    <ENT>Xylenes (total)</ENT>
                                    <ENT>10</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01"> (19) 75-09-2</ENT>
                                    <ENT>Dichloromethane</ENT>
                                    <ENT>0.005</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01"> (20) 120-82-1</ENT>
                                    <ENT>1,2,4-Trichloro- benzene</ENT>
                                    <ENT>.07</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01"> (21) 79-00-5</ENT>
                                    <ENT>1,1,2-Trichloro- ethane</ENT>
                                    <ENT>.005</ENT>
                                </ROW>
                            </GPOTABLE>
                            <P>(b) The Administrator, pursuant to section 1412 of the Act, hereby identifies as indicated in table 2 to this paragraph (b) granular activated carbon (GAC), packed tower aeration (PTA), or oxidation (OX) as the best technology, treatment technique, or other means available for achieving compliance with the maximum contaminant level for organic contaminants identified in paragraphs (a) and (c) of this section, except for per- and polyfluoroalkyl substances (PFAS).</P>
                            <GPOTABLE COLS="5" OPTS="L2" CDEF="xs96,r120,3X3,3X3,3X3">
                                <TTITLE>
                                    Table 2 to Paragraph (
                                    <E T="01">b</E>
                                    )—BAT for Organic Contaminants in Paragraphs (
                                    <E T="01">a</E>
                                    ) and (
                                    <E T="01">c</E>
                                    ) of This Section, Except for PFAS
                                </TTITLE>
                                <BOXHD>
                                    <CHED H="1">CAS No.</CHED>
                                    <CHED H="1">Contaminant</CHED>
                                    <CHED H="1">GAC</CHED>
                                    <CHED H="1">PTA</CHED>
                                    <CHED H="1">OX</CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">15972-60-8</ENT>
                                    <ENT>Alachlor</ENT>
                                    <ENT>X</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">116-06-3</ENT>
                                    <ENT>Aldicarb</ENT>
                                    <ENT>X</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">1646-88-4</ENT>
                                    <ENT>Aldicarb sulfone</ENT>
                                    <ENT>X</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">1646-87-3</ENT>
                                    <ENT>Aldicarb sulfoxide</ENT>
                                    <ENT>X</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">1912-24-9</ENT>
                                    <ENT>Atrazine</ENT>
                                    <ENT>X</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">71-43-2</ENT>
                                    <ENT>Benzene</ENT>
                                    <ENT>X</ENT>
                                    <ENT>X</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">50-32-8</ENT>
                                    <ENT>Benzo[a]pyrene</ENT>
                                    <ENT>X</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">1563-66-2</ENT>
                                    <ENT>Carbofuran</ENT>
                                    <ENT>X</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">56-23-5</ENT>
                                    <ENT>Carbon tetrachloride</ENT>
                                    <ENT>X</ENT>
                                    <ENT>X</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">57-74-9</ENT>
                                    <ENT>Chlordane</ENT>
                                    <ENT>X</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">75-99-0</ENT>
                                    <ENT>Dalapon</ENT>
                                    <ENT>X</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">94-75-7</ENT>
                                    <ENT>2,4-D</ENT>
                                    <ENT>X</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">103-23-1</ENT>
                                    <ENT>Di (2-ethylhexyl) adipate</ENT>
                                    <ENT>X</ENT>
                                    <ENT>X</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">117-81-7</ENT>
                                    <ENT>Di (2-ethylhexyl) phthalate</ENT>
                                    <ENT>X</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">96-12-8</ENT>
                                    <ENT>Dibromochloropropane (DBCP)</ENT>
                                    <ENT>X</ENT>
                                    <ENT>X</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">95-50-1</ENT>
                                    <ENT>o-Dichlorobenzene</ENT>
                                    <ENT>X</ENT>
                                    <ENT>X</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">106-46-7</ENT>
                                    <ENT>para-Dichlorobenzene</ENT>
                                    <ENT>X</ENT>
                                    <ENT>X</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">107-06-2</ENT>
                                    <ENT>1,2-Dichloroethane</ENT>
                                    <ENT>X</ENT>
                                    <ENT>X</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">75-35-4</ENT>
                                    <ENT>1,1-Dichloroethylene</ENT>
                                    <ENT>X</ENT>
                                    <ENT>X</ENT>
                                </ROW>
                                <ROW>
                                    <PRTPAGE P="578"/>
                                    <ENT I="01">156-59-2</ENT>
                                    <ENT>cis-1,2-Dichloroethylene</ENT>
                                    <ENT>X</ENT>
                                    <ENT>X</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">156-60-5</ENT>
                                    <ENT>trans-1,2-Dichloroethylene</ENT>
                                    <ENT>X</ENT>
                                    <ENT>X</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">75-09-2</ENT>
                                    <ENT>Dichloromethane</ENT>
                                    <ENT/>
                                    <ENT>X</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">78-87-5</ENT>
                                    <ENT>1,2-Dichloropropane</ENT>
                                    <ENT>X</ENT>
                                    <ENT>X</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">88-85-7</ENT>
                                    <ENT>Dinoseb</ENT>
                                    <ENT>X</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">85-00-7</ENT>
                                    <ENT>Diquat</ENT>
                                    <ENT>X</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">145-73-3</ENT>
                                    <ENT>Endothall</ENT>
                                    <ENT>X</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">72-20-8</ENT>
                                    <ENT>Endrin</ENT>
                                    <ENT>X</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">100-41-4</ENT>
                                    <ENT>Ethylbenzene</ENT>
                                    <ENT>X</ENT>
                                    <ENT>X</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">106-93-4</ENT>
                                    <ENT>Ethylene Dibromide (EDB)</ENT>
                                    <ENT>X</ENT>
                                    <ENT>X</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">1071-83-6</ENT>
                                    <ENT>Gylphosate</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>X</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">76-44-8</ENT>
                                    <ENT>Heptachlor</ENT>
                                    <ENT>X</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">1024-57-3</ENT>
                                    <ENT>Heptachlor epoxide</ENT>
                                    <ENT>X</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">118-74-1</ENT>
                                    <ENT>Hexachlorobenzene</ENT>
                                    <ENT>X</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">77-47-3</ENT>
                                    <ENT>Hexachlorocyclopentadiene</ENT>
                                    <ENT>X</ENT>
                                    <ENT>X</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">58-89-9</ENT>
                                    <ENT>Lindane</ENT>
                                    <ENT>X</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">72-43-5</ENT>
                                    <ENT>Methoxychlor</ENT>
                                    <ENT>X</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">108-90-7</ENT>
                                    <ENT>Monochlorobenzene</ENT>
                                    <ENT>X</ENT>
                                    <ENT>X</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">23135-22-0</ENT>
                                    <ENT>Oxamyl (Vydate)</ENT>
                                    <ENT>X</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">87-86-5</ENT>
                                    <ENT>Pentachlorophenol</ENT>
                                    <ENT>X</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">1918-02-1</ENT>
                                    <ENT>Picloram</ENT>
                                    <ENT>X</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">1336-36-3</ENT>
                                    <ENT>Polychlorinated biphenyls (PCB)</ENT>
                                    <ENT>X</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">122-34-9</ENT>
                                    <ENT>Simazine</ENT>
                                    <ENT>X</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">100-42-5</ENT>
                                    <ENT>Styrene</ENT>
                                    <ENT>X</ENT>
                                    <ENT>X</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">1746-01-6</ENT>
                                    <ENT>2,3,7,8-TCDD (Dioxin)</ENT>
                                    <ENT>X</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">127-18-4</ENT>
                                    <ENT>Tetrachloroethylene</ENT>
                                    <ENT>X</ENT>
                                    <ENT>X</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">108-88-3</ENT>
                                    <ENT>Toluene</ENT>
                                    <ENT>X</ENT>
                                    <ENT>X</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">8001-35-2</ENT>
                                    <ENT>Toxaphene</ENT>
                                    <ENT>X</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">93-72-1</ENT>
                                    <ENT>2,4,5-TP (Silvex)</ENT>
                                    <ENT>X</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">120-82-1</ENT>
                                    <ENT>1,2,4-Trichlorobenzene</ENT>
                                    <ENT>X</ENT>
                                    <ENT>X</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">71-55-6</ENT>
                                    <ENT>1,1,1-Trichloroethane</ENT>
                                    <ENT>X</ENT>
                                    <ENT>X</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">79-00-5</ENT>
                                    <ENT>1,1,2-Trichloroethane</ENT>
                                    <ENT>X</ENT>
                                    <ENT>X</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">79-01-6</ENT>
                                    <ENT>Trichloroethylene</ENT>
                                    <ENT>X</ENT>
                                    <ENT>X</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">75-01-4</ENT>
                                    <ENT>Vinyl chloride</ENT>
                                    <ENT/>
                                    <ENT>X</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">1330-20-7</ENT>
                                    <ENT>Xylene</ENT>
                                    <ENT>X</ENT>
                                    <ENT>X</ENT>
                                    <ENT/>
                                </ROW>
                            </GPOTABLE>
                            <P>(c) The following maximum contaminant levels (MCLs) in paragraphs (c)(1) and (2) of this section for synthetic organic contaminants apply to community water systems and non-transient, non-community water systems; paragraph (c)(2) of this section also contains health-based water concentrations (HBWCs) for selected per- and poly-fluoroalkyl substances (PFAS) used in calculating the Hazard Index.</P>
                            <P>
                                (1) 
                                <E T="03">MCLs for Synthetic Organic Contaminants, Except for PFAS.</E>
                            </P>
                            <GPOTABLE COLS="3" OPTS="L2" CDEF="s50,r50,12">
                                <BOXHD>
                                    <CHED H="1">CAS No.</CHED>
                                    <CHED H="1">Contaminant</CHED>
                                    <CHED H="1">
                                        MCL
                                        <LI>(mg/l)</LI>
                                    </CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">(i) 15972-60-8</ENT>
                                    <ENT>Alachlor</ENT>
                                    <ENT>0.002</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(ii) 116-06-3</ENT>
                                    <ENT>Aldicarb</ENT>
                                    <ENT>0.003</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(iii) 1646-87-3</ENT>
                                    <ENT>Aldicarb sulfoxide</ENT>
                                    <ENT>0.004</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(iv) 1646-87-4</ENT>
                                    <ENT>Aldicarb sulfone</ENT>
                                    <ENT>0.002</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(v) 1912-24-9</ENT>
                                    <ENT>Atrazine</ENT>
                                    <ENT>0.003</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(vi) 1563-66-2</ENT>
                                    <ENT>Carbofuran</ENT>
                                    <ENT>0.04</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(vii) 57-74-9</ENT>
                                    <ENT>Chlordane</ENT>
                                    <ENT>0.002</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(viii) 96-12-8</ENT>
                                    <ENT>Dibromochloropropane</ENT>
                                    <ENT>0.0002</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(ix) 94-75-7</ENT>
                                    <ENT>2,4-D</ENT>
                                    <ENT>0.07</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(x) 106-93-4</ENT>
                                    <ENT>Ethylene dibromide</ENT>
                                    <ENT>0.00005</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(xi) 76-44-8</ENT>
                                    <ENT>Heptachlor</ENT>
                                    <ENT>0.0004</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(xii) 1024-57-3</ENT>
                                    <ENT>Heptachlor epoxide</ENT>
                                    <ENT>0.0002</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(xiii) 58-89-9</ENT>
                                    <ENT>Lindane</ENT>
                                    <ENT>0.0002</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(xiv) 72-43-5</ENT>
                                    <ENT>Methoxychlor</ENT>
                                    <ENT>0.04</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(xv) 1336-36-3</ENT>
                                    <ENT>Polychlorinated biphenyls</ENT>
                                    <ENT>0.0005</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(xvi) 87-86-5</ENT>
                                    <ENT>Pentachlorophenol</ENT>
                                    <ENT>0.001</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(xvii) 8001-35-2</ENT>
                                    <ENT>Toxaphene</ENT>
                                    <ENT>0.003</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(xviii) 93-72-1</ENT>
                                    <ENT>2,4,5-TP</ENT>
                                    <ENT>0.05</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(xix) 50-32-8</ENT>
                                    <ENT>Benzo[a]pyrene</ENT>
                                    <ENT>0.0002</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(xx) 75-99-0</ENT>
                                    <ENT>Dalapon</ENT>
                                    <ENT>0.2</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(xxi) 103-23-1</ENT>
                                    <ENT>Di(2-ethylhexyl) adipate</ENT>
                                    <ENT>0.4</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(xxii) 117-81-7</ENT>
                                    <ENT>Di(2-ethylhexyl) phthalate</ENT>
                                    <ENT>0.006</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(xxiii) 88-85-7</ENT>
                                    <ENT>Dinoseb</ENT>
                                    <ENT>0.007</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(xxiv) 85-00-7</ENT>
                                    <ENT>Diquat</ENT>
                                    <ENT>0.02</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(xxv) 145-73-3</ENT>
                                    <ENT>Endothall</ENT>
                                    <ENT>0.1</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(xxvi) 72-20-8</ENT>
                                    <ENT>Endrin</ENT>
                                    <ENT>0.002</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(xvii) 1071-53-6</ENT>
                                    <ENT>Glyphosate</ENT>
                                    <ENT>0.7</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(xxviii) 118-74-1</ENT>
                                    <ENT>Hexacholorbenzene</ENT>
                                    <ENT>0.001</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(xxix) 77-47-4</ENT>
                                    <ENT>Hexachlorocyclopentadiene</ENT>
                                    <ENT>0.05</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(xxx) 23135-22-0</ENT>
                                    <ENT>Oxamyl (Vydate)</ENT>
                                    <ENT>0.2</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(xxxi) 1918-02-1</ENT>
                                    <ENT>Picloram</ENT>
                                    <ENT>0.5</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(xxxii) 122-34-9</ENT>
                                    <ENT>Simazine</ENT>
                                    <ENT>0.004</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(xxxiii) 1746-01-6</ENT>
                                    <ENT>2,3,7,8-TCDD (Dioxin)</ENT>
                                    <ENT>
                                        3 × 10
                                        <E T="0731">−</E>
                                        <SU>8</SU>
                                    </ENT>
                                </ROW>
                            </GPOTABLE>
                            <P>
                                (2) 
                                <E T="03">MCLs and HBWCs for PFAS.</E>
                                <PRTPAGE P="579"/>
                            </P>
                            <GPOTABLE COLS="4" OPTS="L2,nj" CDEF="s50,r100,r50,15">
                                <BOXHD>
                                    <CHED H="1">CAS. No.</CHED>
                                    <CHED H="1">Contaminant</CHED>
                                    <CHED H="1">
                                        MCL
                                        <LI>(mg/l) (unless otherwise noted)</LI>
                                    </CHED>
                                    <CHED H="1">
                                        HBWC
                                        <LI>(mg/l) for Hazard Index calculation</LI>
                                    </CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">(i) Not applicable</ENT>
                                    <ENT>Hazard Index PFAS (HFPO-DA, PFBS, PFHxS, and PFNA)</ENT>
                                    <ENT>
                                        1 (unitless) 
                                        <SU>1</SU>
                                    </ENT>
                                    <ENT>Not applicable.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(ii) 122499-17-6</ENT>
                                    <ENT>HFPO-DA</ENT>
                                    <ENT>0.00001</ENT>
                                    <ENT>0.00001.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(iii) 45187-15-3</ENT>
                                    <ENT>PFBS</ENT>
                                    <ENT>No individual MCL</ENT>
                                    <ENT>0.002.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(iv) 108427-53-8</ENT>
                                    <ENT>PFHxS</ENT>
                                    <ENT>0.00001</ENT>
                                    <ENT>0.00001.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(v) 72007-68-2</ENT>
                                    <ENT>PFNA</ENT>
                                    <ENT>0.00001</ENT>
                                    <ENT>0.00001.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(vi) 45285-51-6</ENT>
                                    <ENT>PFOA</ENT>
                                    <ENT>0.0000040</ENT>
                                    <ENT>Not applicable.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(vii) 45298-90-6</ENT>
                                    <ENT>PFOS</ENT>
                                    <ENT>0.0000040</ENT>
                                    <ENT>Not applicable.</ENT>
                                </ROW>
                                <TNOTE>
                                    <SU>1</SU>
                                     The PFAS Mixture Hazard Index (HI) is the sum of component hazard quotients (HQs), which are calculated by dividing the measured component PFAS concentration in water by the relevant health-based water concentration when expressed in the same units (shown in ng/l for simplification). The HBWC for PFHxS is 10 ng/l; the HBWC for HFPO-DA is 10 ng/l; the HBWC for PFNA is 10 ng/l; and the HBWC for PFBS is 2000 ng/l.
                                </TNOTE>
                            </GPOTABLE>
                            <FP SOURCE="FP-2">
                                Hazard Index = ([HFPO-DA
                                <E T="52">water</E>
                                 ng/l]/[10 ng/l]) + ([PFBS
                                <E T="52">water</E>
                                 ng/l]/[2000 ng/l]) + ([PFNA
                                <E T="52">water</E>
                                 ng/l]/[10 ng/l]) + ([PFHxS
                                <E T="52">water</E>
                                 ng/l]/[10 ng/l])
                            </FP>
                            <FP SOURCE="FP-2">HBWC = health-based water concentration</FP>
                            <FP SOURCE="FP-2">HQ = hazard quotient</FP>
                            <FP SOURCE="FP-2">ng/l = nanograms per liter</FP>
                            <FP SOURCE="FP-2">
                                PFAS
                                <E T="52">water</E>
                                 = the concentration of a specific PFAS in water
                            </FP>
                            <P>(d) The Administrator, pursuant to section 1412 of the Act, hereby identifies in table 3 to this paragraph (d) the best technology, treatment technique, or other means available for achieving compliance with the maximum contaminant levels for all regulated PFAS identified in paragraph (c) of this section:</P>
                            <GPOTABLE COLS="2" OPTS="L2" CDEF="s100,r100">
                                <TTITLE>
                                    Table 3 to Paragraph (
                                    <E T="01">d</E>
                                    )—Best Available Technologies for PFAS Listed in Paragraph (
                                    <E T="01">c</E>
                                    ) of This Section
                                </TTITLE>
                                <BOXHD>
                                    <CHED H="1">Contaminant</CHED>
                                    <CHED H="1">BAT</CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">Hazard Index PFAS (HFPO-DA, PFBS, PFHxS, and PFNA)</ENT>
                                    <ENT>Anion exchange, GAC, reverse osmosis, nanofiltration.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">HFPO-DA</ENT>
                                    <ENT>Anion exchange, GAC, reverse osmosis, nanofiltration.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">PFHxS</ENT>
                                    <ENT>Anion exchange, GAC, reverse osmosis, nanofiltration.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">PFNA</ENT>
                                    <ENT>Anion exchange, GAC, reverse osmosis, nanofiltration.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">PFOA</ENT>
                                    <ENT>Anion exchange, GAC, reverse osmosis, nanofiltration.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">PFOS</ENT>
                                    <ENT>Anion exchange, GAC, reverse osmosis, nanofiltration.</ENT>
                                </ROW>
                            </GPOTABLE>
                            <P>(e) The Administrator, pursuant to section 1412 of the Act, hereby identifies in table 4 to this paragraph (e) the affordable technology, treatment technique, or other means available to systems serving 10,000 persons or fewer for achieving compliance with the maximum contaminant levels for all regulated PFAS identified in paragraph (c) of this section:</P>
                            <GPOTABLE COLS="2" OPTS="L2" CDEF="s50,r50">
                                <TTITLE>
                                    Table 4 to Paragraph (
                                    <E T="01">e</E>
                                    )—Small System Compliance Technologies (SSCTs) for PFAS
                                </TTITLE>
                                <BOXHD>
                                    <CHED H="1">
                                        Small system
                                        <LI>compliance</LI>
                                        <LI>
                                            technology 
                                            <SU>1</SU>
                                        </LI>
                                    </CHED>
                                    <CHED H="1">
                                        Affordable for listed small system
                                        <LI>
                                            categories 
                                            <SU>2</SU>
                                        </LI>
                                    </CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">Granular Activated Carbon</ENT>
                                    <ENT>All size categories.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Anion Exchange</ENT>
                                    <ENT>All size categories.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">
                                        Reverse Osmosis, Nanofiltration 
                                        <SU>3</SU>
                                    </ENT>
                                    <ENT>3,301-10,000.</ENT>
                                </ROW>
                                <TNOTE>
                                    <SU>1</SU>
                                     Section 1412(b)(4)(E)(ii) of SDWA specifies that SSCTs must be affordable and technically feasible for small systems.
                                </TNOTE>
                                <TNOTE>
                                    <SU>2</SU>
                                     The Act (ibid.) specifies three categories of small systems: (i) those serving 25 or more, but fewer than 501, (ii) those serving more than 500, but fewer than 3,301, and (iii) those serving more than 3,300, but fewer than 10,001.
                                </TNOTE>
                                <TNOTE>
                                    <SU>3</SU>
                                     “Technologies reject a large volume of water and may not be appropriate for areas where water quantity may be an issue.
                                </TNOTE>
                            </GPOTABLE>
                            <CITA>[56 FR 3593, Jan. 30, 1991, as amended at 56 FR 30280, July 1, 1991; 57 FR 31846, July 17, 1992; 59 FR 34324, July 1, 1994; 89 FR 32744, Apr. 26, 2024; 89 FR 49102, June 11, 2024]</CITA>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 141.62</SECTNO>
                            <SUBJECT>Maximum contaminant levels for inorganic contaminants.</SUBJECT>
                            <P>(a) [Reserved]</P>
                            <P>
                                (b) The maximum contaminant levels for inorganic contaminants specified in paragraphs (b) (2)-(6), (b)(10), and (b) (11)-(16) of this section apply to community water systems and non-transient, non-community water systems. The maximum contaminant level specified in paragraph (b)(1) of this section 
                                <PRTPAGE P="580"/>
                                only applies to community water systems. The maximum contaminant levels specified in (b)(7), (b)(8), and (b)(9) of this section apply to community water systems; non-transient, non-community water systems; and transient non-community water systems.
                            </P>
                            <GPOTABLE COLS="2" OPTS="L2,tp4" CDEF="s25,r25">
                                <BOXHD>
                                    <CHED H="1">Contaminant</CHED>
                                    <CHED H="1">MCL (mg/l)</CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">(1) Fluoride</ENT>
                                    <ENT>4.0</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(2) Asbestos</ENT>
                                    <ENT>7 Million Fibers/liter (longer than 10 µm)</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(3) Barium</ENT>
                                    <ENT>2</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(4) Cadmium</ENT>
                                    <ENT>0.005</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(5) Chromium</ENT>
                                    <ENT>0.1</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(6) Mercury</ENT>
                                    <ENT>0.002</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(7) Nitrate</ENT>
                                    <ENT>10 (as Nitrogen)</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(8) Nitrite</ENT>
                                    <ENT>1 (as Nitrogen)</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(9) Total Nitrate and Nitrite</ENT>
                                    <ENT>10 (as Nitrogen)</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(10) Selenium</ENT>
                                    <ENT>0.05</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(11) Antimony</ENT>
                                    <ENT>0.006</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(12) Beryllium</ENT>
                                    <ENT>0.004</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(13) Cyanide (as free Cyanide)</ENT>
                                    <ENT>0.2</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(14) [Reserved]</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(15) Thallium</ENT>
                                    <ENT>0.002</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">(16) Arsenic</ENT>
                                    <ENT>0.010</ENT>
                                </ROW>
                            </GPOTABLE>
                            <P>(c) The Administrator, pursuant to section 1412 of the Act, hereby identifies the following as the best technology, treatment technique, or other means available for achieving compliance with the maximum contaminant levels for inorganic contaminants identified in paragraph (b) of this section, except fluoride:</P>
                            <GPOTABLE COLS="2" OPTS="L2" CDEF="s75,12">
                                <TTITLE>
                                    BAT for Inorganic Compounds Listed in Section 
                                    <E T="01">141.62(b)</E>
                                </TTITLE>
                                <BOXHD>
                                    <CHED H="1">Chemical Name</CHED>
                                    <CHED H="1">BAT(s)</CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">Antimony</ENT>
                                    <ENT>2,7</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">
                                        Arsenic 
                                        <SU>4</SU>
                                    </ENT>
                                    <ENT>
                                        1, 2, 5, 6, 7, 9, 12 
                                        <SU>5</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Asbestos</ENT>
                                    <ENT>2,3,8</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Barium</ENT>
                                    <ENT>5,6,7,9</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Beryllium</ENT>
                                    <ENT>1,2,5,6,7</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Cadmium</ENT>
                                    <ENT>2,5,6,7</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Chromium</ENT>
                                    <ENT>
                                        2,5,6 
                                        <SU>2</SU>
                                        ,7
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Cyanide</ENT>
                                    <ENT>5,7,13</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Mercury</ENT>
                                    <ENT>
                                        2 
                                        <SU>1</SU>
                                        ,4,6 
                                        <SU>1</SU>
                                        ,7 
                                        <SU>1</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Nickel</ENT>
                                    <ENT>5,6,7</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Nitrate</ENT>
                                    <ENT>5,7,9</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Nitrite</ENT>
                                    <ENT>5,7</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Selenium</ENT>
                                    <ENT>
                                        1,2 
                                        <SU>3</SU>
                                        ,6,7,9
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Thallium</ENT>
                                    <ENT>1,5</ENT>
                                </ROW>
                                <TNOTE>
                                    <SU>1</SU>
                                     BAT only if influent Hg concentrations ≤10µg/1.
                                </TNOTE>
                                <TNOTE>
                                    <SU>2</SU>
                                     BAT for Chromium III only.
                                </TNOTE>
                                <TNOTE>
                                    <SU>3</SU>
                                     BAT for Selenium IV only.
                                </TNOTE>
                                <TNOTE>
                                    <SU>4</SU>
                                     BATs for Arsenic V. Pre-oxidation may be required to convert Arsenic III to Arsenic V.
                                </TNOTE>
                                <TNOTE>
                                    <SU>5</SU>
                                     To obtain high removals, iron to arsenic ratio must be at least 20:1.
                                </TNOTE>
                            </GPOTABLE>
                            <HD SOURCE="HD2">Key to BATS in Table</HD>
                            <EXTRACT>
                                <FP SOURCE="FP-1">1 = Activated Alumina</FP>
                                <FP SOURCE="FP-1">2 = Coagulation/Filtration (not BAT for systems &lt;500 service connections)</FP>
                                <FP SOURCE="FP-1">3 = Direct and Diatomite Filtration</FP>
                                <FP SOURCE="FP-1">4 = Granular Activated Carbon</FP>
                                <FP SOURCE="FP-1">5 = Ion Exchange</FP>
                                <FP SOURCE="FP-1">6 = Lime Softening (not BAT for systems &lt;500 service connections)</FP>
                                <FP SOURCE="FP-1">7 = Reverse Osmosis</FP>
                                <FP SOURCE="FP-1">8 = Corrosion Control</FP>
                                <FP SOURCE="FP-1">9 = Electrodialysis</FP>
                                <FP SOURCE="FP-1">10 = Chlorine</FP>
                                <FP SOURCE="FP-1">11 = Ultraviolet</FP>
                                <FP SOURCE="FP-1">12 = Oxidation/Filtration</FP>
                                <FP SOURCE="FP-1">13 = Alkaline Chlorination (pH ≥8.5)</FP>
                            </EXTRACT>
                            <P>(d) The Administrator, pursuant to section 1412 of the Act, hereby identifies in the following table the affordable technology, treatment technique, or other means available to systems serving 10,000 persons or fewer for achieving compliance with the maximum contaminant level for arsenic:</P>
                            <GPOTABLE COLS="2" OPTS="L2" CDEF="s50,r50">
                                <TTITLE>
                                    Small System Compliance Technologies (SSCTs) 
                                    <SU>1</SU>
                                     for Arsenic 
                                    <SU>2</SU>
                                </TTITLE>
                                <BOXHD>
                                    <CHED H="1">Small system compliance technology</CHED>
                                    <CHED H="1">
                                        Affordable for listed small system categories 
                                        <SU>3</SU>
                                    </CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">Activated Alumina (centralized)</ENT>
                                    <ENT>All size categories.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">
                                        Activated Alumina (Point-of-Use) 
                                        <SU>4</SU>
                                    </ENT>
                                    <ENT>All size categories.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">
                                        Coagulation/Filtration 
                                        <SU>5</SU>
                                    </ENT>
                                    <ENT>501-3,300, 3,301-10,000.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Coagulation-assisted Microfiltration</ENT>
                                    <ENT>501-3,300, 3,301-10,000.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">
                                        Electrodialysis reversal 
                                        <SU>6</SU>
                                    </ENT>
                                    <ENT>501-3,300, 3,301-10,000.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Enhanced coagulation/filtration</ENT>
                                    <ENT>All size categories</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Enhanced lime softening (pH&gt;10.5)</ENT>
                                    <ENT>All size categories.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Ion Exchange</ENT>
                                    <ENT>All size categories.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">
                                        Lime Softening 
                                        <SU>5</SU>
                                    </ENT>
                                    <ENT>501-3,300, 3,301-10,000.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">
                                        Oxidation/Filtration 
                                        <SU>7</SU>
                                    </ENT>
                                    <ENT>All size categories.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">
                                        Reverse Osmosis (centralized) 
                                        <SU>6</SU>
                                    </ENT>
                                    <ENT>501-3,300, 3,301-10,000.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">
                                        Reverse Osmosis (Point-of-Use) 
                                        <SU>4</SU>
                                    </ENT>
                                    <ENT>All size categories.</ENT>
                                </ROW>
                                <TNOTE>
                                    <SU>1</SU>
                                     Section 1412(b)(4)(E)(ii) of SDWA specifies that SSCTs must be affordable and technically feasible for small systems.
                                </TNOTE>
                                <TNOTE>
                                    <SU>2</SU>
                                     SSCTs for Arsenic V. Pre-oxidation may be required to convert Arsenic III to Arsenic V.
                                </TNOTE>
                                <TNOTE>
                                    <SU>3</SU>
                                     The Act (ibid.) specifies three categories of small systems: (i) those serving 25 or more, but fewer than 501, (ii) those serving more than 500, but fewer than 3,301, and (iii) those serving more than 3,300, but fewer than 10,001.
                                </TNOTE>
                                <TNOTE>
                                    <SU>4</SU>
                                     When POU or POE devices are used for compliance, programs to ensure proper long-term operation, maintenance, and monitoring must be provided by the water system to ensure adequate performance.
                                </TNOTE>
                                <TNOTE>
                                    <SU>5</SU>
                                     Unlikely to be installed solely for arsenic removal. May require pH adjustment to optimal range if high removals are needed.
                                </TNOTE>
                                <TNOTE>
                                    <SU>6</SU>
                                     Technologies reject a large volume of water—may not be appropriate for areas where water quantity may be an issue.
                                </TNOTE>
                                <TNOTE>
                                    <SU>7</SU>
                                     To obtain high removals, iron to arsenic ratio must be at least 20:1.
                                </TNOTE>
                            </GPOTABLE>
                            <CITA>[56 FR 3594, Jan. 30, 1991, as amended at 56 FR 30280, July 1, 1991; 57 FR 31847, July 17, 1992; 59 FR 34325, July 1, 1994; 60 FR 33932, June 29, 1995; 66 FR 7063, Jan. 22, 2001; 68 FR 14506, Mar. 25, 2003; 69 FR 38855, June 29, 2004]</CITA>
                        </SECTION>
                        <SECTION>
                            <PRTPAGE P="581"/>
                            <SECTNO>§ 141.63</SECTNO>
                            <SUBJECT>Maximum contaminant levels (MCLs) for microbiological contaminants.</SUBJECT>
                            <P>(a) Until March 31, 2016, the total coliform MCL is based on the presence or absence of total coliforms in a sample, rather than coliform density.</P>
                            <P>(1) For a system that collects at least 40 samples per month, if no more than 5.0 percent of the samples collected during a month are total coliform-positive, the system is in compliance with the MCL for total coliforms.</P>
                            <P>(2) For a system that collects fewer than 40 samples per month, if no more than one sample collected during a month is total coliform-positive, the system is in compliance with the MCL for total coliforms.</P>
                            <P>
                                (b) Until March 31, 2016, any fecal coliform-positive repeat sample or 
                                <E T="03">E. coli</E>
                                -positive repeat sample, or any total coliform-positive repeat sample following a fecal coliform-positive or 
                                <E T="03">E. coli</E>
                                -positive routine sample, constitutes a violation of the MCL for total coliforms. For purposes of the public notification requirements in subpart Q of this part, this is a violation that may pose an acute risk to health.
                            </P>
                            <P>
                                (c) Beginning April 1, 2016, a system is in compliance with the MCL for 
                                <E T="03">E. coli</E>
                                 for samples taken under the provisions of subpart Y of this part unless any of the conditions identified in paragraphs (c)(1) through (c)(4) of this section occur. For purposes of the public notification requirements in subpart Q of this part, violation of the MCL may pose an acute risk to health.
                            </P>
                            <P>
                                (1) The system has an 
                                <E T="03">E. coli</E>
                                -positive repeat sample following a total coliform-positive routine sample.
                            </P>
                            <P>
                                (2) The system has a total coliform-positive repeat sample following an 
                                <E T="03">E. coli</E>
                                -positive routine sample.
                            </P>
                            <P>
                                (3) The system fails to take all required repeat samples following an 
                                <E T="03">E. coli</E>
                                -positive routine sample.
                            </P>
                            <P>
                                (4) The system fails to test for 
                                <E T="03">E. coli</E>
                                 when any repeat sample tests positive for total coliform.
                            </P>
                            <P>
                                (d) Until March 31, 2016, a public water system must determine compliance with the MCL for total coliforms in paragraphs (a) and (b) of this section for each month in which it is required to monitor for total coliforms. Beginning April 1, 2016, a public water system must determine compliance with the MCL for 
                                <E T="03">E. coli</E>
                                 in paragraph (c) of this section for each month in which it is required to monitor for total coliforms.
                            </P>
                            <P>
                                (e) The Administrator, pursuant to section 1412 of the Act, hereby identifies the following as the best technology, treatment techniques, or other means available for achieving compliance with the maximum contaminant level for total coliforms in paragraphs (a) and (b) of this section and for achieving compliance with the maximum contaminant level for 
                                <E T="03">E. coli</E>
                                 in paragraph (c) of this section:
                            </P>
                            <P>(1) Protection of wells from fecal contamination by appropriate placement and construction;</P>
                            <P>(2) Maintenance of a disinfectant residual throughout the distribution system;</P>
                            <P>(3) Proper maintenance of the distribution system including appropriate pipe replacement and repair procedures, main flushing programs, proper operation and maintenance of storage tanks and reservoirs, cross connection control, and continual maintenance of positive water pressure in all parts of the distribution system;</P>
                            <P>(4) Filtration and/or disinfection of surface water, as described in subparts H, P, T, and W of this part, or disinfection of ground water, as described in subpart S of this part, using strong oxidants such as chlorine, chlorine dioxide, or ozone; and</P>
                            <P>(5) For systems using ground water, compliance with the requirements of an EPA-approved State Wellhead Protection Program developed and implemented under section 1428 of the SDWA.</P>
                            <P>
                                (f) The Administrator, pursuant to section 1412 of the Act, hereby identifies the technology, treatment techniques, or other means available identified in paragraph (e) of this section as affordable technology, treatment techniques, or other means available to systems serving 10,000 or fewer people for achieving compliance with the maximum contaminant level for total coliforms in paragraphs (a) and (b) of this section and for achieving compliance with the maximum contaminant 
                                <PRTPAGE P="582"/>
                                level for 
                                <E T="03">E. coli</E>
                                 in paragraph (c) of this section.
                            </P>
                            <CITA>[78 FR 10347, Feb. 13, 2013]</CITA>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 141.64</SECTNO>
                            <SUBJECT>Maximum contaminant levels for disinfection byproducts.</SUBJECT>
                            <P>
                                (a) 
                                <E T="03">Bromate and chlorite.</E>
                                 The maximum contaminant levels (MCLs) for bromate and chlorite are as follows:
                            </P>
                            <GPOTABLE COLS="2" OPTS="L2" CDEF="s50,6.3">
                                <BOXHD>
                                    <CHED H="1">Disinfection byproduct</CHED>
                                    <CHED H="1">MCL (mg/L)</CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">Bromate</ENT>
                                    <ENT>0.010</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Chlorite</ENT>
                                    <ENT>1.0</ENT>
                                </ROW>
                            </GPOTABLE>
                            <P>
                                (1) 
                                <E T="03">Compliance dates for CWSs and NTNCWSs.</E>
                                 Subpart H systems serving 10,000 or more persons must comply with this paragraph (a) beginning January 1, 2002. Subpart H systems serving fewer than 10,000 persons and systems using only ground water not under the direct influence of surface water must comply with this paragraph (a) beginning January 1, 2004.
                            </P>
                            <P>(2) The Administrator, pursuant to section 1412 of the Act, hereby identifies the following as the best technology, treatment techniques, or other means available for achieving compliance with the maximum contaminant levels for bromate and chlorite identified in this paragraph (a):</P>
                            <GPOTABLE COLS="2" OPTS="L2" CDEF="s25,r100">
                                <BOXHD>
                                    <CHED H="1">Disinfection byproduct</CHED>
                                    <CHED H="1">Best available technology</CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">Bromate</ENT>
                                    <ENT>Control of ozone treatment process to reduce production of bromate</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Chlorite</ENT>
                                    <ENT>Control of treatment processes to reduce disinfectant demand and control of disinfection treatment processes to reduce disinfectant levels</ENT>
                                </ROW>
                            </GPOTABLE>
                            <P>(b) TTHM and HAA5. (1) Subpart L—RAA compliance. (i) Compliance dates. Subpart H systems serving 10,000 or more persons must comply with this paragraph (b)(1) beginning January 1, 2002. Subpart H systems serving fewer than 10,000 persons and systems using only ground water not under the direct influence of surface water must comply with this paragraph (b)(1) beginning January 1, 2004. All systems must comply with these MCLs until the date specified for subpart V compliance in § 141.620(c).</P>
                            <GPOTABLE COLS="2" OPTS="L2" CDEF="s50,10">
                                <BOXHD>
                                    <CHED H="1">Disinfection byproduct</CHED>
                                    <CHED H="1">MCL (mg/L)</CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">Total trihalomethanes (TTHM)</ENT>
                                    <ENT>0.080</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Haloacetic acids (five) (HAA5)</ENT>
                                    <ENT>0.060</ENT>
                                </ROW>
                            </GPOTABLE>
                            <P>(ii) The Administrator, pursuant to section 1412 of the Act, hereby identifies the following as the best technology, treatment techniques, or other means available for achieving compliance with the maximum contaminant levels for TTHM and HAA5 identified in this paragraph (b)(1):</P>
                            <GPOTABLE COLS="2" OPTS="L2" CDEF="s50,r50">
                                <BOXHD>
                                    <CHED H="1">Disinfection byproduct</CHED>
                                    <CHED H="1">Best available technology</CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">Total trihalomethanes (TTHM) and Haloacetic acids (five) (HAA5)</ENT>
                                    <ENT>Enhanced coagulation or enhanced softening or GAC10, with chlorine as the primary and residual disinfectant</ENT>
                                </ROW>
                            </GPOTABLE>
                            <P>(2) Subpart V—LRAA compliance. (i) Compliance dates. The subpart V MCLs for TTHM and HAA5 must be complied with as a locational running annual average at each monitoring location beginning the date specified for subpart V compliance in § 141.620(c).</P>
                            <GPOTABLE COLS="2" OPTS="L2" CDEF="s50,10">
                                <BOXHD>
                                    <CHED H="1">Disinfection byproduct</CHED>
                                    <CHED H="1">MCL (mg/L)</CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">Total trihalomethanes (TTHM)</ENT>
                                    <ENT>0.080</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Haloacetic acids (five) (HAA5)</ENT>
                                    <ENT>0.060</ENT>
                                </ROW>
                            </GPOTABLE>
                            <P>(ii) The Administrator, pursuant to section 1412 of the Act, hereby identifies the following as the best technology, treatment techniques, or other means available for achieving compliance with the maximum contaminant levels for TTHM and HAA5 identified in this paragraph (b)(2) for all systems that disinfect their source water:</P>
                            <GPOTABLE COLS="2" OPTS="L2" CDEF="s50,r100">
                                <BOXHD>
                                    <CHED H="1">Disinfection byproduct</CHED>
                                    <CHED H="1">Best available technology</CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">Total trihalomethanes (TTHM) and Haloacetic acids (five) (HAA5)</ENT>
                                    <ENT>Enhanced coagulation or enhanced softening, plus GAC10; or nanofiltration with a molecular weight cutoff ≤1000 Daltons; or GAC20</ENT>
                                </ROW>
                            </GPOTABLE>
                            <P>
                                (iii) The Administrator, pursuant to section 1412 of the Act, hereby identifies the following as the best technology, treatment techniques, or other means available for achieving compliance with the maximum contaminant levels for TTHM and HAA5 identified in this paragraph (b)(2) for consecutive systems and applies only to the disinfected water that consecutive systems buy or otherwise receive:
                                <PRTPAGE P="583"/>
                            </P>
                            <GPOTABLE COLS="2" OPTS="L2" CDEF="s50,r100">
                                <BOXHD>
                                    <CHED H="1">Disinfection byproduct</CHED>
                                    <CHED H="1">Best available technology</CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">Total trihalomethanes (TTHM) and Haloacetic acids (five) (HAA5)</ENT>
                                    <ENT>Systems serving ≥10,000: Improved distribution system and storage tank management to reduce residence time, plus the use of chloramines for disinfectant residual maintenance</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Systems serving &lt;10,000: Improved distribution system and storage tank management to reduce residence time</ENT>
                                </ROW>
                            </GPOTABLE>
                            <CITA>[71 FR 478, Jan. 4, 2006]</CITA>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 141.65</SECTNO>
                            <SUBJECT>Maximum residual disinfectant levels.</SUBJECT>
                            <P>(a) Maximum residual disinfectant levels (MRDLs) are as follows:</P>
                            <GPOTABLE COLS="2" OPTS="L2" CDEF="s25,xs56">
                                <BOXHD>
                                    <CHED H="1">Disinfectant residual</CHED>
                                    <CHED H="1">MRDL (mg/L)</CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">Chlorine</ENT>
                                    <ENT>
                                        4.0 (as Cl
                                        <E T="52">2</E>
                                        ).
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Chloramines</ENT>
                                    <ENT>
                                        4.0 (as Cl
                                        <E T="52">2</E>
                                        ).
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Chlorine dioxide</ENT>
                                    <ENT>
                                        0.8 (as ClO
                                        <E T="52">2</E>
                                        ).
                                    </ENT>
                                </ROW>
                            </GPOTABLE>
                            <P>
                                (b) 
                                <E T="03">Compliance dates</E>
                                —(1) 
                                <E T="03">CWSs and NTNCWSs.</E>
                                 Subpart H systems serving 10,000 or more persons must comply with this section beginning January 1, 2002. Subpart H systems serving fewer than 10,000 persons and systems using only ground water not under the direct influence of surface water must comply with this subpart beginning January 1, 2004.
                            </P>
                            <P>(2) Transient NCWSs. Subpart H systems serving 10,000 or more persons and using chlorine dioxide as a disinfectant or oxidant must comply with the chlorine dioxide MRDL beginning January 1, 2002. Subpart H systems serving fewer than 10,000 persons and using chlorine dioxide as a disinfectant or oxidant and systems using only ground water not under the direct influence of surface water and using chlorine dioxide as a disinfectant or oxidant must comply with the chlorine dioxide MRDL beginning January 1, 2004.</P>
                            <P>(c) The Administrator, pursuant to Section 1412 of the Act, hereby identifies the following as the best technology, treatment techniques, or other means available for achieving compliance with the maximum residual disinfectant levels identified in paragraph (a) of this section: control of treatment processes to reduce disinfectant demand and control of disinfection treatment processes to reduce disinfectant levels.</P>
                            <CITA>[63 FR 69465, Dec. 16, 1998, as amended at 66 FR 3776, Jan. 16, 2001]</CITA>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 141.66</SECTNO>
                            <SUBJECT>Maximum contaminant levels for radionuclides.</SUBJECT>
                            <P>(a) [Reserved]</P>
                            <P>
                                (b) 
                                <E T="03">MCL for combined radium-226 and -228.</E>
                                 The maximum contaminant level for combined radium-226 and radium-228 is 5 pCi/L. The combined radium-226 and radium-228 value is determined by the addition of the results of the analysis for radium-226 and the analysis for radium-228.
                            </P>
                            <P>
                                (c) 
                                <E T="03">MCL for gross alpha particle activity (excluding radon and uranium).</E>
                                 The maximum contaminant level for gross alpha particle activity (including radium-226 but excluding radon and uranium) is 15 pCi/L.
                            </P>
                            <P>
                                (d) 
                                <E T="03">MCL for beta particle and photon radioactivity.</E>
                                 (1) The average annual concentration of beta particle and photon radioactivity from man-made radionuclides in drinking water must not produce an annual dose equivalent to the total body or any internal organ greater than 4 millirem/year (mrem/year).
                            </P>
                            <P>
                                (2) Except for the radionuclides listed in table A, the concentration of man-made radionuclides causing 4 mrem total body or organ dose equivalents must be calculated on the basis of 2 liter per day drinking water intake using the 168 hour data list in “Maximum Permissible Body Burdens and Maximum Permissible Concentrations of Radionuclides in Air and in Water for Occupational Exposure,” NBS (National Bureau of Standards) Handbook 69 as amended August 1963, U.S. Department of Commerce. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies of this document are available from the National Technical Information Service, NTIS ADA 280 282, U.S. Department of Commerce, 5285 Port Royal Road, Springfield, Virginia 22161. The toll-free number is 800-553-6847. Copies may be inspected at EPA's Drinking Water Docket, 401 M Street, SW., Washington, DC 20460; or at the National Archives and Records 
                                <PRTPAGE P="584"/>
                                Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: 
                                <E T="03">http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.</E>
                                 If two or more radionuclides are present, the sum of their annual dose equivalent to the total body or to any organ shall not exceed 4 mrem/year.
                            </P>
                            <GPOTABLE COLS="3" OPTS="L2,p1,6/7" CDEF="s50,r50,r50">
                                <TTITLE>Table A—Average Annual Concentrations Assumed To Produce: a Total Body or Organ Dose of 4 mrem/yr</TTITLE>
                                <ROW>
                                    <ENT I="01">1. Radionuclide</ENT>
                                    <ENT>Critical organ</ENT>
                                    <ENT>pCi per liter</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">2. Tritium</ENT>
                                    <ENT>Total body</ENT>
                                    <ENT>20,000</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">3. Strontium-90</ENT>
                                    <ENT>Bone Marrow</ENT>
                                    <ENT>8</ENT>
                                </ROW>
                            </GPOTABLE>
                            <P>
                                (e) 
                                <E T="03">MCL for uranium.</E>
                                 The maximum contaminant level for uranium is 30 µg/L.
                            </P>
                            <P>
                                (f) 
                                <E T="03">Compliance dates.</E>
                                 (1) Compliance dates for combined radium-226 and -228, gross alpha particle activity, gross beta particle and photon radioactivity, and uranium: Community water systems must comply with the MCLs listed in paragraphs (b), (c), (d), and (e) of this section beginning December 8, 2003 and compliance shall be determined in accordance with the requirements of §§ 141.25 and 141.26. Compliance with reporting requirements for the radionuclides under appendix A to subpart O and appendices A and B to subpart Q is required on December 8, 2003.
                            </P>
                            <P>(2) [Reserved]</P>
                            <P>
                                (g) 
                                <E T="03">Best available technologies (BATs) for radionuclides.</E>
                                 The Administrator, pursuant to section 1412 of the Act, hereby identifies as indicated in the following table the best technology available for achieving compliance with the maximum contaminant levels for combined radium-226 and -228, uranium, gross alpha particle activity, and beta particle and photon radioactivity.
                            </P>
                            <GPOTABLE COLS="2" OPTS="L2" CDEF="s100,r100">
                                <TTITLE>Table B—BAT for Combined Radium-226 and Radium-228, Uranium, Gross Alpha Particle Activity, and Beta Particle and Photon Radioactivity</TTITLE>
                                <BOXHD>
                                    <CHED H="1">Contaminant</CHED>
                                    <CHED H="1">BAT</CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">1. Combined radium-226 and radium-228</ENT>
                                    <ENT>Ion exchange, reverse osmosis, lime softening.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">2. Uranium</ENT>
                                    <ENT>Ion exchange, reverse osmosis, lime softening, coagulation/filtration.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">3. Gross alpha particle activity (excluding Radon and Uranium)</ENT>
                                    <ENT>Reverse osmosis.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">4. Beta particle and photon radioactivity</ENT>
                                    <ENT>Ion exchange, reverse osmosis.</ENT>
                                </ROW>
                            </GPOTABLE>
                            <P>
                                (h) 
                                <E T="03">Small systems compliance technologies list for radionuclides.</E>
                            </P>
                            <GPOTABLE COLS="4" OPTS="L2" CDEF="s55,10C,r50,r50">
                                <TTITLE>Table C—List of Small Systems Compliance Technologies for Radionuclides and Limitations to Use</TTITLE>
                                <BOXHD>
                                    <CHED H="1">Unit technologies</CHED>
                                    <CHED H="1">Limitations (see footnotes)</CHED>
                                    <CHED H="1">
                                        Operator skill level required 
                                        <SU>1</SU>
                                    </CHED>
                                    <CHED H="1">
                                        Raw water quality range and
                                        <LI>
                                            considerations. 
                                            <SU>1</SU>
                                        </LI>
                                    </CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">1. Ion exchange (IE)</ENT>
                                    <ENT>
                                        (
                                        <SU>a</SU>
                                        )
                                    </ENT>
                                    <ENT>Intermediate</ENT>
                                    <ENT>All ground waters.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">
                                        2. Point of use (POU 
                                        <SU>2</SU>
                                        ) IE
                                    </ENT>
                                    <ENT>
                                        (
                                        <SU>b</SU>
                                        )
                                    </ENT>
                                    <ENT>Basic</ENT>
                                    <ENT>All ground waters.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">3. Reverse osmosis (RO)</ENT>
                                    <ENT>
                                        (
                                        <SU>c</SU>
                                        )
                                    </ENT>
                                    <ENT>Advanced</ENT>
                                    <ENT>Surface waters usually require pre-filtration.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">
                                        4. POU 
                                        <SU>2</SU>
                                         RO
                                    </ENT>
                                    <ENT>
                                        (
                                        <SU>b</SU>
                                        )
                                    </ENT>
                                    <ENT>Basic</ENT>
                                    <ENT>Surface waters usually require pre-filtration.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">5. Lime softening</ENT>
                                    <ENT>
                                        (
                                        <SU>d</SU>
                                        )
                                    </ENT>
                                    <ENT>Advanced</ENT>
                                    <ENT>All waters.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">6. Green sand filtration</ENT>
                                    <ENT>
                                        (
                                        <SU>e</SU>
                                        )
                                    </ENT>
                                    <ENT O="xl">Basic.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">7. Co-precipitation with Barium sulfate</ENT>
                                    <ENT>
                                        (
                                        <SU>f</SU>
                                        )
                                    </ENT>
                                    <ENT>Intermediate to Advanced</ENT>
                                    <ENT>Ground waters with suitable water quality.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">8. Electrodialysis/electrodialysis reversal</ENT>
                                    <ENT/>
                                    <ENT>Basic to Intermediate</ENT>
                                    <ENT>All ground waters.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">9. Pre-formed hydrous Manganese oxide filtration</ENT>
                                    <ENT>
                                        (
                                        <SU>g</SU>
                                        )
                                    </ENT>
                                    <ENT>Intermediate</ENT>
                                    <ENT>All ground waters.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">10. Activated alumina</ENT>
                                    <ENT>
                                        (
                                        <SU>a</SU>
                                        ), (
                                        <SU>h</SU>
                                        )
                                    </ENT>
                                    <ENT>Advanced</ENT>
                                    <ENT>All ground waters; competing anion concentrations may affect regeneration frequency.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">11. Enhanced coagulation/filtration</ENT>
                                    <ENT>
                                        (
                                        <SU>i</SU>
                                        )
                                    </ENT>
                                    <ENT>Advanced</ENT>
                                    <ENT>Can treat a wide range of water qualities.</ENT>
                                </ROW>
                                <TNOTE>
                                    <SU>1</SU>
                                     National Research Council (NRC). Safe Water from Every Tap: Improving Water Service to Small Communities. National Academy Press. Washington, D.C. 1997.
                                    <PRTPAGE P="585"/>
                                </TNOTE>
                                <TNOTE>
                                    <SU>2</SU>
                                     A POU, or “point-of-use” technology is a treatment device installed at a single tap used for the purpose of reducing contaminants in drinking water at that one tap. POU devices are typically installed at the kitchen tap. See the April 21, 2000 NODA for more details.
                                </TNOTE>
                                <TNOTE> Limitations Footnotes: Technologies for Radionuclides:</TNOTE>
                                <TNOTE>
                                    <SU>a</SU>
                                     The regeneration solution contains high concentrations of the contaminant ions. Disposal options should be carefully considered before choosing this technology.
                                </TNOTE>
                                <TNOTE>
                                    <SU>b</SU>
                                     When POU devices are used for compliance, programs for long-term operation, maintenance, and monitoring must be provided by water utility to ensure proper performance.
                                </TNOTE>
                                <TNOTE>
                                    <SU>c</SU>
                                     Reject water disposal options should be carefully considered before choosing this technology. See other RO limitations described in the SWTR Compliance Technologies Table.
                                </TNOTE>
                                <TNOTE>
                                    <SU>d</SU>
                                     The combination of variable source water quality and the complexity of the water chemistry involved may make this technology too complex for small surface water systems.
                                </TNOTE>
                                <TNOTE>
                                    <SU>e</SU>
                                     Removal efficiencies can vary depending on water quality.
                                </TNOTE>
                                <TNOTE>
                                    <SU>f</SU>
                                     This technology may be very limited in application to small systems. Since the process requires static mixing, detention basins, and filtration, it is most applicable to systems with sufficiently high sulfate levels that already have a suitable filtration treatment train in place.
                                </TNOTE>
                                <TNOTE>
                                    <SU>g</SU>
                                     This technology is most applicable to small systems that already have filtration in place.
                                </TNOTE>
                                <TNOTE>
                                    <SU>h</SU>
                                     Handling of chemicals required during regeneration and pH adjustment may be too difficult for small systems without an adequately trained operator.
                                </TNOTE>
                                <TNOTE>
                                    <SU>i</SU>
                                     Assumes modification to a coagulation/filtration process already in place.
                                </TNOTE>
                            </GPOTABLE>
                            <GPOTABLE COLS="4" OPTS="L2" CDEF="s65,r40,r40,r40">
                                <TTITLE>Table D—Compliance Technologies by System Size Category for Radionuclide NPDWR's</TTITLE>
                                <BOXHD>
                                    <CHED H="1">Contaminant</CHED>
                                    <CHED H="1">
                                        Compliance technologies 
                                        <SU>1</SU>
                                         for system size categories (population served)
                                    </CHED>
                                    <CHED H="2">25-500</CHED>
                                    <CHED H="2">501-3,300</CHED>
                                    <CHED H="1">3,300-10,000</CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">1. Combined radium-226 and radium-228</ENT>
                                    <ENT>1, 2, 3, 4, 5, 6, 7, 8, 9</ENT>
                                    <ENT>1, 2, 3, 4, 5, 6, 7, 8, 9</ENT>
                                    <ENT>1, 2, 3, 4, 5, 6, 7. 8, 9.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">2. Gross alpha particle activity</ENT>
                                    <ENT>3, 4</ENT>
                                    <ENT>3, 4</ENT>
                                    <ENT>3, 4.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">3. Beta particle activity and photon activity</ENT>
                                    <ENT>1, 2, 3, 4</ENT>
                                    <ENT>1, 2, 3, 4</ENT>
                                    <ENT>1, 2, 3, 4.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">4. Uranium</ENT>
                                    <ENT>1, 2, 4, 10, 11</ENT>
                                    <ENT>1, 2, 3, 4, 5, 10, 11</ENT>
                                    <ENT>1, 2, 3, 4, 5, 10, 11.</ENT>
                                </ROW>
                                <TNOTE>
                                    <E T="04">Note:</E>
                                     
                                    <SU>1</SU>
                                     Numbers correspond to those technologies found listed in the table C of 141.66(h).
                                </TNOTE>
                            </GPOTABLE>
                            <CITA>[65 FR 76748, Dec. 7, 2000]</CITA>
                        </SECTION>
                    </SUBPART>
                    <SUBPART>
                        <HD SOURCE="HED">Subpart H—Filtration and Disinfection</HD>
                        <SOURCE>
                            <HD SOURCE="HED">Source:</HD>
                            <P>54 FR 27527, June 29, 1989, unless otherwise noted.</P>
                        </SOURCE>
                        <SECTION>
                            <SECTNO>§ 141.70</SECTNO>
                            <SUBJECT>General requirements.</SUBJECT>
                            <P>
                                (a) The requirements of this subpart H constitute national primary drinking water regulations. These regulations establish criteria under which filtration is required as a treatment technique for public water systems supplied by a surface water source and public water systems supplied by a ground water source under the direct influence of surface water. In addition, these regulations establish treatment technique requirements in lieu of maximum contaminant levels for the following contaminants: 
                                <E T="03">Giardia lamblia,</E>
                                 viruses, heterotrophic plate count bacteria, 
                                <E T="03">Legionella,</E>
                                 and turbidity. Each public water system with a surface water source or a ground water source under the direct influence of surface water must provide treatment of that source water that complies with these treatment technique requirements. The treatment technique requirements consist of installing and properly operating water treatment processes which reliably achieve:
                            </P>
                            <P>
                                (1) At least 99.9 percent (3-log) removal and/or inactivation of 
                                <E T="03">Giardia lamblia</E>
                                 cysts between a point where the raw water is not subject to recontamination by surface water runoff and a point downstream before or at the first customer; and
                            </P>
                            <P>(2) At least 99.99 percent (4-log) removal and/or inactivation of viruses between a point where the raw water is not subject to recontamination by surface water runoff and a point downstream before or at the first customer.</P>
                            <P>(b) A public water system using a surface water source or a ground water source under the direct influence of surface water is considered to be in compliance with the requirements of paragraph (a) of this section if:</P>
                            <P>(1) It meets the requirements for avoiding filtration in § 141.71 and the disinfection requirements in § 141.72(a); or</P>
                            <P>(2) It meets the filtration requirements in § 141.73 and the disinfection requirements in § 141.72(b).</P>
                            <P>
                                (c) Each public water system using a surface water source or a ground water source under the direct influence of 
                                <PRTPAGE P="586"/>
                                surface water must be operated by qualified personnel who meet the requirements specified by the State.
                            </P>
                            <P>
                                (d) 
                                <E T="03">Additional requirements for systems serving at least 10,000 people.</E>
                                 In addition to complying with requirements in this subpart, systems serving at least 10,000 people must also comply with the requirements in subpart P of this part.
                            </P>
                            <P>
                                (e) 
                                <E T="03">Additional requirements for systems serving fewer than 10,000 people.</E>
                                 In addition to complying with requirements in this subpart, systems serving fewer than 10,000 people must also comply with the requirements in subpart T of this part.
                            </P>
                            <CITA>[54 FR 27527, June 29, 1989, as amended at 63 FR 69516, Dec. 16, 1998; 67 FR 1836, Jan. 14, 2002]</CITA>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 141.71</SECTNO>
                            <SUBJECT>Criteria for avoiding filtration.</SUBJECT>
                            <P>A public water system that uses a surface water source must meet all of the conditions of paragraphs (a) and (b) of this section, and is subject to paragraph (c) of this section, beginning December 30, 1991, unless the State has determined, in writing pursuant to § 1412(b)(7)(C)(iii), that filtration is required. A public water system that uses a ground water source under the direct influence of surface water must meet all of the conditions of paragraphs (a) and (b) of this section and is subject to paragraph (c) of this section, beginning 18 months after the State determines that it is under the direct influence of surface water, or December 30, 1991, whichever is later, unless the State has determined, in writing pursuant to § 1412(b)(7)(C)(iii), that filtration is required. If the State determines in writing pursuant to § 1412(b)(7)(C)(iii) before December 30, 1991, that filtration is required, the system must have installed filtration and meet the criteria for filtered systems specified in §§ 141.72(b) and 141.73 by June 29, 1993. Within 18 months of the failure of a system using surface water or a ground water source under the direct influence of surface water to meet any one of the requirements of paragraphs (a) and (b) of this section or after June 29, 1993, whichever is later, the system must have installed filtration and meet the criteria for filtered systems specified in §§ 141.72(b) and 141.73.</P>
                            <P>
                                (a) 
                                <E T="03">Source water quality conditions.</E>
                                 (1) The fecal coliform concentration must be equal to or less than 20/100 ml, or the total coliform concentration must be equal to or less than 100/100 ml (measured as specified in § 141.74 (a) (1) and (2) and (b)(1)), in representative samples of the source water immediately prior to the first or only point of disinfectant application in at least 90 percent of the measurements made for the 6 previous months that the system served water to the public on an ongoing basis. If a system measures both fecal and total coliforms, the fecal coliform criterion, but not the total coliform criterion, in this paragraph must be met.
                            </P>
                            <P>(2) The turbidity level cannot exceed 5 NTU (measured as specified in § 141.74 (a)(1) and (b)(2)) in representative samples of the source water immediately prior to the first or only point of disinfectant application unless: (i) the State determines that any such event was caused by circumstances that were unusual and unpredictable; and (ii) as a result of any such event, there have not been more than two events in the past 12 months the system served water to the public, or more than five events in the past 120 months the system served water to the public, in which the turbidity level exceeded 5 NTU. An “event” is a series of consecutive days during which at least one turbidity measurement each day exceeds 5 NTU.</P>
                            <P>
                                (b) 
                                <E T="03">Site-specific conditions.</E>
                                 (1)(i) The public water system must meet the requirements of § 141.72(a)(1) at least 11 of the 12 previous months that the system served water to the public, on an ongoing basis, unless the system fails to meet the requirements during 2 of the 12 previous months that the system served water to the public, and the State determines that at least one of these failures was caused by circumstances that were unusual and unpredictable.
                            </P>
                            <P>(ii) The public water system must meet the requirements of § 141.72(a)(2) at all times the system serves water to the public.</P>
                            <P>
                                (iii) The public water system must meet the requirements of § 141.72(a)(3) at all times the system serves water to the public unless the State determines 
                                <PRTPAGE P="587"/>
                                that any such failure was caused by circumstances that were unusual and unpredictable.
                            </P>
                            <P>(iv) The public water system must meet the requirements of § 141.72(a)(4) on an ongoing basis unless the State determines that failure to meet these requirements was not caused by a deficiency in treatment of the source water.</P>
                            <P>
                                (2) The public water system must maintain a watershed control program which minimizes the potential for contamination by 
                                <E T="03">Giardia lamblia</E>
                                 cysts and viruses in the source water. The State must determine whether the watershed control program is adequate to meet this goal. The adequacy of a program to limit potential contamination by 
                                <E T="03">Giardia lamblia</E>
                                 cysts and viruses must be based on: the comprehensiveness of the watershed review; the effectiveness of the system's program to monitor and control detrimental activities occurring in the watershed; and the extent to which the water system has maximized land ownership and/or controlled land use within the watershed. At a minimum, the watershed control program must:
                            </P>
                            <P>(i) Characterize the watershed hydrology and land ownership;</P>
                            <P>(ii) Identify watershed characteristics and activities which may have an adverse effect on source water quality; and</P>
                            <P>(iii) Monitor the occurrence of activities which may have an adverse effect on source water quality.</P>
                            <FP>The public water system must demonstrate through ownership and/or written agreements with landowners within the watershed that it can control all human activities which may have an adverse impact on the microbiological quality of the source water. The public water system must submit an annual report to the State that identifies any special concerns about the watershed and how they are being handled; describes activities in the watershed that affect water quality; and projects what adverse activities are expected to occur in the future and describes how the public water system expects to address them. For systems using a ground water source under the direct influence of surface water, an approved wellhead protection program developed under section 1428 of the Safe Drinking Water Act may be used, if the State deems it appropriate, to meet these requirements.</FP>
                            <P>(3) The public water system must be subject to an annual on-site inspection to assess the watershed control program and disinfection treatment process. Either the State or a party approved by the State must conduct the on-site inspection. The inspection must be conducted by competent individuals such as sanitary and civil engineers, sanitarians, or technicians who have experience and knowledge about the operation and maintenance of a public water system, and who have a sound understanding of public health principles and waterborne diseases. A report of the on-site inspection summarizing all findings must be prepared every year. The on-site inspection must indicate to the State's satisfaction that the watershed control program and disinfection treatment process are adequately designed and maintained. The on-site inspection must include:</P>
                            <P>(i) A review of the effectiveness of the watershed control program;</P>
                            <P>(ii) A review of the physical condition of the source intake and how well it is protected;</P>
                            <P>(iii) A review of the system's equipment maintenance program to ensure there is low probability for failure of the disinfection process;</P>
                            <P>(iv) An inspection of the disinfection equipment for physical deterioration;</P>
                            <P>(v) A review of operating procedures;</P>
                            <P>(vi) A review of data records to ensure that all required tests are being conducted and recorded and disinfection is effectively practiced; and</P>
                            <P>(vii) Identification of any improvements which are needed in the equipment, system maintenance and operation, or data collection.</P>
                            <P>(4) The public water system must not have been identified as a source of a waterborne disease outbreak, or if it has been so identified, the system must have been modified sufficiently to prevent another such occurrence, as determined by the State.</P>
                            <P>
                                (5) The public water system must comply with the maximum contaminant level (MCL) for total coliforms in § 141.63(a) and (b) and the MCL for 
                                <E T="03">
                                    E. 
                                    <PRTPAGE P="588"/>
                                    coli
                                </E>
                                 in § 141.63(c) at least 11 months of the 12 previous months that the system served water to the public, on an ongoing basis, unless the State determines that failure to meet this requirement was not caused by a deficiency in treatment of the source water.
                            </P>
                            <P>(6) The public water system must comply with the requirements for trihalomethanes in §§ 141.12 and 141.30 until December 31, 2001. After December 31, 2001, the system must comply with the requirements for total trihalomethanes, haloacetic acids (five), bromate, chlorite, chlorine, chloramines, and chlorine dioxide in subpart L of this part.</P>
                            <P>
                                (c) 
                                <E T="03">Treatment technique violations.</E>
                                 (1) A system that (i) fails to meet any one of the criteria in paragraphs (a) and (b) of this section and/or which the State has determined that filtration is required, in writing pursuant to § 1412(b)(7)(C)(iii), and (ii) fails to install filtration by the date specified in the introductory paragraph of this section is in violation of a treatment technique requirement.
                            </P>
                            <P>(2) A system that has not installed filtration is in violation of a treatment technique requirement if:</P>
                            <P>(i) The turbidity level (measured as specified in § 141.74(a)(1) and (b)(2)) in a representative sample of the source water immediately prior to the first or only point of disinfection application exceeds 5 NTU; or</P>
                            <P>(ii) The system is identified as a source of a waterborne disease outbreak.</P>
                            <CITA>[54 FR 27527, June 29, 1989, as amended at 63 FR 69516, Dec. 16, 1998; 66 FR 3776, Jan. 16, 2001; 69 FR 38855, June 29, 2004; 78 FR 10347, Feb. 13, 2013]</CITA>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 141.72</SECTNO>
                            <SUBJECT>Disinfection.</SUBJECT>
                            <P>A public water system that uses a surface water source and does not provide filtration treatment must provide the disinfection treatment specified in paragraph (a) of this section beginning December 30, 1991, unless the State determines that filtration is required in writing pursuant to § 1412 (b)(7)(C)(iii). A public water system that uses a ground water source under the direct influence of surface water and does not provide filtration treatment must provide disinfection treatment specified in paragraph (a) of this section beginning December 30, 1991, or 18 months after the State determines that the ground water source is under the influence of surface water, whichever is later, unless the State has determined that filtration is required in writing pursuant to § 1412(b)(7)(C)(iii). If the State has determined that filtration is required, the system must comply with any interim disinfection requirements the State deems necessary before filtration is installed. A system that uses a surface water source that provides filtration treatment must provide the disinfection treatment specified in paragraph (b) of this section beginning June 29, 1993, or beginning when filtration is installed, whichever is later. A system that uses a ground water source under the direct influence of surface water and provides filtration treatment must provide disinfection treatment as specified in paragraph (b) of this section by June 29, 1993, or beginning when filtration is installed, whichever is later. Failure to meet any requirement of this section after the applicable date specified in this introductory paragraph is a treatment technique violation.</P>
                            <P>
                                (a) 
                                <E T="03">Disinfection requirements for public water systems that do not provide filtration.</E>
                                 Each public water system that does not provide filtration treatment must provide disinfection treatment as follows:
                            </P>
                            <P>
                                (1) The disinfection treatment must be sufficient to ensure at least 99.9 percent (3-log) inactivation of 
                                <E T="03">Giardia lamblia</E>
                                 cysts and 99.99 percent (4-log) inactivation of viruses, every day the system serves water to the public, except any one day each month. Each day a system serves water to the public, the public water system must calculate the CT value(s) from the system's treatment parameters, using the procedure specified in § 141.74(b)(3), and determine whether this value(s) is sufficient to achieve the specified inactivation rates for 
                                <E T="03">Giardia lamblia</E>
                                 cysts and viruses. If a system uses a disinfectant other than chlorine, the system may demonstrate to the State, through the use of a State-approved protocol for on-site disinfection challenge studies or other information satisfactory to the State, that CT
                                <E T="52">99.9</E>
                                 values other than 
                                <PRTPAGE P="589"/>
                                those specified in tables 2.1 and 3.1 in § 141.74(b)(3) or other operational parameters are adequate to demonstrate that the system is achieving minimum inactivation rates required by paragraph (a)(1) of this section.
                            </P>
                            <P>(2) The disinfection system must have either (i) redundant components, including an auxiliary power supply with automatic start-up and alarm to ensure that disinfectant application is maintained continuously while water is being delivered to the distribution system, or (ii) automatic shut-off of delivery of water to the distribution system whenever there is less than 0.2 mg/l of residual disinfectant concentration in the water. If the State determines that automatic shut-off would cause unreasonable risk to health or interfere with fire protection, the system must comply with paragraph (a)(2)(i) of this section.</P>
                            <P>(3) The residual disinfectant concentration in the water entering the distribution system, measured as specified in § 141.74 (a)(2) and (b)(5), cannot be less than 0.2 mg/l for more than 4 hours.</P>
                            <P>(4)(i) The residual disinfectant concentration in the distribution system, measured as total chlorine, combined chlorine, or chlorine dioxide, as specified in § 141.74 (a)(2) and (b)(6), cannot be undetectable in more than 5 percent of the samples each month, for any two consecutive months that the system serves water to the public. Water in the distribution system with a heterotrophic bacteria concentration less than or equal to 500/ml, measured as heterotrophic plate count (HPC) as specified in § 141.74(a)(1), is deemed to have a detectable disinfectant residual for purposes of determining compliance with this requirement. Thus, the value “V” in the following formula cannot exceed 5 percent in one month, for any two consecutive months.</P>
                            <MATH SPAN="1" DEEP="24">
                                <MID>EC15NO91.131</MID>
                            </MATH>
                            <EXTRACT>
                                <FP>where:</FP>
                                <FP SOURCE="FP-2">a = number of instances where the residual disinfectant concentration is measured;</FP>
                                <FP SOURCE="FP-2">b = number of instances where the residual disinfectant concentration is not measured but heterotrophic bacteria plate count (HPC) is measured;</FP>
                                <FP SOURCE="FP-2">c = number of instances where the residual disinfectant concentration is measured but not detected and no HPC is measured;</FP>
                                <FP SOURCE="FP-2">d = number of instances where the residual disinfectant concentration is measured but not detected and where the HPC is &gt;500/ml; and</FP>
                                <FP SOURCE="FP-2">e = number of instances where the residual disinfectant concentration is not measured and HPC is &gt;500/ml.</FP>
                            </EXTRACT>
                            <P>(ii) If the State determines, based on site-specific considerations, that a system has no means for having a sample transported and analyzed for HPC by a certified laboratory under the requisite time and temperature conditions specified by § 141.74(a)(1) and that the system is providing adequate disinfection in the distribution system, the requirements of paragraph (a)(4)(i) of this section do not apply to that system.</P>
                            <P>
                                (b) 
                                <E T="03">Disinfection requirements for public water systems which provide filtration.</E>
                                 Each public water system that provides filtration treatment must provide disinfection treatment as follows.
                            </P>
                            <P>
                                (1) The disinfection treatment must be sufficient to ensure that the total treatment processes of that system achieve at least 99.9 percent (3-log) inactivation and/or removal of 
                                <E T="03">Giardia lamblia</E>
                                 cysts and at least 99.99 percent (4-log) inactivation and/or removal of viruses, as determined by the State.
                            </P>
                            <P>(2) The residual disinfectant concentration in the water entering the distribution system, measured as specified in § 141.74 (a)(2) and (c)(2), cannot be less than 0.2 mg/l for more than 4 hours.</P>
                            <P>
                                (3)(i) The residual disinfectant concentration in the distribution system, measured as total chlorine, combined chlorine, or chlorine dioxide, as specified in § 141.74 (a)(2) and (c)(3), cannot be undetectable in more than 5 percent of the samples each month, for any two consecutive months that the system serves water to the public. Water in the distribution system with a heterotrophic bacteria concentration less than or equal to 500/ml, measured as heterotrophic plate count (HPC) as specified in § 141.74(a)(1), is deemed to have a detectable disinfectant residual for purposes of determining compliance with this requirement. Thus, the value “V” in the following formula cannot 
                                <PRTPAGE P="590"/>
                                exceed 5 percent in one month, for any two consecutive months.
                            </P>
                            <MATH SPAN="1" DEEP="24">
                                <MID>EC15NO91.132</MID>
                            </MATH>
                            <EXTRACT>
                                <FP>where:</FP>
                                <FP SOURCE="FP-2">a = number of instances where the residual disinfectant concentration is measured;</FP>
                                <FP SOURCE="FP-2">b = number of instances where the residual disinfectant concentration is not measured but heterotrophic bacteria plate count (HPC) is measured;</FP>
                                <FP SOURCE="FP-2">c = number of instances where the residual disinfectant concentration is measured but not detected and no HPC is measured;</FP>
                                <FP SOURCE="FP-2">d = number of instances where no residual disinfectant concentration is detected and where the HPC is &gt;500/ml; and</FP>
                                <FP SOURCE="FP-2">e = number of instances where the residual disinfectant concentration is not measured and HPC is &gt;500/ml.</FP>
                            </EXTRACT>
                            <P>(ii) If the State determines, based on site-specific considerations, that a system has no means for having a sample transported and analyzed for HPC by a certified laboratory under the requisite time and temperature conditions specified in § 141.74(a)(1) and that the system is providing adequate disinfection in the distribution system, the requirements of paragraph (b)(3)(i) of this section do not apply.</P>
                            <CITA>[54 FR 27527, June 29, 1989, as amended at 69 FR 38855, June 29, 2004]</CITA>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 141.73</SECTNO>
                            <SUBJECT>Filtration.</SUBJECT>
                            <P>A public water system that uses a surface water source or a ground water source under the direct influence of surface water, and does not meet all of the criteria in § 141.71 (a) and (b) for avoiding filtration, must provide treatment consisting of both disinfection, as specified in § 141.72(b), and filtration treatment which complies with the requirements of paragraph (a), (b), (c), (d), or (e) of this section by June 29, 1993, or within 18 months of the failure to meet any one of the criteria for avoiding filtration in § 141.71 (a) and (b), whichever is later. Failure to meet any requirement of this section after the date specified in this introductory paragraph is a treatment technique violation.</P>
                            <P>
                                (a) 
                                <E T="03">Conventional filtration treatment or direct filtration.</E>
                                 (1) For systems using conventional filtration or direct filtration, the turbidity level of representative samples of a system's filtered water must be less than or equal to 0.5 NTU in at least 95 percent of the measurements taken each month, measured as specified in § 141.74 (a)(1) and (c)(1), except that if the State determines that the system is capable of achieving at least 99.9 percent removal and/or inactivation of 
                                <E T="03">Giardia lamblia</E>
                                 cysts at some turbidity level higher than 0.5 NTU in at least 95 percent of the measurements taken each month, the State may substitute this higher turbidity limit for that system. However, in no case may the State approve a turbidity limit that allows more than 1 NTU in more than 5 percent of the samples taken each month, measured as specified in § 141.74 (a)(1) and (c)(1).
                            </P>
                            <P>(2) The turbidity level of representative samples of a system's filtered water must at no time exceed 5 NTU, measured as specified in § 141.74 (a)(1) and (c)(1).</P>
                            <P>(3) Beginning January 1, 2002, systems serving at least 10,000 people must meet the turbidity requirements in § 141.173(a).</P>
                            <P>(4) Beginning January 1, 2005, systems serving fewer than 10,000 people must meet the turbidity requirements in §§ 141.550 through 141.553.</P>
                            <P>
                                (b) 
                                <E T="03">Slow sand filtration.</E>
                                 (1) For systems using slow sand filtration, the turbidity level of representative samples of a system's filtered water must be less than or equal to 1 NTU in at least 95 percent of the measurements taken each month, measured as specified in § 141.74 (a)(1) and (c)(1), except that if the State determines there is no significant interference with disinfection at a higher turbidity level, the State may substitute this higher turbidity limit for that system.
                            </P>
                            <P>(2) The turbidity level of representative samples of a system's filtered water must at no time exceed 5 NTU, measured as specified in § 141.74 (a)(1) and (c)(1).</P>
                            <P>
                                (c) 
                                <E T="03">Diatomaceous earth filtration.</E>
                                 (1) For systems using diatomaceous earth filtration, the turbidity level of representative samples of a system's filtered water must be less than or equal to 1 NTU in at least 95 percent of the measurements taken each month, 
                                <PRTPAGE P="591"/>
                                measured as specified in § 141.74 (a)(1) and (c)(1).
                            </P>
                            <P>(2) The turbidity level of representative samples of a system's filtered water must at no time exceed 5 NTU, measured as specified in § 141.74 (a)(1) and (c)(1).</P>
                            <P>
                                (d) 
                                <E T="03">Other filtration technologies.</E>
                                 A public water system may use a filtration technology not listed in paragraphs (a) through (c) of this section if it demonstrates to the State, using pilot plant studies or other means, that the alternative filtration technology, in combination with disinfection treatment that meets the requirements of § 141.72(b), consistently achieves 99.9 percent removal and/or inactivation of 
                                <E T="03">Giardia lamblia</E>
                                 cysts and 99.99 percent removal and/or inactivation of viruses. For a system that makes this demonstration, the requirements of paragraph (b) of this section apply. Beginning January 1, 2002, systems serving at least 10,000 people must meet the requirements for other filtration technologies in § 141.173(b). Beginning January 14, 2005, systems serving fewer than 10,000 people must meet the requirements for other filtration technologies in § 141.550 through 141.553.
                            </P>
                            <CITA>[54 FR 27527, June 29, 1989, as amended at 63 FR 69516, Dec. 16, 1998; 66 FR 3776, Jan. 16, 2001; 67 FR 1836, Jan. 14, 2002; 69 FR 38855, June 29, 2004]</CITA>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 141.74</SECTNO>
                            <SUBJECT>Analytical and monitoring requirements.</SUBJECT>
                            <P>
                                (a) 
                                <E T="03">Analytical requirements.</E>
                                 Only the analytical method(s) specified in this paragraph, or otherwise approved by EPA, may be used to demonstrate compliance with §§ 141.71, 141.72 and 141.73. Measurements for pH, turbidity, temperature and residual disinfectant concentrations must be conducted by a person approved by the State. Measurement for total coliforms, fecal coliforms and HPC must be conducted by a laboratory certified by the State or EPA to do such analysis. Until laboratory certification criteria are developed for the analysis of fecal coliforms and HPC, any laboratory certified for total coliforms analysis by the State or EPA is deemed certified for fecal coliforms and HPC analysis. The following procedures shall be conducted in accordance with the publications listed in the following section. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies of the methods published in 
                                <E T="03">Standard Methods for the Examination of Water and Wastewater</E>
                                 may be obtained from the American Public Health Association et al., 1015 Fifteenth Street, NW., Washington, DC 20005; copies of the Minimal Medium ONPG-MUG Method as set forth in the article “National Field Evaluation of a Defined Substrate Method for the Simultaneous Enumeration of Total Coliforms and 
                                <E T="03">Esherichia coli</E>
                                 from Drinking Water: Comparison with the Standard Multiple Tube Fermentation Method” (Edberg et al.), Applied and Environmental Microbiology, Volume 54, pp. 1595-1601, June 1988 (as amended under Erratum, Applied and Environmental Microbiology, Volume 54, p. 3197, December, 1988), may be obtained from the American Water Works Association Research Foundation, 6666 West Quincy Avenue, Denver, Colorado, 80235; and copies of the Indigo Method as set forth in the article “Determination of Ozone in Water by the Indigo Method” (Bader and Hoigne), may be obtained from Ozone Science &amp; Engineering, Pergamon Press Ltd., Fairview Park, Elmsford, New York 10523. Copies may be inspected at the U.S. Environmental Protection Agency, Room EB15, 401 M St., SW., Washington, DC 20460 or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: 
                                <E T="03">http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.</E>
                            </P>
                            <P>
                                (1) Public water systems must conduct analysis of pH and temperature in accordance with one of the methods listed at § 141.23(k)(1). Public water systems must conduct analysis of total coliforms, fecal coliforms, heterotrophic bacteria, and turbidity in accordance with one of the following analytical methods or one of the alternative methods listed in appendix A to subpart C of this part and by using analytical test procedures contained in 
                                <E T="03">Technical Notes on Drinking Water Methods,</E>
                                 EPA-600/R-94-173, October 1994. This document is available from the 
                                <PRTPAGE P="592"/>
                                National Service Center for Environmental Publications (NSCEP), P.O. Box 42419, Cincinnati, OH 45242-0419 or 
                                <E T="03">http://www.epa.gov/nscep/.</E>
                            </P>
                            <GPOTABLE COLS="3" OPTS="L2" CDEF="s50,r50,xs50">
                                <BOXHD>
                                    <CHED H="1">Organism</CHED>
                                    <CHED H="1">Methodology</CHED>
                                    <CHED H="1">
                                        Citation 
                                        <SU>1</SU>
                                    </CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">
                                        Total Coliform 
                                        <SU>2</SU>
                                    </ENT>
                                    <ENT>
                                        Total Coliform Fermentation Technique 
                                        <SU>3 4 5</SU>
                                    </ENT>
                                    <ENT>9221 A, B, C</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>
                                        Total Coliform Membrane Filter Technique 
                                        <SU>6</SU>
                                    </ENT>
                                    <ENT>9222 A, B, C</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>
                                        ONPG-MUG Test 
                                        <SU>7</SU>
                                    </ENT>
                                    <ENT>9223</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">
                                        Fecal Coliforms 
                                        <SU>2</SU>
                                    </ENT>
                                    <ENT>
                                        Fecal Coliform Procedure 
                                        <SU>8</SU>
                                    </ENT>
                                    <ENT>9221 E</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Fecal Coliform Filter Procedure</ENT>
                                    <ENT>9222 D</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">
                                        Heterotrophic bacteria 
                                        <SU>2</SU>
                                    </ENT>
                                    <ENT>Pour Plate Method</ENT>
                                    <ENT>9215 B</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>
                                        SimPlate 
                                        <SU>11</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">
                                        Turbidity 
                                        <SU>13</SU>
                                    </ENT>
                                    <ENT>Nephelometric Method</ENT>
                                    <ENT>2130 B</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Nephelometric Method</ENT>
                                    <ENT>
                                        180.1 
                                        <SU>9</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Great Lakes Instruments</ENT>
                                    <ENT>
                                        Method 2 
                                        <SU>10</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Hach FilterTrak</ENT>
                                    <ENT>
                                        10133 
                                        <SU>12</SU>
                                    </ENT>
                                </ROW>
                                <TNOTE>
                                    The procedures shall be done in accordance with the documents listed below. The incorporation by reference of the following documents listed in footnotes 1, 6, 7 and 9-12 was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies of the documents may be obtained from the sources listed below. Information regarding obtaining these documents can be obtained from the Safe Drinking Water Hotline at 800-426-4791. Documents may be inspected at EPA's Drinking Water Docket, 1301 Constitution Avenue, NW., EPA West, Room B102, Washington DC 20460 (Telephone: 202-566-2426); or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: 
                                    <E T="03">http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.</E>
                                </TNOTE>
                                <TNOTE>
                                    <SU>1</SU>
                                     Except where noted, all methods refer to 
                                    <E T="03">Standard Methods for the Examination of Water and Wastewater,</E>
                                     18th edition (1992), 19th edition (1995), or 20th edition (1998), American Public Health Association, 1015 Fifteenth Street, NW., Washington, DC 20005. The cited methods published in any of these three editions may be used. In addition, the following online versions may also be used: 2130 B-01, 9215 B-00, 9221 A, B, C, E-99, 9222 A, B, C, D-97, and 9223 B-97. Standard Methods Online are available at 
                                    <E T="03">http://www.standardmethods.org.</E>
                                     The year in which each method was approved by the Standard Methods Committee is designated by the last two digits in the method number. The methods listed are the only Online versions that may be used.
                                </TNOTE>
                                <TNOTE>
                                    <SU>2</SU>
                                     The time from sample collection to initiation of analysis may not exceed 8 hours. Systems must hold samples below 10 deg. C during transit.
                                </TNOTE>
                                <TNOTE>
                                    <SU>3</SU>
                                     Lactose broth, as commercially available, may be used in lieu of lauryl tryptose broth, if the system conducts at least 25 parallel tests between this medium and lauryl tryptose broth using the water normally tested, and this comparison demonstrates that the false-positive rate and false-negative rate for total coliform, using lactose broth, is less than 10 percent.
                                </TNOTE>
                                <TNOTE>
                                    <SU>4</SU>
                                     Media should cover inverted tubes at least one-half to two-thirds after the sample is added.
                                </TNOTE>
                                <TNOTE>
                                    <SU>5</SU>
                                     No requirement exists to run the completed phase on 10 percent of all total coliform-positive confirmed tubes.
                                </TNOTE>
                                <TNOTE>
                                    <SU>6</SU>
                                     MI agar also may be used. Preparation and use of MI agar is set forth in the article, “New medium for the simultaneous detection of total coliform and 
                                    <E T="03">Escherichia coli</E>
                                     in water” by Brenner, K.P., et. al., 1993, Appl. Environ. Microbiol. 59:3534-3544. Also available from the Office of Water Resource Center (RC-4100T), 1200 Pennsylvania Avenue, NW., Washington DC 20460, EPA/600/J-99/225. Verification of colonies is not required.
                                </TNOTE>
                                <TNOTE>
                                    <SU>7</SU>
                                     The ONPG-MUG Test is also known as the Autoanalysis Colilert System.
                                </TNOTE>
                                <TNOTE>
                                    <SU>8</SU>
                                     A-1 broth may be held up to 7 days in a tightly closed screw cap tube at 4 °C.
                                </TNOTE>
                                <TNOTE>
                                    <SU>9</SU>
                                     “Methods for the Determination of Inorganic Substances in Environmental Samples”, EPA/600/R-93/100, August 1993. Available at NTIS, PB94-121811.
                                </TNOTE>
                                <TNOTE>
                                    <SU>10</SU>
                                     GLI Method 2, “Turbidity,” November 2, 1992, Great Lakes Instruments, Inc., 8855 North 55th Street, Milwaukee, WI 53223.
                                </TNOTE>
                                <TNOTE>
                                    <SU>11</SU>
                                     A description of the SimPlate method, “IDEXX SimPlate TM HPC Test Method for Heterotrophs in Water,” November 2000, can be obtained from IDEXX Laboratories, Inc., 1 IDEXX Drive, Westbrook, ME 04092, telephone (800) 321-0207.
                                </TNOTE>
                                <TNOTE>
                                    <SU>12</SU>
                                     A description of the Hach FilterTrak Method 10133, “Determination of Turbidity by Laser Nephelometry,” January 2000, Revision 2.0, can be obtained from; Hach Co., P.O. Box 389, Loveland, CO 80539-0389, telephone: 800-227-4224.
                                </TNOTE>
                                <TNOTE>
                                    <SU>13</SU>
                                     Styrene divinyl benzene beads (e.g., AMCO-AEPA-1 or equivalent) and stabilized formazin (e.g., Hach StablCal 
                                    <SU>TM</SU>
                                     or equivalent) are acceptable substitutes for formazin.
                                </TNOTE>
                            </GPOTABLE>
                            <P>
                                (2) Public water systems must measure residual disinfectant concentrations with one of the analytical methods in the following table or one of the alternative methods listed in appendix A to subpart C of this part. If approved by the State, residual disinfectant concentrations for free chlorine and combined chlorine also may be measured by using DPD colorimetric test kits. In addition States may approve the use of the ITS free chlorine test strip for the determination of free chlorine. Use of the test strips is described in Method D99-003, “Free Chlorine Species (HOCl
                                <E T="51">−</E>
                                 and OCl
                                <E T="51">−</E>
                                ) by Test Strip,” Revision 3.0, November 21, 2003, available from Industrial Test Systems, Inc., 1875 Langston St., Rock Hill, SC 29730. Free and total chlorine residuals may be measured continuously by adapting a specified chlorine residual method for use with a continuous monitoring instrument provided the chemistry, accuracy, and precision remain the same. Instruments used for continuous monitoring must be calibrated with a grab sample measurement at least every five days, or with a protocol approved by the State.
                            </P>
                            <GPOTABLE COLS="5" OPTS="L2" CDEF="s35,r90,r30,r32,xs48">
                                <BOXHD>
                                    <CHED H="1">Residual</CHED>
                                    <CHED H="1">Methodology</CHED>
                                    <CHED H="1">
                                        SM 
                                        <SU>1</SU>
                                    </CHED>
                                    <CHED H="1">
                                        SM Online 
                                        <SU>2</SU>
                                    </CHED>
                                    <CHED H="1">Other</CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">Free Chlorine</ENT>
                                    <ENT>Amperometric Titration</ENT>
                                    <ENT>4500-Cl D</ENT>
                                    <ENT>4500-Cl D-00</ENT>
                                    <ENT>
                                        D1253-03 
                                        <SU>3</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>DPD Ferrous Titrimetric</ENT>
                                    <ENT>4500-Cl F</ENT>
                                    <ENT>4500-Cl F-00</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>DPD Colorimetric</ENT>
                                    <ENT>4500-Cl G</ENT>
                                    <ENT>4500-Cl G-00</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Syringaldazine (FACTS)</ENT>
                                    <ENT>4500-Cl H</ENT>
                                    <ENT>4500-Cl H-00</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Total Chlorine</ENT>
                                    <ENT>Amperometric Titration</ENT>
                                    <ENT>4500-Cl D</ENT>
                                    <ENT>4500-Cl D-00</ENT>
                                    <ENT>
                                        D1253-03 
                                        <SU>3</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Amperometric Titration (low level measurement)</ENT>
                                    <ENT>4500-Cl E</ENT>
                                    <ENT>4500-Cl E-00</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>DPD Ferrous Titrimetric</ENT>
                                    <ENT>4500-Cl F</ENT>
                                    <ENT>4500-Cl F-00</ENT>
                                </ROW>
                                <ROW>
                                    <PRTPAGE P="593"/>
                                    <ENT I="22"> </ENT>
                                    <ENT>DPD Colorimetric</ENT>
                                    <ENT>4500-Cl G</ENT>
                                    <ENT>4500-Cl G-00</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Iodometric Electrode</ENT>
                                    <ENT>4500-Cl I</ENT>
                                    <ENT>4500-Cl I-00</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Chlorine Dioxide</ENT>
                                    <ENT>Amperometric Titration</ENT>
                                    <ENT>
                                        4500-ClO
                                        <E T="52">2</E>
                                         C
                                    </ENT>
                                    <ENT>
                                        4500-ClO
                                        <E T="52">2</E>
                                         C-00
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>DPD Method</ENT>
                                    <ENT>
                                        4500-ClO
                                        <E T="52">2</E>
                                         D
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Amperometric Titration</ENT>
                                    <ENT>
                                        4500-ClO
                                        <E T="52">2</E>
                                         E
                                    </ENT>
                                    <ENT>
                                        4500-ClO
                                        <E T="52">2</E>
                                         E-00
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="22"> </ENT>
                                    <ENT>Spectrophotometric</ENT>
                                    <ENT/>
                                    <ENT/>
                                    <ENT>
                                        327.0, Revision 1.1 
                                        <SU>4</SU>
                                    </ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Ozone</ENT>
                                    <ENT>Indigo Method</ENT>
                                    <ENT>
                                        4500-O
                                        <E T="52">3</E>
                                         B
                                    </ENT>
                                    <ENT>
                                        4500-O
                                        <E T="52">3</E>
                                         B-97
                                    </ENT>
                                </ROW>
                                <TNOTE>
                                    <SU>1</SU>
                                     All the listed methods are contained in the 18th, 19th, and 20th editions of 
                                    <E T="03">Standard Methods for the Examination of Water and Wastewater,</E>
                                     1992, 1995, and 1998; the cited methods published in any of these three editions may be used.
                                </TNOTE>
                                <TNOTE>
                                    <SU>2</SU>
                                     Standard Methods Online are available at 
                                    <E T="03">http://www.standardmethods.org.</E>
                                     The year in which each method was approved by the Standard Methods Committee is designated by the last two digits in the method number. The methods listed are the only Online versions that may be used.
                                </TNOTE>
                                <TNOTE>
                                    <SU>3</SU>
                                     
                                    <E T="03">Annual Book of ASTM Standards,</E>
                                     Vol. 11.01, 2004 ; ASTM International; any year containing the cited version of the method may be used. Copies of this method may be obtained from ASTM International, 100 Barr Harbor Drive, P.O. Box C700 West Conshohocken, PA 19428-2959.
                                </TNOTE>
                                <TNOTE>
                                    <SU>4</SU>
                                     EPA Method 327.0, Revision 1.1, “Determination of Chlorine Dioxide and Chlorite Ion in Drinking Water Using Lissamine Green B and Horseradish Peroxidase with Detection by Visible Spectrophotometry,” USEPA, May 2005, EPA 815-R-05-008. Available online at 
                                    <E T="03">http://www.epa.gov/safewater/methods/sourcalt.html.</E>
                                </TNOTE>
                            </GPOTABLE>
                            <P>
                                (b) 
                                <E T="03">Monitoring requirements for systems that do not provide filtration.</E>
                                 A public water system that uses a surface water source and does not provide filtration treatment must begin monitoring, as specified in this paragraph (b), beginning December 31, 1990, unless the State has determined that filtration is required in writing pursuant to § 1412(b)(7)(C)(iii), in which case the State may specify alternative monitoring requirements, as appropriate, until filtration is in place. A public water system that uses a ground water source under the direct influence of surface water and does not provide filtration treatment must begin monitoring as specified in this paragraph (b) beginning December 31, 1990, or 6 months after the State determines that the ground water source is under the direct influence of surface water, whichever is later, unless the State has determined that filtration is required in writing pursuant to § 1412(b)(7)(C)(iii), in which case the State may specify alternative monitoring requirements, as appropriate, until filtration is in place.
                            </P>
                            <P>(1) Fecal coliform or total coliform density measurements as required by § 141.71(a)(1) must be performed on representative source water samples immediately prior to the first or only point of disinfectant application. The system must sample for fecal or total coliforms at the following minimum frequency each week the system serves water to the public:</P>
                            <GPOTABLE COLS="2" OPTS="L2" CDEF="s25,8">
                                <BOXHD>
                                    <CHED H="1">System size (persons served)</CHED>
                                    <CHED H="1">
                                        Samples/week 
                                        <SU>1</SU>
                                    </CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">≤500</ENT>
                                    <ENT>1</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">501 to 3,300</ENT>
                                    <ENT>2</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">3,301 to 10,000</ENT>
                                    <ENT>3</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">10,001 to 25,000</ENT>
                                    <ENT>4</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">&gt;25,000</ENT>
                                    <ENT>5</ENT>
                                </ROW>
                                <TNOTE>
                                    <SU>1</SU>
                                     Must be taken on separate days.
                                </TNOTE>
                            </GPOTABLE>
                            <FP>Also, one fecal or total coliform density measurement must be made every day the system serves water to the public and the turbidity of the source water exceeds 1 NTU (these samples count towards the weekly coliform sampling requirement) unless the State determines that the system, for logistical reasons outside the system's control, cannot have the sample analyzed within 30 hours of collection.</FP>
                            <P>(2) Turbidity measurements as required by § 141.71(a)(2) must be performed on representative grab samples of source water immediately prior to the first or only point of disinfectant application every four hours (or more frequently) that the system serves water to the public. A public water system may substitute continuous turbidity monitoring for grab sample monitoring if it validates the continuous measurement for accuracy on a regular basis using a protocol approved by the State.</P>
                            <P>
                                (3) The total inactivation ratio for each day that the system is in operation must be determined based on the CT
                                <E T="52">99.9</E>
                                 values in tables 1.1-1.6, 2.1, and 3.1 of this section, as appropriate. The parameters necessary to determine the total inactivation ratio must be monitored as follows:
                                <PRTPAGE P="594"/>
                            </P>
                            <P>(i) The temperature of the disinfected water must be measured at least once per day at each residual disinfectant concentration sampling point.</P>
                            <P>(ii) If the system uses chlorine, the pH of the disinfected water must be measured at least once per day at each chlorine residual disinfectant concentration sampling point.</P>
                            <P>(iii) The disinfectant contact time(s) (“T”) must be determined for each day during peak hourly flow.</P>
                            <P>(iv) The residual disinfectant concentration(s) (“C”) of the water before or at the first customer must be measured each day during peak hourly flow.</P>
                            <P>
                                (v) If a system uses a disinfectant other than chlorine, the system may demonstrate to the State, through the use of a State-approved protocol for on-site disinfection challenge studies or other information satisfactory to the State, that CT
                                <E T="52">99.9</E>
                                 values other than those specified in tables 2.1 and 3.1 in this section other operational parameters are adequate to demonstrate that the system is achieving the minimum inactivation rates required by § 141.72(a)(1).
                            </P>
                            <GPOTABLE COLS="8" OPTS="L2" CDEF="s12,5,4,4,4,4,4,5">
                                <TTITLE>
                                    Table 1.1—CT Values (CT
                                    <E T="52">99.9</E>
                                    ) for 99.9 Percent Inactivation of Giardia Lamblia Cysts by Free Chlorine at 0.5 °C or Lower 
                                    <SU>1</SU>
                                </TTITLE>
                                <BOXHD>
                                    <CHED H="1">Residual (mg/l)</CHED>
                                    <CHED H="1">pH</CHED>
                                    <CHED H="2">≤6.0</CHED>
                                    <CHED H="2">6.5</CHED>
                                    <CHED H="2">7.0</CHED>
                                    <CHED H="2">7.5</CHED>
                                    <CHED H="2">8.0</CHED>
                                    <CHED H="2">8.5</CHED>
                                    <CHED H="2">≤9.0</CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">≤0.4</ENT>
                                    <ENT>137</ENT>
                                    <ENT>163</ENT>
                                    <ENT>195</ENT>
                                    <ENT>237</ENT>
                                    <ENT>277</ENT>
                                    <ENT>329</ENT>
                                    <ENT>390</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">0.6</ENT>
                                    <ENT>141</ENT>
                                    <ENT>168</ENT>
                                    <ENT>200</ENT>
                                    <ENT>239</ENT>
                                    <ENT>286</ENT>
                                    <ENT>342</ENT>
                                    <ENT>407</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">0.8</ENT>
                                    <ENT>145</ENT>
                                    <ENT>172</ENT>
                                    <ENT>205</ENT>
                                    <ENT>246</ENT>
                                    <ENT>295</ENT>
                                    <ENT>354</ENT>
                                    <ENT>422</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">1.0</ENT>
                                    <ENT>148</ENT>
                                    <ENT>176</ENT>
                                    <ENT>210</ENT>
                                    <ENT>253</ENT>
                                    <ENT>304</ENT>
                                    <ENT>365</ENT>
                                    <ENT>437</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">1.2</ENT>
                                    <ENT>152</ENT>
                                    <ENT>180</ENT>
                                    <ENT>215</ENT>
                                    <ENT>259</ENT>
                                    <ENT>313</ENT>
                                    <ENT>376</ENT>
                                    <ENT>451</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">1.4</ENT>
                                    <ENT>155</ENT>
                                    <ENT>184</ENT>
                                    <ENT>221</ENT>
                                    <ENT>266</ENT>
                                    <ENT>321</ENT>
                                    <ENT>387</ENT>
                                    <ENT>464</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">1.6</ENT>
                                    <ENT>157</ENT>
                                    <ENT>189</ENT>
                                    <ENT>226</ENT>
                                    <ENT>273</ENT>
                                    <ENT>329</ENT>
                                    <ENT>397</ENT>
                                    <ENT>477</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">1.8</ENT>
                                    <ENT>162</ENT>
                                    <ENT>193</ENT>
                                    <ENT>231</ENT>
                                    <ENT>279</ENT>
                                    <ENT>338</ENT>
                                    <ENT>407</ENT>
                                    <ENT>489</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">2.0</ENT>
                                    <ENT>165</ENT>
                                    <ENT>197</ENT>
                                    <ENT>236</ENT>
                                    <ENT>286</ENT>
                                    <ENT>346</ENT>
                                    <ENT>417</ENT>
                                    <ENT>500</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">2.2</ENT>
                                    <ENT>169</ENT>
                                    <ENT>201</ENT>
                                    <ENT>242</ENT>
                                    <ENT>297</ENT>
                                    <ENT>353</ENT>
                                    <ENT>426</ENT>
                                    <ENT>511</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">2.4</ENT>
                                    <ENT>172</ENT>
                                    <ENT>205</ENT>
                                    <ENT>247</ENT>
                                    <ENT>298</ENT>
                                    <ENT>361</ENT>
                                    <ENT>435</ENT>
                                    <ENT>522</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">2.6</ENT>
                                    <ENT>175</ENT>
                                    <ENT>209</ENT>
                                    <ENT>252</ENT>
                                    <ENT>304</ENT>
                                    <ENT>368</ENT>
                                    <ENT>444</ENT>
                                    <ENT>533</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">2.8</ENT>
                                    <ENT>178</ENT>
                                    <ENT>213</ENT>
                                    <ENT>257</ENT>
                                    <ENT>310</ENT>
                                    <ENT>375</ENT>
                                    <ENT>452</ENT>
                                    <ENT>543</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">3.0</ENT>
                                    <ENT>181</ENT>
                                    <ENT>217</ENT>
                                    <ENT>261</ENT>
                                    <ENT>316</ENT>
                                    <ENT>382</ENT>
                                    <ENT>460</ENT>
                                    <ENT>552</ENT>
                                </ROW>
                                <TNOTE>
                                    <SU>1</SU>
                                     These CT values achieve greater than a 99.99 percent inactivation of viruses. CT values between the indicated pH values may be determined by linear interpolation. CT values between the indicated temperatures of different tables may be determined by linear interpolation. If no interpolation is used, use the CT
                                    <E T="52">99.9</E>
                                     value at the lower temperature and at the higher pH.
                                </TNOTE>
                            </GPOTABLE>
                            <GPOTABLE COLS="8" OPTS="L2" CDEF="s12,5,4,4,4,4,4,5">
                                <TTITLE>
                                    Table 1.2—CT Values (CT 
                                    <E T="52">99.9</E>
                                    ) for 99.9 Percent Inactivation of Giardia Lamblia Cysts by Free Chlorine at 5.0 °C 
                                    <SU>1</SU>
                                </TTITLE>
                                <BOXHD>
                                    <CHED H="1">Free residual (mg/l)</CHED>
                                    <CHED H="1">pH</CHED>
                                    <CHED H="2">≤6.0</CHED>
                                    <CHED H="2">6.5</CHED>
                                    <CHED H="2">7.0</CHED>
                                    <CHED H="2">7.5</CHED>
                                    <CHED H="2">8.0</CHED>
                                    <CHED H="2">8.5</CHED>
                                    <CHED H="2">≤9.0</CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">≤0.4</ENT>
                                    <ENT>97</ENT>
                                    <ENT>117</ENT>
                                    <ENT>139</ENT>
                                    <ENT>166</ENT>
                                    <ENT>198</ENT>
                                    <ENT>236</ENT>
                                    <ENT>279</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="02">0.6</ENT>
                                    <ENT>100</ENT>
                                    <ENT>120</ENT>
                                    <ENT>143</ENT>
                                    <ENT>171</ENT>
                                    <ENT>204</ENT>
                                    <ENT>244</ENT>
                                    <ENT>291</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="02">0.8</ENT>
                                    <ENT>103</ENT>
                                    <ENT>122</ENT>
                                    <ENT>146</ENT>
                                    <ENT>175</ENT>
                                    <ENT>210</ENT>
                                    <ENT>252</ENT>
                                    <ENT>301</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="02">1.0</ENT>
                                    <ENT>105</ENT>
                                    <ENT>125</ENT>
                                    <ENT>149</ENT>
                                    <ENT>179</ENT>
                                    <ENT>216</ENT>
                                    <ENT>260</ENT>
                                    <ENT>312</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="02">1.2</ENT>
                                    <ENT>107</ENT>
                                    <ENT>127</ENT>
                                    <ENT>152</ENT>
                                    <ENT>183</ENT>
                                    <ENT>221</ENT>
                                    <ENT>267</ENT>
                                    <ENT>320</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="02">1.4</ENT>
                                    <ENT>109</ENT>
                                    <ENT>130</ENT>
                                    <ENT>155</ENT>
                                    <ENT>187</ENT>
                                    <ENT>227</ENT>
                                    <ENT>274</ENT>
                                    <ENT>329</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="02">1.6</ENT>
                                    <ENT>111</ENT>
                                    <ENT>132</ENT>
                                    <ENT>158</ENT>
                                    <ENT>192</ENT>
                                    <ENT>232</ENT>
                                    <ENT>281</ENT>
                                    <ENT>337</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="02">1.8</ENT>
                                    <ENT>114</ENT>
                                    <ENT>135</ENT>
                                    <ENT>162</ENT>
                                    <ENT>196</ENT>
                                    <ENT>238</ENT>
                                    <ENT>287</ENT>
                                    <ENT>345</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="02">2.0</ENT>
                                    <ENT>116</ENT>
                                    <ENT>138</ENT>
                                    <ENT>165</ENT>
                                    <ENT>200</ENT>
                                    <ENT>243</ENT>
                                    <ENT>294</ENT>
                                    <ENT>353</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="02">2.2</ENT>
                                    <ENT>118</ENT>
                                    <ENT>140</ENT>
                                    <ENT>169</ENT>
                                    <ENT>204</ENT>
                                    <ENT>248</ENT>
                                    <ENT>300</ENT>
                                    <ENT>361</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="02">2.4</ENT>
                                    <ENT>120</ENT>
                                    <ENT>143</ENT>
                                    <ENT>172</ENT>
                                    <ENT>209</ENT>
                                    <ENT>253</ENT>
                                    <ENT>306</ENT>
                                    <ENT>368</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="02">2.6</ENT>
                                    <ENT>122</ENT>
                                    <ENT>146</ENT>
                                    <ENT>175</ENT>
                                    <ENT>213</ENT>
                                    <ENT>258</ENT>
                                    <ENT>312</ENT>
                                    <ENT>375</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="02">2.8</ENT>
                                    <ENT>124</ENT>
                                    <ENT>148</ENT>
                                    <ENT>178</ENT>
                                    <ENT>217</ENT>
                                    <ENT>263</ENT>
                                    <ENT>318</ENT>
                                    <ENT>382</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="02">3.0</ENT>
                                    <ENT>126</ENT>
                                    <ENT>151</ENT>
                                    <ENT>182</ENT>
                                    <ENT>221</ENT>
                                    <ENT>268</ENT>
                                    <ENT>324</ENT>
                                    <ENT>389</ENT>
                                </ROW>
                                <TNOTE>
                                    <SU>1</SU>
                                     These CT values achieve greater than a 99.99 percent inactivation of viruses. CT values between the indicated pH values may be determined by linear interpolation. CT values between the indicated temperatures of different tables may be determined by linear interpolation. If no interpolation is used, use the CT
                                    <E T="52">99.9</E>
                                     value at the lower temperature, and at the higher pH.
                                </TNOTE>
                            </GPOTABLE>
                            <GPOTABLE COLS="8" OPTS="L2" CDEF="s12,5,4,4,4,4,4,5">
                                <TTITLE>
                                    Table 1.3—CT Values (CT 
                                    <E T="52">99.9</E>
                                    ) for 99.9 Percent Inactivation of Giardia Lamblia Cysts by Free Chlorine at 10.0 °C 
                                    <SU>1</SU>
                                </TTITLE>
                                <BOXHD>
                                    <CHED H="1">Free residual (mg/l)</CHED>
                                    <CHED H="1">pH</CHED>
                                    <CHED H="2">≤6.0</CHED>
                                    <CHED H="2">6.5</CHED>
                                    <CHED H="2">7.0</CHED>
                                    <CHED H="2">7.5</CHED>
                                    <CHED H="2">8.0</CHED>
                                    <CHED H="2">8.5</CHED>
                                    <CHED H="2">≤9.0</CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">≤0.4</ENT>
                                    <ENT>73</ENT>
                                    <ENT>88</ENT>
                                    <ENT>104</ENT>
                                    <ENT>125</ENT>
                                    <ENT>149</ENT>
                                    <ENT>177</ENT>
                                    <ENT>209</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="02">0.6</ENT>
                                    <ENT>75</ENT>
                                    <ENT>90</ENT>
                                    <ENT>107</ENT>
                                    <ENT>128</ENT>
                                    <ENT>153</ENT>
                                    <ENT>183</ENT>
                                    <ENT>218</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="02">0.8</ENT>
                                    <ENT>78</ENT>
                                    <ENT>92</ENT>
                                    <ENT>110</ENT>
                                    <ENT>131</ENT>
                                    <ENT>158</ENT>
                                    <ENT>189</ENT>
                                    <ENT>226</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="02">1.0</ENT>
                                    <ENT>79</ENT>
                                    <ENT>94</ENT>
                                    <ENT>112</ENT>
                                    <ENT>134</ENT>
                                    <ENT>162</ENT>
                                    <ENT>195</ENT>
                                    <ENT>234</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="02">1.2</ENT>
                                    <ENT>80</ENT>
                                    <ENT>95</ENT>
                                    <ENT>114</ENT>
                                    <ENT>137</ENT>
                                    <ENT>166</ENT>
                                    <ENT>200</ENT>
                                    <ENT>240</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="02">1.4</ENT>
                                    <ENT>82</ENT>
                                    <ENT>98</ENT>
                                    <ENT>116</ENT>
                                    <ENT>140</ENT>
                                    <ENT>170</ENT>
                                    <ENT>206</ENT>
                                    <ENT>247</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="02">1.6</ENT>
                                    <ENT>83</ENT>
                                    <ENT>99</ENT>
                                    <ENT>119</ENT>
                                    <ENT>144</ENT>
                                    <ENT>174</ENT>
                                    <ENT>211</ENT>
                                    <ENT>253</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="02">1.8</ENT>
                                    <ENT>86</ENT>
                                    <ENT>101</ENT>
                                    <ENT>122</ENT>
                                    <ENT>147</ENT>
                                    <ENT>179</ENT>
                                    <ENT>215</ENT>
                                    <ENT>259</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="02">2.0</ENT>
                                    <ENT>87</ENT>
                                    <ENT>104</ENT>
                                    <ENT>124</ENT>
                                    <ENT>150</ENT>
                                    <ENT>182</ENT>
                                    <ENT>221</ENT>
                                    <ENT>265</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="02">2.2</ENT>
                                    <ENT>89</ENT>
                                    <ENT>105</ENT>
                                    <ENT>127</ENT>
                                    <ENT>153</ENT>
                                    <ENT>186</ENT>
                                    <ENT>225</ENT>
                                    <ENT>271</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="02">2.4</ENT>
                                    <ENT>90</ENT>
                                    <ENT>107</ENT>
                                    <ENT>129</ENT>
                                    <ENT>157</ENT>
                                    <ENT>190</ENT>
                                    <ENT>230</ENT>
                                    <ENT>276</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="02">2.6</ENT>
                                    <ENT>92</ENT>
                                    <ENT>110</ENT>
                                    <ENT>131</ENT>
                                    <ENT>160</ENT>
                                    <ENT>194</ENT>
                                    <ENT>234</ENT>
                                    <ENT>281</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="02">2.8</ENT>
                                    <ENT>93</ENT>
                                    <ENT>111</ENT>
                                    <ENT>134</ENT>
                                    <ENT>163</ENT>
                                    <ENT>197</ENT>
                                    <ENT>239</ENT>
                                    <ENT>287</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="02">3.0</ENT>
                                    <ENT>95</ENT>
                                    <ENT>113</ENT>
                                    <ENT>137</ENT>
                                    <ENT>166</ENT>
                                    <ENT>201</ENT>
                                    <ENT>243</ENT>
                                    <ENT>292</ENT>
                                </ROW>
                                <TNOTE>
                                    <SU>1</SU>
                                     These CT values achieve greater than a 99.99 percent inactivation of viruses. CT values between the indicated pH values may be determined by linear interpolation. CT values between the indicated temperatures of different tables may be determined by linear interpolation. If no interpolation is used, use the CT
                                    <E T="52">99.9</E>
                                     value at the lower temperature, and at the higher pH.
                                </TNOTE>
                            </GPOTABLE>
                            <GPOTABLE COLS="8" OPTS="L2" CDEF="s12,5,4,4,4,4,4,5">
                                <TTITLE>
                                    Table 1.4—CT Values (CT 
                                    <E T="52">99.9</E>
                                    ) for 99.9 Percent Inactivation of Giardia Lamblia Cysts by Free Chlorine at 15.0 °C 
                                    <SU>1</SU>
                                </TTITLE>
                                <BOXHD>
                                    <CHED H="1">Free residual (mg/l)</CHED>
                                    <CHED H="1">pH</CHED>
                                    <CHED H="2">≤6.0</CHED>
                                    <CHED H="2">6.5</CHED>
                                    <CHED H="2">7.0</CHED>
                                    <CHED H="2">7.5</CHED>
                                    <CHED H="2">8.0</CHED>
                                    <CHED H="2">8.5</CHED>
                                    <CHED H="2">≤9.0</CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">≤0.4</ENT>
                                    <ENT>49</ENT>
                                    <ENT>59</ENT>
                                    <ENT>70</ENT>
                                    <ENT>83</ENT>
                                    <ENT>99</ENT>
                                    <ENT>118</ENT>
                                    <ENT>140</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="02">0.6</ENT>
                                    <ENT>50</ENT>
                                    <ENT>60</ENT>
                                    <ENT>72</ENT>
                                    <ENT>86</ENT>
                                    <ENT>102</ENT>
                                    <ENT>122</ENT>
                                    <ENT>146</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="02">0.8</ENT>
                                    <ENT>52</ENT>
                                    <ENT>61</ENT>
                                    <ENT>73</ENT>
                                    <ENT>88</ENT>
                                    <ENT>105</ENT>
                                    <ENT>126</ENT>
                                    <ENT>151</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="02">1.0</ENT>
                                    <ENT>53</ENT>
                                    <ENT>63</ENT>
                                    <ENT>75</ENT>
                                    <ENT>90</ENT>
                                    <ENT>108</ENT>
                                    <ENT>130</ENT>
                                    <ENT>156</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="02">1.2</ENT>
                                    <ENT>54</ENT>
                                    <ENT>64</ENT>
                                    <ENT>76</ENT>
                                    <ENT>92</ENT>
                                    <ENT>111</ENT>
                                    <ENT>134</ENT>
                                    <ENT>160</ENT>
                                </ROW>
                                <ROW>
                                    <PRTPAGE P="595"/>
                                    <ENT I="02">1.4</ENT>
                                    <ENT>55</ENT>
                                    <ENT>65</ENT>
                                    <ENT>78</ENT>
                                    <ENT>94</ENT>
                                    <ENT>114</ENT>
                                    <ENT>137</ENT>
                                    <ENT>165</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="02">1.6</ENT>
                                    <ENT>56</ENT>
                                    <ENT>66</ENT>
                                    <ENT>79</ENT>
                                    <ENT>96</ENT>
                                    <ENT>116</ENT>
                                    <ENT>141</ENT>
                                    <ENT>169</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="02">1.8</ENT>
                                    <ENT>57</ENT>
                                    <ENT>68</ENT>
                                    <ENT>81</ENT>
                                    <ENT>98</ENT>
                                    <ENT>119</ENT>
                                    <ENT>144</ENT>
                                    <ENT>173</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="02">2.0</ENT>
                                    <ENT>58</ENT>
                                    <ENT>69</ENT>
                                    <ENT>83</ENT>
                                    <ENT>100</ENT>
                                    <ENT>122</ENT>
                                    <ENT>147</ENT>
                                    <ENT>177</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="02">2.2</ENT>
                                    <ENT>59</ENT>
                                    <ENT>70</ENT>
                                    <ENT>85</ENT>
                                    <ENT>102</ENT>
                                    <ENT>124</ENT>
                                    <ENT>150</ENT>
                                    <ENT>181</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="02">2.4</ENT>
                                    <ENT>60</ENT>
                                    <ENT>72</ENT>
                                    <ENT>86</ENT>
                                    <ENT>105</ENT>
                                    <ENT>127</ENT>
                                    <ENT>153</ENT>
                                    <ENT>184</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="02">2.6</ENT>
                                    <ENT>61</ENT>
                                    <ENT>73</ENT>
                                    <ENT>88</ENT>
                                    <ENT>107</ENT>
                                    <ENT>129</ENT>
                                    <ENT>156</ENT>
                                    <ENT>188</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="02">2.8</ENT>
                                    <ENT>62</ENT>
                                    <ENT>74</ENT>
                                    <ENT>89</ENT>
                                    <ENT>109</ENT>
                                    <ENT>132</ENT>
                                    <ENT>159</ENT>
                                    <ENT>191</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="02">3.0</ENT>
                                    <ENT>63</ENT>
                                    <ENT>76</ENT>
                                    <ENT>91</ENT>
                                    <ENT>111</ENT>
                                    <ENT>134</ENT>
                                    <ENT>162</ENT>
                                    <ENT>195</ENT>
                                </ROW>
                                <TNOTE>
                                    <SU>1</SU>
                                     These CT values achieve greater than a 99.99 percent inactivation of viruses. CT values between the indicated pH values may be determined by linear interpolation. CT values between the indicated temperatures of different tables may be determined by linear interpolation. If no interpolation is used, use the CT
                                    <E T="52">99.9</E>
                                     value at the lower temperature, and at the higher pH.
                                </TNOTE>
                            </GPOTABLE>
                            <GPOTABLE COLS="8" OPTS="L2" CDEF="s12,5,4,4,4,4,4,5">
                                <TTITLE>
                                    Table 1.5—CT Values (CT
                                    <E T="52">99.9</E>
                                    ) for 99.9 Percent Inactivation of Giardia Lamblia Cysts by Free Chlorine at 20 °C 
                                    <SU>1</SU>
                                </TTITLE>
                                <BOXHD>
                                    <CHED H="1">Free residual (mg/l)</CHED>
                                    <CHED H="1">pH</CHED>
                                    <CHED H="2">≤6.0</CHED>
                                    <CHED H="2">6.5</CHED>
                                    <CHED H="2">7.0</CHED>
                                    <CHED H="2">7.5</CHED>
                                    <CHED H="2">8.0</CHED>
                                    <CHED H="2">8.5</CHED>
                                    <CHED H="2">≤9.0</CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">≤0.4</ENT>
                                    <ENT>36</ENT>
                                    <ENT>44</ENT>
                                    <ENT>52</ENT>
                                    <ENT>62</ENT>
                                    <ENT>74</ENT>
                                    <ENT>89</ENT>
                                    <ENT>105</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">0.6</ENT>
                                    <ENT>38</ENT>
                                    <ENT>45</ENT>
                                    <ENT>54</ENT>
                                    <ENT>64</ENT>
                                    <ENT>77</ENT>
                                    <ENT>92</ENT>
                                    <ENT>109</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">0.8</ENT>
                                    <ENT>39</ENT>
                                    <ENT>46</ENT>
                                    <ENT>55</ENT>
                                    <ENT>66</ENT>
                                    <ENT>79</ENT>
                                    <ENT>95</ENT>
                                    <ENT>113</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">1.0</ENT>
                                    <ENT>39</ENT>
                                    <ENT>47</ENT>
                                    <ENT>56</ENT>
                                    <ENT>67</ENT>
                                    <ENT>81</ENT>
                                    <ENT>98</ENT>
                                    <ENT>117</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">1.2</ENT>
                                    <ENT>40</ENT>
                                    <ENT>48</ENT>
                                    <ENT>57</ENT>
                                    <ENT>69</ENT>
                                    <ENT>83</ENT>
                                    <ENT>100</ENT>
                                    <ENT>120</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">1.4</ENT>
                                    <ENT>41</ENT>
                                    <ENT>49</ENT>
                                    <ENT>58</ENT>
                                    <ENT>70</ENT>
                                    <ENT>85</ENT>
                                    <ENT>103</ENT>
                                    <ENT>123</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">1.6</ENT>
                                    <ENT>42</ENT>
                                    <ENT>50</ENT>
                                    <ENT>59</ENT>
                                    <ENT>72</ENT>
                                    <ENT>87</ENT>
                                    <ENT>105</ENT>
                                    <ENT>126</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">1.8</ENT>
                                    <ENT>43</ENT>
                                    <ENT>51</ENT>
                                    <ENT>61</ENT>
                                    <ENT>74</ENT>
                                    <ENT>89</ENT>
                                    <ENT>108</ENT>
                                    <ENT>129</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">2.0</ENT>
                                    <ENT>44</ENT>
                                    <ENT>52</ENT>
                                    <ENT>62</ENT>
                                    <ENT>75</ENT>
                                    <ENT>91</ENT>
                                    <ENT>110</ENT>
                                    <ENT>132</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">2.2</ENT>
                                    <ENT>44</ENT>
                                    <ENT>53</ENT>
                                    <ENT>63</ENT>
                                    <ENT>77</ENT>
                                    <ENT>93</ENT>
                                    <ENT>113</ENT>
                                    <ENT>135</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">2.4</ENT>
                                    <ENT>45</ENT>
                                    <ENT>54</ENT>
                                    <ENT>65</ENT>
                                    <ENT>78</ENT>
                                    <ENT>95</ENT>
                                    <ENT>115</ENT>
                                    <ENT>138</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">2.6</ENT>
                                    <ENT>46</ENT>
                                    <ENT>55</ENT>
                                    <ENT>66</ENT>
                                    <ENT>80</ENT>
                                    <ENT>97</ENT>
                                    <ENT>117</ENT>
                                    <ENT>141</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">2.8</ENT>
                                    <ENT>47</ENT>
                                    <ENT>56</ENT>
                                    <ENT>67</ENT>
                                    <ENT>81</ENT>
                                    <ENT>99</ENT>
                                    <ENT>119</ENT>
                                    <ENT>143</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">3.0</ENT>
                                    <ENT>47</ENT>
                                    <ENT>57</ENT>
                                    <ENT>68</ENT>
                                    <ENT>83</ENT>
                                    <ENT>101</ENT>
                                    <ENT>122</ENT>
                                    <ENT>146</ENT>
                                </ROW>
                                <TNOTE>
                                    <SU>1</SU>
                                     These CT values achieve greater than a 99.99 percent inactivation of viruses. CT values between the indicated pH values may be determined by linear interpolation. CT values between the indicated temperatures of different tables may be determined by linear interpolation. If no interpolation is used, use the CT
                                    <E T="52">99.9</E>
                                     value at the lower temperature, and at the higher pH.
                                </TNOTE>
                            </GPOTABLE>
                            <GPOTABLE COLS="8" OPTS="L2" CDEF="s12,5,4,4,4,4,4,5">
                                <TTITLE>
                                    Table 1.6—CT Values (CT
                                    <E T="52">99.9</E>
                                    ) for 99.9 Percent Inactivation of Giardia Lamblia Cysts by Free Chlorine at 25 °C 
                                    <SU>1</SU>
                                     and Higher
                                </TTITLE>
                                <BOXHD>
                                    <CHED H="1">Free residual (mg/l)</CHED>
                                    <CHED H="1">pH</CHED>
                                    <CHED H="2">≤6.0</CHED>
                                    <CHED H="2">6.5</CHED>
                                    <CHED H="2">7.0</CHED>
                                    <CHED H="2">7.5</CHED>
                                    <CHED H="2">8.0</CHED>
                                    <CHED H="2">8.5</CHED>
                                    <CHED H="2">≤9.0</CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">≤0.4</ENT>
                                    <ENT>24</ENT>
                                    <ENT>29</ENT>
                                    <ENT>35</ENT>
                                    <ENT>42</ENT>
                                    <ENT>50</ENT>
                                    <ENT>59</ENT>
                                    <ENT>70</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">0.6</ENT>
                                    <ENT>25</ENT>
                                    <ENT>30</ENT>
                                    <ENT>36</ENT>
                                    <ENT>43</ENT>
                                    <ENT>51</ENT>
                                    <ENT>61</ENT>
                                    <ENT>73</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">0.8</ENT>
                                    <ENT>26</ENT>
                                    <ENT>31</ENT>
                                    <ENT>37</ENT>
                                    <ENT>44</ENT>
                                    <ENT>53</ENT>
                                    <ENT>63</ENT>
                                    <ENT>75</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">1.0</ENT>
                                    <ENT>26</ENT>
                                    <ENT>31</ENT>
                                    <ENT>37</ENT>
                                    <ENT>45</ENT>
                                    <ENT>54</ENT>
                                    <ENT>65</ENT>
                                    <ENT>78</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">1.2</ENT>
                                    <ENT>27</ENT>
                                    <ENT>32</ENT>
                                    <ENT>38</ENT>
                                    <ENT>46</ENT>
                                    <ENT>55</ENT>
                                    <ENT>67</ENT>
                                    <ENT>80</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">1.4</ENT>
                                    <ENT>27</ENT>
                                    <ENT>33</ENT>
                                    <ENT>39</ENT>
                                    <ENT>47</ENT>
                                    <ENT>57</ENT>
                                    <ENT>69</ENT>
                                    <ENT>82</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">1.6</ENT>
                                    <ENT>28</ENT>
                                    <ENT>33</ENT>
                                    <ENT>40</ENT>
                                    <ENT>48</ENT>
                                    <ENT>58</ENT>
                                    <ENT>70</ENT>
                                    <ENT>84</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">1.8</ENT>
                                    <ENT>29</ENT>
                                    <ENT>34</ENT>
                                    <ENT>41</ENT>
                                    <ENT>49</ENT>
                                    <ENT>60</ENT>
                                    <ENT>72</ENT>
                                    <ENT>86</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">2.0</ENT>
                                    <ENT>29</ENT>
                                    <ENT>35</ENT>
                                    <ENT>41</ENT>
                                    <ENT>50</ENT>
                                    <ENT>61</ENT>
                                    <ENT>74</ENT>
                                    <ENT>88</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">2.2</ENT>
                                    <ENT>30</ENT>
                                    <ENT>35</ENT>
                                    <ENT>42</ENT>
                                    <ENT>51</ENT>
                                    <ENT>62</ENT>
                                    <ENT>75</ENT>
                                    <ENT>90</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">2.4</ENT>
                                    <ENT>30</ENT>
                                    <ENT>36</ENT>
                                    <ENT>43</ENT>
                                    <ENT>52</ENT>
                                    <ENT>63</ENT>
                                    <ENT>77</ENT>
                                    <ENT>92</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">2.6</ENT>
                                    <ENT>31</ENT>
                                    <ENT>37</ENT>
                                    <ENT>44</ENT>
                                    <ENT>53</ENT>
                                    <ENT>65</ENT>
                                    <ENT>78</ENT>
                                    <ENT>94</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">2.8</ENT>
                                    <ENT>31</ENT>
                                    <ENT>37</ENT>
                                    <ENT>45</ENT>
                                    <ENT>54</ENT>
                                    <ENT>66</ENT>
                                    <ENT>80</ENT>
                                    <ENT>96</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">3.0</ENT>
                                    <ENT>32</ENT>
                                    <ENT>38</ENT>
                                    <ENT>46</ENT>
                                    <ENT>55</ENT>
                                    <ENT>67</ENT>
                                    <ENT>81</ENT>
                                    <ENT>97</ENT>
                                </ROW>
                                <TNOTE>
                                    <SU>1</SU>
                                     These CT values achieve greater than a 99.99 percent inactivation of viruses. CT values between the indicated pH values may be determined by linear interpolation. CT values between the indicated temperatures of different tables may be determined by linear interpolation. If no interpolation is used, use the CT
                                    <E T="52">99.9</E>
                                     value at the lower temperature, and at the higher pH.
                                </TNOTE>
                            </GPOTABLE>
                            <GPOTABLE COLS="7" OPTS="L2" CDEF="s12,5.1,5.1,5.1,4.2,4.2,4.2">
                                <TTITLE>
                                    Table 2.1—CT Values (CT
                                    <E T="52">99.9</E>
                                    ) for 99.9 Percent Inactivation of Giardia Lamblia Cysts by Chlorine Dioxide and Ozone 
                                    <SU>1</SU>
                                </TTITLE>
                                <BOXHD>
                                    <CHED H="1"> </CHED>
                                    <CHED H="1">Temperature</CHED>
                                    <CHED H="2">&lt;1 °C</CHED>
                                    <CHED H="2">5 °C</CHED>
                                    <CHED H="2">10 °C</CHED>
                                    <CHED H="2">15 °C</CHED>
                                    <CHED H="2">20 °C</CHED>
                                    <CHED H="2">≥25 °C</CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">Chlorine dioxide</ENT>
                                    <ENT>63</ENT>
                                    <ENT>26</ENT>
                                    <ENT>23</ENT>
                                    <ENT>19</ENT>
                                    <ENT>15</ENT>
                                    <ENT>11</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Ozone</ENT>
                                    <ENT>2.9</ENT>
                                    <ENT>1.9</ENT>
                                    <ENT>1.4</ENT>
                                    <ENT>0.95</ENT>
                                    <ENT>0.72</ENT>
                                    <ENT>0.48</ENT>
                                </ROW>
                                <TNOTE>
                                    <SU>1</SU>
                                     These CT values achieve greater than 99.99 percent inactivation of viruses. CT values between the indicated temperatures may be determined by linear interpolation. If no interpolation is used, use the CT
                                    <E T="52">99.9</E>
                                     value at the lower temperature for determining CT
                                    <E T="52">99.9</E>
                                     values between indicated temperatures.
                                </TNOTE>
                            </GPOTABLE>
                            <PRTPAGE P="596"/>
                            <GPOTABLE COLS="6" OPTS="L2" CDEF="5,5,5,5,5,5">
                                <TTITLE>
                                    Table 3.1—CT Values (CT 
                                    <E T="52">99.9</E>
                                    ) for 99.9 Percent Inactivation of Giardia Lamblia Cysts By Chloramines 
                                    <SU>1</SU>
                                </TTITLE>
                                <BOXHD>
                                    <CHED H="1">Temperature</CHED>
                                    <CHED H="2">&lt;1 °C</CHED>
                                    <CHED H="2">5 °C</CHED>
                                    <CHED H="2">10 °C</CHED>
                                    <CHED H="2">15 °C</CHED>
                                    <CHED H="2">20 °C</CHED>
                                    <CHED H="2">25 °C</CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="11">3,800</ENT>
                                    <ENT>2,200</ENT>
                                    <ENT>1,850</ENT>
                                    <ENT>1,500</ENT>
                                    <ENT>1,100</ENT>
                                    <ENT>750</ENT>
                                </ROW>
                                <TNOTE>
                                    <SU>1</SU>
                                     These values are for pH values of 6 to 9. These CT values may be assumed to achieve greater than 99.99 percent inactivation of viruses only if chlorine is added and mixed in the water prior to the addition of ammonia. If this condition is not met, the system must demonstrate, based on on-site studies or other information, as approved by the State, that the system is achieving at least 99.99 percent inactivation of viruses. CT values between the indicated temperatures may be determined by linear interpolation. If no interpolation is used, use the CT
                                    <E T="52">99.9</E>
                                     value at the lower temperature for determining CT
                                    <E T="52">99.9</E>
                                     values between indicated temperatures.
                                </TNOTE>
                            </GPOTABLE>
                            <P>(4) The total inactivation ratio must be calculated as follows:</P>
                            <P>(i) If the system uses only one point of disinfectant application, the system may determine the total inactivation ratio based on either of the following two methods:</P>
                            <P>
                                (A) One inactivation ratio (CTcalc/CT
                                <E T="52">99.9</E>
                                ) is determined before or at the first customer during peak hourly flow and if the CTcalc/CT
                                <E T="52">99.9</E>
                                 ≥1.0, the 99.9 percent 
                                <E T="03">Giardia lamblia</E>
                                 inactivation requirement has been achieved; or
                            </P>
                            <P>
                                (B) Successive CTcalc/CT
                                <E T="52">99.9</E>
                                 values, representing sequential inactivation ratios, are determined between the point of disinfectant application and a point before or at the first customer during peak hourly flow. Under this alternative, the following method must be used to calculate the total inactivation ratio:
                            </P>
                            <MATH SPAN="2" DEEP="95">
                                <MID>EC15NO91.133</MID>
                            </MATH>
                            <FP>
                                <E T="03">lamblia</E>
                                 inactivation requirement has been achieved.
                            </FP>
                            <P>
                                (ii) If the system uses more than one point of disinfectant application before or at the first customer, the system must determine the CT value of each disinfection sequence immediately prior to the next point of disinfectant application during peak hourly flow. The CTcalc/CT
                                <E T="52">99.9</E>
                                 value of each sequence and
                            </P>
                            <MATH SPAN="1" DEEP="27">
                                <MID>EC15NO91.134</MID>
                            </MATH>
                            <FP>must be calculated using the method in paragraph (b)(4)(i)(B) of this section to determine if the system is in compliance with § 141.72(a).</FP>
                            <P>(iii) Although not required, the total percent inactivation for a system with one or more points of residual disinfectant concentration monitoring may be calculated by solving the following equation:</P>
                            <MATH SPAN="1" DEEP="59">
                                <MID>EC15NO91.135</MID>
                            </MATH>
                            <P>
                                (5) The residual disinfectant concentration of the water entering the distribution system must be monitored continuously, and the lowest value must be recorded each day, except that if there is a failure in the continuous monitoring equipment, grab sampling every 4 hours may be conducted in lieu of continuous monitoring, but for no more than 5 working days following the failure of the equipment, and systems serving 3,300 or fewer persons may take grab samples in lieu of providing continuous monitoring on an ongoing 
                                <PRTPAGE P="597"/>
                                basis at the frequencies prescribed below:
                            </P>
                            <GPOTABLE COLS="2" OPTS="L2" CDEF="s25,8">
                                <BOXHD>
                                    <CHED H="1">System size by population</CHED>
                                    <CHED H="1">
                                        Samples/day 
                                        <SU>1</SU>
                                    </CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">&lt;500</ENT>
                                    <ENT>1</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">501 to 1,000</ENT>
                                    <ENT>2</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">1,001 to 2,500</ENT>
                                    <ENT>3</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">2,501 to 3,300</ENT>
                                    <ENT>4</ENT>
                                </ROW>
                                <TNOTE>
                                    <SU>1</SU>
                                     The day's samples cannot be taken at the same time. The sampling intervals are subject to State review and approval.
                                </TNOTE>
                            </GPOTABLE>
                            <FP>If at any time the residual disinfectant concentration falls below 0.2 mg/l in a system using grab sampling in lieu of continuous monitoring, the system must take a grab sample every 4 hours until the residual concentration is equal to or greater than 0.2 mg/l.</FP>
                            <P>(6)(i) Until March 31, 2016, the residual disinfectant concentration must be measured at least at the same points in the distribution system and at the same time as total coliforms are sampled, as specified in § 141.21. Beginning April 1, 2016, the residual disinfectant concentration must be measured at least at the same points in the distribution system and at the same time as total coliforms are sampled, as specified in §§ 141.854 through 141.858. The State may allow a public water system which uses both a surface water source or a ground water source under direct influence of surface water, and a ground water source, to take disinfectant residual samples at points other than the total coliform sampling points if the State determines that such points are more representative of treated (disinfected) water quality within the distribution system. Heterotrophic bacteria, measured as heterotrophic plate count (HPC) as specified in paragraph (a)(1) of this section, may be measured in lieu of residual disinfectant concentration.</P>
                            <P>(ii) If the State determines, based on site-specific considerations, that a system has no means for having a sample transported and analyzed for HPC by a certified laboratory under the requisite time and temperature conditions specified by paragraph (a)(1) of this section and that the system is providing adequate disinfection in the distribution system, the requirements of paragraph (b)(6)(i) of this section do not apply to that system.</P>
                            <P>
                                (c) 
                                <E T="03">Monitoring requirements for systems using filtration treatment.</E>
                                 A public water system that uses a surface water source or a ground water source under the influence of surface water and provides filtration treatment must monitor in accordance with this paragraph (c) beginning June 29, 1993, or when filtration is installed, whichever is later.
                            </P>
                            <P>(1) Turbidity measurements as required by § 141.73 must be performed on representative samples of the system's filtered water every four hours (or more frequently) that the system serves water to the public. A public water system may substitute continuous turbidity monitoring for grab sample monitoring if it validates the continuous measurement for accuracy on a regular basis using a protocol approved by the State. For any systems using slow sand filtration or filtration treatment other than conventional treatment, direct filtration, or diatomaceous earth filtration, the State may reduce the sampling frequency to once per day if it determines that less frequent monitoring is sufficient to indicate effective filtration performance. For systems serving 500 or fewer persons, the State may reduce the turbidity sampling frequency to once per day, regardless of the type of filtration treatment used, if the State determines that less frequent monitoring is sufficient to indicate effective filtration performance.</P>
                            <P>(2) The residual disinfectant concentration of the water entering the distribution system must be monitored continuously, and the lowest value must be recorded each day, except that if there is a failure in the continuous monitoring equipment, grab sampling every 4 hours may be conducted in lieu of continuous monitoring, but for no more than 5 working days following the failure of the equipment, and systems serving 3,300 or fewer persons may take grab samples in lieu of providing continuous monitoring on an ongoing basis at the frequencies each day prescribed below:</P>
                            <GPOTABLE COLS="2" OPTS="L2" CDEF="s25,8">
                                <BOXHD>
                                    <CHED H="1">System size by population</CHED>
                                    <CHED H="1">
                                        Samples/day 
                                        <SU>1</SU>
                                    </CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">±500</ENT>
                                    <ENT>1</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">501 to 1,000</ENT>
                                    <ENT>2</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">1,001 to 2,500</ENT>
                                    <ENT>3</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">2,501 to 3,300</ENT>
                                    <ENT>4</ENT>
                                </ROW>
                                <TNOTE>
                                    <SU>1</SU>
                                     The day's samples cannot be taken at the same time. The sampling intervals are subject to State review and approval.
                                </TNOTE>
                            </GPOTABLE>
                            <PRTPAGE P="598"/>
                            <FP>If at any time the residual disinfectant concentration falls below 0.2 mg/l in a system using grab sampling in lieu of continuous monitoring, the system must take a grab sample every 4 hours until the residual disinfectant concentration is equal to or greater than 0.2 mg/l.</FP>
                            <P>(3)(i) Until March 31, 2016, the residual disinfectant concentration must be measured at least at the same points in the distribution system and at the same time as total coliforms are sampled, as specified in § 141.21. Beginning April 1, 2016, the residual disinfectant concentration must be measured at least at the same points in the distribution system and at the same time as total coliforms are sampled, as specified in §§ 141.854 through 141.858. The State may allow a public water system which uses both a surface water source or a ground water source under direct influence of surface water, and a ground water source, to take disinfectant residual samples at points other than the total coliform sampling points if the State determines that such points are more representative of treated (disinfected) water quality within the distribution system. Heterotrophic bacteria, measured as heterotrophic plate count (HPC) as specified in paragraph (a)(1) of this section, may be measured in lieu of residual disinfectant concentration.</P>
                            <P>(ii) If the State determines, based on site-specific considerations, that a system has no means for having a sample transported and analyzed for HPC by a certified laboratory under the requisite time and temperature conditions specified by paragraph (a)(1) of this section and that the system is providing adequate disinfection in the distribution system, the requirements of paragraph (c)(3)(i) of this section do not apply to that system.</P>
                            <CITA>[54 FR 27527, June 29, 1989, as amended at 59 FR 62470, Dec. 5, 1994; 60 FR 34086, June 29, 1995; 64 FR 67465, Dec. 1, 1999; 67 FR 65252, Oct. 23, 2002; 67 FR 65901, Oct. 29, 2002; 69 FR 38856, June 29, 2004; 72 FR 11247, Mar. 12, 2007; 74 FR 30958, June 29, 2009; 78 FR 10347, Feb. 13, 2013]</CITA>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 141.75</SECTNO>
                            <SUBJECT>Reporting and recordkeeping requirements.</SUBJECT>
                            <P>(a) A public water system that uses a surface water source and does not provide filtration treatment must report monthly to the State the information specified in this paragraph (a) beginning December 31, 1990, unless the State has determined that filtration is required in writing pursuant to section 1412(b)(7)(C)(iii), in which case the State may specify alternative reporting requirements, as appropriate, until filtration is in place. A public water system that uses a ground water source under the direct influence of surface water and does not provide filtration treatment must report monthly to the State the information specified in this paragraph (a) beginning December 31, 1990, or 6 months after the State determines that the ground water source is under the direct influence of surface water, whichever is later, unless the State has determined that filtration is required in writing pursuant to § 1412(b)(7)(C)(iii), in which case the State may specify alternative reporting requirements, as appropriate, until filtration is in place.</P>
                            <P>(1) Source water quality information must be reported to the State within 10 days after the end of each month the system serves water to the public. Information that must be reported includes:</P>
                            <P>(i) The cumulative number of months for which results are reported.</P>
                            <P>(ii) The number of fecal and/or total coliform samples, whichever are analyzed during the month (if a system monitors for both, only fecal coliforms must be reported), the dates of sample collection, and the dates when the turbidity level exceeded 1 NTU.</P>
                            <P>(iii) The number of samples during the month that had equal to or less than 20/100 ml fecal coliforms and/or equal to or less than 100/100 ml total coliforms, whichever are analyzed.</P>
                            <P>(iv) The cumulative number of fecal or total coliform samples, whichever are analyzed, during the previous six months the system served water to the public.</P>
                            <P>
                                (v) The cumulative number of samples that had equal to or less than 20/100 ml fecal coliforms or equal to or less than 100/100 ml total coliforms, 
                                <PRTPAGE P="599"/>
                                whichever are analyzed, during the previous six months the system served water to the public.
                            </P>
                            <P>(vi) The percentage of samples that had equal to or less than 20/100 ml fecal coliforms or equal to or less than 100/100 ml total coliforms, whichever are analyzed, during the previous six months the system served water to the public.</P>
                            <P>(vii) The maximum turbidity level measured during the month, the date(s) of occurrence for any measurement(s) which exceeded 5 NTU, and the date(s) the occurrence(s) was reported to the State.</P>
                            <P>(viii) For the first 12 months of recordkeeping, the dates and cumulative number of events during which the turbidity exceeded 5 NTU, and after one year of recordkeeping for turbidity measurements, the dates and cumulative number of events during which the turbidity exceeded 5 NTU in the previous 12 months the system served water to the public.</P>
                            <P>(ix) For the first 120 months of recordkeeping, the dates and cumulative number of events during which the turbidity exceeded 5 NTU, and after 10 years of recordkeeping for turbidity measurements, the dates and cumulative number of events during which the turbidity exceeded 5 NTU in the previous 120 months the system served water to the public.</P>
                            <P>(2) Disinfection information specified in § 141.74(b) must be reported to the State within 10 days after the end of each month the system serves water to the public. Information that must be reported includes:</P>
                            <P>(i) For each day, the lowest measurement of residual disinfectant concentration in mg/l in water entering the distribution system.</P>
                            <P>(ii) The date and duration of each period when the residual disinfectant concentration in water entering the distribution system fell below 0.2 mg/l and when the State was notified of the occurrence.</P>
                            <P>(iii) The daily residual disinfectant concentration(s) (in mg/l) and disinfectant contact time(s) (in minutes) used for calculating the CT value(s).</P>
                            <P>(iv) If chlorine is used, the daily measurement(s) of pH of disinfected water following each point of chlorine disinfection.</P>
                            <P>(v) The daily measurement(s) of water temperature in °C following each point of disinfection.</P>
                            <P>
                                (vi) The daily CTcalc and CTcalc/CT
                                <E T="52">99.9</E>
                                 values for each disinfectant measurement or sequence and the sum of all CTcalc/CT
                                <E T="52">99.9</E>
                                 values ((CTcalc/CT
                                <E T="52">99.9</E>
                                )) before or at the first customer.
                            </P>
                            <P>
                                (vii) The daily determination of whether disinfection achieves adequate 
                                <E T="03">Giardia</E>
                                 cyst and virus inactivation, 
                                <E T="03">i.e.</E>
                                , whether (CTcalc/CT
                                <E T="52">99.9</E>
                                ) is at least 1.0 or, where disinfectants other than chlorine are used, other indicator conditions that the State determines are appropriate, are met.
                            </P>
                            <P>(viii) The following information on the samples taken in the distribution system in conjunction with total coliform monitoring pursuant to § 141.72:</P>
                            <P>(A) Number of instances where the residual disinfectant concentration is measured;</P>
                            <P>(B) Number of instances where the residual disinfectant concentration is not measured but heterotrophic bacteria plate count (HPC) is measured;</P>
                            <P>(C) Number of instances where the residual disinfectant concentration is measured but not detected and no HPC is measured;</P>
                            <P>(D) Number of instances where the residual disinfectant concentration is detected and where HPC is &gt;500/ml;</P>
                            <P>(E) Number of instances where the residual disinfectant concentration is not measured and HPC is &gt;500/ml;</P>
                            <P>(F) For the current and previous month the system served water to the public, the value of “V” in the following formula:</P>
                            <MATH SPAN="1" DEEP="24">
                                <MID>EC15NO91.136</MID>
                            </MATH>
                            <EXTRACT>
                                <FP>where:</FP>
                                <FP SOURCE="FP-2">a = the value in paragraph (a)(2)(viii)(A) of this section,</FP>
                                <FP SOURCE="FP-2">b = the value in paragraph (a)(2)(viii)(B) of this section,</FP>
                                <FP SOURCE="FP-2">c = the value in paragraph (a)(2)(viii)(C) of this section,</FP>
                                <FP SOURCE="FP-2">d = the value in paragraph (a)(2)(viii)(D) of this section, and</FP>
                                <FP SOURCE="FP-2">e = the value in paragraph (a)(2)(viii)(E) of this section.</FP>
                            </EXTRACT>
                            <PRTPAGE P="600"/>
                            <P>(G) If the State determines, based on site-specific considerations, that a system has no means for having a sample transported and analyzed for HPC by a certified laboratory under the requisite time and temperature conditions specified by § 141.74(a)(1) and that the system is providing adequate disinfection in the distribution system, the requirements of paragraph (a)(2)(viii) (A)-(F) of this section do not apply to that system.</P>
                            <P>(ix) A system need not report the data listed in paragraphs (a)(2) (i), and (iii)-(vi) of this section if all data listed in paragraphs (a)(2) (i)-(viii) of this section remain on file at the system, and the State determines that:</P>
                            <P>(A) The system has submitted to the State all the information required by paragraphs (a)(2) (i)-(viii) of this section for at least 12 months; and</P>
                            <P>(B) The State has determined that the system is not required to provide filtration treatment.</P>
                            <P>(3) No later than ten days after the end of each Federal fiscal year (September 30), each system must provide to the State a report which summarizes its compliance with all watershed control program requirements specified in § 141.71(b)(2).</P>
                            <P>(4) No later than ten days after the end of each Federal fiscal year (September 30), each system must provide to the State a report on the on-site inspection conducted during that year pursuant to § 141.71(b)(3), unless the on-site inspection was conducted by the State. If the inspection was conducted by the State, the State must provide a copy of its report to the public water system.</P>
                            <P>(5)(i) Each system, upon discovering that a waterborne disease outbreak potentially attributable to that water system has occurred, must report that occurrence to the State as soon as possible, but no later than by the end of the next business day.</P>
                            <P>(ii) If at any time the turbidity exceeds 5 NTU, the system must consult with the primacy agency as soon as practical, but no later than 24 hours after the exceedance is known, in accordance with the public notification requirements under § 141.203(b)(3).</P>
                            <P>(iii) If at any time the residual falls below 0.2 mg/l in the water entering the distribution system, the system must notify the State as soon as possible, but no later than by the end of the next business day. The system also must notify the State by the end of the next business day whether or not the residual was restored to at least 0.2 mg/l within 4 hours.</P>
                            <P>(b) A public water system that uses a surface water source or a ground water source under the direct influence of surface water and provides filtration treatment must report monthly to the State the information specified in this paragraph (b) beginning June 29, 1993, or when filtration is installed, whichever is later.</P>
                            <P>(1) Turbidity measurements as required by § 141.74(c)(1) must be reported within 10 days after the end of each month the system serves water to the public. Information that must be reported includes:</P>
                            <P>(i) The total number of filtered water turbidity measurements taken during the month.</P>
                            <P>(ii) The number and percentage of filtered water turbidity measurements taken during the month which are less than or equal to the turbidity limits specified in § 141.73 for the filtration technology being used.</P>
                            <P>(iii) The date and value of any turbidity measurements taken during the month which exceed 5 NTU.</P>
                            <P>(2) Disinfection information specified in § 141.74(c) must be reported to the State within 10 days after the end of each month the system serves water to the public. Information that must be reported includes:</P>
                            <P>(i) For each day, the lowest measurement of residual disinfectant concentration in mg/l in water entering the distribution system.</P>
                            <P>(ii) The date and duration of each period when the residual disinfectant concentration in water entering the distribution system fell below 0.2 mg/l and when the State was notified of the occurrence.</P>
                            <P>(iii) The following information on the samples taken in the distribution system in conjunction with total coliform monitoring pursuant to § 141.72:</P>
                            <P>
                                (A) Number of instances where the residual disinfectant concentration is measured;
                                <PRTPAGE P="601"/>
                            </P>
                            <P>(B) Number of instances where the residual disinfectant concentration is not measured but heterotrophic bacteria plate count (HPC) is measured;</P>
                            <P>(C) Number of instances where the residual disinfectant concentration is measured but not detected and no HPC is measured;</P>
                            <P>(D) Number of instances where no residual disinfectant concentration is detected and where HPC is &gt;500/ml;</P>
                            <P>(E) Number of instances where the residual disinfectant concentration is not measured and HPC is &gt;500/ml;</P>
                            <P>(F) For the current and previous month the system serves water to the public, the value of “V” in the following formula:</P>
                            <MATH SPAN="1" DEEP="24">
                                <MID>EC15NO91.137</MID>
                            </MATH>
                            <EXTRACT>
                                <FP>where:</FP>
                                <FP SOURCE="FP-2">a = the value in paragraph (b)(2)(iii)(A) of this section,</FP>
                                <FP SOURCE="FP-2">b = the value in paragraph (b)(2)(iii)(B) of this section,</FP>
                                <FP SOURCE="FP-2">c = the value in paragraph (b)(2)(iii)(C) of this section,</FP>
                                <FP SOURCE="FP-2">d = the value in paragraph (b)(2)(iii)(D) of this section, and</FP>
                                <FP SOURCE="FP-2">e = the value in paragraph (b)(2)(iii)(E) of this section.</FP>
                            </EXTRACT>
                            <P>(G) If the State determines, based on site-specific considerations, that a system has no means for having a sample transported and analyzed for HPC by a certified laboratory within the requisite time and temperature conditions specified by § 141.74(a)(1) and that the system is providing adequate disinfection in the distribution system, the requirements of paragraph (b)(2)(iii) (A)-(F) of this section do not apply.</P>
                            <P>(iv) A system need not report the data listed in paragraph (b)(2)(i) of this section if all data listed in paragraphs (b)(2) (i)-(iii) of this section remain on file at the system and the State determines that the system has submitted all the information required by paragraphs (b)(2) (i)-(iii) of this section for at least 12 months.</P>
                            <P>(3)(i) Each system, upon discovering that a waterborne disease outbreak potentially attributable to that water system has occurred, must report that occurrence to the State as soon as possible, but no later than by the end of the next business day.</P>
                            <P>(ii) If at any time the turbidity exceeds 5 NTU, the system must consult with the primacy agency as soon as practical, but no later than 24 hours after the exceedance is known, in accordance with the public notification requirements under § 141.203(b)(3).</P>
                            <P>(iii) If at any time the residual falls below 0.2 mg/l in the water entering the distribution system, the system must notify the State as soon as possible, but no later than by the end of the next business day. The system also must notify the State by the end of the next business day whether or not the residual was restored to at least 0.2 mg/l within 4 hours.</P>
                            <CITA>[54 FR 27527, June 29, 1989, as amended at 65 FR 26022, May 4, 2000; 69 FR 38856, June 29, 2004]</CITA>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 141.76</SECTNO>
                            <SUBJECT>Recycle provisions.</SUBJECT>
                            <P>
                                (a) 
                                <E T="03">Applicability.</E>
                                 All subpart H systems that employ conventional filtration or direct filtration treatment and that recycle spent filter backwash water, thickener supernatant, or liquids from dewatering processes must meet the requirements in paragraphs (b) through (d) of this section.
                            </P>
                            <P>
                                (b) 
                                <E T="03">Reporting.</E>
                                 A system must notify the State in writing by December 8, 2003, if the system recycles spent filter backwash water, thickener supernatant, or liquids from dewatering processes. This notification must include, at a minimum, the information specified in paragraphs (b)(1) and (2) of this section.
                            </P>
                            <P>(1) A plant schematic showing the origin of all flows which are recycled (including, but not limited to, spent filter backwash water, thickener supernatant, and liquids from dewatering processes), the hydraulic conveyance used to transport them, and the location where they are re-introduced back into the treatment plant.</P>
                            <P>(2) Typical recycle flow in gallons per minute (gpm), the highest observed plant flow experienced in the previous year (gpm), design flow for the treatment plant (gpm), and State-approved operating capacity for the plant where the State has made such determinations.</P>
                            <P>
                                (c) 
                                <E T="03">Treatment technique requirement.</E>
                                 Any system that recycles spent filter 
                                <PRTPAGE P="602"/>
                                backwash water, thickener supernatant, or liquids from dewatering processes must return these flows through the processes of a system's existing conventional or direct filtration system as defined in § 141.2 or at an alternate location approved by the State by June 8, 2004. If capital improvements are required to modify the recycle location to meet this requirement, all capital improvements must be completed no later than June 8, 2006.
                            </P>
                            <P>
                                (d) 
                                <E T="03">Recordkeeping.</E>
                                 The system must collect and retain on file recycle flow information specified in paragraphs (d)(1) through (6) of this section for review and evaluation by the State beginning June 8, 2004.
                            </P>
                            <P>(1) Copy of the recycle notification and information submitted to the State under paragraph (b) of this section.</P>
                            <P>(2) List of all recycle flows and the frequency with which they are returned.</P>
                            <P>(3) Average and maximum backwash flow rate through the filters and the average and maximum duration of the filter backwash process in minutes.</P>
                            <P>(4) Typical filter run length and a written summary of how filter run length is determined.</P>
                            <P>(5) The type of treatment provided for the recycle flow.</P>
                            <P>(6) Data on the physical dimensions of the equalization and/or treatment units, typical and maximum hydraulic loading rates, type of treatment chemicals used and average dose and frequency of use, and frequency at which solids are removed, if applicable.</P>
                            <CITA>[66 FR 31103, June 8, 2001]</CITA>
                        </SECTION>
                    </SUBPART>
                    <SUBPART>
                        <HD SOURCE="HED">Subpart I—Control of Lead and Copper</HD>
                        <SOURCE>
                            <HD SOURCE="HED">Source:</HD>
                            <P>56 FR 26548, June 7, 1991, unless otherwise noted.</P>
                        </SOURCE>
                        <SECTION>
                            <SECTNO>§ 141.80</SECTNO>
                            <SUBJECT>General requirements and action level.</SUBJECT>
                            <P>
                                (a) 
                                <E T="03">Applicability, effective date, and compliance deadlines.</E>
                                 The requirements of this subpart constitute the national primary drinking water regulations for lead and copper.
                            </P>
                            <P>(1) The provisions of this subpart apply to community water systems and non-transient, non-community water systems (in this subpart referred to as “water systems” or “systems”) as defined at § 141.2.</P>
                            <P>(2) The requirements of this subpart are effective as of December 30, 2024.</P>
                            <P>(3) Community water systems and non-transient non-community water systems must comply with the requirements of this subpart no later than November 1, 2027, except where otherwise specified in §§ 141.81, 141.84, 141.85, 141.86, and 141.90, or where an exemption in accordance with 40 CFR part 142, subpart C or F, has been issued by the Administrator.</P>
                            <P>(4)(i) Between October 30, 2024, and November 1, 2027, community water systems and non-transient non-community water systems must comply with 40 CFR 141.2, 141.31(d), and 141.80 through 141.91, as codified on July 1, 2020, except systems must also comply with 40 CFR 141.84(a)(1) through (10) (excluding paragraphs (a)(6) and (7)), 141.85(a)(1)(ii) and (e), 141.90(e)(1) and (13), (f)(4), and (h)(3), 141.201(a)(3)(vi) and (c)(3), and 141.202(a)(10); 40 CFR part 141, appendix A to subpart Q, entry I.C.1 (excluding § 141.90, except paragraphs (e)(1) and (13) and (f)(4)) and entry I.C.2; 40 CFR part 141, appendix B to subpart Q, entry D.23; and 40 CFR 141.31(d)(2), as codified on July 1, 2024.</P>
                            <P>(ii) If an exemption from subpart I of this part has been issued in accordance with 40 CFR part 142, subpart C or F, prior to December 16, 2021, then the water systems must comply with 40 CFR 141.80 through 141.91, as codified on July 1, 2020, until the expiration of that exemption.</P>
                            <P>
                                (b) 
                                <E T="03">Scope.</E>
                                 The regulations in this subpart constitute a treatment technique rule that includes treatment techniques to control corrosion, treat source water, replace service lines, and provide public education. The regulations in this subpart include requirements to support the treatment technique including a service line inventory, tap sampling, and monitoring for lead in schools and child care facilities. Some of the requirements in this subpart only apply if there is an exceedance of the lead or copper action levels, specified in paragraph (c) of this section, as measured in samples collected at consumers' taps.
                                <PRTPAGE P="603"/>
                            </P>
                            <P>
                                (c) 
                                <E T="03">Lead and copper action levels and method for determining whether there is an exceedance of the action level.</E>
                                 Action levels must be determined based on tap water samples that must be considered for inclusion under § 141.86(e) for the purpose of calculating the 90th percentile and tested using the analytical methods specified in § 141.89. The action levels described in this paragraph (c) are applicable to all sections of subpart I of this part. Action levels for lead and copper are as follows:
                            </P>
                            <P>(1) The lead action level is exceeded if the 90th percentile concentration of lead as specified in paragraph (c)(3) of this section is greater than 0.010 mg/L.</P>
                            <P>(2) The copper action level is exceeded if the 90th percentile concentration of copper as specified in paragraph (c)(3) of this section is greater than 1.3 mg/L.</P>
                            <P>(3) For purposes of this subpart, the 90th percentile concentration must be derived as follows:</P>
                            <P>(i) For water systems that do not have Tier 1 and/or Tier 2 sites and only have sites identified as Tier 3, 4, or 5 under § 141.86(a):</P>
                            <P>(A) The results of all lead or copper samples taken during a tap sampling period and eligible for inclusion in the 90th percentile calculation under § 141.86(e) must be placed in ascending order from the sample with the lowest concentration of lead or copper to the sample with the highest concentration of lead or copper. Each sampling result must be assigned a number, in ascending order beginning with the number 1 for the sample with the lowest concentration of lead or copper. The number assigned to the sample with the highest concentration must be equal to the total number of samples taken and considered for inclusion in the 90th percentile calculation, in accordance with § 141.86(e).</P>
                            <P>(B) The number of samples taken during the tap sampling period must be multiplied by 0.9.</P>
                            <P>(C) The 90th percentile concentration is the concentration of lead or copper in the numbered sample yielded after multiplying the number of samples by 0.9 in paragraph (c)(3)(i)(B) of this section.</P>
                            <P>(D) For water systems that collect five samples per tap sampling period, the 90th percentile concentration is the average of the highest and second highest concentration from the results in paragraph (c)(3)(i)(A) of this section.</P>
                            <P>(E) For a water system that is allowed by the State to collect fewer than five samples in accordance with § 141.86(a)(2) or has failed to meet their required minimum number of samples and collected fewer than five samples, the sample result with the highest concentration from the results in paragraph (c)(3)(i)(A) of this section is considered the 90th percentile value.</P>
                            <P>(ii) For water systems with sites identified as Tier 1 or 2 under § 141.86(a) with sufficient Tier 1 and 2 sites to meet the minimum number of sites required in § 141.86(c) or (d) as applicable:</P>
                            <P>(A) For lead, water systems must include the higher of the first-liter and fifth-liter lead sample results at each Tier 1 and 2 site (or first-liter lead sample if tiering is based on premise plumbing) taken during the tap sampling period in paragraphs (c)(3)(ii)(B) through (D) of this section. For copper, water systems must include all first-liter copper samples collected at each Tier 1 and 2 site taken during the tap sampling period. Lead or copper sample results from Tier 3, 4, or 5 sites cannot be included in this calculation.</P>
                            <P>(B) The results of the lead or copper samples taken during a tap sampling period and eligible for inclusion in the 90th percentile calculation under § 141.86(e) identified in paragraph (c)(3)(ii)(A) of this section must be placed in ascending order from the sample with the lowest concentration to the sample with the highest concentration. Each sampling result must be assigned a number, in ascending order beginning with the number 1 for the sample with the lowest concentration. The number assigned to the sample with the highest concentration must be equal to the total number of samples.</P>
                            <P>(C) The number of samples identified in paragraph (c)(3)(ii)(B) must be multiplied by 0.9.</P>
                            <P>
                                (D) The 90th percentile concentration is the concentration of lead or copper in the numbered sample yielded after multiplying the number of samples by 0.9 in paragraph (c)(3)(ii)(C) of this section.
                                <PRTPAGE P="604"/>
                            </P>
                            <P>(E) For water systems that collect samples from five sites per tap sampling period, the 90th percentile concentration is the average of the highest and second highest concentration from the results in paragraph (c)(3)(ii)(B) of this section.</P>
                            <P>(F) For a water system that is allowed by the State to collect fewer than five copper samples or five first-liter-and-fifth-liter-paired lead samples in accordance with § 141.86(a)(2), or has failed to collect at least five copper samples or five first-liter-and fifth-liter-paired lead samples, the sample result with the highest concentration from the results in paragraph (c)(3)(ii)(B) is considered the 90th percentile value.</P>
                            <P>(iii) For water systems with sites identified as Tier 1 or 2 under § 141.86(a) with an insufficient number of Tier 1 or 2 sites to meet the minimum number of sites required in § 141.86(c) or (d) as applicable:</P>
                            <P>
                                (A) For lead, the system must use the higher value of the first-liter and fifth-liter lead sample for each Tier 1 or 2 site (or first-liter lead sample if tiering is based on premise plumbing) and the first-liter lead samples from sites in the next highest available tier (
                                <E T="03">i.e.,</E>
                                 Tier 3, 4, and 5) to meet the minimum number of sites required in § 141.86(c) or (d) sampled during a tap sampling period for the steps in paragraphs (c)(3)(iii)(B) through (D) of this section. For copper, the system must use all first-liter copper samples collected.
                            </P>
                            <P>(B) The results of all of the lead or copper samples identified in paragraph (c)(3)(iii)(A) of this section must be placed in ascending order from the sample with the lowest concentration to the sample with the highest concentration. The water system must reduce this list to only include samples with the highest concentrations such that the number of sample results equals the minimum number of sites required to be sampled by § 141.86(c) or (d), as applicable. From this reduced list, each sampling result must be assigned a number, in ascending order beginning with the number 1 for the sample with the lowest concentration. The number assigned to the sample with the highest concentration must be equal to the minimum number of sites required by § 141.86(c) or (d), as applicable.</P>
                            <P>(C) The number of samples identified in paragraph (c)(3)(iii)(B) must be multiplied by 0.9.</P>
                            <P>(D) The 90th percentile concentration is the concentration of lead or copper in the numbered sample yielded after multiplying the number of samples by 0.9 in paragraph (c)(3)(iii)(C) of this section.</P>
                            <P>(E) For water systems that collect samples from five sites per tap sampling period, the 90th percentile concentration is the average of the highest and second highest concentration from the results in paragraph (c)(3)(iii)(B) of this section.</P>
                            <P>(F) For a water system that is allowed by the State to collect fewer than five copper samples or five first-liter-and-fifth-liter-paired lead samples in accordance with § 141.86(a)(2), or has failed to collect at least five copper samples or five first-and-fifth—liter-paired lead samples, the sample result with the highest concentration from the results in paragraph (c)(3)(iii)(B) is considered the 90th percentile value.</P>
                            <P>(G) If a water system does not collect enough samples sufficient to meet the minimum number of sites required in § 141.86(c) or (d), the system must calculate the 90th percentile lead and copper levels following the steps in § 141.80(c)(3)(i)(A) through (C).</P>
                            <CITA>[56 FR 26548, June 7, 1991; 57 FR 28788, June 29, 1992, as amended at 72 FR 57814, Oct. 10, 2007; 86 FR 4282, Jan. 15, 2021; 86 FR 31947, June 16, 2021; 89 FR 86626, Oct. 30, 2024]</CITA>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 141.81</SECTNO>
                            <SUBJECT>Applicability of corrosion control treatment steps to small, medium, and large water systems.</SUBJECT>
                            <P>
                                (a) 
                                <E T="03">Corrosion control treatment.</E>
                                 All water systems are required to install, optimize, or re-optimize optimal corrosion control treatment (OCCT) in accordance with this section. This section sets forth when a system must complete the corrosion control treatment steps under paragraph (d) or (e) of this section based on size, whether the system has corrosion control treatment, and whether it has exceeded the lead practical quantitation limit, lead action level, and/or the copper action level.
                                <PRTPAGE P="605"/>
                            </P>
                            <P>
                                (1) 
                                <E T="03">Large water systems (serving &gt;50,000 people).</E>
                                 (i) Large water systems with corrosion control treatment that exceed either the lead action level or copper action level must complete the re-optimized OCCT steps specified in paragraph (d) of this section unless the system:
                            </P>
                            <P>(A) Has re-optimized OCCT once under paragraph (d) of this section after the compliance date in § 141.80(a)(3);</P>
                            <P>(B) Is meeting optimal water quality parameters designated by the State; and</P>
                            <P>(C) Is continuing to operate and maintain corrosion control treatment as required in § 141.82(g).</P>
                            <P>(ii) The State may require a large water system that does not have to re-optimize under paragraphs (a)(1)(i)(A) through (C) of this section to re-optimize under § 141.82(h).</P>
                            <P>(iii) A large water system must meet the requirements under paragraph (d) of this section if it exceeds the lead action level at the end of a tap sampling period after completing service line replacement in accordance with the requirements in § 141.84(d) and there are no lead, galvanized requiring replacement, or lead status unknown service lines remaining in the system's inventory.</P>
                            <P>(iv) Large water systems with corrosion control treatment with 90th percentile results as calculated in accordance with § 141.80(c)(3) that exceed the lead practical quantitation limit of 0.005 mg/L but do not exceed the lead action level or the copper action level may be required by the State to complete the re-optimized OCCT steps in paragraph (d) of this section.</P>
                            <P>(v) Large water systems without corrosion control treatment with 90th percentile results as calculated in accordance with § 141.80(c)(3) that exceed either the lead practical quantitation limit of 0.005 mg/L or the copper action level must complete steps to study and install OCCT, as specified in paragraph (e) of this section.</P>
                            <P>
                                (2) 
                                <E T="03">Medium water systems (serving &gt;10,000 and ≤50,000 people).</E>
                                 (i) Medium water systems with corrosion control treatment that exceed either the lead action level or copper action level must complete the re-optimized OCCT steps specified in paragraph (d) of this section unless the system:
                            </P>
                            <P>(A) Has re-optimized OCCT once under paragraph (d) of this section after the compliance date in § 141.80(a)(3);</P>
                            <P>(B) Is meeting optimal water quality parameters designated by the State; and</P>
                            <P>(C) Is continuing to operate and maintain corrosion control treatment as required in § 141.82(g).</P>
                            <P>(ii) The State may require a medium water system that does not have to re-optimize under paragraphs (a)(2)(i)(A) through (C) of this section to re-optimize under § 141.82(h).</P>
                            <P>(iii) After completing service line replacement in accordance with the requirements in § 141.84(d) and there are no lead, galvanized requiring replacement, or lead status unknown service lines remaining in the inventory, if at the end of a subsequent tap sampling period, the system exceeds the lead action level, a medium water system with corrosion control treatment must meet the requirements under paragraph (d) of this section.</P>
                            <P>(iv) Medium water systems with corrosion control treatment that do not exceed either the lead action level or the copper action level and do not have optimal water quality parameters designated by the State must complete the steps specified in paragraph (d) of this section starting with step 6 under paragraph (d)(6) of this section unless the system is deemed optimized under paragraph (b)(3) of this section.</P>
                            <P>(v) Medium water systems without corrosion control treatment that exceed either the lead or copper action level must complete the OCCT steps specified in paragraph (e) of this section.</P>
                            <P>
                                (3) 
                                <E T="03">Small water systems (serving ≤10,000 people) and non-transient non-community water systems.</E>
                                 (i) Small and non-transient non-community water systems with corrosion control treatment that exceed either the lead action level or the copper action level, must complete the re-optimized OCCT steps specified in paragraph (d) of this section unless the system:
                            </P>
                            <P>
                                (A) Has re-optimized OCCT once under paragraph (d) of this section 
                                <PRTPAGE P="606"/>
                                after the compliance date in § 141.80(a)(3);
                            </P>
                            <P>(B) Is meeting optimal water quality parameters designated by the State; and</P>
                            <P>(C) Is continuing to operate and maintain corrosion control treatment as required in § 141.82(g).</P>
                            <P>(ii) The State may require a small water system that does not have to re-optimize under paragraphs (a)(3)(i)(A) through (C) of this section to re-optimize under § 141.82(h).</P>
                            <P>(iii) After completing service line replacement in accordance with the requirements in § 141.84(d) and there are no lead, galvanized requiring replacement, or lead status unknown service lines remaining in the inventory, if at the end of a subsequent tap sampling period, the system exceeds the lead action level, a small water system with corrosion control treatment must meet the requirements under paragraph (d) of this section.</P>
                            <P>(iv) Small and non-transient non-community water systems without corrosion control treatment that exceed either the lead action level or copper action level must complete the corrosion control treatment steps specified in paragraph (e) of this section.</P>
                            <P>
                                (b) 
                                <E T="03">Systems deemed to have optimized corrosion control.</E>
                                 A system without corrosion control treatment is deemed to have OCCT as defined in § 141.2 if the system meets the requirement of either paragraph (b)(1) or (3) of this section. A system with corrosion control treatment is deemed to have OCCT as defined in § 141.2 or re-optimized OCCT if the system meets the requirements of either paragraphs (b)(1) and (4) or (b)(3) and (4) of this section. Systems must submit documentation of meeting the applicable requirements to the State in accordance with § 141.90(c)(1) by the applicable deadline for submitting tap sampling results under § 141.90(a)(2).
                            </P>
                            <P>(1) A medium water system without corrosion control treatment or a small water system is deemed to have OCCT if the water system does not exceed the lead action level and copper action level during two consecutive six-month tap monitoring periods and then remains at or below the lead action level and copper action level in all tap sampling periods conducted in accordance with § 141.86.</P>
                            <P>(i) A small water system with corrosion control treatment is not eligible to be deemed to have OCCT pursuant to this paragraph (b)(1) where the State has set optimal water quality parameters (OWQPs) under paragraph (d) or (e) of this section.</P>
                            <P>(ii) If a medium water system without corrosion control treatment or a small water system deemed to have OCCT under this paragraph (b)(1) exceeds the lead action level or copper action level, the system must follow the requirements in paragraph (a) of this section.</P>
                            <P>(2) [Reserved]</P>
                            <P>(3) A water system is deemed to have optimized or re-optimized corrosion control treatment if it submits tap sampling results in accordance with § 141.86 demonstrating that the 90th percentile lead level is less than or equal to the lead practical quantitation limit of 0.005 mg/L for two consecutive six-month tap monitoring periods, it does not exceed the copper action level for two consecutive six-month tap monitoring periods, and it does not have OWQPs designated by the State under paragraph (d) or (e) of this section.</P>
                            <P>(i) A system with 90th percentile tap sampling results that later exceeds the lead practical quantitation limit of 0.005 mg/L or copper action level during any tap sampling period is not eligible to be deemed to have optimized OCCT in accordance with this paragraph (b)(3) until the system has completed the treatment steps specified in paragraph (d) or (e) of this section.</P>
                            <P>(ii) A system deemed to have OCCT in accordance with this paragraph (b)(3) must continue monitoring for lead and copper at the tap no less frequently than once every three calendar years using the reduced number of sites specified in § 141.86(d)(1) and collecting samples at times and locations specified in § 141.86(d)(2)(iii).</P>
                            <P>
                                (4) A system with corrosion control treatment deemed to have OCCT under 
                                <PRTPAGE P="607"/>
                                this paragraph (b) must continue to operate and maintain the corrosion control treatment and also meet any additional requirements that the State determines are appropriate to ensure OCCT is maintained.
                            </P>
                            <P>(c) [Reserved]</P>
                            <P>
                                (d) 
                                <E T="03">Treatment steps and deadlines for water systems re-optimizing optimal corrosion control treatment.</E>
                                 Water systems with corrosion control treatment that are required to re-optimize optimal corrosion control treatment under paragraph (a) of this section must complete the following steps (described in the referenced portions of §§ 141.82, 141.86, and 141.87) by the indicated time periods. Water systems must conduct tap sampling for lead and copper in accordance with the requirements of § 141.86 while they complete the corrosion control steps in this section.
                            </P>
                            <P>
                                (1) 
                                <E T="03">Step 1: Initiate mandatory pipe rig/loop or CCT study or treatment recommendation.</E>
                                 (i) Large or medium water systems with lead service lines that exceed the lead action level must harvest lead service lines from the distribution system and construct flowthrough pipe rigs/loops and operate the rigs/loops with finished water within one year after the end of the tap sampling period in which they exceeds the lead action level. These water systems must proceed to step 3 in paragraph (d)(3) of this section and conduct the corrosion control studies for re-optimization under paragraph (d)(3)(i) of this section using the pipe rigs/loops.
                            </P>
                            <P>(ii) Large water systems without lead service lines that exceed the lead action level or copper action level must conduct the corrosion control studies for re-optimization under paragraph (d)(3)(ii) of this section (step 3).</P>
                            <P>(iii) A water system other than those covered in paragraph (d)(1)(i) or (ii) of this section must recommend re-optimized optimal corrosion control treatment (§ 141.82(a)) within six months after the end of the tap sampling period in which the system exceeded either the lead action level or copper action level.</P>
                            <P>(iv) Systems may make an existing corrosion control treatment modification recommendation to the State within six months after the end of the tap sampling period in which the system exceeded the lead action level. The State must evaluate a system's past corrosion control treatment study results prior to approving an existing treatment modification. When a State approves existing treatment modifications, the State must specify re-optimized OCCT within 12 months after the end of the tap sampling period in which the system exceeded the lead action level. The system must complete modifications to corrosion control treatment to have re-optimized OCCT installed within six months of the State specifying re-optimized OCCT. These systems must proceed to step 6 in paragraph (d)(6) of this section and conduct follow-up monitoring.</P>
                            <P>
                                (2) 
                                <E T="03">Step 2: State requires CCT study or State designates re-optimized OCCT.</E>
                                 Within one year after the end of the tap sampling period in which a medium water system without lead service lines or a small system exceeded the lead action level or copper action level, the State may require the water system to perform corrosion control studies for re-optimization (§ 141.82(c)(2)). If the State does not require the system to perform such studies, the State must specify re-optimized optimal corrosion control treatment (§ 141.82(d)) within the timeframes specified in paragraphs (d)(2)(i) and (ii) of this section. The State must provide its determination to the system in writing:
                            </P>
                            <P>(i) For a medium water system, within one year after the end of the tap sampling period during which such water system exceeded the lead action level or copper action level.</P>
                            <P>(ii) For a small water system, within 18 months after the end of the tap sampling period in which such water system exceeded the lead action level or copper action level.</P>
                            <P>
                                (3) 
                                <E T="03">Step 3: Study duration.</E>
                                 (i) Any water system with lead service lines that exceeds the lead action level, in accordance with paragraph (d)(1)(i) of this section, must complete the pipe rig/loop corrosion control treatment studies and recommend re-optimized OCCT within 30 months after the end of the tap sampling period in which the system exceeded the lead action level.
                            </P>
                            <P>
                                (ii) If the water system is required to perform corrosion control studies under paragraph (d)(1)(ii) or (d)(2) of 
                                <PRTPAGE P="608"/>
                                this section, the water system must complete the studies (§ 141.82(c)) and recommend re-optimized OCCT within 18 months after the end of the tap sampling period in which the system exceeded the lead or copper action level or after the State requires that such studies be conducted.
                            </P>
                            <P>
                                (4) 
                                <E T="03">Step 4: State designation of re-optimized OCCT based on CCT study results.</E>
                                 The State must designate re-optimized OCCT (§ 141.82(d)) within six months after the water system completes paragraph (d)(3)(i) or (ii) of this section (step 3).
                            </P>
                            <P>
                                (5) 
                                <E T="03">Step 5: Re-optimized OCCT installation deadlines.</E>
                                 Water systems must install re-optimized OCCT (§ 141.82(e)) within one year after the State completes paragraph (d)(4) of this section (step 4) or the State completes paragraph (d)(2)(i) or (ii) of this section (step 2).
                            </P>
                            <P>
                                (6) 
                                <E T="03">Step 6: Follow-up monitoring.</E>
                                 Water systems must complete standard monitoring for at least two consecutive tap monitoring periods under § 141.86(c)(2)(iii)(D) and water quality parameter monitoring under § 141.87(b)(3) after completing paragraph (d)(5) of this section (step 5). The first tap monitoring period for standard monitoring must begin on January 1 or July 1, whichever is sooner, after completing paragraph (d)(5) (step 5).
                            </P>
                            <P>
                                (7) 
                                <E T="03">Step 7: State sets optimal water quality parameters (OWQPs).</E>
                                 The State must review the water system's re-optimized OCCT and designate OWQPs (§ 141.82(f)) within six months after completing paragraph (d)(6) of this section (step 6).
                            </P>
                            <P>
                                (8) 
                                <E T="03">Step 8: Systems meet OWQPs to demonstrate compliance.</E>
                                 Water systems must comply with the State-designated OWQPs (§ 141.82(g)) and conduct tap sampling under § 141.86(c)(2)(iii)(E) and water quality parameter monitoring under § 141.87(b)(4).
                            </P>
                            <P>
                                (e) 
                                <E T="03">Treatment steps and deadlines for systems without corrosion control treatment.</E>
                                 Except as provided in paragraph (b) of this section, water systems without corrosion control treatment must complete the following corrosion control treatment steps (described in the referenced portions of §§ 141.82, 141.86, and 141.87) by the indicated time periods. Water systems must conduct tap sampling for lead and copper in accordance with the requirements of § 141.86 while they complete the corrosion control steps in this section.
                            </P>
                            <P>
                                (1) 
                                <E T="03">Step 1: Initiate mandatory pipe rig/loop or CCT study or treatment recommendation.</E>
                                 (i) A medium or large water system with lead service lines that exceeds the lead action level must harvest lead pipes from the distribution system and construct flowthrough pipe rigs/loops and operate the rigs/loops with finished water within one year after the end of the tap sampling period during which the system exceeded the lead action level. These water systems must proceed to step 3 in paragraph (e)(3) of this section and conduct the corrosion control studies for optimization under paragraph (e)(3)(i) of this section using the pipe rigs/loops.
                            </P>
                            <P>(ii) Large water systems under paragraph (a)(1)(v) of this section must conduct the corrosion control studies for optimization under paragraph (e)(3) of this section (step 3).</P>
                            <P>(iii) A water system other than those covered in paragraph (e)(1)(i) or (ii) of this section must recommend optimal corrosion control treatment (OCCT) (§ 141.82(a)) within six months after the end of the tap sampling period during which the system exceeded either the lead action level or copper action level.</P>
                            <P>
                                (2) 
                                <E T="03">Step 2: State requires CCT study or State designates OCCT.</E>
                                 Within one year after the end of the tap sampling period in which the water system exceeded the lead action level or copper action level, the State may require the water system to perform corrosion control studies (§ 141.82(b)(1)) if those studies are not otherwise required by this subpart. The State must notify the system in writing of the requirement in the preceding sentence. If the State does not require the system to perform such studies, the State must specify OCCT (§ 141.82(d)) within the timeframes established in paragraphs (e)(2)(i) and (ii) of this section. The State must provide its determination to the system in writing:
                            </P>
                            <P>
                                (i) For a medium water system, within 18 months after the end of the tap sampling period in which such water system exceeds the lead action level or copper action level.
                                <PRTPAGE P="609"/>
                            </P>
                            <P>(ii) For a small water system, within 24 months after the end of the tap sampling period in which such water system exceeds the lead action level or copper action level.</P>
                            <P>
                                (3) 
                                <E T="03">Step 3: Study duration.</E>
                                 (i) Large and medium water systems with lead service lines that exceed the lead action level must complete the corrosion control treatment studies and recommend OCCT within 30 months after the end of the tap sampling period in which they exceeded the lead action level.
                            </P>
                            <P>(ii) If a water system is required to perform corrosion control studies under paragraph (e)(1)(ii) or (e)(2) of this section, the water system must complete the studies (§ 141.82(c)) and recommend OCCT within 18 months after the end of the tap sampling period in which the system exceeded the lead or copper action level or the State notifies the system in writing that such studies must be conducted.</P>
                            <P>
                                (4) 
                                <E T="03">Step 4: State designation of OCCT based on CCT study results.</E>
                                 The State must designate OCCT (§ 141.82(d)) within six months after water systems complete paragraph (e)(3)(i) or (ii) of this section (step 3).
                            </P>
                            <P>
                                (5) 
                                <E T="03">Step 5: OCCT installation deadlines.</E>
                                 Water systems must install OCCT (§ 141.82(e)) within 24 months after the State designates OCCT under paragraph (e)(2) or (4) of this section (step 2 or step 4).
                            </P>
                            <P>
                                (6) 
                                <E T="03">Step 6: Follow-up monitoring.</E>
                                 Water systems must complete standard monitoring for at least two consecutive tap monitoring periods under § 141.86(c)(2)(iii)(D) and water quality parameter monitoring under § 141.87(b)(3) after completing paragraph (e)(5) of this section (step 5). The first tap monitoring period for standard monitoring must begin on January 1 or July 1, whichever is sooner, after completing paragraph (e)(5) (step 5).
                            </P>
                            <P>
                                (7) 
                                <E T="03">Step 7: State sets optimal water quality parameters (OWQPs).</E>
                                 The State must review the water system's installation of treatment and designate OWQPs (§ 141.82(f)) within six months after completing paragraph (e)(6) of this section (step 6).
                            </P>
                            <P>
                                (8) 
                                <E T="03">Step 8: Systems meet OWQPs to demonstrate compliance.</E>
                                 Water systems must comply with the State-designated OWQPs (§ 141.82(g)) and conduct tap sampling under § 141.86(c)(2)(iii)(E) and water quality parameter monitoring under § 141.87(b)(4).
                            </P>
                            <P>
                                (f) 
                                <E T="03">Systems with lead or galvanized requiring replacement service lines that can complete full service line replacement in five years or less.</E>
                                 (1) A water system with one or more lead or galvanized requiring replacement service lines is not required to complete the steps under paragraph (d) or (e) of this section if the system meets all the following requirements:
                            </P>
                            <P>(i) Deadline to complete mandatory service line replacement.</P>
                            <P>(A) A water system must complete the service line replacement requirements under § 141.84(d) in five years or less from the date of the end of the tap sampling period in which the system first exceeds the lead action level; or</P>
                            <P>(B) A large water system without corrosion control treatment must complete the service line replacement requirements under § 141.84(d) in five years or less from the date of the end of the tap sampling period in which the system's 90th percentile results first exceed the lead practical quantitation limit; and</P>
                            <P>(C) For a water system with less than five years remaining to complete mandatory service line replacement in accordance with § 141.84(d), the system must complete the service line replacement requirements under this paragraph (f)(1)(i) by that deadline.</P>
                            <P>
                                (ii) At a minimum, a system must replace the total number of lead and/or galvanized requiring replacement service lines each year, as identified in that system's inventory on the date of the end of the tap sampling period in which the system first exceeds the lead action level or in which the system's 90th percentile first exceeds the lead practical quantitation limit, whichever applies, at an annual rate equally divided by the total number of years for service line replacement provided in paragraph (f)(1)(i) of this section. For purposes of calculating the annual rate, the system must replace all lead and galvanized requiring replacement service lines within the least number of years feasible not to exceed five years from the date of the end of the tap sampling period in which the system first exceeds 
                                <PRTPAGE P="610"/>
                                the lead action level or in which the system's 90th percentile first exceeds the lead practical quantitation limit, whichever applies. If the State determines a replacement deadline less than five years is feasible for a water system, the system must replace service lines by that deadline and establish an annual replacement rate based on that number of years until that deadline.
                            </P>
                            <P>
                                (iii) By the end of the five-year-or-less period in paragraph (f)(1)(i) of this section, the system must have replaced all lead and galvanized requiring replacement service lines calculated in accordance with § 141.84(d)(6) (
                                <E T="03">i.e.,</E>
                                 no lead, galvanized requiring replacement or lead status unknown service lines remain in the inventory), and identified the material of all lead status unknown service lines, completed the inventory validation requirements in accordance with § 141.84(b)(5), and replaced all unknowns found to be lead or galvanized requiring replacement service lines.
                            </P>
                            <P>(iv) Except as provided in this section, all other requirements in § 141.84(d) apply.</P>
                            <P>(2) Throughout the five-year-or-less period in paragraph (f)(1)(i) of this section, systems with corrosion control treatment must continue to operate and maintain corrosion control treatment in addition to completing the mandatory service line replacement requirements under this section.</P>
                            <P>(3) A water system that does not replace lead and/or galvanized requiring replacement service lines calculated in accordance with § 141.84(d)(6) at the minimum annual rate provided in paragraph (f)(1)(ii) of this section in any one year of the five-year-or-less period in paragraph (f)(1)(i) of this section or complete the service line replacement requirements under § 141.84(d) in accordance with paragraph (f)(1)(iii) of this section, must meet the requirements under paragraph (d) or (e) of this section, as applicable, starting immediately after the system fails to meet the annual removal requirements under paragraph (f)(1)(ii).</P>
                            <P>(4) At the end of each year of the five-year-or-less period, the system must submit written documentation to the State about the number of lead and galvanized requiring replacement service lines removed that year and whether the minimum annual replacement rate in paragraph (f)(1)(ii) of this section was met. If a system reports or a State determines that the system did not meet its minimum annual replacement rate that year, the system is no longer eligible to defer the requirements under paragraph (d) or (e) of this section, and must meet those requirements, as applicable.</P>
                            <P>(5) After completing service line replacement in accordance with the requirements in this paragraph (f), a water system must meet the requirements under paragraph (d) or (e) of this section, as applicable, if at the end of a subsequent tap sampling period, the system either exceeds the lead action level or the lead practical quantitation limit, whichever is applicable.</P>
                            <P>
                                (g) 
                                <E T="03">Completing corrosion control steps for small and medium water systems without corrosion control treatment.</E>
                                 (1) Any small or medium water system without corrosion control treatment required to complete the steps in paragraph (e) of this section that does not exceed the lead action level and copper action level during two consecutive six-month tap monitoring periods pursuant to § 141.86 prior to the start of step 3 in paragraph (e)(3) of this section or prior to or concurrent with the end of step 4 in paragraph (e)(4) of this section may stop completing the steps and is not required to complete paragraph (e)(3) or (5) (step 3 or step 5), respectively, except that medium water systems without corrosion control treatment and with lead service lines must complete a corrosion control treatment study under paragraph (e)(3)(i) of this section. A 90th percentile level at or below the lead action level or copper action level based on less than the required minimum number of samples under § 141.86 cannot be used to meet the requirements of this paragraph (g)(1). Eligible systems can only use the exception in this paragraph (g)(1) once.
                            </P>
                            <P>
                                (2) Any system that starts step 5 in accordance with paragraph (e)(5) of this section must complete all remaining steps (
                                <E T="03">i.e.,</E>
                                 steps 6 through 8) in paragraphs (e)(6) through (8) of this section and is not permitted to stop the steps.
                                <PRTPAGE P="611"/>
                            </P>
                            <P>(3) Any small or medium water system without corrosion control treatment under paragraph (g)(1) of this section that stopped the steps in paragraph (e) of this section and subsequently exceeds either the lead action level or copper action level must complete the corrosion control treatment steps in paragraph (e) beginning with the first treatment step that was not completed.</P>
                            <P>(4) The State may require a water system to repeat treatment steps previously completed by the water system when the State determines that this is necessary to implement the treatment requirements of this section. The State must notify the system in writing of such a determination and explain the basis for its decision.</P>
                            <P>
                                (h) 
                                <E T="03">Notification requirements for upcoming long-term change in treatment or source.</E>
                                 At a time specified by the State, or if no specific time is designated, as early as possible but no later than six months prior to the addition of a new source or any long-term change in water treatment, a water system must submit written documentation describing the addition of a new source or long-term change in treatment to the State. Systems may not implement the addition of a new source or long-term treatment change without State approval. The State must review and approve the addition of a new source or long-term change in water treatment before it can be implemented by the water system. The State may require any such water system to take actions before or after the addition of a new source or long-term treatment change to ensure that the water system will operate and maintain optimal corrosion control treatment, such as additional water quality parameter monitoring, additional lead or copper tap sampling, and re-evaluating corrosion control treatment. Examples of long-term treatment changes include but are not limited to the addition of a new treatment process or modification of an existing treatment process. Examples of modifications include switching secondary disinfectants, switching coagulants (
                                <E T="03">e.g.,</E>
                                 alum to ferric chloride), and switching corrosion inhibitor products (
                                <E T="03">e.g.,</E>
                                 orthophosphate to blended phosphate). Long-term treatment changes can also include dose changes to existing chemicals if the system is planning long-term changes to its finished water pH or residual inhibitor concentration. Long-term treatment changes would not include chemical dose fluctuations associated with daily raw water quality changes where a new source has not been added.
                            </P>
                            <CITA>[89 FR 86627, Oct. 30, 2024]</CITA>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 141.82</SECTNO>
                            <SUBJECT>Description of corrosion control treatment requirements.</SUBJECT>
                            <P>This section provides the requirements for systems and States designating optimal corrosion control treatment (OCCT) for a system that is optimizing or re-optimizing OCCT. All systems must complete the corrosion control treatment requirements in this section as applicable under § 141.81.</P>
                            <P>
                                (a) 
                                <E T="03">System recommendation regarding corrosion control treatment.</E>
                                 (1) Any system without corrosion control treatment that is required to recommend a treatment option in accordance with § 141.81(e)(1)(iii) must, based on the results of lead and copper tap sampling and water quality parameter monitoring, recommend designating one or more of the corrosion control treatments listed in paragraph (c)(1) of this section to the State as the optimal corrosion control treatment for that system. The State may require the system to conduct additional water quality parameter monitoring to assist the State in reviewing the system's recommendation.
                            </P>
                            <P>(2) Any system with corrosion control treatment that exceeds the lead action level that is required to recommend a treatment option to the State in accordance with § 141.81(d)(1)(iii) must recommend designating one or more of the corrosion control treatments listed in paragraph (c)(2) of this section as the optimal corrosion control treatment for that system.</P>
                            <P>
                                (3) States may waive the requirement for a system to recommend OCCT if the State requires the system, in writing, to complete a corrosion control study within three months after the end of the tap sampling period in which the lead or copper action level exceedance occurred. These systems must proceed 
                                <PRTPAGE P="612"/>
                                directly to paragraph (c) of this section and complete a corrosion control study.
                            </P>
                            <P>
                                (b) 
                                <E T="03">State decision to require studies to identify initial OCCT under § 141.81(e)(2) and re-optimized OCCT under § 141.81(d)(2).</E>
                                 (1) The State may require any small or medium water system without corrosion control treatment that exceeds either the lead action level or copper action level to perform corrosion control treatment studies under paragraph (c)(1) of this section to identify OCCT for the system.
                            </P>
                            <P>
                                (2) The State may require any small or medium water system with corrosion control treatment exceeding either the lead action level or copper action level to perform corrosion control treatment studies under paragraph (c)(2) of this section to identify re-optimized OCCT for the system (
                                <E T="03">i.e.,</E>
                                 OCCT after a re-optimization evaluation).
                            </P>
                            <P>
                                (c) 
                                <E T="03">Performance of corrosion control studies.</E>
                                 (1) Systems without corrosion control treatment required to conduct corrosion control studies under § 141.81(e) must evaluate the effectiveness of each of the following treatments, and if appropriate, combinations of the following treatments, to identify OCCT for the system:
                            </P>
                            <P>(i) Alkalinity and pH adjustment;</P>
                            <P>(ii) The addition of an orthophosphate- or a silicate-based corrosion inhibitor at a concentration sufficient to maintain an effective corrosion inhibitor residual concentration in all test samples;</P>
                            <P>
                                (iii) The addition of an orthophosphate-based corrosion inhibitor at a concentration sufficient to maintain an orthophosphate residual concentration of 1 mg/L (as PO
                                <E T="52">4</E>
                                ) in all test samples; and
                            </P>
                            <P>
                                (iv) The addition of an orthophosphate-based corrosion inhibitor at a concentration sufficient to maintain an orthophosphate residual concentration of 3 mg/L (as PO
                                <E T="52">4</E>
                                ) in all test samples.
                            </P>
                            <P>(2) Systems with corrosion control treatment required to conduct corrosion control studies under § 141.81(d) must evaluate the effectiveness of the following treatments, and if appropriate, combinations of the following treatments, to identify re-optimized OCCT for the system:</P>
                            <P>(i) Alkalinity and/or pH adjustment or re-adjustment;</P>
                            <P>(ii) The addition of an orthophosphate- or a silicate-based corrosion inhibitor at a concentration sufficient to maintain an effective corrosion inhibitor residual concentration in all test samples if no such inhibitor is currently utilized;</P>
                            <P>
                                (iii) The addition of an orthophosphate-based corrosion inhibitor at a concentration sufficient to maintain an orthophosphate residual concentration of 1 mg/L (as PO
                                <E T="52">4</E>
                                ) in all test samples unless the current inhibitor process already meets this residual; and
                            </P>
                            <P>
                                (iv) The addition of an orthophosphate-based corrosion inhibitor at a concentration sufficient to maintain an orthophosphate residual concentration of 3 mg/L (as PO
                                <E T="52">4</E>
                                ) in all test samples unless the current inhibitor process already meets this residual.
                            </P>
                            <P>(3) Systems must evaluate each of the corrosion control treatments specified in paragraph (c)(1) or (2) of this section individually or, if appropriate, in combinations, using pipe rig/loop tests, metal coupon tests, partial-system tests, and/or analyses based on documented analogous treatments with similar size systems that have a similar water chemistry and similar distribution system configurations. Large and medium water systems with lead service lines, and other systems as required by the State, that exceed the lead action level must conduct pipe rig/loop studies using harvested lead service lines from their distribution systems to assess the effectiveness of corrosion control treatment options on the existing pipe scale. Metal coupon tests can be used as a screen to reduce the number of options evaluated in the pipe rig/loop studies to the current water quality and at least two additional treatment options.</P>
                            <P>(4) Systems must measure the following water quality parameters in any tests conducted under paragraph (c)(3) of this section both before and after evaluating the corrosion control treatments listed in paragraph (c)(1) or (2) of this section:</P>
                            <P>(i) Lead;</P>
                            <P>
                                (ii) Copper;
                                <PRTPAGE P="613"/>
                            </P>
                            <P>(iii) pH;</P>
                            <P>(iv) Alkalinity;</P>
                            <P>
                                (v) Orthophosphate as PO
                                <E T="52">4</E>
                                 (when an orthophosphate-based inhibitor is used);
                            </P>
                            <P>(vi) Silicate (when a silicate-based inhibitor is used); and</P>
                            <P>(vii) Any additional parameters necessary to evaluate the effectiveness of a corrosion control treatment as determined by the State.</P>
                            <P>(5) Systems must identify all chemical or physical constraints that limit or prohibit the use of a particular corrosion control treatment and document those constraints by providing either of the following:</P>
                            <P>(i) Data and documentation showing a particular corrosion control treatment has adversely affected other drinking water treatment processes when used by another water system with comparable water quality characteristics. Systems using metal coupon tests to screen and/or pipe rig/loop studies to evaluate treatment options cannot exclude treatment strategies from the studies based on the constraints identified in this paragraph (c)(5)(i).</P>
                            <P>(ii) Data and documentation demonstrating the water system previously attempted to evaluate a particular corrosion control treatment and found the treatment was ineffective or adversely affects other drinking water quality treatment processes. Systems using metal coupon tests to screen and/or pipe rig/loop studies to evaluate treatment options cannot exclude treatment strategies from the studies based on the constraints identified in this paragraph (c)(5)(ii), unless the treatment was found to be ineffective in a previous pipe rig/loop study.</P>
                            <P>(6) Systems must evaluate the effect of the chemicals used for corrosion control treatment on other drinking water quality treatment processes. Systems using metal coupon tests to screen and/or pipe rig/loop studies to evaluate treatment options cannot exclude any of the required treatment strategies specified in paragraph (c)(1) or (2) of this section from the studies based on the effects identified in this section.</P>
                            <P>(7) Based on the data and analysis for each treatment option evaluated under this paragraph (c), systems must recommend to the State, in writing, the treatment option that the corrosion control studies indicate constitutes OCCT for that system as defined in § 141.2. Systems must provide the State with a rationale for the OCCT recommendation and all supporting documentation specified in paragraph (c)(1) or (2) and paragraphs (c)(3) through (7) of this section.</P>
                            <P>
                                (d) 
                                <E T="03">State designation of OCCT and re-optimized OCCT</E>
                                —(1) 
                                <E T="03">Designation of OCCT or re-optimized OCCT.</E>
                                 Based on available information including, where applicable, studies conducted under paragraph (c)(1) or (2) of this section and/or a system's recommended corrosion control treatment option, the State must either approve the corrosion control treatment option recommended by the system or designate alternative corrosion control treatment(s) from among those listed in paragraph (c)(1) or (2) of this section, as applicable. The State must notify the water system, in writing, of its designation of OCCT or re-optimized OCCT and explain the basis for this determination.
                            </P>
                            <P>(i) When designating OCCT, the State must consider the effects that additional corrosion control treatment will have on water quality parameters and other drinking water quality treatment processes.</P>
                            <P>(ii) If the State requests additional information to aid its review, the water system must provide that information.</P>
                            <P>(2) [Reserved]</P>
                            <P>
                                (e) 
                                <E T="03">Installation of OCCT and re-optimized OCCT.</E>
                                 Each system must install and operate the OCCT or re-optimized OCCT designated by the State under paragraph (d) of this section throughout its distribution system.
                            </P>
                            <P>
                                (f) 
                                <E T="03">State review of treatment and designation of optimal water quality parameters for OCCT and re-optimized OCCT.</E>
                                 The State must evaluate the results of all lead and copper tap and water quality parameter sampling submitted by the water system and determine whether the water system has installed and operated the OCCT designated by the State in paragraph (d) of this section. Upon reviewing the system's tap and water quality parameter sampling 
                                <PRTPAGE P="614"/>
                                results, both before and after the water system installs OCCT, or re-optimizes OCCT, the State must designate each of the following:
                            </P>
                            <P>(1) A minimum value or a range of values for pH measured at each entry point to the distribution system.</P>
                            <P>(2) A minimum pH value measured in all distribution system samples. This value must be equal to or greater than 7.0, unless the State determines that meeting a pH level of 7.0 is not technologically feasible or is not necessary for OCCT.</P>
                            <P>
                                (3) If a corrosion inhibitor is used, a minimum concentration or a range of concentrations for orthophosphate (as PO
                                <E T="52">4</E>
                                ) or silicate measured at each entry point to the distribution system.
                            </P>
                            <P>
                                (4) If a corrosion inhibitor is used, a minimum orthophosphate (as PO
                                <E T="52">4</E>
                                ) or silicate concentration measured in all tap samples that the State determines is necessary to form a passivating film on the interior walls of the pipes of the distribution system. When orthophosphate is used, for OCCT designations for systems previously without corrosion control treatment, the orthophosphate concentration must be equal to or greater than 0.5 mg/L (as PO
                                <E T="52">4</E>
                                ) and for OCCT designations for systems previously with corrosion control treatment, the orthophosphate concentration must be equal to or greater than 1.0 mg/L, unless the State determines that meeting the applicable minimum orthophosphate residual is not technologically feasible or is not necessary for OCCT.
                            </P>
                            <P>(5) If alkalinity is adjusted as part of OCCT, a minimum concentration or a range of concentrations for alkalinity, measured at each entry point to the distribution system and in all tap samples.</P>
                            <P>(6) The values for the applicable water quality parameters in paragraphs (f)(1) through (5) of this section must be the values the State determines reflect OCCT or re-optimized OCCT for the water system. The State may designate values for additional water quality parameters the State determines reflect OCCT or re-optimized OCCT for the water system. The State must notify the system, in writing, of these determinations and explain the basis for its decisions.</P>
                            <P>
                                (g) 
                                <E T="03">Continued operation and monitoring for OCCT and re-optimized OCCT.</E>
                                 All systems, including those optimizing or re-optimizing OCCT, must continue to operate and maintain OCCT, including maintaining water quality parameters at or above the minimum values or within the ranges designated by the State under paragraph (f) of this section, in accordance with this paragraph (g) for all water quality parameter samples collected under § 141.87(b)(4) through (d). The requirements of this paragraph (g) apply to all systems, including consecutive systems that distribute water that has been treated to control corrosion by another system, and any water system with corrosion control treatment, OCCT, or re-optimized OCCT that is not required to monitor water quality parameters under § 141.87.
                            </P>
                            <P>(1) Compliance with the requirements of this paragraph (g) must be determined every six months, as specified under § 141.87(b)(4). A water system is out of compliance with the requirements of this paragraph (g) for a six-month period if it has excursions for any State-specified parameter on more than nine days, cumulatively, during the period. An excursion occurs whenever the daily value for one or more of the water quality parameters measured at a sampling location is below the minimum value or outside the range designated by the State. Daily values are calculated as set out in paragraph (g)(2) of this section. States have discretion to not include results of obvious sampling errors from this calculation. Sampling errors must still be recorded even when not included in calculations.</P>
                            <P>
                                (2)(i) On days when more than one measurement for the water quality parameter is collected at the sampling location, the daily value must be the average of all results collected at that sampling location during the same day regardless of whether they are collected through continuous monitoring, grab sampling, or a combination of both. If EPA has approved an alternative formula under § 142.16(d)(1)(ii) of this chapter in the State's application for a program revision submitted pursuant to § 142.12 of this chapter, the 
                                <PRTPAGE P="615"/>
                                State's formula must be used to aggregate multiple measurements taken at a sampling point for the water quality parameters in lieu of the formula in this paragraph (g)(2).
                            </P>
                            <P>(ii) On days when only one measurement for the water quality parameter is collected at the sampling location, the daily value must be the result of that measurement.</P>
                            <P>(iii) On days when no measurement is collected for the water quality parameter at the sampling location, the daily value must be the daily value calculated on the most recent day on which the water quality parameter was measured at the sampling location.</P>
                            <P>
                                (h) 
                                <E T="03">Modification of State treatment determination for OCCT and re-optimized OCCT.</E>
                                 Upon its own initiative or in response to a request by a water system or other interested party, a State may modify its determination of OCCT under paragraph (d) of this section, or optimal water quality parameters under paragraph (f) of this section. A request for modification by a system or other interested party must be in writing, explaining why the modification is appropriate, and providing supporting documentation. The State may require a system to conduct a CCT study to support modification of the determination of OCCT or re-optimized OCCT. The State may modify its determination where it concludes that such change is necessary to ensure that the water system continues to optimize corrosion control treatment. A revised designation must be made in writing, set forth the new treatment requirements and/or optimal water quality parameters, explain the basis for the State's determination, and provide an implementation schedule for completing the treatment modifications for re-optimized corrosion control treatment.
                            </P>
                            <P>
                                (i) 
                                <E T="03">Treatment decisions by EPA in lieu of the State on OCCT and re-optimized OCCT.</E>
                                 Pursuant to the procedures in § 142.19 of this chapter, the EPA Regional Administrator may review OCCT determinations made by a State under paragraph (d), (f), or (h) of this section and issue Federal corrosion control treatment determinations consistent with the requirements of paragraph (d), (f), or (h) where the EPA Regional Administrator finds that:
                            </P>
                            <P>(1) A State failed to issue a treatment determination by the applicable deadlines contained in § 141.81;</P>
                            <P>(2) A State abused its discretion; or</P>
                            <P>(3) The technical aspects of a State's determination would be indefensible in a Federal enforcement action taken against a water system.</P>
                            <P>
                                (j) 
                                <E T="03">Distribution System and Site Assessment for tap sample sites with lead results that exceed 0.010 mg/L.</E>
                                 The water system must conduct the following steps when the lead results from an individual tap sample site sampled under § 141.86 exceed 0.010 mg/L and the site is included in the site sample plan under § 141.86(a)(1):
                            </P>
                            <P>
                                (1) 
                                <E T="03">Step 1: Corrosion control treatment assessment.</E>
                                 Within five days of receiving the tap sampling results, the water system must sample at a water quality parameter site in accordance with paragraph (j)(1)(ii) of this section that is on the same size water main in the same pressure zone and located within a half mile radius of the site with the lead result exceeding 0.010 mg/L. Water systems without corrosion control treatment are not required to collect these samples.
                            </P>
                            <P>(i) The water system must measure the following water quality parameters:</P>
                            <P>(A) pH;</P>
                            <P>(B) Alkalinity;</P>
                            <P>
                                (C) Orthophosphate (as PO
                                <E T="52">4</E>
                                ), when an inhibitor containing an orthophosphate compound is used; and
                            </P>
                            <P>(D) Silica, when an inhibitor containing a silicate compound is used.</P>
                            <P>(ii) The water system must measure at the following locations:</P>
                            <P>(A) Water systems with an existing water quality parameter site that meets the requirements in this paragraph (j)(1) can conduct this sampling at that site.</P>
                            <P>
                                (B) All water systems required to meet optimal water quality parameters but do not have an existing water quality parameter site that meets the requirements in this paragraph (j)(1) must add new sites to the minimum number of sites as described in § 141.87(b)(1)(i). Sites must be added until a system has twice the minimum number of sites listed in table 1 to 
                                <PRTPAGE P="616"/>
                                § 141.87(b)(1)(i). When a system exceeds twice the number of sites, the State has discretion to determine if these additional newer sites can better assess the effectiveness of the corrosion control treatment and whether to remove existing sites during sanitary survey evaluation of OCCT.
                            </P>
                            <P>
                                (2) 
                                <E T="03">Step 2: Site assessment.</E>
                                 Within 30 days of receiving the tap sampling results, water systems must collect and analyze a follow-up sample for lead at any tap sample site that exceeds 0.010 mg/L. These follow-up samples may use different sample volumes or different sample collection procedures to assess the source of elevated lead levels. Samples collected under this section must be submitted to the State but cannot be included in the 90th percentile calculation for compliance monitoring under § 141.86. If the water system is unable to collect a follow-up sample at a site, the water system must provide documentation to the State, as specified in § 141.90(g)(2), explaining why it was unable to collect a follow-up sample.
                            </P>
                            <P>
                                (3) 
                                <E T="03">Step 3: Evaluate results and system treatment recommendation.</E>
                                 Water systems must evaluate the results of the sampling conducted under paragraphs (j)(1) and (2) of this section to determine if either localized or centralized adjustment of the OCCT or other distribution system actions are necessary and submit the recommendation to the State within six months after the end of the tap sampling period in which the site(s) exceeded 0.010 mg/L. Corrosion control treatment modification may not be necessary to address every exceedance of 0.010 mg/L. Other distribution system actions may include flushing to reduce water age. Water systems must note the cause of the elevated lead level, if known from the site assessment, in their recommendation to the State as site-specific issues can be an important factor in why the system is not recommending any adjustment of corrosion control treatment or other distribution system actions. Systems in the process of optimizing or re-optimizing OCCT under paragraphs (a) through (f) of this section do not need to submit a treatment recommendation for distribution system and site assessment.
                            </P>
                            <P>
                                (4) 
                                <E T="03">Step 4: State approval of treatment recommendation.</E>
                                 The State must approve the treatment recommendation or specify a different approach within six months of completing step 3 as described in paragraph (j)(3) of this section and notify the water system in writing.
                            </P>
                            <P>
                                (5) 
                                <E T="03">Step 5: Modifications to OCCT.</E>
                                 If the State-approved treatment recommendation requires the water system to adjust the OCCT process, the water system must complete modifications to its corrosion control treatment within 12 months of receiving notification from the State as described in paragraph (j)(4) of this section. Systems without corrosion control treatment required to install OCCT must follow the schedule in § 141.81(e).
                            </P>
                            <P>
                                (6) 
                                <E T="03">Step 6: Follow-up sampling.</E>
                                 Water systems adjusting OCCT must complete follow-up sampling in accordance with §§ 141.86(c)(2)(iii)(D) and 141.87(b)(3) within 12 months after completing step 5 as described in paragraph (j)(5) of this section and submit sampling results to the State in accordance with §§ 141.86 and 141.87.
                            </P>
                            <P>
                                (7) 
                                <E T="03">Step 7: State OWQP designation.</E>
                                 For water systems adjusting OCCT, the State must review the water system's modification of corrosion control treatment and designate optimal water quality parameters in accordance with paragraph (f) of this section within six months of receiving sampling result in paragraph (j)(6) of this section.
                            </P>
                            <P>
                                (8) 
                                <E T="03">Step 8: Operate in compliance.</E>
                                 For a water system adjusting OCCT, the water system must operate in compliance with the State-designated optimal water quality parameters in accordance with paragraph (g) of this section and continue to conduct tap sampling in accordance with §§ 141.86(c)(2)(iii)(E) and 141.87(b)(4).
                            </P>
                            <CITA>[89 FR 86631, Oct. 30, 2024]</CITA>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 141.83</SECTNO>
                            <SUBJECT>Source water treatment requirements.</SUBJECT>
                            <P>
                                Systems shall complete the applicable source water monitoring and treatment requirements (described in the referenced portions of paragraph (b) of this section, and in §§ 141.86, and 141.88) by the following deadlines.
                                <PRTPAGE P="617"/>
                            </P>
                            <P>
                                (a) 
                                <E T="03">Deadlines for completing source water treatment steps</E>
                                —(1) 
                                <E T="03">Step 1:</E>
                                 A system exceeding the lead or copper action level shall complete lead and copper source water monitoring (§ 141.88(b)) and make a treatment recommendation to the State (§ 141.83(b)(1)) no later than 180 days after the end of the monitoring period during which the lead or copper action level was exceeded.
                            </P>
                            <P>
                                (2) 
                                <E T="03">Step 2:</E>
                                 The State shall make a determination regarding source water treatment (§ 141.83(b)(2)) within 6 months after submission of monitoring results under step 1.
                            </P>
                            <P>
                                (3) 
                                <E T="03">Step 3:</E>
                                 If the State requires installation of source water treatment, the system shall install the treatment (§ 141.83(b)(3)) within 24 months after completion of step 2.
                            </P>
                            <P>
                                (4) 
                                <E T="03">Step 4.</E>
                                 The system shall complete follow-up tap water monitoring (§ 141.86(c)(2)(iii)(F)) and source water monitoring (§ 141.88(c)) within 36 months after completion of step 2 as described in paragraph (a)(2) of this section.
                            </P>
                            <P>
                                (5) 
                                <E T="03">Step 5:</E>
                                 The State shall review the system's installation and operation of source water treatment and specify maximum permissible source water levels (§ 141.83(b)(4)) within 6 months after completion of step 4.
                            </P>
                            <P>
                                (6) 
                                <E T="03">Step 6:</E>
                                 The system shall operate in compliance with the State-specified maximum permissible lead and copper source water levels (§ 141.83(b)(4)) and continue source water monitoring (§ 141.88(d)).
                            </P>
                            <P>
                                (b) 
                                <E T="03">Description of source water treatment requirements</E>
                                —(1) 
                                <E T="03">System treatment recommendation.</E>
                                 Any system which exceeds the lead or copper action level shall recommend in writing to the State the installation and operation of one of the source water treatments listed in paragraph (b)(2) of this section. A system may recommend that no treatment be installed based upon a demonstration that source water treatment is not necessary to minimize lead and copper levels at users' taps.
                            </P>
                            <P>
                                (2) 
                                <E T="03">State determination regarding source water treatment.</E>
                                 The State shall complete an evaluation of the results of all source water samples submitted by the water system to determine whether source water treatment is necessary to minimize lead or copper levels in water delivered to users' taps. If the State determines that treatment is needed, the State shall either require installation and operation of the source water treatment recommended by the system (if any) or require the installation and operation of another source water treatment from among the following: Ion exchange, reverse osmosis, lime softening or coagulation/filtration. If the State requests additional information to aid in its review, the water system shall provide the information by the date specified by the State in its request. The State shall notify the system in writing of its determination and set forth the basis for its decision.
                            </P>
                            <P>
                                (3) 
                                <E T="03">Installation of source water treatment.</E>
                                 Each system shall properly install and operate the source water treatment designated by the State under paragraph (b)(2) of this section.
                            </P>
                            <P>
                                (4) 
                                <E T="03">State review of source water treatment and specification of maximum permissible source water levels.</E>
                                 The State shall review the source water samples taken by the water system both before and after the system installs source water treatment, and determine whether the system has properly installed and operated the source water treatment designated by the State. Based upon its review, the State shall designate the maximum permissible lead and copper concentrations for finished water entering the distribution system. Such levels shall reflect the contaminant removal capability of the treatment properly operated and maintained. The State shall notify the system in writing and explain the basis for its decision.
                            </P>
                            <P>
                                (5) 
                                <E T="03">Continued operation and maintenance.</E>
                                 Each water system shall maintain lead and copper levels below the maximum permissible concentrations designated by the State at each sampling point monitored in accordance with § 141.88. The system is out of compliance with this paragraph if the level of lead or copper at any sampling point is greater than the maximum permissible concentration designated by the State.
                            </P>
                            <P>
                                (6) 
                                <E T="03">Modification of State treatment decisions.</E>
                                 Upon its own initiative or in response to a request by a water system or other interested party, a State may 
                                <PRTPAGE P="618"/>
                                modify its determination of the source water treatment under paragraph (b)(2) of this section, or maximum permissible lead and copper concentrations for finished water entering the distribution system under paragraph (b)(4) of this section. A request for modification by a system or other interested party shall be in writing, explain why the modification is appropriate, and provide supporting documentation. The State may modify its determination where it concludes that such change is necessary to ensure that the system continues to minimize lead and copper concentrations in source water. A revised determination shall be made in writing, set forth the new treatment requirements, explain the basis for the State's decision, and provide an implementation schedule for completing the treatment modifications.
                            </P>
                            <P>
                                (7) 
                                <E T="03">Treatment decisions by EPA in lieu of the State.</E>
                                 Pursuant to the procedures in § 142.19, the EPA Regional Administrator may review treatment determinations made by a State under paragraphs (b) (2), (4), or (6) of this section and issue Federal treatment determinations consistent with the requirements of those paragraphs where the Administrator finds that:
                            </P>
                            <P>(i) A State has failed to issue a treatment determination by the applicable deadlines contained in § 141.83(a),</P>
                            <P>(ii) A state has abused its discretion in a substantial number of cases or in cases affecting a substantial population, or</P>
                            <P>(iii) The technical aspects of a State's determination would be indefensible in an expected Federal enforcement action taken against a system.</P>
                            <CITA>[56 FR 26548, June 7, 1991, as amended at 72 FR 57815, Oct. 10, 2007; 89 FR 86634, Oct. 30, 2024]</CITA>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 141.84</SECTNO>
                            <SUBJECT>Service line inventory and replacement requirements.</SUBJECT>
                            <P>
                                (a) 
                                <E T="03">Service line and connector inventory development.</E>
                                 All water systems must develop a service line inventory that identifies the material and location of each service line connected to the public water distribution system. The inventory must include all service lines connected to the public water distribution system regardless of ownership status (
                                <E T="03">e.g.,</E>
                                 where service line ownership is shared, the inventory includes both the portion of the service line owned by the water system and the portion of the service line owned by the customer). The inventory must meet the following requirements:
                            </P>
                            <P>(1) All water systems are required to develop an initial inventory and submit it to the State by October 16, 2024, as specified in § 141.80(a)(4)(i).</P>
                            <P>
                                (2) All water systems must develop an updated initial inventory, known as the “baseline inventory”. Systems must submit the baseline inventory to the State by the compliance date in § 141.80(a)(3). Newly regulated public water systems, as defined in § 141.2, must develop a baseline inventory on a schedule established by the State that does not exceed three years from the date the system becomes subject to National Primary Drinking Water Regulations in this part. The baseline inventory must include each service line and identified connector that is connected to the public water distribution system regardless of ownership status (
                                <E T="03">e.g.,</E>
                                 where service line ownership is shared, the inventory includes both the portion of the service line owned by the water system and the portion of the service line owned by the customer).
                            </P>
                            <P>(i) For the baseline inventory, water systems must conduct a review of any information listed in paragraphs (b)(2)(i) through (iii) of this section that describes connector materials and locations. Water systems must also conduct a review of any information on lead and galvanized iron or steel materials that they have identified pursuant to § 141.42(d) to identify connector materials and locations. The water system may use other sources of information not listed in paragraphs (b)(2)(i) through (iii) if approved or required by the State.</P>
                            <P>(ii) Water systems must include each connector identified in paragraph (a)(2)(i) of this section in their baseline inventory. Connector materials must be categorized in the following manner:</P>
                            <P>(A) “Lead” where the connector is made of lead.</P>
                            <P>
                                (B) “Non-Lead” where the connector is determined through an evidence-based record, method, or technique not to be made of lead. Water systems are not required to identify the specific 
                                <PRTPAGE P="619"/>
                                material of a non-lead connector; however, they may use the material (
                                <E T="03">e.g.,</E>
                                 copper or galvanized) as an alternative to categorizing it as “Non-Lead”.
                            </P>
                            <P>(C) “Unknown” where the material of the connector is not known.</P>
                            <P>
                                (D) “No connector present” where there is no connector at the location (
                                <E T="03">e.g.,</E>
                                 where a service line directly connects a water main to a building inlet).
                            </P>
                            <P>(iii) All water systems must include any new information on service line materials from all applicable sources described in paragraph (b)(2) of this section in the baseline inventory.</P>
                            <P>(3) Each service line, or portion of the service line where ownership is shared, must be categorized in the following manner:</P>
                            <P>(i) “Lead” where the service line is a lead service line as defined in § 141.2.</P>
                            <P>(ii) “Galvanized Requiring Replacement” where the service line is a galvanized requiring replacement service line as defined in § 141.2.</P>
                            <P>
                                (iii) “Non-Lead” where the service line is determined through an evidence-based record, method, or technique not to be a lead or galvanized requiring replacement service line. Water systems are not required to identify the specific material of a non-lead service line; however, they may use the material (
                                <E T="03">e.g.,</E>
                                 plastic or copper) as an alternative to categorizing it as “Non-Lead”.
                            </P>
                            <P>(iv) “Lead Status Unknown” or “Unknown” where the service line material is not known to be lead, galvanized requiring replacement, or non-lead, such as where there is no documented evidence or evidence reliably supporting material categorization. Water systems may elect to provide more information regarding their unknown service lines as long as the inventory clearly distinguishes unknown service lines from those where the categorization of the material is based on the categorization methods approved under paragraph (b)(2) of this section.</P>
                            <P>(4) The inventory must include a street address associated with each service line and connector. Where a street address is not available for an individual service line or connector, a unique locational identifier (e.g., block, Global Positioning System or GPS coordinates, intersection, or landmark) may be used.</P>
                            <P>(5) The inventory must be publicly accessible.</P>
                            <P>(i) The publicly accessible inventory must include the information described in paragraphs (a)(2) through (4) of this section and be updated in accordance with paragraph (b) of this section.</P>
                            <P>(ii) Water systems serving greater than 50,000 persons must make the publicly accessible inventory available online.</P>
                            <P>(6) When a water system has no lead, galvanized requiring replacement, or lead status unknown service lines, no known lead connectors, and no connectors of unknown material, it may comply with the requirements in paragraph (a)(5) of this section using a written statement in lieu of the publicly accessible inventory, declaring that the distribution system has no lead, galvanized requiring replacement, or lead status unknown service lines, no known lead connectors, and no connectors of unknown material. The statement must include a general description of all applicable sources used in the inventory as described in paragraphs (a)(1) and (2) and (b)(2) of this section to make this determination.</P>
                            <P>(7) Instructions to access the publicly accessible inventory (including inventories consisting only of a statement in accordance with paragraph (a)(6) of this section) must be included in the Consumer Confidence Report in accordance with § 141.153(h)(8)(ii).</P>
                            <P>
                                (b) 
                                <E T="03">Additional requirements for service line and connector inventory maintenance.</E>
                                 (1) All water systems must update the baseline inventory of service lines and connectors developed in paragraph (a)(2) of this section and submit the updates to the State on an annual basis in accordance with § 141.90(e)(4). These updates begin one year after the compliance date in § 141.80(a)(3). The publicly accessible inventory must reflect any updates no later than the deadline to submit the updated inventory to the State.
                            </P>
                            <P>
                                (i) All water systems must identify the material of all lead status unknown service lines by the applicable mandatory service line replacement deadline in paragraph (d)(4) of this section.
                                <PRTPAGE P="620"/>
                            </P>
                            <P>(ii) Water systems whose inventories contain only non-lead service lines and non-lead connectors or no connectors present are not required to provide updated inventories to the State or updates to the publicly accessible inventory. If, in the future, such a water system discovers a lead service line, galvanized requiring replacement service line, or lead connector within its system, the system must notify the State no later than 60 days after the discovery, prepare an updated inventory in accordance with this section on a schedule established by the State, replace the lead or galvanized requiring replacement service line in accordance with paragraph (d)(4)(ii) of this section, and replace any lead connector along the service line in accordance with paragraph (e) of this section.</P>
                            <P>(2) Water systems must update the inventory annually with any new information acquired from all applicable sources described in paragraphs (b)(2) through (4) of this section and follow all applicable requirements for the inventory in paragraphs (a) and (b) of this section. The water system may update the inventory using other sources of information not listed in paragraphs (b)(2)(i) through (iii) of this section if the use of those sources is approved or required by the State.</P>
                            <P>(i) All construction and plumbing codes, permits, and records or other documentation that indicate the service line and connector materials used to connect structures to the distribution system.</P>
                            <P>(ii) All water system records on service lines and connectors, including distribution system maps and drawings, recent or historical records on each service connection and connector, meter installation records, historical capital improvement or master plans, and standard operating procedures.</P>
                            <P>(iii) All records of inspections in the distribution system that indicate the material composition of the service connections and connectors that connect a structure to the distribution system.</P>
                            <P>(iv) Water systems must update their inventory annually based on any lead or galvanized requiring replacement service line replacements, service line material inspections, or lead connector replacements that have been conducted. Each updated inventory and subsequent update to the publicly accessible inventory must include the following information regarding service line material identification and replacement:</P>
                            <P>(A) The total number of lead service lines in the inventory;</P>
                            <P>(B) The total number of galvanized requiring replacement service lines in the inventory;</P>
                            <P>(C) The total number of lead status unknown service lines in the inventory;</P>
                            <P>(D) The total number of non-lead service lines in the inventory;</P>
                            <P>(E) The total number of lead connectors in the inventory;</P>
                            <P>(F) The total number of connectors of unknown material in the inventory;</P>
                            <P>(G) The total number of full lead service line replacements and full galvanized requiring replacement service line replacements that have been conducted in each preceding program year as defined in paragraph (d)(5)(iii) of this section; and</P>
                            <P>(H) The total number of partial lead service line replacements and partial galvanized requiring replacement service line replacements that have been conducted in each preceding program year as defined in paragraph (d)(5)(iii) of this section.</P>
                            <P>
                                (v) Water systems must identify service line material in accordance with paragraph (a)(3) of this section, connector material in accordance with paragraph (a)(2) of this section, and addresses in accordance with paragraph (a)(4) of this section as they are encountered in the course of normal operations (
                                <E T="03">e.g.,</E>
                                 checking service line materials when reading water meters or performing maintenance activities). Water systems must update the inventory annually based on the identified service line materials, connector materials and addresses.
                            </P>
                            <P>
                                (3) Water systems that discover a lead or galvanized requiring replacement service line that was previously inventoried as non-lead must update their inventory in accordance with paragraph (b)(2) of this section and, if applicable, paragraph (b)(1)(ii) of this section. Water systems must notify the State in accordance with § 141.90(e) and 
                                <PRTPAGE P="621"/>
                                comply with any additional actions required by the State to address the inventory inaccuracy.
                            </P>
                            <P>(4) If a consumer or customer (if different from the person served at that service connection) notifies the water system of a suspected incorrect categorization of their service line material in the inventory, the system must respond to the consumer or customer within 30 days of receiving the notification to make an offer to inspect the service line.</P>
                            <P>(5) All water systems must validate the accuracy of the non-lead service line category in the inventory as follows:</P>
                            <P>
                                (i) The water system must identify a validation pool consisting of all service lines categorized as “non-lead,” but excluding non-lead service lines identified by the following: records showing the service line was installed after June 19, 1988, or after the compliance date of a State or local law prohibiting the use of service lines that do not meet the 1986 definition of lead free in accordance with section 1417 of the Safe Drinking Water Act, as amended in 1986 (Pub. L. 99-339, title I, sec. 109(a), 100 Stat. 651) and 40 CFR 141.43(d)(1) and (2), as codified on July 1, 1991, whichever is earlier; visual inspection of the pipe exterior at a minimum of two points (
                                <E T="03">e.g.,</E>
                                 excavation, visual inspection in the meter pit or stop box, or visual inspection inside the home); or previously replaced lead or galvanized requiring replacement service lines.
                            </P>
                            <P>
                                (ii) The water system must confirm the service line material of a random sample (
                                <E T="03">e.g.,</E>
                                 a sample selected by use of a random number generator or lottery method) of non-lead service lines from the validation pool. Confirmation of service line material must be done by visual inspection of the pipe exterior at a minimum of two points. Where ownership is shared, the water system must conduct at least one visual inspection on each portion of the service line. Where ownership is shared and only one portion of the service line is included in the validation pool, systems must conduct at least one point of visual inspection on the unconfirmed portion of the service line. Water systems must validate at least as many service lines as are required in table 1 to this paragraph (b)(5)(ii).
                            </P>
                            <GPOTABLE COLS="2" OPTS="L2" CDEF="s50,r50">
                                <TTITLE>
                                    Table 1 to Paragraph 
                                    <E T="01">(b)(5)(ii)</E>
                                </TTITLE>
                                <BOXHD>
                                    <CHED H="1">Size of validation pool</CHED>
                                    <CHED H="1">Number of validations required</CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">&lt;1,500</ENT>
                                    <ENT>20 percent of validation pool.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">1,500 to 2,000</ENT>
                                    <ENT>322.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">2,001 to 3,000</ENT>
                                    <ENT>341.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">3,001 to 4,000</ENT>
                                    <ENT>351.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">4,001 to 6,000</ENT>
                                    <ENT>361.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">6,001 to 10,000</ENT>
                                    <ENT>371.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">10,001 to 50,000</ENT>
                                    <ENT>381.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">&gt;50,000</ENT>
                                    <ENT>384.</ENT>
                                </ROW>
                            </GPOTABLE>
                            <P>(iii) If physical access to private property is necessary to complete the validation and the water system is unable to gain access, the system is not required to conduct a validation at that site. The system must replace the site by randomly selecting a new service line that meets the requirements of paragraph (b)(5)(i) of this section to conduct the validation.</P>
                            <P>(iv) The deadlines for inventory validation are:</P>
                            <P>(A) No later than December 31 following seven years after the compliance date in § 141.80(a)(3) for water systems subject to the mandatory service line replacement deadline in paragraph (d)(4) of this section or water systems who have reported only non-lead service lines in their baseline inventory, submitted to the State in accordance with § 141.90(e)(9);</P>
                            <P>(B) A deadline established by the State for water systems conducting mandatory service line replacement on a shortened deadline for service line replacement as established by the State in accordance with paragraph (d)(5)(v) of this section; or</P>
                            <P>(C) A deadline established by the State to be no later than three years prior to the deadline for completing mandatory service line replacement if the water system is eligible for and plans to use a deferred deadline under paragraph (d)(5)(vi) of this section or an extended schedule for mandatory service line replacement pursuant to an exemption or a variance.</P>
                            <P>
                                (v) Water systems that conduct inventory validation pursuant to this paragraph (b)(5) must complete the validation by the applicable deadline described in paragraph (b)(5)(iv) of this 
                                <PRTPAGE P="622"/>
                                section, submit the results of the validation in accordance with § 141.90(e)(9), and comply with any additional actions required by the State to address inventory inaccuracies. The system must submit to the State the specific version (including the date) of the service line inventory that was used to determine the number of non-lead service lines included in the validation pool in accordance with § 141.90(e)(9).
                            </P>
                            <P>(vi) Water systems may make a written request to the State to approve a waiver of the inventory validation requirements in this paragraph (b). To obtain a waiver, the water system must submit documentation to the State to demonstrate the system has conducted an inventory validation that is at least as stringent as the inventory validation requirements specified in paragraphs (b)(5)(i) through (iii) of this section by the compliance date in § 141.80(a)(3) and obtain written approval of the waiver from the State.</P>
                            <P>
                                (c) 
                                <E T="03">Service line replacement plan.</E>
                                 All water systems with one or more lead, galvanized requiring replacement, or lead status unknown service lines in their distribution system must create a service line replacement plan by the compliance date in § 141.80(a)(3) and submit a service line replacement plan to the State in accordance with § 141.90(e). The service line replacement plan must be sufficiently detailed to ensure a system is able to comply with the service line inventory and replacement requirements in this section.
                            </P>
                            <P>(1) The service line replacement plan must include a description of:</P>
                            <P>(i) A strategy for determining the material composition of lead status unknown service lines in the service line inventory under paragraph (a) of this section;</P>
                            <P>
                                (ii) A standard operating procedure for conducting full service line replacement (
                                <E T="03">e.g.,</E>
                                 techniques to replace service lines);
                            </P>
                            <P>
                                (iii) A communication strategy to inform consumers (
                                <E T="03">i.e.,</E>
                                 persons served at the service connection) and customers before a full or partial lead or galvanized requiring replacement service line replacement consistent with the requirements for notification and mitigation in paragraph (h) of this section;
                            </P>
                            <P>(iv) A procedure for consumers and customers to flush service lines and premise plumbing of particulate lead following disturbance of a lead, galvanized requiring replacement, or lead status unknown service line in accordance with § 141.85(f) and following full or partial replacement of a lead or galvanized requiring replacement service line consistent with the requirements for notification and mitigation in paragraph (h) of this section;</P>
                            <P>(v) A strategy to prioritize service line replacement based on factors including, but not limited to, known lead and galvanized requiring replacement service lines and community-specific factors, such as populations disproportionately impacted by lead and populations most sensitive to the effects of lead;</P>
                            <P>(vi) A funding strategy for conducting service line replacement. Where the water system intends to charge customers for the cost to replace all or a portion of the service line because it is authorized or required to do so under State or local law or water tariff agreement, the funding strategy must include a description of whether and how the water system intends to assist customers who are unable to pay to replace the portion of the service line they own;</P>
                            <P>
                                (vii) A communication strategy to inform residential and non-residential customers and consumers (
                                <E T="03">e.g.,</E>
                                 property owners, renters, and tenants) served by the water system about the service line replacement plan and program; and
                            </P>
                            <P>(viii) Identification of any laws, regulations, and/or water tariff agreements that affect the water system's ability to gain access to conduct full lead and galvanized requiring replacement service line replacement, including the citation to the specific laws, regulations, or water tariff agreement provisions. This includes identification of any laws, regulations, and/or water tariff agreements that require customer consent and/or require or authorize customer cost-sharing.</P>
                            <P>
                                (ix) For any water system that identifies any lead-lined galvanized service lines in the service line inventory as described in paragraphs (a) and (b) of this section, a strategy to determine 
                                <PRTPAGE P="623"/>
                                the extent of the use of lead-lined galvanized service lines in the distribution system and categorize any lead-lined galvanized service lines as lead pursuant to table 2 to paragraph (d)(6)(iii)(A) of this section.
                            </P>
                            <P>(x) For any water system that is eligible for and plans to use a deferred deadline pursuant to paragraph (d)(5)(vi) of this section:</P>
                            <P>(A) Documentation to support the system's determination that it is eligible for a deferred deadline, showing that 10 percent of the total number of known lead and galvanized requiring replacement service lines in the replacement pool exceeds 39 annual replacements per 1,000 service connections as calculated in paragraph (d)(5)(vi)(A) of this section;</P>
                            <P>(B) Identification of the deferred deadline and the associated cumulative average replacement rate that the system considers to be the fastest feasible but no slower than a deadline and replacement rate corresponding to 39 annual replacements per 1,000 service connections as calculated in paragraph (d)(5)(vi)(A) of this section, as well as the annual number of replacements required, the length of time (in years and months), and the date of completion for this deadline and rate; and</P>
                            <P>(C) Information supporting the system's determination that replacing lead and galvanized requiring replacement service lines by an earlier date and faster rate than provided under the deferred deadline provision in paragraph (d)(5)(vi) of this section is not feasible.</P>
                            <P>(2) The service line replacement plan must be made accessible to the public. Water systems serving greater than 50,000 persons must make the plan available to the public online.</P>
                            <P>(3) Water systems must annually update the service line replacement plan to include any new or updated information and submit the updates to the State on an annual basis in accordance with § 141.90(e). The water system must make the updated plan publicly accessible no later than the deadline to submit the updated plan to the State.</P>
                            <P>(i) If there is no new or updated information to include in the service line replacement plan since the previous iteration, the water system may certify to the State that the plan has no updates in lieu of resubmitting the plan unless the system is replacing service lines in accordance with a deferred deadline and paragraph (c)(3)(ii) of this section applies.</P>
                            <P>(ii) If there is no new or updated information to include in the service line replacement plan and the water system is replacing service lines in accordance with a deferred deadline pursuant to paragraph (d)(5)(vi) of this section, every three years after the initial submission of the plan, the system must update the information specified in paragraph (c)(1)(x) of this section to support why the system continues to need the deferred deadline and resubmit the plan to the State.</P>
                            <P>(iii) If there are no longer lead, galvanized requiring replacement, and unknown service lines in the inventory as described in paragraphs (a) and (b) of this section, water systems are not required to resubmit the service line replacement plan or certify to the State that the plan has no updates.</P>
                            <P>
                                (d) 
                                <E T="03">Mandatory full service line replacement.</E>
                                 (1) All water systems must replace all lead and galvanized requiring replacement service lines under the control of the water system unless the replacement would leave in place a partial lead service line.
                            </P>
                            <P>
                                (2) Where a water system has access (
                                <E T="03">e.g.,</E>
                                 legal access, physical access) to conduct full service line replacement, the service line is under its control, and the water system must replace the service line. Where a water system does not have access to conduct full service line replacement, the water system is not required by this subpart to replace the line, but the water system must document the reasons that the water system does not have access and include any specific laws, regulations, and/or water tariff agreements that affect the water system's ability to gain access to conduct full replacement of lead and galvanized requiring replacement service lines. The water system must provide this documentation to the State pursuant to § 141.90(e)(10).
                            </P>
                            <P>
                                (i) This subpart does not establish the criteria for determining whether a system has access to conduct full service line replacement. Any applicable State or local laws or water tariff 
                                <PRTPAGE P="624"/>
                                agreement requirements to gain access to conduct full service line replacement must be identified in the service line replacement plan as described in paragraph (c) of this section.
                            </P>
                            <P>(ii) [Reserved]</P>
                            <P>(3) Where a water system has legal access to conduct full service line replacement only if property owner consent is obtained, the water system must make a “reasonable effort” to obtain property owner consent. If such a water system does not obtain consent after making a “reasonable effort” to obtain it from any property owner, then the water system is not required by this subpart to replace any portion of the service line at that address unless there is a change in ownership of the property as described in paragraph (d)(3)(ii) of this section. The water system must provide documentation of the reasonable effort to the State pursuant to § 141.90(e)(10).</P>
                            <P>
                                (i) A “reasonable effort” must include at least four attempts to engage the property owner using at least two different methods of communication (
                                <E T="03">e.g.,</E>
                                 in-person conversation, phone call, text message, email, written letter, postcard, or information left at the door such as a door hanger) before the applicable deadline of mandatory service line replacement as described in paragraph (d)(4) of this section. The State may require systems to conduct additional attempts and may require specific outreach methods to be used.
                            </P>
                            <P>(ii) Within six months of any change in ownership of the property, the water system must offer full service line replacement to any new property owner. Systems may use new service initiation or service transfer to a new customer to identify when there is a change in ownership. Within one year of any change in ownership of the property, the system must make a “reasonable effort” to obtain the property owner's consent as described in paragraph (d)(3)(i) of this section. If the water system is unable to obtain consent from the current property owner after making a “reasonable effort” to obtain it, the water system is not required under this subpart to replace the line. This paragraph (d)(3)(ii) continues to apply until all lead and galvanized requiring replacement service lines are replaced.</P>
                            <P>(4) The deadline for water systems to replace all lead and galvanized requiring replacement service lines under the control of the water system is no later than 10 program years after the compliance date specified in § 141.80(a)(3) unless the system is subject to a different deadline under paragraphs (d)(5)(v) and (vi) of this section.</P>
                            <P>(i) Water systems must start mandatory service line replacement programs no later than the compliance date specified in § 141.80(a)(3).</P>
                            <P>(ii) If a lead or galvanized requiring replacement service line is discovered when the system's inventory is comprised of only non-lead service lines, the system must complete the following requirements:</P>
                            <P>(A) Update the replacement pool calculated under paragraph (d)(6)(i) of this section.</P>
                            <P>(B) Conduct a full service line replacement of the affected service line as soon as practicable but no later than 180 days after the date the service line is discovered. Where a system determines that it is not practicable to conduct full service line replacement within 180 days after the date of discovery (e.g., due to freezing ground conditions), the system may request State approval for an extension of no later than one year after the date the service line was discovered to replace the affected service line. The request for an extension must be made no later than 90 days after the date of discovery of the affected service line.</P>
                            <P>(5) Water systems must meet a minimum cumulative average annual replacement rate for completing mandatory service line replacement in accordance with this paragraph (d)(5):</P>
                            <P>
                                (i) 
                                <E T="03">Annual replacement rate.</E>
                                 A water system must replace lead and galvanized requiring replacement service lines as described in paragraph (d)(6) of this section at an average annual replacement rate of at least 10 percent calculated across a cumulative period unless the system is subject to a shortened replacement rate or eligible for a deferred replacement rate in accordance with paragraphs (d)(5)(v) and (vi) of this section.
                                <PRTPAGE P="625"/>
                            </P>
                            <P>
                                (ii) 
                                <E T="03">Cumulative percent of service lines replaced.</E>
                                 To calculate the cumulative percent of service lines replaced, at the end of each mandatory service line replacement “program year” as specified in paragraph (d)(5)(iii) of this section, water systems must divide the total number of lead and galvanized requiring replacement service lines replaced thus far in the program in accordance with paragraph (d)(6)(iii) of this section by the number of service lines within the replacement pool in accordance with paragraph (d)(6)(i) of this section.
                            </P>
                            <P>
                                (iii) 
                                <E T="03">Program year.</E>
                                 The first mandatory service line replacement “program year” is from the compliance date specified in § 141.80(a)(3) to the end of the next calendar year. Every program year thereafter is on a calendar year basis. This paragraph (d)(5)(iii) applies for the purposes of this section.
                            </P>
                            <P>
                                (iv) 
                                <E T="03">Cumulative average replacement rate.</E>
                                 The annual replacement rate in paragraph (d)(5)(i) of this section is assessed annually as a cumulative average. The first cumulative average replacement rate must be assessed at the end of the third program year and is calculated by dividing the cumulative percent of service lines replaced in accordance with paragraph (d)(5)(ii) of this section by the number of completed program years (or three in this case). Annually thereafter, at the end of each program year, systems must assess the cumulative average replacement rate by dividing the most recent cumulative percent of service lines replaced in accordance with paragraph (d)(5)(ii) by the number of completed program years. Except as provided in paragraph (d)(5)(iv)(A) of this section, the cumulative average replacement rate must be 10 percent or greater each program year, and the water system must replace all lead and galvanized requiring replacement service lines under its control by the applicable deadline for completing mandatory service line replacement in accordance with paragraph (d)(4) of this section.
                            </P>
                            <P>(A) A water system is not required by this section to meet the cumulative average replacement rate described in this paragraph (d)(5) where, after the compliance date specified in § 141.80(a)(3), the system has replaced all lead and galvanized requiring replacement service lines in the replacement pool as described in paragraph (d)(6)(i) of this section that are under the control of the system, identified all unknown service lines in the inventory, and documented and submitted to the State the reasons the system currently does not have access to conduct full replacement of the remaining lead and galvanized requiring replacement service lines in the replacement pool in accordance with paragraphs (d)(2) and (3) of this section. When lead and galvanized requiring replacement service lines come under the control of the system, the water system is required to replace the service lines as described in this paragraph (d). This paragraph (d)(5)(iv)(A) continues to apply until all lead and galvanized requiring replacement service lines are replaced.</P>
                            <P>(B) [Reserved]</P>
                            <P>
                                (v) 
                                <E T="03">Shortened deadline and associated replacement rate.</E>
                                 Where the State determines that a shortened replacement deadline is feasible for a water system (
                                <E T="03">e.g.,</E>
                                 by considering the number of lead and galvanized requiring replacement service lines in a system's inventory), the system must replace service lines by the State-determined deadline and by a faster minimum replacement rate in accordance with paragraph (d)(5)(v)(A) of this section. The State must make this determination in writing and notify the system of its finding. The State must set a shortened deadline at any time throughout a system's replacement program if a State determines a shorter deadline is feasible. This paragraph (d)(5)(v) also applies to systems eligible for a deferred deadline as specified in paragraph (d)(5)(vi) of this section.
                            </P>
                            <P>
                                (A) Systems must replace lead and galvanized requiring replacement service lines at an average annual replacement rate calculated by dividing 100 by the number of years needed to meet the shortened deadline determined by the State, expressed as a percentage. Systems must comply with the cumulative average replacement rate in accordance with paragraph (d)(5)(iv) of this section, where the first cumulative average replacement rate is assessed at the end of the program year that is at least one year after the shortened deadline determination, as determined 
                                <PRTPAGE P="626"/>
                                by the State, unless the shortened replacement deadline is less than three years. If the system's shortened replacement deadline is less than three years, the cumulative average replacement rate must be assessed on a schedule determined by the State.
                            </P>
                            <P>(B) [Reserved]</P>
                            <P>
                                (vi) 
                                <E T="03">Deferred deadlines and associated replacement rates.</E>
                                 A water system may defer service line replacement past the deadline in paragraph (d)(4) of this section if the system meets the following criteria:
                            </P>
                            <P>(A) If a water system replacing 10 percent of the total number of known lead and galvanized requiring replacement service lines in a system's replacement pool results in an annual number of service line replacements by the water system that exceeds 39 per 1,000 service connections, the system may complete replacement of all lead and galvanized requiring replacement service lines by a deadline that corresponds to the system conducting 39 annual replacements per 1,000 service connections at a cumulative average replacement rate assessed in accordance with paragraph (d)(5)(iv) of this section. This paragraph (d)(5)(vi)(A) is also applicable if a water system with service lines newly under their control, after previously not having control as described in paragraph (d)(5)(iv)(A) of this section, is required to conduct more than 39 annual replacements per 1,000 service connections. The number of annual replacements corresponding to 39 annual replacements per 1,000 service connections can be calculated by multiplying the number of service connections in a system by 0.039. The number of years needed to complete replacement is the total number of known lead and galvanized requiring replacement service lines in a system's replacement pool divided by the calculated number of annual replacements. To calculate the minimum cumulative average replacement rate, the system must divide 100 by the number of years needed to achieve replacing 39 annual replacements per 1,000 service connections, expressed as a percentage.</P>
                            <P>(B) Any water system that is eligible for and plans to use a deferred deadline must include information, in accordance with paragraph (c)(1)(x) of this section, to support the use of a deferred deadline including identifying the deadline and associated cumulative average rate of replacement to meet this deferred deadline in the system's initial service line replacement plan and subsequent updates to the plan in accordance with paragraph (c) of this section. The system must identify an annual replacement rate that is no less than 39 annual replacements per 1,000 service connections.</P>
                            <P>(C) As soon as practicable, but no later than the end of the second program year as defined in paragraph (d)(5)(iii) of this section, and every three years thereafter, the State must determine in writing whether the deferred deadline and associated cumulative average replacement rate the system documented in paragraph (c)(1)(x)(B) of this section are the fastest feasible to conduct mandatory service line replacement and either approve the continued use of this deferred deadline and replacement rate as the fastest feasible for the system, or set a shorter deferred deadline and identify an associated replacement rate to ensure the system is replacing service lines at the fastest feasible rate for the system. The State must consider information that includes, but is not limited to, the system's submissions of the service line inventory and replacement plan in accordance with paragraph (a) through (c) of this section and information collected from other water systems conducting mandatory service line replacement. The State may require the system to provide additional information for the State to consider in its assessment of the continued use of a deferred deadline and the fastest feasible replacement rate.</P>
                            <P>
                                (D) In the first two program years, the system must comply with the annual replacement rate identified in its initial replacement plan (unless the State determines a faster rate is feasible sooner). In subsequent program years, the system must comply with the applicable deferred deadline and associated replacement rate identified in the State's written determination of the deadline and replacement rate in paragraph (d)(5)(vi)(C) of this section.
                                <PRTPAGE P="627"/>
                            </P>
                            <P>(6) Calculation of the replacement pool, the annual number of replacements required, and the number of service lines replaced each year to calculate a system's cumulative average replacement rate described in paragraph (d)(5) of this section are as follows:</P>
                            <P>
                                (i) 
                                <E T="03">Replacement pool.</E>
                                 To calculate the replacement pool, systems must add the total number of lead, galvanized requiring replacement, and lead status unknown service lines in the baseline inventory submitted by the compliance date specified in § 141.80(a)(3). The water system must not subtract lead or galvanized requiring replacement service lines from the replacement pool when they are replaced. The water system must not subtract service lines that are not under the control of the system from the replacement pool. At the beginning of each program year, water systems must update the replacement pool according to the counts of specific types of recategorized service lines in the inventory annually thereafter as described in this paragraph (d)(6)(i):
                            </P>
                            <P>(A) Unknown service lines that are identified as non-lead service lines must be subtracted from the replacement pool. Unknown service lines that are identified as lead or galvanized requiring replacement service lines must be recategorized appropriately in the inventory and replacement pool, but they do not change the number of service lines in the replacement pool because recategorization does not remove these service lines from the replacement pool.</P>
                            <P>(B) Non-lead service lines discovered to be lead or galvanized requiring replacement service lines must be added to the replacement pool.</P>
                            <P>(C) Lead or galvanized requiring replacement service lines discovered to be non-lead service lines must be subtracted from the replacement pool.</P>
                            <P>(D) Each entire service line must count only once for purposes of calculating the replacement pool.</P>
                            <P>
                                (ii) 
                                <E T="03">Annual number of replacements required.</E>
                                 To calculate the number of lead and galvanized requiring replacement service lines a system is required to replace in a given program year, divide the number of service lines in the most up-to-date replacement pool, calculated at the beginning of each program year, by the total number of years remaining under paragraph (d)(4) of this section to complete mandatory service line replacement (e.g., 10 years).
                            </P>
                            <P>
                                (iii) 
                                <E T="03">Number of service lines replaced.</E>
                                 When calculating the cumulative average replacement rate, the water system may only include full service line replacements of lead or galvanized requiring replacement service lines when counting the number of service lines replaced. Wherever the system conducts a replacement of a lead or galvanized requiring replacement service line (either a portion of a service line or the entire service line), the replacement counts as a full service line replacement only if, after the replacement, the entire service line can be categorized in the inventory as non-lead under paragraph (a)(3)(iii) of this section.
                            </P>
                            <P>(A) For purposes of mandatory service line replacement, systems must count each entire service line once, including where ownership of the service line is shared, with a single material categorization in accordance with table 2 to this paragraph (d)(6)(iii)(A).</P>
                            <GPOTABLE COLS="3" OPTS="L2" CDEF="s50,r50,r50">
                                <TTITLE>
                                    Table 2 to Paragraph 
                                    <E T="01">(d)(6)(iii)</E>
                                    (A)
                                </TTITLE>
                                <BOXHD>
                                    <CHED H="1">System-owned portion</CHED>
                                    <CHED H="1">Customer-owned portion</CHED>
                                    <CHED H="1">
                                        Categorization for entire
                                        <LI>service line</LI>
                                    </CHED>
                                </BOXHD>
                                <ROW>
                                    <ENT I="01">Lead</ENT>
                                    <ENT>Lead</ENT>
                                    <ENT>Lead.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Lead</ENT>
                                    <ENT>Galvanized Requiring Replacement</ENT>
                                    <ENT>Lead.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Lead</ENT>
                                    <ENT>Non-lead</ENT>
                                    <ENT>Lead.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Lead</ENT>
                                    <ENT>Lead Status Unknown</ENT>
                                    <ENT>Lead.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Non-lead</ENT>
                                    <ENT>Lead</ENT>
                                    <ENT>Lead.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Non-lead and never previously lead</ENT>
                                    <ENT>Non-lead, specifically galvanized pipe material</ENT>
                                    <ENT>Non-lead.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Non-lead</ENT>
                                    <ENT>Non-lead, material other than galvanized pipe material</ENT>
                                    <ENT>Non-lead.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Non-lead</ENT>
                                    <ENT>Lead Status Unknown</ENT>
                                    <ENT>Lead Status Unknown.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Non-lead, but system is unable to demonstrate it was not previously Lead</ENT>
                                    <ENT>Galvanized Requiring Replacement</ENT>
                                    <ENT>Galvanized Requiring Replacement.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Lead Status Unknown</ENT>
                                    <ENT>Lead</ENT>
                                    <ENT>Lead.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Lead Status Unknown</ENT>
                                    <ENT>Galvanized Requiring Replacement</ENT>
                                    <ENT>Galvanized Requiring Replacement.</ENT>
                                </ROW>
                                <ROW>
                                    <PRTPAGE P="628"/>
                                    <ENT I="01">Lead Status Unknown</ENT>
                                    <ENT>Non-lead</ENT>
                                    <ENT>Lead Status Unknown.</ENT>
                                </ROW>
                                <ROW>
                                    <ENT I="01">Lead Status Unknown</ENT>
                                    <ENT>Lead Status Unknown</ENT>
                                    <ENT>Lead Status Unknown.</ENT>
                                </ROW>
                            </GPOTABLE>
                            <P>(B) A full service line replacement is counted where a non-lead service line is installed for use and the lead or galvanized requiring replacement service line is disconnected from the water main or other service line. If the lead or galvanized requiring replacement service line is disconnected from the water main or system-owned portion of the service line but not removed, the water system must be subject to a State or local law or have a written policy to preclude the water system from reconnecting the lead or galvanized requiring replacement service line to the water main or other service line.</P>
                            <P>
                                (C) A full service line replacement may be counted where a system physically disconnects a service line that is not in use and the water system does not install a new non-lead service line because there is no service line in use (
                                <E T="03">e.g.,</E>
                                 at an abandoned property). If the disconnected lead or galvanized requiring replacement service line is not removed, the water system must be subject to a State or local law or have a written policy to preclude the water system from reconnecting the disconnected service line (
                                <E T="03">i.e.,</E>
                                 a new non-lead service line must be installed if active use is to resume).
                            </P>
                            <P>(D) Water systems must not count the following as a full service line replacement for purposes of this subpart:</P>
                            <P>
                                (
                                <E T="03">1</E>
                                ) Where the service line is partially replaced as defined in § 141.2.
                            </P>
                            <P>
                                (
                                <E T="03">2</E>
                                ) Where a lead, galvanized requiring replacement, or unknown service line is determined to be a non-lead service line.
                            </P>
                            <P>
                                (
                                <E T="03">3</E>
                                ) Where only a lead connector is replaced.
                            </P>
                            <P>
                                (
                                <E T="03">4</E>
                                ) Where pipe lining or coating technologies are used while the lead or galvanized requiring replacement service line remains in use.
                            </P>
                            <P>
                                (
                                <E T="03">5</E>
                                ) Where a water system does not replace a lead or galvanized requiring replacement service line because it is not be under the control of the system as described in paragraph (d)(2) of this section.
                            </P>
                            <P>
                                (e) 
                                <E T="03">Replacement of lead connectors when encountered by a water system.</E>
                                 (1) The water system must replace any lead connector when encountered during planned or unplanned water system infrastructure work unless the connector is not under the control of the system (e.g., where the system does not have and cannot obtain access to conduct the connector replacement).
                            </P>
                            <P>(i) Upon replacement of any connector that is attached to a lead or galvanized requiring replacement service line, the water system must follow risk mitigation measures for disturbances as specified in § 141.85(f)(2).</P>
                            <P>(ii) Following replacement of a lead connector, the water system must update the information on the connector material and location in its inventory in accordance with paragraphs (a)(2)(ii) and (b)(2) of this section.</P>
                            <P>(2) The water system must comply with any State or local laws that require additional connectors to be replaced.</P>
                            <P>
                                (f) 
                                <E T="03">Replacement of a service line prompted by the customer.</E>
                                 If State or local laws or water tariff agreements do not prevent customers from conducting partial lead or galvanized requiring replacement service line replacements (“customer-initiated replacements”), the water system must meet the following requirements:
                            </P>
                            <P>(1) If the water system is notified by the customer that the customer intends to conduct a partial lead or galvanized requiring replacement service line replacement, the water system must:</P>
                            <P>(i) Replace the remaining portion of the lead or galvanized requiring replacement service line at the same time as, or as soon as practicable after, the customer-initiated replacement, but no later than 45 days from the date the customer conducted the partial replacement;</P>
                            <P>
                                (ii) Provide notification and risk mitigation measures in accordance with paragraph (h) of this section, as applicable, before the affected service line is returned to service; and
                                <PRTPAGE P="629"/>
                            </P>
                            <P>(iii) Notify the State within 30 days if it cannot meet the deadline in paragraph (f)(1)(i) of this section and complete the replacement no later than 180 days from the date the customer conducted the partial replacement.</P>
                            <P>(2) If the water system is notified or otherwise learns that a customer-initiated replacement occurred within the previous six months and left in place the system-owned portion of a lead or galvanized requiring replacement service line, the water system must:</P>
                            <P>(i) Replace any remaining portion of the affected service line within 45 days from the day of becoming aware of the customer-initiated replacement; and</P>
                            <P>(ii) Provide notification and risk mitigation measures in accordance with paragraph (h) of this section within 24 hours of becoming aware of the customer replacement.</P>
                            <P>(iii) Notify the State within 30 days if it cannot meet the deadline in paragraph (f)(2)(i) of this section and complete the replacement no later than 180 days of the date the system learns of the customer-initiated replacement.</P>
                            <P>(3) When a water system is notified or otherwise learns of a customer-initiated replacement of a lead or galvanized requiring replacement service line that occurred more than six months in the past, this section does not require the water system to complete the lead or galvanized requiring replacement service line replacement of the system-owned portion under this paragraph (f). However, the remaining portion of the lead or galvanized requiring replacement service line must be identified in the inventory in accordance with paragraph (b) of this section and replaced in accordance with paragraph (d) of this section.</P>
                            <P>
                                (g) 
                                <E T="03">Requirements for conducting partial service line replacements.</E>
                                 This paragraph (g) prohibits water systems from conducting a partial lead service line replacement or a partial galvanized requiring replacement service line replacement as defined under § 141.2 unless it is conducted as part of an emergency repair or in coordination with planned infrastructure work that impacts service lines, excluding planned infrastructure work solely for the purposes of lead or galvanized requiring replacement service line replacement. Where a water system has access to conduct full service line replacement as specified in paragraph (d)(2) of this section, the water system must fully replace the service line. Where a water system conducts partial service line replacement, the system must comply with the notification and mitigation requirements specified in paragraphs (h)(1) and (2) of this section.
                            </P>
                            <P>
                                (1) Whenever a water system conducts a partial replacement of a lead or galvanized requiring replacement service line, the system must include a dielectric coupling separating the remaining service line and the replaced service line (
                                <E T="03">i.e.,</E>
                                 newly installed service line) to prevent galvanic corrosion unless the replaced service line is made of plastic.
                            </P>
                            <P>(2) [Reserved]</P>
                            <P>
                                (h) 
                                <E T="03">Protocols for notification and mitigation for partial and full service line replacements</E>
                                —(1) 
                                <E T="03">Notification and mitigation requirements for planned partial service line replacement.</E>
                                 Whenever a water system plans to partially replace a lead or galvanized requiring replacement service line in coordination with planned infrastructure work that impacts service lines, the water system must provide written notice to the property owner, or the owner's authorized agent, as well as non-owner occupant(s) served by the affected service line at least 45 days prior to the replacement. Where a water system has access to conduct full service line replacement only if property owner consent is obtained, the water system must make a reasonable effort to obtain property owner consent to replace the remaining portion of the service line in accordance with paragraph (d)(3)(i) of this section. The reasonable effort must be completed before the partial lead service line replacement.
                            </P>
                            <P>
                                (i) Before the affected service line is returned to service, the water system must provide written notification that explains that consumers may experience a temporary increase of lead levels in their drinking water due to the replacement and that meets the content requirements of § 141.85(a)(1)(ii) through (iv) and contact information for the water system. In instances where multi-family dwellings or multiple non-residential occupants are 
                                <PRTPAGE P="630"/>
                                served by the affected service line to be partially replaced, the water system may elect to post the information at a conspicuous location instead of providing individual written notification to all residents or non-residential occupants.
                            </P>
                            <P>(ii) Before the affected service line is returned to service, the water system must provide written information about a procedure for consumers to flush service lines and premise plumbing of particulate lead following partial replacement of a lead or galvanized requiring replacement service line.</P>
                            <P>
                                (iii) Before the affected service line is returned to service, the water system must provide the consumer with a pitcher filter or point-of-use device certified by an American National Standards Institute accredited certifier to reduce lead, six months of replacement cartridges, and instructions for use. If the affected service line serves more than one residence or non-residential unit (
                                <E T="03">e.g.,</E>
                                 a multi-unit building), the water system must provide a pitcher filter or point-of-use device, six months of replacement cartridges and use instructions to every residential and non-residential unit in the building.
                            </P>
                            <P>(iv) The water system must offer to the consumer to collect a follow up tap sample between three months and six months after the completion of any partial replacement of a lead service line. The tap sample must be a first- and fifth-liter paired sample after at least six hours of stagnation, following the tap sampling protocol under § 141.86(b). The water system must provide the results of the sample to the persons served by the service line in accordance with § 141.85(d).</P>
                            <P>
                                (2) 
                                <E T="03">Notification and mitigation requirements for emergency partial service line replacement.</E>
                                 Any water system that creates a partial replacement of a lead or galvanized requiring replacement service line due to an emergency repair must provide notice and risk mitigation measures to the persons served by the affected service line in accordance with paragraphs (h)(1)(i) through (iv) of this section before the affected service line is returned to service. The water system must offer to the property owner, or the owner's authorized agent, to replace the partial service line created by the emergency repair within 45 days.
                            </P>
                            <P>
                                (3) 
                                <E T="03">Notification and mitigation requirements for full service line replacement.</E>
                                 Any water system that conducts a full lead or galvanized requiring replacement service line replacement must provide written notice to the persons served by the affected service line before the affected service line is returned to service; written notice must be provided to the owner or the owner's authorized agent, no later than 30 days following completion of the replacement.
                            </P>
                            <P>(i) The written notification must explain that consumers may experience a temporary increase of lead levels in their drinking water due to the replacement and must meet the content requirements of § 141.85(a)(1)(ii) through (iv) as well as contact information for the water system. In instances where multi-family dwellings or multiple non-residential occupants are served by the lead or galvanized requiring replacement service line to be replaced, the water system may elect to post the information at a conspicuous location instead of providing individual written notification to all persons served in residential and non-residential units.</P>
                            <P>(ii) Before the replaced service line is returned to service, the water system must provide written information about a procedure for consumers to flush service lines and premise plumbing of particulate lead following full replacement of a lead or galvanized requiring replacement service line.</P>
                            <P>
                                (iii) Before the replaced service line is returned to service, the water system must provide the consumer with a pitcher filter or point-of-use device certified by an American National Standards Institute accredited certifier to reduce lead, six months of replacement cartridges, and instructions for use. If the lead service line serves more than one residence or non-residential unit (
                                <E T="03">e.g.,</E>
                                 a multi-unit building), the water system must provide a pitcher filter or point-of-use device, six months of replacement cartridges and instructions for use to every residential and non-residential unit in the building.
                            </P>
                            <P>
                                (iv) The water system must offer to the consumer to collect a follow up tap 
                                <PRTPAGE P="631"/>
                                sample between three months and six months after completion of any full replacement of a lead or galvanized requiring replacement service line. The tap sample must be a first-liter sample after at least six hours of stagnation, following the tap sampling protocol under § 141.86(b). The water system must provide the results of the sample to the consumer in accordance with § 141.85(d).
                            </P>
                            <P>
                                (i) 
                                <E T="03">Reporting to demonstrate compliance to the State.</E>
                                 To demonstrate compliance with paragraphs (a) through (h) of this section, a water system must report to the State the information specified in § 141.90(e).
                            </P>
                            <CITA>[89 FR 86634, Oct. 30, 2024]</CITA>
                        </SECTION>
                        <SECTION>
                            <SECTNO>§ 141.85</SECTNO>
                            <SUBJECT>Public education and supplemental monitoring and mitigation requirements.</SUBJECT>
                            <P>A water system that exceeds the lead action level based on tap water samples collected in accordance with § 141.86 must distribute the public education materials contained in paragraph (a) of this section in accordance with the delivery requirements in paragraph (b) of this section. Water systems that exceed the lead action level must offer to sample the tap water of any person served by the water system who requests it in accordance with paragraph (c) of this section. Water systems must offer to sample for lead in the tap water of any person served by a lead, galvanized requiring replacement, or lead status unknown service line who requests it in accordance with paragraph (c) of this section. All water systems must deliver a consumer notice of lead tap water monitoring results and copper tap water monitoring results to persons served by the water system at sites that are sampled, as specified in paragraph (d) of this section. A water system with lead, galvanized requiring replacement, or lead status unknown service lines must deliver public education materials to persons with a lead, galvanized requiring replacement, or lead status unknown service line as specified in paragraphs (e) and (f) of this section. All community water systems that do not meet the minimum replacement rate for mandatory service line replacement as required under § 141.84(d) must conduct outreach activities as specified in paragraph (h) of this section. All community water systems must conduct annual outreach to local and State health agencies as outlined in paragraph (i) of this section. Water systems with multiple lead action level exceedances, as specified in paragraph (j)(1) of this section, must conduct public outreach and make filters certified to reduce lead available as specified in paragraphs (j)(2) through (6) of this section. For water systems serving a large proportion of consumers with limited English proficiency, as determined by the State, all public education materials required under this section must comply with the language requirements in paragraph (b)(1) of this section.</P>
                            <P>
                                (a) 
                                <E T="03">Content of written public education materials</E>
                                —(1) 
                                <E T="03">Community water systems and non-transient non-community water systems.</E>
                                 Water systems must include the following elements in written materials (
                                <E T="03">e.g.,</E>
                                 printed or digital brochures and pamphlets) in the same order as listed in paragraphs (a)(1)(i) through (vii) of this section. In addition, language in paragraphs (a)(1)(i), (ii), and (vii) of this section must be included in the materials, exactly as written, except for the text in brackets for which the water system must include system-specific information. States may approve changes to the content requirements if the State determines the changes are more protective of human health. Any additional information presented by a water system must be consistent with the information in paragraphs (a)(1)(i) through (vii) of this section and be in plain language that can be understood by the general public. Water systems must submit a copy of all written public education materials to the State prior to delivery. The State may require the system to obtain approval of the content of written public education materials prior to delivery.
                            </P>
                            <P>
                                (i) 
                                <E T="03">Important information about lead in your drinking water.</E>
                            </P>
                            <HD SOURCE="HD1">
                                Figure 1 to Paragraph 
                                <E T="01">(a)(1)(i)</E>
                            </HD>
                            <HD SOURCE="HD3">Important Information About Lead in Your Drinking Water</HD>
                            <P>
                                [INSERT NAME OF WATER SYSTEM] found elevated levels of lead in 
                                <PRTPAGE P="632"/>
                                drinking water in some homes/buildings. Lead can cause serious health problems, especially for pregnant people and young children. Please read this information closely to see what you can do to reduce lead in your drinking water.
                            </P>
                            <P>
                                (ii) 
                                <E T="03">Health effects of lead.</E>
                            </P>
                            <HD SOURCE="HD1">
                                Figure 2 to Paragraph 
                                <E T="01">(a)(1)(ii)</E>
                            </HD>
                            <P>There is no safe level of lead in drinking water. Exposure to lead in drinking water can cause serious health effects in all age groups, especially pregnant people, infants (both formula-fed and breastfed), and young children. Some of the health effects to infants and children include decreases in IQ and attention span. Lead exposure can also result in new or worsened learning and behavior problems. The children of persons who are exposed to lead before or during pregnancy may be at increased risk of these harmful health effects. Adults have increased risks of heart disease, high blood pressure, kidney or nervous system problems. Contact your health care provider for more information about your risks.</P>
                            <P>
                                (iii) 
                                <E T="03">Sources of lead.</E>
                                 (A) Explain what lead is.
                            </P>
                            <P>(B) Explain possible sources of lead in drinking water and how lead enters drinking water. Include information on home/building plumbing materials, service lines, and connectors that may contain lead and include information about the definition of lead free as provided in Safe Drinking Water Act section 1417 of 1986 and as subsequently revised in 2011. Explain that lead levels may vary and therefore lead exposure is possible even when tap sampling results do not detect lead at one point in time.</P>
                            <P>
                                (C) Discuss other important sources of lead exposure in addition to drinking water (
                                <E T="03">e.g.,</E>
                                 paint).
                            </P>
                            <P>
                                (iv) 
                                <E T="03">Consumer steps to reduce lead exposure.</E>
                                 Discuss the steps the consumer can take to reduce their exposure to lead in drinking water.
                            </P>
                            <P>(A) Explain that using a filter, certified by an American National Standards Institute accredited certifier to reduce lead, is effective in reducing lead exposures. If the system makes filters available in accordance with paragraph (j)(2) of this section, also include information on how the consumer can obtain a filter.</P>
                            <P>(B) Encourage running the water to flush out the lead. Explain that lead levels increase over time as water sits in lead-containing plumbing materials and regular water usage in the building can reduce lead levels in drinking water. Advise consumers served by lead and galvanized requiring replacement service lines that they may need to flush the water for longer periods.</P>
                            <P>(C) Explain concerns with using hot water from the tap and specifically caution against the use of hot water for preparing baby formula.</P>
                            <P>(D) Explain that boiling water does not reduce lead levels.</P>
                            <P>(E) Encourage regular cleaning of faucet aerators.</P>
                            <P>(F) Discuss other steps consumers can take to reduce exposure to lead in drinking water, especially for pregnant persons, infants, and young children, such as using alternative sources of water.</P>
                            <P>(G) Suggest that parents have their child's blood tested for lead. Provide contact information for the State and/or local health department.</P>
                            <P>(H) Tell consumers how to get their water tested, including information in accordance with paragraph (c) of this section.</P>
                            <P>
                                (v) 
                                <E T="03">Levels of lead in drinking water.</E>
                                 Explain why there are elevated levels of lead in the system's drinking water (if known) and what the water system is doing to reduce the lead levels in homes/buildings in this area.
                            </P>
                            <P>
                                (vi) 
                                <E T="03">Information on lead, galvanized requiring replacement, and unknown service lines.</E>
                                 For systems with lead, galvanized requiring replacement, or lead status unknown service lines in the system's inventory pursuant to § 141.84(a) and (b), public education materials must meet the requirements of paragraphs (a)(1)(vi)(A) through (G) of this section. For systems with lead connectors or connectors of unknown material in the system's inventory pursuant to § 141.84(a) and (b), public education materials must meet the requirements of paragraph (a)(1)(vi)(C) of this section:
                            </P>
                            <P>
                                (A) Discuss opportunities to replace lead and galvanized requiring replacement servi