[Federal Register Volume 59, Number 232 (Monday, December 5, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-29692]


[[Page Unknown]]

[Federal Register: December 5, 1994]


     
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Part II





Environmental Protection Agency





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40 CFR Parts 141 and 143



Analytical Methods for Regulated Drinking Water Contaminants; Final 
Rule
ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 141 and 143

[WH-FRL-5116-4]
RIN 2040-AC12

 

National Primary and Secondary Drinking Water Regulations: 
Analytical Methods for Regulated Drinking Water Contaminants.

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: EPA is promulgating the use of several new analytical methods 
and updated versions of previously approved methods for a number of 
regulated contaminants in drinking water. At the same time, the Agency 
is withdrawing approval of outdated methods or outdated versions of the 
same methods. The purpose of the rule is to approve new methods, 
withdraw outdated methods, and update older methods for analysis of 
regulated contaminants in drinking water. The rule is expected to 
eliminate unnecessary duplication by withdrawing older versions of the 
same method, and satisfy public requests for approval of new 
technologies in drinking water analyses.

DATES: This final rule is effective on January 4, 1995. The 
incorporation of the publications listed in this document are approved 
by the Director of the Federal Register as of January 4, 1995.

ADDRESSES: Copies of the public comments received on the proposal, 
EPA's responses, and all other supporting documents are available for 
review at the U.S. Environmental Protection Agency (EPA), Drinking 
Water Docket, 401 M Street, S.W., Washington, D.C. 20460. For access to 
the docket material, call (202) 260-3027 on Monday through Friday, 
excluding Federal holidays, between 9:00 am and 3:30 pm Eastern Time 
for an appointment.

FOR FURTHER INFORMATION CONTACT: Dr. Jitendra Saxena, Drinking Water 
Standards Division, Office of Ground Water and Drinking Water (4603), 
U.S. Environmental Protection Agency, 401 M Street, S.W., Washington, 
D.C. 20460, (202) 260-9579. General information may also be obtained 
from the EPA Safe Drinking Water Hotline. Callers within the United 
States may reach the Hotline at (800) 426-4791. The Hotline is open 
Monday through Friday, excluding Federal holidays, from 9:00 am to 5:30 
pm Eastern Time.
    For technical information regarding chemistry methods, contact 
Richard Reding, Ph.D., Office of Ground Water and Drinking Water (TSD), 
U.S. Environmental Protection Agency, Cincinnati, Ohio 45268, telephone 
(513) 569-7946, or Baldev Bathija, Ph.D., Office of Ground Water and 
Drinking Water (MC-4603), U.S. Environmental Protection Agency, 
Washington, D.C. 20460, telephone (202) 260-3040. For technical 
questions regarding microbiology methods, contact Paul S. Berger, 
Ph.D., Office of Ground Water and Drinking Water (MC-4603), U.S. 
Environmental Protection Agency, Washington, D.C. 20460, telephone, 
(202) 260-3039.

SUPPLEMENTARY INFORMATION:

    EPA Regional Offices:

I JFK Federal Bldg., One Congress Street, 11th floor, Boston, MA 
02203, Phone: (617)565-3610, Jerry Healey
II 26 Federal Plaza, Room 824, New York, NY 10278, Phone: (212) 264-
1800, Walter Andrews
III 841 Chestnut Building, Philadelphia, PA 19107, Phone: (215) 597-
9873, Stuart Kerzner
IV 345 Courtland Street, N.E., Atlanta, GA 30365, Phone: (404) 347-
3633, Wayne Aronson
V 77 West Jackson Boulevard, Chicago, IL 60604, Phone: (312) 353-
2151, Ed Watters
VI 1445 Ross Avenue, Dallas, TX 75202, Phone: (214) 655-7150, Thomas 
Love
VII 726 Minnesota Avenue,Kansas City, KS 66101,Phone: (913) 276-
7032, Ralph Langemeir
VIII One Denver Place, 999 18th Street, Suite 500, Denver, CO 80202-
2466, Phone: (303) 293-1652, Patrick Crotty
IX 75 Hawthorne Street, San Francisco, CA 94105, Phone: (415) 744-
1817, William Thurston
X 1200 Sixth Avenue, Seattle, WA 98101, Phone: (206) 553-4092, 
Kenneth Feigner

Table of Contents

I. Statutory Authority
II. Regulatory Background
III. Explanation of Today's Action
IV. Response to Comments Received on the Proposed Rule and Notice of 
Availability
V. Availability and Sources for Methods Information
VI. Regulation Assessment Requirements
VII. References

I. Statutory Authority

    The Safe Drinking Water Act (SDWA), as amended in 1986, requires 
EPA to promulgate national primary drinking water regulations (NPDWRs) 
which specify maximum contaminant levels (MCLs) or treatment techniques 
for drinking water contaminants (42 U.S.C. 300g-1). NPDWRs apply to 
public water systems (42 U.S.C. 300f(1)(A)). According to section 
1401(1)(D) of the Act, NPDWRs include ``criteria and procedures to 
assure a supply of drinking water which dependably complies with such 
maximum contaminant levels; including quality control and testing 
procedures. * * *'' In addition, Section 1445(a) of the Act authorizes 
the Administrator to establish regulations for monitoring to assist in 
determining whether persons are acting in compliance with the 
requirements of the SDWA. EPA's promulgation of analytical methods is 
authorized under these sections of the SDWA as well as the general 
rulemaking authority in SDWA Section 1450(a) (42 U.S.C. 300j-9(a)).

II. Regulatory Background

    EPA has promulgated analytical methods for all currently regulated 
drinking water contaminants for which MCLs or monitoring requirements 
have been promulgated. In most cases, the Agency has promulgated 
regulations specifying (i.e., approving) use of more than one 
analytical method for a contaminant, and laboratories may use any one 
of them for determining compliance with an MCL or monitoring 
requirement. After any regulation is published, EPA may amend the 
regulations to approve additional methods, or modifications to approved 
methods, or withdraw methods that become obsolete.
    On December 15, 1993, EPA proposed to approve the use of several 
new methods and modifications of existing methods that EPA believed 
were as good as, or better than, current methods and procedures (58 FR 
65622). The Agency also proposed to withdraw approval for outdated 
methods or outdated versions of the same methods. In addition, EPA 
published a Notice of Availability (NOA) (59 FR 35891) on July 14, 
1994, to make available data from EPA's evaluation of several new 
analytical methods, and to propose withdrawal of approval for several 
outdated EPA methods. EPA requested public comments on the proposal and 
on the NOA. Today's notice takes final action on the methods covered by 
the proposal and the NOA.

III. Explanation of Today's Action

    With a few minor exceptions, which are described below, the actions 
described in the 1993 proposed rule and the 1994 NOA are approved in 
today's rule. The coliform transit time will remain at 30 hours, and 
the Agency will not require systems to hold samples at 10  deg.C during 
transit. EPA will approve the Colisure test for simultaneously 
determining the presence of total coliforms and E. coli.
    In the July 1994 NOA, EPA described the new versions of EPA Methods 
200.7, 200.8, 200.9, 245.1 (EPA, 1994a) and 504.1 (EPA, 1993d) that are 
approved in today's rule. Mercury and sodium have been added to the 
analytical scope of Methods 200.8 and 200.7, respectively. EPA is 
approving EPA Method 508.1 (EPA, 1994c), which allows liquid-solid 
extraction (LSE) procedures to be used under Method 508 conditions for 
analysis of many analytes contained in EPA Methods 507 and 508. A minor 
revision to dioxin method 1613 that allows use of LSE is approved. 
Hexachlorocyclo-pentadiene has been added to the analytical scope of 
EPA Method 508.
    Trimethylsilyldiazomethane may be used as an alternative 
derivatizing reagent in Methods 515.1 and 515.2. EPA Methods 150.1, 
150.2 and 515.1 are not withdrawn. Turbidity measurements of samples 
need not be made immediately before beginning an analysis for metals; 
it is only necessary that the sample be acidified and held for sixteen 
hours. For EPA Method 531.1 (carbamates), samples no longer need to be 
frozen, thereby eliminating the possibility of frozen samples breaking 
the sample vial. Standard Method 6610 is approved as an alternative to 
Method 531.1. Analysis for 2,3,7,8-TCDD (dioxin) with Method 1613, or 
for asbestos with Method 100.1 or 100.2 can be simplified by using the 
guidance contained in the EPA document, Technical Notes on Drinking 
Water Methods (EPA, 1994d).
    Technical Notes contains mandatory and optional procedures that 
will be cited in the drinking water regulations.
    EPA is also correcting minor errors in the 1993 proposal. An 
erroneous listing of USGS methods I-2822-85 and I-2823-85 for sulfate, 
and ASTM D2036-91A for cyanide are removed in today's rule. The ASTM 
method had been listed twice in the table of approved methods. A 
typographical error occurred in listing the USGS method for silver and 
the ASTM method for chloride. The correct listings are USGS I-3720-85 
(silver) and ASTM D4327-91 (chloride).
    The effective date for all actions in this rule, except withdrawal 
of obsolete methods, is January 4, 1995. The withdrawal date for 
obsolete methods is July 1, 1996 (or 18 months from publication, 
whichever is later), which is a year later than proposed. After this 
date, EPA's manual ``Methods for Chemical Analysis of Water and 
Wastes'' (EPA, 1983a) will contain only three approved drinking water 
methods--Methods 150.1, 150.2, and 245.2. To spare new laboratories the 
expense of purchasing this manual, EPA will provide single copies of 
these methods to users who do not have a copy of the 1983 manual. For 
the convenience of readers and for clarity of the rules, methods that 
are withdrawn will be specified only by tabulating them in the 
document, Technical Notes on Drinking Water Methods (EPA, 1994d), and 
in the next revision of the Manual for the Certification of 
Laboratories Analyzing Drinking Water (EPA, 1990b).

IV. Response to Comments Received on the Proposed Rule and Notice 
of Availability

    EPA received 136 comments on the December 15, 1993, proposal; 92 
comments were related to chemical-analytical methods and 79 comments 
were related to the methods associated with the coliform and surface 
water treatment rules. The Agency received twenty comments on the July 
14, 1994, Notice of Availability. The commenters included analytical 
laboratories, water utilities, analytical instrument manufacturers, 
State and local regulators, and trade associations.
    A summary of major comments and the Agency's response to the issues 
raised are presented in this section. The Agency's detailed response to 
the comments received on the 1993 proposed rule and the 1994 NOA is 
available in the public docket for this rule (EPA, 1994e).

A. New Methods

    Comment on the ten new methods was favorable. These methods, EPA 
methods 100.2, 551, 552.1, 555, Standard Methods 4500-Cl-E, 4500-Cl-H, 
4500-Cl-I, 4500-O3-B, 4500-ClO2-E and Great Lakes Instruments 
Method 2 were described in the 1993 proposal. Specific public comments 
on some of the methods are answered below.
    EPA Method 100.2 (asbestos)  Four comments contained several 
suggestions and criticisms. Method 100.2 has been editorially revised 
to reflect the comments. These changes, however, do not affect the 
performance, cost or applicability of the method. One commenter asked 
EPA to approve SM 2570 for asbestos, which was published in a 1994 
supplement to the eighteenth edition of Standard Methods (APHA, 1994). 
EPA does not approve SM 2570 for asbestos in today's rule, because this 
method differs in significant ways from Method 100.2. For example, SM 
2570 uses a larger pore filter (0.45 micron) to trap asbestos fibers, 
while EPA method 100.2 uses a 0.22 micron filter. The commenter did not 
provide any data comparing asbestos trapping efficiency of these two 
filters, whereas EPA has data (EPA, 1994e) to show that larger pore-
size filters trap fewer asbestos fibers in drinking water samples.
    Method 552.1  A commenter asked that the sodium hydroxide rinse in 
Method 552.1 be optional, because the rinse is not compatible with 
their LSE product. Method 552.1 was developed and validated with ion 
exchange cartridges to take advantage of the special chemical 
properties of dalapon and the other acids covered by the method. To 
efficiently extract the acids the ion exchange resin must be activated 
with a sodium hydroxide rinse. Sorbent conditioning and elution steps, 
which are specified in Method 552.1 or any LSE method, cannot be 
modified or eliminated to accommodate the support material. Thus, EPA 
will not allow the sodium hydroxide rinse in Method 552.1 to be 
optional, because EPA has received no data to support the commenter's 
request to make the rinse optional.
    The same commenter asked for a more generic definition of LSE media 
in Method 552.1 and in other LSE methods. The commenter believes EPA is 
unnecessarily narrowing the choice of LSE disks and cartridges. EPA 
does not believe LSE methods are overly restrictive in allowing use of 
alternative LSE disks or cartridges. However, EPA believes that 
additional guidance to help users correctly choose alternative LSE 
media without compromising the reliability of the analysis would be 
useful. The guidance is summarized below and will be published in 
Technical Notes on Drinking Water Methods (EPA, 1994d). The guidance is 
applicable to all LSE methods and supersedes the phrase ``or 
equivalent'' that is used in some methods to describe selection of 
alternative LSE cartridges or disks.
    Liquid-solid extraction is performed using various sorbents that 
are either packed into a cartridge or enmeshed in a disk of inert 
support material. EPA methods describe the cartridge or disk that was 
used to develop the LSE procedure, and to produce the data which is 
published in the method. If a product is mentioned in the methods, it 
is for information purposes only. EPA believes various LSE cartridges 
and disks may be used, provided they meet all quality control 
requirements of the method, and provided they contain a sorbent that 
uses the same physicochemical principles as the cartridge or disk that 
is described in the approved LSE method. To demonstrate that 
alternative LSE cartridges and disks meet all quality control criteria, 
the analyst must be aware of the chemistry of the method. For example, 
in evaluating Method 552.1 the recovery of the free acid (not a 
chemical derivative) from the water sample must be tested with the 
alternative LSE cartridge or disk.
    In judging LSE disk media, both the sorbent and the support must be 
evaluated. In the case of sorbents, similarities in polarity are not 
sufficient. For example, a C18-Silica sorbent may not perform the 
same as a styrene divinylbenzene copolymer sorbent. Thus, these 
sorbents would not be considered to be equivalent. In judging supports, 
any physical support used to hold the sorbent is acceptable provided 
the support is inert and compatible with the solutions or solvents 
required in the conditioning and elution steps of the method. However, 
any sorbent conditioning or elution steps, which are specified in the 
method must not be modified or eliminated to accommodate the support 
material.
    EPA Method 555  Several commenters noted that the method detection 
limits (MDLs) for some analytes were greater than MDLs in the 
alternative method (EPA Method 515.1), or were too high to meet 
monitoring triggers, which are specified at 40 CFR 141.24(h)(18). Thus, 
they questioned whether Method 555 was a suitable alternative to Method 
515.2. EPA believes commenters mistakenly looked at MDLs in Table 2 of 
Method 555, which shows the results of spikes at 10 ppb. However, 
spikes at 0.5 ppb (Table 5 in the method) resulted in MDLs that are 
equivalent to Method 515.1 MDLs, and these MDLs have been validated in 
a second laboratory (EPA, 1992a). EPA also notes that monitoring 
triggers for several organic contaminants, including Method 555 
analytes, may be amended in a future rulemaking (EPA, 1993b, 1994f).
    Great Lakes Instruments (GLI) Method 2 (turbidity)  Some commenters 
objected to the method because it is vendor and instrument-specific. 
EPA generally develops and approves methods that are not vendor-
specific. Users are not limited to the GLI method; generic methods SM 
2130B and EPA 180.1 are approved for turbidity. However, under the 
Alternative Test Procedures (ATP) program EPA has approved vendor-
specific methods or products as alternatives to approved methods (53 FR 
5142, February 19, 1988). GLI Method 2 was evaluated under EPA's ATP 
program and recommended for approval as an alternative method. EPA 
realizes GLI is the source of copies of GLI Method 2, which is a factor 
a laboratory choosing to adopt this method must consider.
    Some commenters believed the GLI method should be approved as a 
version of an international procedure, ISO 7027. The ISO procedure 
measures turbidity via either 90 deg. scattered or transmitted light 
depending on concentration. Although instruments conforming to ISO 7027 
specifications are similar to the GLI instrument, only the GLI 
instrument uses pulsed, multiple detectors to simultaneously read both 
90 deg. scattered and transmitted light. EPA has received no data on 
the ISO 7027 use of separate 90 deg. scattered or transmitted light 
measurements to judge equivalency to other approved turbidity methods.
    SM 4500-Cl-E, Low Level Amperometric Titration  A commenter noted a 
typographical error in a calculation in SM 4500-Cl-E, which the 
Standard Methods Committee has agreed to correct. In approving SM 4500-
Cl-E, EPA will print the correct formula for SM 4500-Cl-E in Technical 
Notes on Drinking Water Methods (EPA, 1994d). The Standard Methods 
Committee will publish a correction to this method in the next (19th) 
edition of Standard Methods (Eaton, 1993a).
    SM 6610 (APHA, 1994)  A commenter asked to approve this method as 
an alternative to EPA Method 531.1. EPA aided the development of this 
method, which was published in 1994 in a supplement to the eighteenth 
edition of Standard Methods. EPA agrees with the commenter, and will 
approve SM6610 for analysis of aldicarb, aldicarb sulfone, aldicarb 
sulfoxide, carbaryl, carbofuran, 3-hydroxycarbofuran, methomyl, and 
oxamyl.
    EPA Method 1613, Revision B, dioxin (EPA, 1994i)  EPA was asked to 
replace the approved Revision A of Method 1613 with Revision B. EPA 
agrees with the suggestion. As with Revision A, users can greatly 
simplify use of Revision B of Method 1613 when only 2,3,7,8-
tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) is to be determined in 
drinking water samples by using procedures described in Technical Notes 
on Drinking Water Methods (EPA, 1994d).
    EPA proposed Revision A of Method 1613 for the monitoring of 
several chlorinated dioxins and furans under the Clean Water Act on 
February 7, 1991 (56 FR 5090), and approved it only for measurement of 
2,3,7,8-TCDD under the Safe Drinking Water Act on July 17, 1992 (57 FR 
31803). In response to comments on the 1991 proposal, EPA developed 
Revision B. The only technical changes made in Revision B that affect 
determination of 2,3,7,8-TCDD in drinking water matrices are (1) slight 
changes in performance specifications based on the compilation of data 
from interlaboratory and other studies, (2) additional language 
intended to provide analysts with increased flexibility to use liquid 
solid extraction procedures, and (3) further clarification of the 
documentation required when analysts employ the flexibility provided in 
the method to use alternate techniques not explicitly described in the 
method.

B. Expanded Scope for Already Approved Methods

    Comments on expanding the analytical scope of these five methods 
were favorable. These methods, EPA Methods 200.8, 200.9, 300.0, SM 
4110B, and American Society for Testing and Materials (ASTM) method 
D4327-91, were discussed in the 1993 proposal or the 1994 NOA. Specific 
comments requesting that approved methods cover additional analytes are 
described and answered below.
    A commenter asked EPA to expand the scope of Method 200.8 to 
include additional metals that are not currently regulated by EPA. 
While EPA encourages laboratories to use any approved method for all 
contaminants that are within the analytical scope of the method, EPA 
can only approve a method for contaminants that are regulated. One 
commenter asked why Method 200.9 did not include the secondary drinking 
water contaminant, zinc. EPA believes analysis of zinc with Method 
200.9 is impractical, because the instrument and procedure used are 
very sensitive to small amounts of lead. The analysis is subject to 
random contamination, and the concentration range of zinc that can be 
reliably measured is too narrow to be of use with typical drinking 
water samples. EPA recommends more suitable methods (EPA 200.7, 200.9, 
SM 3120B and SM 3111B) for measurement of zinc in drinking water 
samples.
    Commenters were concerned about expanding the scope of the ion 
chromatography methods to include fluoride. They believed that EPA did 
not have data to show that interference problems would not preclude use 
of ion chromatography for the analysis of fluoride in drinking water 
samples. EPA's 1990 study (Bionetics) which involved participation of 
seventeen laboratories demonstrated that fluoride can be reliably 
measured in drinking water samples with ion chromatography. Thus, EPA 
has no hesitation in approving the three proposed ion chromatography 
methods for the analysis of fluoride in drinking water.

C. Updated Methods

    Comment on updating earlier versions of six methods to the current 
versions was favorable. These methods, EPA Methods 504.1, 515.2, 524.2, 
525.2, 548.1 and 549.1, were discussed in the 1993 proposal or the 1994 
NOA. Problems were reported by a commenter with the use of 
trimethylsilyldiazomethane (TMSD) for derivatization of the analytes in 
Methods 515.1 and 515.2. The commenter suggested that EPA also allow 
the use of diazomethane for this purpose. EPA agrees with the commenter 
and, as discussed in the 1993 proposal, EPA allows use of either 
derivatizing reagent. However, because dalapon is not adequately 
derivatized by TMSD, the use of TMSD in Method 515.1 is not approved 
for analysis of dalapon. Procedures for using TMSD with Methods 515.1 
and 515.2 are described in the document Technical Notes on Drinking 
Water Methods (EPA, 1994d).

D. Updates to Methods by Reference to Most Recent Manual

    Comments were favorable on approving versions of previously 
approved methods that are now contained in the eighteenth edition of 
Standard Methods (APHA, 1992) and in five new EPA manuals (EPA, 1994a, 
1991, 1990a, 1992b and 1993a). These publications were described and 
discussed in the 1993 proposal or the 1994 NOA. Questions or requests 
from commenters about some of the methods contained in these 
publications are described and answered below.
    1994 EPA Metals Manual (EPA, 1994a)  Three commenters asked to add 
other regulated metals to the scope of Method 200.7, because use of a 
new axial configured inductively coupled plasma (ICP) atomic emission 
spectroscopy (AES) instrument improves the sensitivity of the method to 
the required regulatory limits. EPA will not approve this request in 
today's rule, because Method 200.7 as written allows use of other types 
of ICP/AES instruments that cannot meet the regulatory limits for the 
additional metals. To extend the scope of Method 200.7 as suggested by 
the commenters would require either a formal ATP approval (EPA, 1993c), 
or publication of a new AES method that allowed only instruments with 
an axial configuration.
    1991 Organic Methods Manual (EPA, 1991)  One commenter requested a 
change in the scope of EPA Method 505 because of the detection limits 
for some method analytes. These changes included withdrawal of 
alachlor, atrazine and simazine, and addition of toxaphene. EPA is 
evaluating the detection limits in several methods. When this 
evaluation is complete, EPA may propose to withdraw approval of methods 
or modify the scope of methods, such as Method 505. In the interim, EPA 
does not agree that the scope of Method 505 should be changed to 
withdraw alachlor, atrazine and simazine. However, EPA agrees that 
analysis for these nitrogen-containing compounds may require use of a 
nitrogen-phosphorous detector (NPD) rather than the electron capture 
detector (ECD). Today's rule specifies that an NPD should be 
substituted for the ECD in Method 505 (or another approved method 
should be used) to determine alachlor, atrazine and simazine, if lower 
detection limits are required.
    EPA agrees with the comment about toxaphene. In today's rule EPA is 
correcting an omission in the 1993 proposal by continuing to approve 
Method 505 for toxaphene. However, EPA notes that the Method 505 MDL 
for toxaphene is very close to the MCL. To improve the sensitivity of 
the analysis analysts may wish to use Method 508 for toxaphene and 
other Method 505 analytes for which use of an NPD will not improve the 
sensitivity. Method 508 is very similar to Method 505 except that the 
MDLs are lower, because a larger sample volume is extracted.
    MCL compliance determination for PCBs requires that EPA method 505 
or 508 be used as a screen for PCBs as Aroclors prior to quantitation 
as decachlorobiphenyl by EPA Method 508A. Three commenters requested 
that EPA switch the sequence of compliance methods for PCBs, i.e., use 
Method 508A to screen and Method 505 or 508 to quantify PCBs. The 
suggested change in the sequence of compliance methods is beyond the 
scope of this rule since it would require amending the MCL compliance 
determination sequence in 40 CFR 141.24(h)(13)(i)-(iii). Only Method 
508A can measure decachlorobiphenyl, and Sec. 141.24(h)(13)(ii) 
specifically requires ``using Method 508A to quantify PCBs as 
decachlorobiphenyl''.
    It was suggested by a commenter that EPA include hexachloro- 
cyclopentadiene (HCP) in the scope of EPA Method 508. EPA agrees with 
the commenter, and will allow measurement of HCP with EPA Method 508. 
However, the analyst must show that the analyte recoveries and other 
criteria, which are specified for HCP in Section 9 of Method 508.1 are 
achieved using Method 508 procedures. This option will be described in 
the document, Technical Notes on Drinking Water Methods (EPA, 1994d).
    1993 EPA Inorganic Methods Manual (EPA, 1993a)  A commenter asked 
what the differences were between Method 335.3 and the updated version, 
Method 335.4, since both versions require manual distillation of the 
sample to prepare it for measurement of cyanide. The technical 
differences between these methods are minor. EPA improved the 
automation of procedures in Method 335.4, and added the option to use a 
labor-saving distillation procedure. The distillation option is 
described in Method 335.4, and it is approved and described for other 
spectrophotometric methods in Technical Notes on Drinking Water Methods 
(EPA, 1994d).
    Two commenters objected to replacement of Method 335.3 with 335.4. 
The objection appeared to be based on the mistaken belief that Method 
335.4 requires a manual distillation of the sample to prepare it for 
measurement of cyanide and that the earlier version, Method 335.3, did 
not. EPA has never allowed spectrophotometric measurements of cyanide 
in water samples without manual distillation of the sample using SM 
4500-CN-C (cf. 40 CFR 136.3, Table 1B; 59 FR 4507, January 31, 1994; 
and 57 FR 31839, July 17, 1992). Commenters may have been misled by a 
discussion in Method 335.3 of an alternate ultraviolet (UV) digestion 
procedure that does not require manual distillation. EPA has never 
approved this optional UV procedure for compliance measurements of 
cyanide, because EPA has no data to show that UV digestion would not 
provide inaccurate results that underestimate the level of 
contamination. To avoid manual distillation of the sample, laboratories 
may use a selective electrode method for cyanide.
    EPA notes that the ``amenable'' spectrophotometric methods, ASTM 
D2036-91B and SM 4500-CN-G, also require distillation prior to either 
free or total cyanide measurements. To further clarify EPA's intent to 
require manual distillation for all spectrophotometric determinations 
of cyanide, these methods will be listed at 40 CFR 141.23(k) in today's 
rule under the phrase ``Manual distillation followed by''. Immediately 
following this phrase, the rules specify use of SM 4500-CN-C to conduct 
this distillation.
Microbiological Methods
    The vast majority of comments on the eighteenth edition version of 
microbiology methods concerned the maximum time between sample 
collection and analysis (transit time) of drinking water samples. 
Commenters opposed reducing this time from 30 hours (16th edition of 
Standard Methods) to 24 hours (18th edition of Standard Methods). The 
Standard Methods committee reduced the transit time because of its 
concern about coliform die-off in the sample over time. Commenters 
opposed reducing the time because it would (1) be logistically 
impractical if not impossible to do, (2) increase costs for sample 
transport and resampling, (3) cause hardships in sample collection, and 
(4) complicate and decrease laboratory flexibility. A few commenters 
claimed that the reduced transit time is not supported by data.
    Coliforms usually die off over time, especially when water 
temperatures are warm, but EPA recognizes that there is debate among 
investigators over the rate of that decline. EPA is currently 
conducting additional studies on this question, using fecal coliforms 
and E. coli, and results are anticipated by the end of 1994. Given the 
logistical and other problems that might result by decreasing the 
transit time to 24 hours, EPA is deferring a decision on whether to 
reduce the transit time until more data become available. For the time 
being, the Agency has added a footnote to the Table in 
Sec. 141.21(f)(3), allowing a maximum transit time of 30 hours. If EPA 
decides that a reduction from 30 hours is warranted, the Agency will 
work with the States to minimize the hardships identified in the public 
comments. Meanwhile, EPA strongly encourages States and systems to 
review their procedures and identify practical alternatives for 
providing samples to laboratories more quickly.
    Other commenters objected to the requirement in the 18th edition of 
Standard Methods to hold samples at less than 10  deg.C during transit. 
The Standard Methods committee specified this value because of its 
concern about coliform die-off in the sample at higher temperatures, 
where the bacterial metabolism of coliforms and non-coliforms alike is 
normally greater.
    Commenters objected to any EPA requirement that would require them 
to keep samples cool during sample transit. They asserted that this 
requirement would (1) be unnecessary and would complicate sample 
transport logistics, (2) increase sampling costs and shipping costs for 
both systems and laboratories, because coolers and ice packs cost money 
and samples are heavier and thus more expensive to ship, and (3) lead 
to problems with frozen samples or a significantly increased number of 
invalid samples. Commenters also stated that under the presence-absence 
concept, sample cooling was less important than under the earlier rule 
based on coliform density.
    EPA is deferring a decision on sample transit temperature until the 
Agency initiates a review, and possible revision, of the Total Coliform 
Rule. For the time being, the Agency has added a footnote to the Table 
in Sec. 141.21(f)(3) encouraging, but not requiring, systems to hold 
samples at less than 10  deg.C during transit. Nevertheless, the Agency 
strongly encourages systems to cool their samples during transit, 
especially during warm summer months, to minimize coliform die-off. The 
Agency is currently conducting additional studies on this question, 
using fecal coliforms and E. coli, and results are anticipated by the 
end of 1994. If EPA decides that a reduction is warranted, the Agency 
will work with the States to minimize the hardships identified in the 
public comments.
    EPA is also approving a new method, the Colisure test, for 
simultaneously determining the presence of total coliforms and E. coli, 
both of which must be monitored under the Total Coliform Rule (40 CFR 
141.21). Data supporting the use of this method was presented in the 
notice of July 14, 1994 (NOA).
    Most commenters supported approval of the Colisure test, but 
several raised questions about the test, primarily concerning the 
incubation time. They cited the Broadway et al. (1992) data that 
indicated that only 64% and 69% of the bottles were total coliform-
positive and E. coli-positive, respectively, after 24 hours compared to 
the 48-hour results. According to the Broadway et al. data, 85% and 88% 
of the bottles were total coliform-positive and E. coli-positive, 
respectively, after 28 hours compared to the 48-hour results.
    EPA agrees with the commenters who contended that 24 hours of 
incubation was insufficient for the Colisure test. The Agency, however, 
believes that the recovery rate after 28 hours is reasonable, and will 
approve the Colisure test as a 28-hour test. Moreover, based on 
additional data from the product manufacturer showing that the false-
positive rate after 48 hours is small, EPA will allow laboratories to 
hold the test up to 48 hours before observing results.
Chemical Methods
    There were only minor comments on the proposal to update chemistry 
methods to the versions contained in the 18th edition of Standard 
Methods. The 18th edition versions contain no or minor changes to 
earlier versions, and EPA received no comments to document specific 
hardships in converting to 18th edition chemical methods. Several 
commenters noted that, although thallium is not in the scope of SM 
3113B, EPA erroneously approved SM 3113B for thallium (57 FR 31840, 
July 17, 1992). EPA agrees and will delete this approval in today's 
rule.
    A commenter noted that the 18th edition version of SM 4500-Cl-G 
omits instructions that would allow measurement of total residual 
chlorine in drinking water samples using a colorimetric method. The 
Standard Methods Committee has written (Eaton, 1993b) that an editorial 
omission, not a technical change, occurred in recent versions of SM 
4500-Cl-G. The error will be corrected in the next (19th) edition of 
Standard Methods. EPA corrects the error today by describing the 
omitted instructions in Technical Notes on Drinking Water Methods (EPA, 
1994d).

E. Methods To Be Withdrawn and Replaced

General Comments Received on Withdrawal of Methods
    One commenter suggested that all methods carry a ``draft'' status 
for three years after publication; other commenters asked EPA to 
approve new methods more quickly. It would defeat EPA's intent to 
provide modern technology quickly, if a method had to be published, 
proposed, and then kept in draft status for three years. EPA balances 
this problem by allowing optional use of old or new methods during a 
transitional period, which in the case of this rule extends to July 1, 
1996 (or 18 months after publication, whichever is later).
    Several commenters believed EPA was eliminating, or intended to 
eliminate, all autoanalyzer or colorimetric methods. This is incorrect; 
EPA is replacing only obsolete methods with equivalent ASTM, EPA and 
Standard Methods. EPA is not eliminating colorimetric or autoanalyzer 
technology for any regulated contaminant, except arsenic. Evidence of 
EPA's intent is in the 1993 methods manual (EPA, 1993a), which updated 
colorimetric methods for cyanide (335.4), nitrite and nitrate (353.2), 
and sulfate (375.2). EPA has and continues to approve autoanalyzer and 
colorimetric ASTM and Standard Methods for cyanide, fluoride, nitrite, 
nitrate and sulfate.
    Some commenters stated that changing from EPA methods to equivalent 
Standard Methods and ASTM methods would be very time-consuming and 
expensive, but provided no specific information to support this 
statement. EPA is withdrawing methods that are incomplete and often 
require users to rely on the equivalent ASTM or Standard Methods. Thus 
the change, in many cases, has already taken place. In other cases, 
there are very minor differences between the withdrawn and the 
replacement methods. EPA notes that laboratories may continue to use a 
withdrawn method for other than compliance monitoring samples. EPA's 
actions in today's rule save laboratories money, because they need only 
support one version of an ASTM, EPA, or Standard Method. Prior to this 
rule, laboratories were required to use methods in the 14th, 16th, 
17th, and 18th editions of Standard Methods, and at least two different 
versions of EPA Methods 200.7 and 524.2.
    EPA received numerous comments requesting an extension of the 
withdrawal date for analytical methods. The suggested dates ranged from 
July 1, 1995, to July 1, 2000. Based on these comments, EPA will extend 
the methods withdrawal date from July 1, 1995, to July 1, 1996 (or 18 
months from publication, whichever is later), which is beyond the 
withdrawal date suggested by most commenters. New methods or new 
versions of current methods will be approved within 30 days of 
publication of the rule. This overlap in approval dates for new methods 
and withdrawal of obsolete methods will give laboratories sufficient 
time to become certified with the new methods.
Comments on Withdrawal of Specific Methods
    Packed-Column EPA Methods Commenters generally favored withdrawal 
of packed column methods for volatile organic compounds (VOCs) and 
trihalomethanes (THMs), and replacing them with technologically 
advanced capillary column methods. Additional costs incurred in 
supporting older, obsolete methods until EPA withdraws these methods, 
and the suitability of capillary columns to handle the increasing 
number of regulated contaminants were cited as reasons for supporting 
withdrawal. The July 1, 1995, withdrawal date may be too early, as 
pointed out by some commenters. EPA will extend the date to July 1, 
1996 (or 18 months from publication, whichever is later), to give 
laboratories more time to plan an orderly transition to capillary 
column methods.
    Some commenters asked EPA for continuation of the use of packed-
column methods, if they meet current regulatory requirements. EPA feels 
that packed-column methods have many drawbacks. For example, the cis 
and trans dichloroethene isomers cannot be separated with the packed-
columns specified for VOC analysis (Lyter, 1994). Such separation 
problems with packed-column methods have limited EPA's ability to 
prepare samples for EPA's laboratory performance evaluation (PE) 
program. To accommodate packed-column methods, separate PE samples are 
prepared for THMs and VOCs to minimize THM and VOC interferences that 
users of packed column EPA methods will experience. If only capillary 
columns are approved, EPA will have more latitude to mix VOCs and THMs 
in PE samples to better test laboratories with concentrations and 
mixtures of THMs and VOCs, as might realistically occur in drinking 
waters. EPA notes that laboratories may continue to use packed column 
methods for other than compliance monitoring analyses, such as routine 
plant operation or source evaluation samples.
    A commenter asked why EPA proposed to withdraw THM Methods 501.1 
and 501.2 in the 1993 proposal, but subsequently proposed to continue 
approval of these packed column methods in the Information Collection 
Rule (ICR) (59 FR 6354 and 6413-6414, February 10, 1994). In today's 
rule, EPA is clarifying why and how Methods 501.1 and 501.2 can and 
should be withdrawn without affecting analytical needs that were 
described in the ICR proposal. In the ICR, EPA proposed Methods 501.1 
and 501.2 only because ICR data must be gathered quickly to support 
pending disinfectant byproduct control regulations. To support these 
regulations, EPA proposed to conduct THM monitoring at a limited number 
of PWS for eighteen months beginning in 1995. Since this data must be 
collected by laboratories certified to conduct THM analyses, it could 
be a hardship to revoke the certification of laboratories now using 
Methods 501.1 and 501.2. EPA notes that EPA also proposed and 
encouraged laboratories to use one of the capillary column methods (EPA 
Methods 502.2, 524.2 and 551) to conduct THM monitoring for the ICR. 
And in a subsequent disinfection byproduct rule (59 FR 38668, July 29, 
1994) EPA proposed only capillary methods for THM compliance monitoring 
(59 FR 38821).
    As explained in the 1993 proposal and in the 1992 THM methods rule 
(58 FR 41344, August 3, 1993), EPA intends to and will withdraw packed 
column methods for THM and VOC compliance analysis. To accommodate the 
special and immediate information collection needs of the ICR, EPA is 
deferring withdrawal of packed column Methods 501.1 and 501.2 until 
July 1, 1996 (or 18 months after publication, whichever is later). This 
date is expected to be after the beginning of the proposed ICR 
monitoring period. When the ICR rule is promulgated, certification 
under Methods 501.1 and 501.2 will be granted such that the withdrawal 
date will not impede collection of THM data for the ICR.
    Colorimetric Methods for Arsenic--A commenter requested that EPA 
not withdraw colorimetric methods for arsenic. Because the detection 
limits of these methods are very near the MCL for arsenic, colorimetric 
measurements do not provide a reliable indication of variability of, or 
trends in, ambient concentrations of arsenic in the water supply when 
these concentrations are less than the MCL. EPA believes the detection 
limit deficiency warrants withdrawal of colorimetric methods for 
arsenic.
    In addition, since EPA approves other methods that measure all 
twelve regulated metals, including arsenic, it is not cost-effective to 
measure arsenic separately with a colorimetric method. The cost of a 
complete, broad-spectrum metals analysis by atomic absorption or ICP is 
not reduced if arsenic is not included. And EPA knows of no situation 
where arsenic is the only metal to be determined in a compliance 
sample. EPA believes that there is no scientific reason or economic 
need for a colorimetric method that only measures arsenic. However, EPA 
notes that withdrawal of these methods does not preclude their use for 
other than compliance monitoring samples.
    EPA Methods 208.2 and 354.1--A commenter asked EPA to replace EPA 
Methods 208.2 (barium) and 354.1 (nitrite) with the equivalent methods 
SM 3113B and SM 4500-NO2-B, which are published in the 18th 
edition of Standard Methods (APHA, 1992). EPA agrees and will withdraw 
Methods 208.2 and 354.1, since equivalent methods using the same 
equipment and procedures are approved.
    EPA Method 340.2 (fluoride)--Commenters expressed concern that 
withdrawal of this ion-selective electrode method will require use of 
EPA Method 300.0, which requires purchase of an ion chromatograph. This 
is incorrect; only the EPA ion-selective electrode method will be 
withdrawn. The ASTM and SM methods, which use the same equipment as the 
EPA method, are approved for fluoride compliance determinations.
    Hydrazine Methods for Nitrate and Nitrite--A commenter agreed with 
EPA's withdrawal of hydrazine method 353.1, stating that the method is 
obsolete. The commenter, however, wanted EPA to make available at least 
one hydrazine method for nitrite and nitrate by approving SM 4500-
NO3-H. EPA is withdrawing Method 353.1 because hydrazine is 
carcinogenic and toxic, and creates a significant hazardous waste 
disposal problem. SM 4500-NO3-H has the same problems and, 
therefore, cannot be approved. EPA believes users of hydrazine methods 
will be able to convert easily to the approved cadmium reduction 
methods for nitrate and nitrite by changing their reagent from 
hydrazine to cadmium when their supply of hydrazine is depleted. The 
cadmium methods, which have been approved for nitrate and nitrite since 
1991, use the same equipment as the hydrazine methods.
    Flame AA for metals--Three commenters requested that flame atomic 
absorption (AA) and graphite furnace methods not be withdrawn. EPA has 
not withdrawn flame AA and graphite furnace methods published by ASTM 
or Standard Methods; only the obsolete EPA versions of these methods 
are withdrawn.
    Direct Aspiration Flame AA Methods--Some commenters wanted EPA to 
expand the scope of these methods to include metals other than barium 
and nickel. EPA cannot expand the scope, because the methods are not 
sensitive enough to measure metals other than barium and nickel.
    Method 515.1--EPA received many comments requesting that this 
method not be withdrawn, primarily for two reasons. First, neither 
proposed replacement method, 552.1 or 515.2, covers all of the 
regulated chemicals that are in Method 515.1. Secondly, the new dalapon 
method (552.1) requires significantly different equipment, procedures 
and skills than Method 515.1. Four commenters agreed with EPA's 
proposal to withdraw Method 515.1, because a combination of Methods 
515.2 and 552.1 meets their regulatory needs. EPA agrees with the 
majority of commenters and will not withdraw Method 515.1.
    Methods for Secondary Contaminants--Some commenters believed that 
delisting a secondary contaminant method precludes its use for other 
than compliance monitoring samples. This is not correct; EPA does not 
certify laboratories for secondary monitoring, and EPA only recommends 
methods for secondary contaminants. Unless State requirements provide 
otherwise, laboratories may use methods other than those cited at 40 
CFR 143.4(b) for measurement of secondary contaminants.
    EPA Method 245.2 (mercury)--EPA was asked to withdraw this method, 
which is an automated, cold vapor method for mercury. EPA cannot 
withdraw this method because there is no other equivalent version of 
the method. Because EPA does not have enough information to assess the 
effect that withdrawal of Method 245.2 would have, it is deferring a 
decision on withdrawal.
    EPA Methods 150.1, 150.2 (pH)--In the 1994 NOA, EPA proposed to 
replace these methods with equivalent ASTM and Standard Methods for pH. 
A commenter noted that the EPA methods are easier to use under field 
conditions. The commenter indicated that since many pH measurements are 
made in the field at the point of sample collection, withdrawal of the 
EPA methods would pose a significant hardship. EPA agrees with the 
commenter, and will not withdraw these methods until ASTM or Standard 
Methods pH methods are simplified for field use.

F. Miscellaneous

    Reformat Listing of Methods in 40 CFR Parts 141 and 143--Commenters 
have asked EPA to improve the organization and clarity of the drinking 
water regulations. Commenters have criticized the organization of the 
rules, and noted difficulty in obtaining copies of drinking water 
regulations. They need the regulations, because they contain tables and 
lists of approved methods, and because mandatory method instructions 
are included in the text of the rules and in footnotes to the tables of 
methods. These instructions are not contained in the approved methods, 
because they were developed after the method was published. In today's 
rule, EPA is minimizing the use of footnotes and lengthy technical 
instructions in drinking water rules. EPA is accomplishing this by 
including these instructions in the document Technical Notes on 
Drinking Water Methods (EPA, 1994d). This EPA publication contains 
mandatory procedures, clarifications and helpful options, such as 
guidance on more efficient ways to conduct asbestos and dioxin 
compliance measurements. EPA will place these instructions in the 
affected method when the method is revised and published. EPA intends 
to use this document to publish future method corrections or 
modifications (after notice and comment in the Federal Register as 
necessary). EPA believes Technical Notes will be easier for users to 
obtain, read and photocopy than the tables of approved methods in the 
drinking water rules. Incorporating Technical Notes on Drinking Water 
Methods by reference in the rule has the effect of making its 
provisions as mandatory as those in the approved drinking water 
methods.
    EPA is improving the clarity of the rules by consolidating listings 
of analytical methods. Analytical methods for THMs have been moved from 
Sec. 141.30 to Sec. 141.24(e). Appendix C of Sec. 141.30, which 
contained THM Methods 501.1 and 501.2, is withdrawn immediately, but 
the methods may be used for compliance monitoring under Sec. 141.30 
until July 1, 1996 (or 18 months from publication, whichever is later). 
And analytical methods formerly specified for lead, copper, and 
corrosivity at 40 CFR 141.89(a) and sodium at Sec. 141.41(d) are now 
listed with other inorganic methods at Sec. 141.23(k)(1). EPA notes 
that although sodium was removed from the list of 83 contaminants 
included in the 1986 amendments to the SDWA (53 FR 26487), the 
provisions at Sec. 141.41 still obtain.
    Specifications for Continuous Chlorine Monitoring Methods--
Commenters favored the proposed specification for continuous chlorine 
monitoring measurements to be based on calibration with an approved 
grab sample method. Two commenters asked EPA to extend the calibration 
period to seven days. EPA has no data to support such an extension. 
However, the EPA protocol for continuous chlorine monitoring allows a 
laboratory to use an alternative protocol, if it is approved by the 
State. EPA believes it is prudent for States to monitor and approve 
changes to the EPA protocol, such as those suggested by commenters. The 
protocol approved in today's rule is specified at 40 CFR 141.74(a)(2), 
and allows States to grant variations, including certain changes in the 
chemistry of the method.
    Allow Interchange of Detectors in EPA Methods 505, 507, 508--
Commenters favored this proposal. Two commenters noted that data with 
alternative detectors must be verified, and were concerned about poor 
ECD response of some nitrogen-containing compounds. EPA agrees that 
data must be verified when changing detectors, and that the results for 
all chemicals in Methods 505, 507 or 508 may not meet quality control 
requirements when an alternative detector is used. This is why Section 
6.8.3 of Methods 507 and 508, and Section 10.4 of Methods 505, 507 and 
508 allow alternative detectors only if the initial demonstration of 
capability criteria in Section 10 of each method is met by the 
alternative detector.
    One commenter wanted to allow use of other detectors with EPA 
Method 504. EPA cannot approve this request, because EPA has no data to 
justify use of alternative detectors in Methods 504 or 504.1, which use 
an electron capture detector (ECD). The ECD has been the only detector 
capable of routinely measuring EDB and DBCP at the required parts-per-
trillion concentrations (56 FR 3550, January 30, 1991).
    Guidance on Preserving Samples--A commenter asked that biocide 
procedures be dropped from the VOC methods, because EPA has dropped 
mercuric chloride as a biocide in synthetic organic chemical (SOC) 
methods. EPA dropped mercuric chloride from SOC methods, because EPA 
has no data to show that biodegradation of a regulated SOC occurs in a 
typical drinking water sample, and because mercuric chloride is toxic 
and a hazardous waste. However, EPA has data to show degradation (EPA, 
1994e) in samples collected for measurement of VOCs. The biocide 
procedures required in the VOC methods require some combination of 
chilling, rapid transit and analysis, or acidification. None of these 
procedures pose health or waste disposal problems that compare with the 
problems associated with preservation using mercuric chloride. 
Therefore, EPA continues to require use of a biocide in VOC methods.
    Liquid-Solid Extraction (LSE) in EPA Methods 507 and 508--Some 
commenters believed more data were needed before EPA allowed use of LSE 
in Methods 507 and 508; EPA agrees. EPA stated in the December proposal 
that ``the Agency regards this proposed modification as tentative and 
will base a final decision on whether to approve on public comment and 
additional EPA performance data.'' After studying this option and 
developing additional data (EPA, 1994e), EPA has decided not to add LSE 
as an option in Methods 507 and 508, because EPA does not have data to 
support use of this technique for all of the chemicals in the methods. 
As an alternative, EPA has developed and is approving Method 508.1 
(EPA, 1994c). Method 508.1 uses the procedures and the electron capture 
detector that are used in Method 508, and it allows use of LSE. The 
scope of Method 508.1 covers many of the Method 507 and 508 analytes 
that are subject to regulated or unregulated contaminant monitoring 
requirements, but it does not include butachlor, PCBs or toxaphene. In 
today's rule EPA will approve Method 508.1 for measurement of alachlor, 
atrazine, chlordane, endrin, heptachlor, heptachlor epoxide, 
hexachloro-benzene, hexachlorocyclopentadiene, lindane, methoxychlor, 
and simazine, which are regulated SOCs. It is also approved for aldrin, 
dieldrin, metolachlor, metribuzin, and propachlor, which are 
unregulated SOCs.
    Methods for Other Contaminants--In the 1993 proposal EPA provided 
guidance to systems that wish to measure chemicals that are not 
regulated, and need advice on what method to use. The guidance stated 
that ``although EPA approves methods only for contaminants regulated 
under the Safe Drinking Water Act, the Agency encourages laboratories 
to use these methods for other contaminants if the method description 
specifically includes these contaminants.'' One commenter mistakenly 
believed that this eliminates the use of other methods or techniques, 
such as test kits. Although EPA encourages laboratories to save money 
by using a compliance method to measure all chemicals of interest that 
are in the analytical scope of the method, this does not preclude 
systems from using other methods, including test kits, for samples 
other than compliance monitoring samples.
    EPA cautions users to carefully evaluate the performance of a 
method when using it for samples other than compliance monitoring 
samples or for contaminants not regulated under the SDWA. For example, 
EDB and DBCP appear in the scope of EPA Methods 504.1, 502.2, 524.2 and 
551. However, Methods 502.2 and 524.2 are not approved for compliance 
analyses, because they do not have the sensitivity to measure 
compliance with the EDB and DBCP MCLs.
    Methods Approval Process--Several commenters believe that the 
process of proposing and approving methods or method modifications will 
always be too slow to accommodate the technical and certification needs 
of the laboratory community. To solve this problem, commenters asked 
EPA to specify performance criteria in drinking water rules, or in the 
approved methods. The purpose of this would be to allow laboratories to 
use any analytical method, provided it met the mandatory criteria. EPA 
agrees that the present methods approval system is slow. To solve this 
problem, EPA and other organizations are seeking to consolidate methods 
across regulatory programs and media, and to write generic method 
performance criteria (EPA, 1994g). A performance-based method system, 
as suggested by commenters, might be part of the final solution. There 
are two groups working on this problem. The groups are the 
Intergovernmental Task Force on Monitoring, and EPA's Environmental 
Monitoring Management Council. A recommendation of these groups may be 
for EPA to propose a new method approval and method-writing protocol. 
The protocol would be designed to expedite approval of drinking water 
method modifications while maintaining the degree of control needed to 
ensure effective enforcement of drinking water regulations.
    Field and Test Kits--Two commenters noted an omission in the rule 
text in the 1993 proposal that appears to eliminate an important 
option. This option allows States to approve use of DPD colorimetric 
test kits for measurement of chlorine residuals. EPA did not intend to 
eliminate this option, and agrees the wording in the 1993 proposal (58 
FR 65631) may be misleading. Today's rule clearly allows use of the DPD 
kits, provided the State also approves use of the kits. This option is 
specified at 40 CFR 141.74(a)(2).
    A commenter asked EPA to approve field kits for pH, and methods for 
continuous monitoring of pH and residual chlorine. EPA does not need to 
approve field methods for pH because currently, analysis with an 
approved pH method may be conducted in the field or in the laboratory. 
Regarding continuous monitoring methods, in today's rule, EPA provides 
criteria for continuous monitoring of chlorine residuals (40 CFR 
141.74(a)(2)). Since EPA does not require continuous pH monitoring, EPA 
does not approve or disapprove methods for continuous measurement of 
pH.
    Turbidity--A commenter asked that turbidity measurements, which are 
specified in the drinking water regulations, be waived if no 
particulate or cloudiness is visible to the analyst. The present 
requirement is that turbidity be measured in all samples, and that 
digestion be performed if the turbidity is one NTU or greater. EPA 
cannot waive turbidity measurements on samples that appear to be clear, 
because samples with turbidity of up to three NTU can appear clear to 
the unaided eye.
    Corrosivity--One commenter noted the proposed rule made no 
reference to updating the methods for corrosivity in 40 CFR 141.42(c). 
These methods were published in 1980 and 1982 (45 FR 57346, August 27, 
1980 and 47 FR 10999, March 12, 1982). In the Lead and Copper Rule (56 
FR 26460, June 7, 1991), EPA agreed that corrosion control strategies 
could be developed or evaluated by measuring alkalinity and other 
parameters (56 FR 26489 and 26496). However, the Lead and Copper Rule 
did not update or specify use of the methods in 40 CFR 141.42(c). 
Instead, more current methods were specified in 40 CFR 141.89(a) (56 FR 
26509-26510). In today's rule, EPA eliminates possible confusion 
between the requirements in 40 CFR 141.89 and 141.42 by removing 
subparagraphs 40 CFR 141.42(a)-(c).
    New Technologies--Comments were received asking the Agency to 
evaluate and develop methods based on new technologies, such as 
bioassay, ELISA, and capillary electrophoresis. The Agency continues to 
incorporate new technologies in methods, and appreciates the many 
articles that were sent to draw attention to new technologies. In the 
last twenty years, the Agency has aided the development of the mass 
spectrometer into a powerful and routine analytical instrument. With 
suggestions from the laboratory community (56 FR 3550, January 30, 
1991), the Agency moved from packed to capillary column gas 
chromatographic technology, and expects to adopt innovative procedures 
and instruments in future methods.
    In the 1993 proposal, EPA invited public suggestions that EPA might 
consider approving in this rule or in a later rulemaking. This 
invitation was not meant to imply that new methods or method 
modifications submitted as suggestions would or could bypass 
requirements that are specified at 40 CFR 141.27. Some commenters 
expressed interest in having their method or instrumentation included 
in EPA-approved methods. EPA suggests that these commenters submit 
their data to EPA's Alternative Test Procedures (ATP) program for 
evaluation. A method or instrument can be considered for approval by 
EPA after it has received a favorable evaluation under the ATP program. 
A protocol for submitting ATP data is available from EPA (EPA, 1993c).

V. Availability and Sources for Methods Information

    Commenters requested help in obtaining copies of analytical methods 
cited in drinking water rules. Sources of all approved methods are 
contained in the References section of this rule. These methods are 
available for review but not distribution at the EPA Drinking Water 
Docket (MC 4101), 401 M Street SW., Washington, DC 20460. For access to 
the docket material, please call (202) 260-3027 between 9 am and 3:30 
pm, EST, Monday through Friday, excluding federal holidays. EPA only 
stocks or distributes copies of methods published by EPA. All other 
methods must be obtained from the publisher. Sources (with addresses) 
for all approved methods are cited at 40 CFR Parts 141 and 143, and in 
the References section of today's rule. Most EPA methods and the 
document, Technical Notes on Drinking Water Methods, may be purchased 
from the National Technical Information Service (NTIS), U.S. Department 
of Commerce, 5285 Port Royal Road, Springfield, VA 22161. The toll-free 
number is: (800) 553-6847, local: (703) 487-4650. Refer to the drinking 
water rules or the References section of this rule to obtain the NTIS 
order number and purchase information, or contact the Safe Drinking 
Water hotline. The hotline operates from 9 a.m. and 5:30 p.m. EST, 
Monday through Friday, excluding federal holidays. The toll-free number 
is (800) 426-4791. EPA Methods 504.1, 508.1 and 525.2 are not published 
in an NTIS manual. These methods may be obtained directly from EPA, 
Environmental Monitoring Systems Laboratory, Cincinnati, OH 45268; the 
phone number is (513) 569-7586. Since Methods 150.1 (pH), 150.2 (pH) 
and 245.2 (mercury) are published in ``Methods for Chemical Analysis of 
Water and Wastes'' (EPA, 1983a), owners of this EPA manual do not need 
to reorder these methods.
    EPA believes most laboratories will need only the more recently 
published or approved methods that are listed in today's rule. These 
methods (or manuals) are as follows. Technical Notes on Drinking Water 
Methods, October 1994, NTIS PB95-104766; EPA Method 508.1, 
``Determination of Chlorinated Pesticides, Herbicides, and 
Organohalides in Water Using Liquid-Solid Extraction and Electron 
Capture Gas Chromatography'', October 1994; EPA Method 100.2, 
``Determination of Asbestos Structures over 10m in Length in 
Drinking Water'', June 1994, NTIS PB94- 201902; ``Methods for the 
Determination of Metals in Environmental Samples--Supplement I'', May 
1994, NTIS PB94-184942; EPA Method 525.2, ``Determination of Organic 
Compounds in Drinking Water by Liquid-Solid Extraction in Capillary 
Column Gas Chromatography/Mass Spectrometry'', March 1994; EPA Method 
504.1, ``1,2-Dibromoethane (EDB), 1,2-Dibromo-3-chloropropane (DBCP), 
and 1,2,3-Trichloropropane (123TCP) in Water by Microextraction and Gas 
Chromatography'', 1993; ``Methods for the Determination of Inorganic 
Substances in Environmental Samples'', August 1993, NTIS PB91-231498; 
``Methods for the Determination of Organic Compounds in Drinking 
Water--Supplement II,'' August 1992, NTIS PB92- 207703; Standard 
Methods for the Examination of Water and Wastewater 18th Edition 
Supplement, 1994; Colisure, Millipore Corp., 1994; and GLI Method 2, 
``Turbidity'', Great Lakes Instruments, Inc., November 2, 1992.
    The American Society for Testing and Materials (ASTM) annually 
reprints all of the methods contained in the Annual Book of ASTM 
Methods, even methods that have not been editorially or technically 
revised. Thus, it is permissible to use any edition that contains the 
EPA-approved version of the compliance method. EPA notes that Orion 
Method 601 ``Standard Method of Test for Nitrate in Drinking Water'', 
which is equivalent to SM 4500-NO3-D (APHA, 1992), is 
identical to Orion Method WeWWG/5880. Method WeWWG/5880 is approved for 
nitrate analysis. ATI Orion republished the method in 1994 and 
renumbered it as 601, because the 1985 manual ``Orion Guide to Water 
and Wastewater Analysis'', which contained WeWWG/5880, is no longer 
available. In today's rule EPA cites WeWWG/5880 as 601 at 40 CFR 
141.23(k)(1).

VI. Regulation Assessment Requirements

A. Executive Order 12866

    Under Executive Order 12866 (58 FR 51735, October 4, 1993), the 
Agency must determine whether the regulatory action is ``significant'' 
and therefore subject to OMB review and the requirements of the 
Executive Order. The Order defines ``significant regulatory action'' as 
one that is likely to result in a rule that may:
    (1) Have an annual effect on the economy of $100 million or more, 
or adversely affect in a material way the economy, a sector of the 
economy, productivity, competition, jobs, the environment, public 
health or safety, or State, local, or tribal governments or 
communities;
    (2) Create a serious inconsistency or otherwise interfere with an 
action taken or planned by another agency;
    (3) Materially alter the budgetary impact of entitlements, grants, 
user fees, or loan programs or the rights and obligations of recipients 
thereof; or
    (4) Raise novel legal or policy issues arising out of legal 
mandates, the President's priorities, or the principles set forth in 
the Executive Order.
    It has been determined that this rule is not a ``significant 
regulatory action'' under the terms of Executive Order 12866 and is 
therefore not subject to OMB review.

B. Regulatory Flexibility Act

    The Regulatory Flexibility Act requires EPA to explicitly consider 
the effect of these regulations on small entities. By policy, EPA has 
decided to consider regulatory alternatives if there is any economic 
impact on any number of small entities.
    This rule is consistent with the objectives of the Regulatory 
Flexibility Act because it will not have any economic impact on any 
small entities. This rule specifies analytical methods that 
laboratories must use for testing regulated drinking water 
contaminants. Monitoring requirements were promulgated in earlier 
notices. The rule would require laboratories to use the most recent 
version of a method and imposes no additional requirements. It is 
actually expected to reduce cost of analysis by eliminating current 
requirements to use different versions of the same method, and by 
allowing more contaminants to be analyzed simultaneously by using a 
single method. Therefore, the Agency believes that this notice would 
have no adverse effect on any number of small entities.

C. Paperwork Reduction Act

    The rule contains no requests for information and consequently is 
not subject to the Paperwork Reduction Act, 44 U.S.C. 3501 et seq.

D. Science Advisory Board, National Drinking Water Advisory Council, 
and Secretary of Health and Human Services

    In accordance with section 1412(d) and (e) of the SDWA, the Agency 
consulted with the Science Advisory Board, the National Drinking Water 
Advisory Council, and the Secretary of Health and Human Services on 
this action and took their comments into account.

VII. References

APHA. 1992. Eighteenth edition of Standard Methods for the 
Examination of Water and Wastewater, 1992, American Public Health 
Association, 1015 Fifteenth Street NW, Washington, D.C. 20005.
APHA. 1994. Method 6610 ``Carbamate Pesticides'' in Standard Methods 
for the Examination of Water and Wastewater, 18th Edition 
Supplement, 1994, American Public Health Association, 1015 Fifteenth 
Street NW, Washington, D.C. 20005. APHA.
ASTM. 1994. Annual Book of ASTM Methods, 1994, Vol. 11.01 and 11.02, 
American Society for Testing and Materials, 1916 Race Street, 
Philadelphia, PA 19103.
Bionetics. Report from Kenneth W. Edgell, et al., ``Determination of 
Inorganic Anions in Water by Ion Chromatography: Collaborative 
Study'', Bionetics Corp., 16 Triangle Park Drive, Cincinnati, Ohio 
45246, 1991.
Broadway, S., B. Pyle, G. McFeters. 1992. Final report of 
equivalency testing for Colisure. Montana State University, Bozeman, 
MT.
Eaton. 1993a. Letter from Andrew D. Eaton, Standard Methods 
Committee, ``Error in 4500-Cl E'', American Public Health 
Association, 1015 Fifteenth Street NW, Washington, D.C. 20005, June 
4, 1993.
Eaton. 1993b. Letter from Andrew D. Eaton, Standard Methods 
Committee, ``Inquiry on Chlorine Residual 4500-Cl (18th Edition)'', 
American Public Health Association, 1015 Fifteenth Street NW, 
Washington, D.C. 20005, October 26, 1993.
EPA. 1974. Method 245.2, ``Mercury, Automated Cold Vapor 
Technique'', EPA, Environmental Monitoring Systems Laboratory, 
Cincinnati, OH 45268, 1974. Also contained in reference EPA, 1983a.
EPA. 1978. Method 150.1, ``pH, Electrometric'', EPA, Environmental 
Monitoring Systems Laboratory, Cincinnati, OH 45268, 1978. Also 
contained in reference EPA, 1983a.
EPA. 1982. Method 150.2, ``pH Continuous Monitoring, Electro-
metric'', EPA, Environmental Monitoring Systems Laboratory, 
Cincinnati, OH 45268, December 1982. Also contained in reference 
EPA, 1983a.
EPA. 1983a. ``Methods for Chemical Analysis of Water and Wastes'', 
EPA, March 1983, NTIS PB84-128677.
EPA. 1983b. Method 100.1, ``Analytical Method for the Determination 
of Asbestos Fibers in Water'', September 1983, NTIS PB83-260471.
EPA. 1990a. ``Methods for the Determination of Organic Compounds in 
Drinking Water--Supplement I'', July 1990, NTIS PB91-146027.
EPA. 1990b. Manual for the Certification of Laboratories Analyzing 
Drinking Water, Third Edition, Office of Water Resource Center (RC-
4100), 401 M. Street S.W., Washington, D.C. 20460, EPA 570-9-90-008, 
April 1990.
EPA. 1991. ``Methods for the Determination of Organic Compounds in 
Drinking Water'', December 1988, revised July 1991, NTIS PB91-
231480.
EPA. 1992a. Memorandum from Richard L. Carr, ``Second Laboratory 
Validation of Method 555'', December 10, 1992, U.S. Environmental 
Protection Agency.
EPA. 1992b. ``Methods for the Determination of Organic Compounds in 
Drinking Water--Supplement II,'' August 1992, NTIS PB92-207703.
EPA. 1993a. ``Methods for the Determination of Inorganic Substances 
in Environmental Samples'', August 1993, NTIS PB94-121811.
EPA. 1993b. Memorandum from James R. Elder, ``Detection Limits in 
Compliance Monitoring'', December 16, 1993, U.S. Environmental 
Protection Agency.
EPA. 1993c. ``Protocol for Nationwide Approval of New or Revised 
Methods'', Rev. 1.4, EPA, Environmental Monitoring Systems 
Laboratory, Cincinnati, OH 45268, July 14, 1993.
EPA. 1993d. Method 504.1, ``1,2-Dibromoethane (EDB), 1,2-Dibromo-3-
chloropropane (DBCP), and 1,2,3-Trichloropropane (123TCP) in Water 
by Microextraction and Gas Chromatography'', EPA, Environmental 
Monitoring Systems Laboratory, Cincinnati, OH 45268, 1993.
EPA. 1994a. ``Methods for the Determination of Metals in 
Environmental Samples--Supplement I'', May 1994, NTIS PB94-184942.
EPA. 1994b. Method 525.2, Rev. 1.0, ``Determination of Organic 
Compounds in Drinking Water by Liquid-Solid Extraction in Capillary 
Column Gas Chromatography/Mass Spectrometry'', EPA, Environmental 
Monitoring Systems Laboratory, Cincinnati, OH 45268, March 1994.
EPA. 1994c. Method 508.1, Rev. 1.0, ``Determination of Chlorinated 
Pesticides, Herbicides, and Organohalides by Liquid-Solid Extraction 
and Electron Capture Gas Chromatography'', EPA, Environmental 
Monitoring Systems Laboratory, Cincinnati, OH 45268, 1994.
EPA. 1994d. Technical Notes on Drinking Water Methods, EPA-600/R-94-
173, October 1994, NTIS PB95-104766.
EPA. 1994e. ``Response to Comments on December 15, 1993, Analytical 
Methods Proposal, 58 FR 65622'', Office of Water Docket (MC 4601), 
401 M. St. S.W., Washington, D.C. 20460, October 1994.
EPA. 1994f. Memorandum from Mary Ann Feige, et al., ``Detection 
Limits in the Regulations'', March 11, 1994, U.S. Environmental 
Protection Agency.
EPA. 1994g. Memorandum from Robert M. Sussman, ``EMMC Activities'', 
May 13, 1994, U.S. Environmental Protection Agency.
EPA. 1994h. Method 100.2, ``Determination of Asbestos Structures 
over 10m in Length in Drinking Water'', June 1994, NTIS 
PB94-201902.
EPA. 1994i. Method 1613: ``Tetra-through Octa-Chlorinated Dioxins 
and Furans by Isotope-Dilution HRGC/HRMS'', October 1994, NTIS PB95-
104774.
Great Lakes. GLI Method 2, ``Turbidity'', Great Lakes Instruments, 
Inc., 8855 North 55th Street, Milwaukee, WI 53223, November 2, 1992.
Lyter. Letter from P. Ted Lyter, Dept. of Environmental Resources, 
Commonwealth of Pennsylvania, P.O. Box 1467, Harrisburg, PA 17105-
1467, January 12, 1994.
Millipore. ``Waters Test Method for Determination of Nitrite/Nitrate 
in Water Using Single Column Ion Chromatography'', Method B-1011, 
Millipore Corporation, Waters Chromatography Division, 34 Maple 
Street, Milford, MA 01757.
Millipore. 1994. Colisure Presence/Absence Test for Detection and 
Identification of Coliform Bacteria and Escherichia coli in Drinking 
Water. February 28, 1994. Millipore Corp., Technical Services 
Department, 80 Ashby Road, Bedford, MA 01730.
Orion. Technical Bulletin 601, ``Standard Method of Test for Nitrate 
in Drinking Water'', PN 221890-001, ATI Orion, 529 Main Street, 
Boston, MA 02129, July 1994.
Technicon. 1972. Industrial Method No. 129-71W, ``Fluoride in Water 
and Wastewater'', Technicon Industrial Systems, Tarrytown, NY 10591, 
December 1972.
Technicon. 1989. Method No. 380-75WE, ``Fluoride in Water and 
Wastewater'', Technicon Industrial Systems, Tarrytown, NY 10591, 
February 1976.
USGS. 1989. Methods I-3720-85, I-3300-85, I-1030-85, I-1601-85, I-
2598-85, I-1700-85 and I-2700-85 in Techniques of Water Resources 
Investigations of the U.S. Geological Survey, Book 5, Chapter A-1, 
3rd ed., U.S. Geological Survey, Books and Open File Reports 
Section, Box 25425, Federal Center, Denver, CO 80225-0425, 1989.
USGS. 1993. Method I-2601-90 in Methods of Analysis by the U.S. 
Geological Survey National Water Quality Laboratory--Determination 
of Inorganic and Organic Constituents in Water and Fluvial 
Sediments, Open File Report 93-125, U.S. Geological Survey, Books 
and Open File Reports Section, Box 25425, Federal Center, Denver, CO 
80225-0425, 1993.

List of Subjects

40 CFR Part 141

    Environmental Protection, Chemicals, Incorporation by reference, 
Intergovernmental relations, Water supply.

40 CFR Part 143

    Chemicals, Incorporation by reference, Intergovernmental relations, 
Water supply.

    Dated: November 25, 1994.
Carol M. Browner,
Administrator.
    For the reasons set out in the preamble, parts 141 and 143 of title 
40, Code of Federal Regulations, are amended as follows:

PART 141--NATIONAL PRIMARY DRINKING WATER REGULATIONS

    1. The authority citation for part 141 continues to read as 
follows:

    Authority: 42 U.S.C. 300f, 300g-1, 300g-2 300g-3, 300g-4, 300g-
5, 300g-6, 300j-4, 300j-9.

    2. Section 141.21 is amended by revising paragraph (f)(3), removing 
and reserving (f)(4), revising the next to last sentence of (f)(5), 
revising the second sentence of (f)(6)(i), revising the second sentence 
of (f)(6)(ii), Adding (F)(6)(iv), and adding a new sentence as the next 
to last sentence in (f)(8) to read as follows:


Sec. 141.21  Coliform sampling.

* * * * *
    (f) * * *
    (3) Public water systems must conduct total coliform analyses in 
accordance with one of the analytical methods in the following table. 
These methods are contained in the 18th edition of Standard Methods for 
the Examination of Water and Wastewater, 1992, American Public Health 
Association, 1015 Fifteenth Street NW., Washington, DC 20005. A 
description of the Colisure Test may be obtained from the Millipore 
Corporation, Technical Services Department, 80 Ashby Road, Bedford, MA 
01730. The toll-free phone number is (800) 645-5476.

------------------------------------------------------------------------
         Organism                   Methodology             Citation    
------------------------------------------------------------------------
Total Coliforms1..........  Total Coliform              9221A, B.       
                             Fermentation                               
                             Technique2,3,4.                            
                            Total Coliform Membrane     9222A, B, C.    
                             Filter Technique.                          
                            Presence-Absence (P-A)      9221D.          
                             Coliform Test4,5.                          
                            ONPG-MUG Test6............  9223.           
                            Colisure Test7............                  
------------------------------------------------------------------------
\1\The time from sample collection to initiation of analysis may not    
  exceed 30 hours.                                                      
\2\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 for total coliforms, using lactose broth, is less than  
  10 percent.                                                           
\3\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.                                                                
\4\No requirement exists to run the completed phase on 10 percent of all
  total coliform-positive confirmed tubes.                              
\5\Six-times formulation strength may be used if the medium is filter-  
  sterilized rather than autoclaved.                                    
\6\The ONPG-MUG Test is also known as the Autoanalysis Colilert System. 
\7\The Colisure Test must be incubated for 28 hours before examining the
  results. If an examination of the results at 28 hours is not          
  convenient, then results may be examined at any time between 28 hours 
  and 48 hours.                                                         

    (4) [Reserved]
    (5) * * * The preparation of EC medium is described in the 18th 
edition of Standard Methods for the Examination of Water and 
Wastewater, 1992, Method 9221E--p. 9-52, paragraph 1a. * * *
    (6) * * *
    (i) * * * EC medium is described in the 18th edition of Standard 
Methods for the Examination of Water and Wastewater, 1992, Method 
9221E--p. 9-52, paragraph 1a. * * *
    (ii) * * * Nutrient Agar is described in the 18th edition of 
Standard Methods for the Examination of Water and Wastewater, 1992, p. 
9-47 to 9-48.
    (iii) * * *
    (iv) The Colisure Test. A description of the Colisure Test may be 
obtained from the Millipore Corporation, Technical Services Department, 
80 Ashby Road, Bedford, MA 01730.
* * * * *
    (8) * * * A description of the Colisure Test may be obtained from 
the Millipore Corp., Technical Services Department, 80 Ashby Road, 
Bedford, MA 01730. * * *
* * * * *
    3. Section 141.22(a) is amended by removing the next to last 
sentence and revising the last sentence to read as follows:


Sec. 141.22  Turbidity sampling and analytical requirements.

* * * * *
    (a) * * * Turbidity measurements shall be made as directed in 
Sec. 141.74(a)(1).
* * * * *
    4. Section 141.23 is amended by removing paragraph (k)(2) and 
redesignating paragraph (k)(4) as (k)(2), by removing paragraph (k)(3) 
and redesignating paragraph (k)(5) as (k)(3), by removing and reserving 
paragraph (q), and revising paragraph (k)(1) to read as follows:


Sec. 141.23  Inorganic chemical sampling and analytical requirements.

* * * * *
    (k) * * *
    (1) Analysis for the following contaminants shall be conducted in 
accordance with the methods in the following Table, 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 Technical Notes on 
Drinking Water Methods, EPA-600/R-94-173, October 1994. This document 
also contains approved analytical test methods which remain available 
for compliance monitoring until July 1, 1996. These methods will not be 
available for use after July 1, 1996. This document is available from 
the National Technical Information Service, NTIS PB95-104766, U.S. 
Department of Commerce, 5285 Port Royal Road, Springfield, Virginia 
22161. The toll-free number is 800-553-6847.

----------------------------------------------------------------------------------------------------------------
     Contaminant        Methodology        EPA             ASTM\3\                SM\4\               Other     
----------------------------------------------------------------------------------------------------------------
Antimony............  ICP-Mass            \2\200.8                                                              
                       Spectrometry.                                                                            
                      Hydride-Atomic   ...........  D-3697-92                                                   
                       Absorption.                                                                              
                      Atomic              \2\200.9                                                              
                       Absorption;                                                                              
                       Platform.                                                                                
                      Atomic           ...........  ....................  3113B...............                  
                       Absorption;                                                                              
                       Furnace.                                                                                 
Arsenic.............  Inductively         \2\200.7  ....................  3120B...............                  
                       Coupled Plasma.                                                                          
                      ICP-Mass            \2\200.8                                                              
                       Spectrometry.                                                                            
                      Atomic              \2\200.9                                                              
                       Absorption;                                                                              
                       Platform.                                                                                
                      Atomic           ...........  D-2972-93C            3113B...............                  
                       Absorption;                                                                              
                       Furnace.                                                                                 
                      Hydride Atomic   ...........  D-2972-93B            3114B...............                  
                       Absorption.                                                                              
Asbestos............  Transmission        \9\100.1                                                              
                       Electron                                                                                 
                       Microscopy.                                                                              
                      Transmission       \10\100.2                                                              
                       Electron                                                                                 
                       Microscopy.                                                                              
Barium..............  Inductively         \2\200.7  ....................  3120B...............                  
                       Coupled Plasma.                                                                          
                      ICP-Mass            \2\200.8                                                              
                       Spectrometry.                                                                            
                      Atomic           ...........  ....................  3111D...............                  
                       Absorption;                                                                              
                       Direct.                                                                                  
                      Atomic           ...........  ....................  3113B...............                  
                       Absorption;                                                                              
                       Furnace.                                                                                 
Beryllium...........  Inductively         \2\200.7  ....................  3120B...............                  
                       Coupled Plasma.                                                                          
                      ICP-Mass            \2\200.8                                                              
                       Spectrometry.                                                                            
                      Atomic              \2\200.9                                                              
                       Absorption;                                                                              
                       Platform.                                                                                
                      Atomic           ...........  D-3645-93B            3113B...............                  
                       Absorption;                                                                              
                       Furnace.                                                                                 
Cadmium.............  Inductively         \2\200.7                                                              
                       Coupled Plasma.                                                                          
                      ICP-Mass            \2\200.8                                                              
                       Spectrometry.                                                                            
                      Atomic              \2\200.9                                                              
                       Absorption;                                                                              
                       Platform.                                                                                
                      Atomic           ...........  ....................  3113B...............                  
                       Absorption;                                                                              
                       Furnace.                                                                                 
Chromium............  Inductively         \2\200.7  ....................  3120B...............                  
                       Coupled Plasma.                                                                          
                      ICP-Mass            \2\200.8                                                              
                       Spectrometry.                                                                            
                      Atomic              \2\200.9                                                              
                       Absorption;                                                                              
                       Platform.                                                                                
                      Atomic           ...........  ....................  3113B...............                  
                       Absorption;                                                                              
                       Furnace.                                                                                 
Cyanide.............  Manual           ...........  ....................  4500-CN-C...........                  
                       Distillation                                                                             
                       followed by.                                                                             
                      Spectrophotomet  ...........  D2036-91B             4500CN-G............                  
                       ric, Amenable.                                                                           
                      Spectrophotomet  ...........  D2036-91A             4500-CN-E...........  \5\I-3300-85    
                       ric Manual.                                                                              
                      Semi-automated.     \6\335.4                                                              
                      Selective        ...........  ....................  4500CN-F............                  
                       Electrode.                                                                               
Fluoride............  Ion                 \6\300.0  D4327-91              4110B...............                  
                       Chromatography.                                                                          
                      Manual           ...........  ....................  4500F-B,D...........                  
                       Distill.;                                                                                
                       Color. SPADNS.                                                                           
                      Manual           ...........  D1179-93B             4500F-C.............                  
                       Electrode.                                                                               
                      Automated        ...........  ....................  ....................  \11\380-75WE    
                       Electrode.                                                                               
                      Automated        ...........  ....................  4500F-E.............  \11\129-71W     
                       Alizarin.                                                                                
Mercury.............  Manual, Cold        \2\245.1  D3223-91              3112B...............                  
                       Vapor.                                                                                   
                      Automated, Cold     \1\245.2                                                              
                       Vapor.                                                                                   
                      ICP-Mass            \2\200.8                                                              
                       Spectrometry.                                                                            
Nickel..............  Inductively         \2\200.7  ....................  3120B...............                  
                       Coupled Plasma.                                                                          
                      ICP-Mass            \2\200.8                                                              
                       Spectrometry.                                                                            
                      Atomic              \2\200.9                                                              
                       Absorption;                                                                              
                       Platform.                                                                                
                      Atomic           ...........  ....................  3111B...............                  
                       Absorption;                                                                              
                       Direct.                                                                                  
                      Atomic           ...........  ....................  3113B...............                  
                       Absorption;                                                                              
                       Furnace.                                                                                 
Nitrate.............  Ion                 \6\300.0  D4327-91              4110B...............  \8\B-1011       
                       Chromatography.                                                                          
                      Automated           \6\353.2  D3867-90A             4500-NO3-F..........                  
                       Cadmium                                                                                  
                       Reduction.                                                                               
                      Ion Selective    ...........  ....................  4500-NO3-D..........  \7\601          
                       Electrode.                                                                               
                      Manual Cadmium   ...........  D3867-90B             4500-NO3-E..........                  
                       Reduction.                                                                               
Nitrite.............  Ion                 \6\300.0  D4327-91              4110B...............  \8\B-1011       
                       Chromatography.                                                                          
                      Automated           \6\353.2  D3867-90A             4500-NO3-F..........                  
                       Cadmium                                                                                  
                       Reduction.                                                                               
                      Manual Cadmium   ...........  D3867-90B             4500-NO3-E..........                  
                       Reduction.                                                                               
                      Spectrophotomet  ...........  ....................  4500-NO2-B..........                  
                       ric.                                                                                     
Selenium............  Hydride-Atomic   ...........  D3859-93A             3114B...............                  
                       Absorption.                                                                              
                      ICP-Mass            \2\200.8                                                              
                       Spectrometry.                                                                            
                      Atomic              \2\200.9                                                              
                       Absorption;                                                                              
                       Platform.                                                                                
                      Atomic           ...........  D3859-93B             3113B...............                  
                       Absorption;                                                                              
                       Furnace.                                                                                 
Thallium............  ICP-Mass            \2\200.8                                                              
                       Spectrometry.                                                                            
                      Atomic              \2\200.9                                                              
                       Absorption;                                                                              
                       Platform.                                                                                
Lead................  Atomic           ...........  D3559-90D             3113B...............                  
                       absorption;                                                                              
                       furnace.                                                                                 
                      ICP-Mass            \2\200.8                                                              
                       spectrometry.                                                                            
                      Atomic              \2\200.9                                                              
                       absorption;                                                                              
                       platform.                                                                                
Copper..............  Atomic           ...........  D1688-90C             3113B...............                  
                       absorption;                                                                              
                       furnace.                                                                                 
                      Atomic           ...........  D1688-90A             3111B...............                  
                       absorption;                                                                              
                       direct                                                                                   
                       aspiration.                                                                              
                      ICP............     \2\200.7  ....................  3120B...............                  
                      ICP-Mass            \2\200.8                                                              
                       spectrometry.                                                                            
                      Atomic              \2\200.9                                                              
                       absorption;                                                                              
                       platform.                                                                                
pH..................  Electrometric..     \1\150.1  D1293-84              4500-H+-B...........                  
                      ...............     \1\150.2                                                              
Conductivity........  Conductance....  ...........  D1125-91A             2510B...............                  
Calcium.............  EDTA             ...........  D511-93A              3500-Ca-D...........                  
                       titrimetric.                                                                             
                      Atomic           ...........  D511-93B              3111B...............                  
                       absorption;                                                                              
                       direct                                                                                   
                       aspiration.                                                                              
                      Inductively-        \2\200.7  ....................  3120B...............                  
                       coupled plasma.                                                                          
Alkalinity..........  Titrimetric....  ...........  D1067-92B             2320B...............                  
                      Electrometric    ...........  ....................  ....................  \5\I-1030-85    
                       titration.                                                                               
Orthophosphate\12\..  Colorimetric,       \6\365.1  ....................  4500-P-F............                  
                       automated,                                                                               
                       ascorbic acid.                                                                           
                      Colorimetric,    ...........  D515-88A              4500-P-E............                  
                       ascorbic acid,                                                                           
                       single reagent.                                                                          
                      Colorimetric,    ...........  ....................  ....................  \5\I-1601-85    
                       phosphomolybda                                                                           
                       te;.                                                                                     
                      automated-       ...........  ....................  ....................  \5\I-2601-90    
                       segmented                                                                                
                       flow;.                                                                                   
                      automated        ...........  ....................  ....................  \5\I-2598-85    
                       discrete.                                                                                
                      Ion                 \6\300.0  D4327-91              4110................                  
                       Chromatography.                                                                          
Silica..............  Colorimetric,    ...........  ....................  ....................  \5\I-1700-85    
                       molybdate                                                                                
                       blue;.                                                                                   
                      automated-       ...........  ....................  ....................  \5\I-2700-85    
                       segmented flow.                                                                          
                      Colorimetric...  ...........  D859-88                                                     
                      Molybdosilicate  ...........  ....................  4500-Si-D...........                  
                      Heteropoly blue  ...........  ....................  4500-Si-E...........                  
                      Automated        ...........  ....................  4500-Si-F...........                  
                       method for                                                                               
                       molybdate-                                                                               
                       reactive                                                                                 
                       silica.                                                                                  
                      Inductively-        \2\200.7  ....................  3120B...............                  
                       coupled plasma.                                                                          
Temperature.........  Thermometric...  ...........  ....................  2550B...............                  
Sodium..............  Inductively-        \2\200.7                                                              
                       coupled plasma.                                                                          
                      Atomic           ...........  ....................  3111B...............                  
                       Absorption;                                                                              
                       direct                                                                                   
                       aspiration.                                                                              
----------------------------------------------------------------------------------------------------------------
Footnotes:                                                                                                      
\1\Methods 150.1, 150.2 and 245.2 are available from US EPA, EMSL, Cincinnati, OH 45268. The identical methods  
  were formerly in ``Methods for Chemical Analysis of Water and Wastes'', EPA-600/4-79-020, March 1983, which is
  available at NTIS, PB84-128677.                                                                               
\2\``Methods for the Determination of Metals in Environmental Samples--Supplement I'', EPA-600/R-94-111, May    
  1994. Available at NTIS, PB 94-184942.                                                                        
\3\The procedures shall be done in accordance with the Annual Book of ASTM Standards, 1994, Vols. 11.01 and     
  11.02, American Society for Testing and Materials. 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 obtained 
  from the American Society for Testing and Materials, 1916 Race Street, Philadelphia, PA 19103. Copies may be  
  inspected at EPA's Drinking Water Docket, 401 M Street, SW., Washington, DC 20460; or at the Office of the    
  Federal Register, 800 North Capitol Street, NW., Suite 700, Washington, DC.                                   
\4\The procedures shall be done in accordance with the 18th edition of Standard Methods for the Examination of  
  Water and Wastewater, 1992, American Public Health Association. 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   
  obtained from the American Public Health Association, 1015 Fifteenth Street NW, Washington, DC 20005. Copies  
  may be inspected at EPA's Drinking Water Docket, 401 M Street, SW., Washington, DC 20460; or at the Office of 
  the Federal Register, 800 North Capitol Street, NW., Suite 700, Washington, DC.                               
\5\Available from Books and Open-File Reports Section, U.S. Geological Survey, Federal Center, Box 25425,       
  Denver, CO 80225-0425.                                                                                        
\6\``Methods for the Determination of Inorganic Substances in Environmental Samples'', EPA-600/R-93-100, August 
  1993. Available at NTIS, PB94-121811.                                                                         
\7\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. 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 obtained from ATI Orion, 529 Main Street, Boston, MA 02129. Copies may be inspected at 
  EPA's Drinking Water Docket, 401 M Street, SW., Washington, DC 20460; or at the Office of the Federal         
  Register, 800 North Capitol Street, NW., Suite 700, Washington, DC.                                           
\8\Method B-1011, ``Waters Test Method for Determination of Nitrite/Nitrate in Water Using Single Column Ion    
  Chromatography'', Millipore Corporation, Waters Chromatography Division, 34 Maple Street, Milford, MA 01757.  
\9\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.                                                               
\10\Method 100.2, ``Determination Of Asbestos Structure Over 10-m In Length In Drinking Water'', EPA-  
  600/R-94-134, June 1994. Available at NTIS, PB94-201902.                                                      
\11\The procedures shall be done in accordance with the 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. 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 obtained from the Technicon      
  Industrial Systems, Tarrytown, NY 10591. Copies may be inspected at EPA's Drinking Water Docket, 401 M Street,
  SW., Washington, DC 20460; or at the Office of Federal Register, 800 Capitol Street, NW., Suite 700,          
  Washington, DC.                                                                                               
\12\Unfiltered, no digestion or hydrolysis.                                                                     

* * * * *
    (q) [Reserved]
    5. Section 141.24 is amended by removing and reserving paragraphs 
(f)(16), and (h)(12), adding paragraphs (e), reviewing paragraph 
(h)(13), introductory text, and paragraph (h)(13)(i) to read as 
follows:


Sec. 141.24  Organic chemicals other than total trihalomethanes, 
sampling and analytical requirements.

* * * * *
    (e) Analyses for the contaminants in this section shall be 
conducted using the following EPA methods or their equivalent as 
approved by EPA. Methods 502.2, 505, 507, 508, 508A, 515.1 and 531.1 
are in Methods for the Determination of Organic Compounds in Drinking 
Water, EPA-600/4-88-039, December 1988, Revised, July 1991. Methods 
506, 547, 550, 550.1 and 551 are in Methods for the Determination of 
Organic Compounds in Drinking Water--Supplement I, EPA-600-4-90-020, 
July 1990. Methods 515.2, 524.2, 548.1, 549.1, 552.1 and 555 are in 
Methods for the Determination of Organic Compounds in Drinking Water--
Supplement II, EPA-600/R-92-129, August 1992. 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 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 the 18th edition of Standard Methods for the 
Examination of Water and Wastewater, 1992, American Public Health 
Association. 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 obtained from the American Public Health 
Association, 1015 Fifteenth Street NW., Washington, DC 20005. Copies 
may be inspected at EPA's Drinking Water Docket, 401 M Street, SW., 
Washington, DC 20460; or at the Office of the Federal Register, 800 
North Capitol Street, NW., Suite 700, Washington, DC. Method 6610 shall 
be followed in accordance with the Supplement to the 18th edition of 
Standard Methods for the Examination of Water and Wastewater, 1994, 
American Public Health Association. 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 obtained from the 
American Public Health Association, 1015 Fifteenth Street NW., 
Washington, DC 20005. Copies may be inspected at EPA's Drinking Water 
Docket, 401 M Street, SW., Washington, DC 20460; or at the Office of 
the Federal Register, 800 North Capitol Street, NW., Suite 700, 
Washington, DC. Other analytical test procedures are contained in 
Technical Notes on Drinking Water Methods, EPA-600/R-94-173, October 
1994, NTIS PB95-104766. This document also contains approved analytical 
methods which remain available for compliance monitoring until July 1, 
1996. These methods will not be available for use after July 1, 1996. 
EPA Methods 504.1, 508.1 and 525.2 are available from US EPA EMSL, 
Cincinnati, OH 45268. The phone number is 513-569-7586.

------------------------------------------------------------------------
            Contaminant                             Method              
------------------------------------------------------------------------
Benzene............................  502.2, 524.2.                      
Carbon tetrachloride...............  502.2, 524.2, 551.                 
Chlorobenzene......................  502.2, 524.2.                      
1,2-Dichlorobenzene................  502.2, 524.2.                      
1,4-Dichlorobenzene................  502.2, 524.2.                      
1,2-Dichloroethane.................  502.2, 524.2.                      
cis-Dichloroethylene...............  502.2, 524.2.                      
trans-Dichloroethylene.............  502.2, 524.2.                      
Dichloromethane....................  502.2, 524.2.                      
1,2-Dichloropropane................  502.2, 524.2.                      
Ethylbenzene.......................  502.2, 524.2.                      
Styrene............................  502.2, 524.2.                      
Tetrachloroethylene................  502.2, 524.2, 551.                 
1,1,1-Trichloroethane..............  502.2, 524.2, 551.                 
Trichloroethylene..................  502.2, 524.2, 551.                 
Toluene............................  502.2, 524.2.                      
1,2,4-Trichlorobenzene.............  502.2, 524.2.                      
1,1-Dichloroethylene...............  502.2, 524.2.                      
1,1,2-Trichloroethane..............  502.2, 524.2.                      
Vinyl chloride.....................  502.2, 524.2.                      
Xylenes (total)....................  502.2, 524.2.                      
2,3,7,8-TCDD (dioxin)..............  1613.                              
2,4-D..............................  515.2, 555, 515.1.                 
2,4,5-TP (Silvex)..................  515.2, 555, 515.1.                 
Alachlor...........................  505\1\, 507, 525.2, 508.1.         
Atrazine...........................  505\1\, 507, 525.2, 508.1.         
Benzo(a)pyrene.....................  525.2, 550, 550.1.                 
Carbofuran.........................  531.1, 6610.                       
Chlordane..........................  505, 508, 525.2, 508.1.            
Dalapon............................  552.1, 515.1.                      
Di(2-ethylhexyl) adipate...........  506, 525.2.                        
Di(2-ethylhexyl) phthalate.........  506, 525.2.                        
Dibromochloropropane (DBCP)........  504.1, 551.                        
Dinoseb............................  515.2, 555, 515.1.                 
Diquat.............................  549.1.                             
Endothall..........................  548.1.                             
Endrin.............................  505, 508, 525.2, 508.1.            
Ethylene dibromide (EDB)...........  504.1, 551.                        
Glyphosate.........................  547, 6651.                         
Heptachlor.........................  505, 508, 525.2, 508.1.            
Heptachlor Epoxide.................  505, 508, 525.2, 508.1.            
Hexachlorobenzene..................  505, 508, 525.2, 508.1.            
Hexachlorocyclopentadiene..........  505, 525.2, 508, 508.1.            
Lindane............................  505, 508, 525.2, 508.1.            
Methoxychlor.......................  505, 508, 525.2, 508.1.            
Oxamyl.............................  531.1, 6610.                       
PCBs\2\ (as decachlorobiphenyl)....  508A.                              
  (as Aroclors)....................  505, 508.                          
Pentachlorophenol..................  515.2, 525.2, 555, 515.1.          
Picloram...........................  515.2, 555, 515.1.                 
Simazine...........................  505\1\, 507, 525.2, 508.1.         
Toxaphene..........................  505, 508, 525.2.                   
Total Trihalomethanes..............  502.2, 524.2, 551.                 
------------------------------------------------------------------------
\1\A nitrogen-phosphorous detector should be substituted for the        
  electron capture detector in Method 505 (or another approved method   
  should be used) to determine alachlor, atrazine and simazine, if lower
  detection limits are required.                                        
\2\PCBs are qualitatively identified as Aroclors and measured for       
  compliance purposes as decachlorobiphenyl.                            

* * * * *
    (h) * * *
    (12) (Reserved)
    (13) Analysis for PCBs shall be conducted as follows using the 
methods in paragraph (e) of this section:
    (i) Each system which monitors for PCBs shall analyze each sample 
using either Method 505 or Method 508.
* * * * *
    6. Section 141.30 is amended by revising paragraph (e) and by 
removing removing Appendix A, Appendix B, and Appendix C to read as 
follows:


Sec. 141.30  Total trihalomethane sampling, analytical and other 
requirements.

* * * * *
    (e) Sampling and analyses made pursuant to this section shall be 
conducted by the total trihalomethane methods as directed in 
Sec. 141.24(e), and in Technical Notes on Drinking Water Methods, EPA-
600/R-94-173, October 1994, which is available at NTIS, PB95-104766.
* * * * *
    7. Section 141.40 is amended by revising paragraphs (g), (n)(11), 
and (n)(12) to read as follows:


Sec. 141.40  Special monitoring for inorganic and organic chemicals.

* * * * *
    (g) Analysis for the unregulated contaminants listed under 
paragraphs (e) and (j) of this section shall be conducted using EPA 
Methods 502.2 or 524.2, or their equivalent as determined by EPA, 
except analysis for bromodichloromethane, bromoform, 
chlorodibromomethane and chloroform under paragraph (e) of this section 
also may be conducted by EPA Method 551, and analysis for 1,2,3-
trichloropropane also may be conducted by EPA Method 504.1. A source 
for the EPA methods is referenced at Sec. 141.24(e).
* * * * *
    (n) * * *
    (11) Systems shall monitor for the unregulated organic contaminants 
listed below, using the method(s) identified below and using the 
analytical test procedures contained in Technical Notes on Drinking 
Water Methods, EPA-600/R-94-173, October 1994, which is available at 
NTIS, PB95-104766. Method 6610 shall be followed in accordance with the 
Standard Methods for the Examination of Water and Wastewater 18th 
Edition Supplement, 1994, American Public Health Association. 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 obtained from the American Public Health Association, 1015 
Fifteenth Street NW, Washington, DC 20005. Copies may be inspected at 
EPA's Drinking Water Docket, 401 M Street, SW., Washington, DC 20460; 
or at the Office of the Federal Register, 800 North Capitol Street, 
NW., Suite 700, Washington, DC. A source for EPA methods 505, 507, 508, 
508.1, 515.2, 525.2 and 531.1 is referenced at Sec. 141.24(e).

------------------------------------------------------------------------
            Contaminants                            Method              
------------------------------------------------------------------------
aldicarb...........................  531.1, 6610.                       
aldicarb sulfone...................  531.1, 6610.                       
aldicarb sulfoxide.................  531.1, 6610.                       
aldrin.............................  505, 508, 525.2, 508.1.            
butachlor..........................  507, 525.2.                        
carbaryl...........................  531.1, 6610.                       
dicamba............................  515.2, 555, 515.1.                 
dieldrin...........................  505, 508, 525.2, 508.1.            
3-hydroxycarbofuran................  531.1, 6610.                       
methomyl...........................  531.1, 6610.                       
metolachlor........................  507, 525.2, 508.1.                 
metribuzin.........................  507, 525.2, 508.1.                 
propachlor.........................  508, 525.2, 508.1.                 
------------------------------------------------------------------------

    (12) Systems shall monitor for sulfate, an unregulated inorganic 
contaminant, by using the methods listed at Sec. 143.4(b).
* * * * *
    8. Section 141.41 is amended by revising paragraph (d) to read as 
follows:


Sec. 141.41  Special monitoring for sodium.

* * * * *
    (d) Analyses for sodium shall be conducted as directed in 
Sec. 141.23(k)(1).
    9. Section 141.42 is amended by removing and reserving paragraphs 
(a) through (c).
    10. Section 141.74 is amended by revising paragraphs (a)(1) and 
(a)(2), and removing paragraphs (a)(3) through (a)(7) to read as 
follows:


Sec. 141.74  Analytical and monitoring requirements.

    (a) * * *
    (1) Public water systems must conduct analysis of pH in accordance 
with one of the methods listed at Sec. 141.23(k)(1). Public water 
systems must conduct analyses of total coliforms, fecal coliforms, 
heterotrophic bacteria, turbidity, and temperature in accordance with 
one of the following analytical methods and by using analytical test 
procedures contained in Technical Notes on Drinking Water Methods, EPA-
600/R-94-173, October 1994, which is available at NTIS PB95-104766.

------------------------------------------------------------------------
        Organism                 Methodology             Citation\1\    
------------------------------------------------------------------------
Total Coliforms.........  Total Coliform            9221A, B, C         
                           Fermentation Technique/                      
                           3,4,5/.                                      
                          Total Coliform Membrane   9222A, B, C         
                           Filter Technique.                            
                          ONPG-MUG Test\6\........  9223                
Fecal Coliforms.........  Fecal Coliform MPN        9221E               
                           Procedure\7\.                                
                          Fecal Coliforms Membrane  9222D               
                           Filter Procedure.                            
Heterotrophic             Pour Plate Method.......  9215B               
 bacteria\2\.                                                           
Turbidity...............  Nephelometric Method....  2130B               
                          Nephelometric Method....  180.1\8\            
                          Great Lakes Instruments.  Method 2\9\         
Temperature.............  ........................  2550                
------------------------------------------------------------------------
Footnotes:                                                              
\1\Except where noted, all methods refer to the 18th edition of Standard
  Methods for the Examination of Water and Wastewater, 1992, American   
  Public Health Association, 1015 Fifteenth Street NW, Washington, D.C. 
  20005.                                                                
\2\The time from sample collection to initiation of analysis may not    
  exceed 8 hours.                                                       
\3\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 for total coliforms, using lactose broth, is less than  
  10 percent.                                                           
\4\Media should cover inverted tubes at least one-half to two-thirds    
  after the sample is added.                                            
\5\No requirement exists to run the completed phase on 10 percent of all
  total coliform-positive confirmed tubes.                              
\6\The ONPG-MUG Test is also known as the Autoanalysis Colilert System. 
\7\A-1 Broth may be held up to three months in a tightly closed screwcap
  tube at 4 deg.C.                                                      
\8\``Methods for the Determination of Inorganic Substances in           
  Environmental Samples'', EPA-600/R-93-100, August 1993. Available at  
  NTIS, PB94-121811.                                                    
\9\GLI Method 2, ``Turbidity'', November 2, 1992, Great Lakes           
  Instruments, Inc., 8855 North 55th Street, Milwaukee, Wisconsin 53223.

    (2) Public water systems must measure residual disinfectant 
concentrations with one of the analytical methods in the following 
table. The methods are contained in the 18th edition of Standard 
Methods for the Examination of Water and Wastewater, 1992. Other 
analytical test procedures are contained in Technical Notes on Drinking 
Water Methods, EPA-600/R-94-173, October 1994, which is available at 
NTIS PB95-104766. If approved by the State, residual disinfectant 
concentrations for free chlorine and combined chlorine also may be 
measured by using DPD colorimetric test kits. 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 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.

------------------------------------------------------------------------
        Residual                 Methodology               Methods      
------------------------------------------------------------------------
Free Chlorine...........  Amperometric Titration..  4500-Cl D           
                          DPD Ferrous Titrimetric.  4500-Cl F           
                          DPD Colorimetric........  4500-Cl G           
                          Syringaldazine (FACTS)..  4500-Cl H           
Total Chlorine..........  Amperometric Titration..  4500-Cl D           
                          Amperometric Titration    4500-Cl E           
                           (low level measurement).                     
                          DPD Ferrous Titrimetric.  4500-Cl F           
                          DPD Colorimetric........  4500-Cl G           
                          Iodometric Electrode....  4500-Cl I           
Chlorine Dioxide........  Amperometric Titration..  4500-ClO2 C         
                          DPD Method..............  4500-ClO2 D         
                          Amperometric Titration..  4500-ClO2 E         
Ozone...................  Indigo Method...........  4500-O3 B           
------------------------------------------------------------------------

* * * * *
    11. Section 141.89 is amended by revising paragraph (a) 
introductory text; removing the table in paragraph (a); and by removing 
and reserving paragraph (b) to read as follows:


Sec. 141.89  Analytical methods.

    (a) Analyses for lead, copper, pH, conductivity, calcium, 
alkalinity, orthophosphate, silica, and temperature shall be conducted 
with the methods in Sec. 141.23(k)(1).
* * * * *

PART 143--NATIONAL SECONDARY DRINKING WATER REGULATIONS

    1. The authority citation for part 143 continues to read as 
follows:

    Authority: 42 U.S.C. 300f, 300g-1, 300g-2 300g-3, 300g-4, 300g-
5, 300g-6, 300j-4, 300j-9.

    2. Section 143.4 is amended by revising paragraph (b) to read as 
follows:


Sec. 143.4  Monitoring.

* * * * *
    (b) Measurement of pH, copper and fluoride to determine compliance 
under Sec. 143.3 may be conducted with one of the methods in 
Sec. 141.23(k)(1). Analyses of aluminum, chloride, foaming agents, 
iron, manganese, odor, silver, sulfate, total dissolved solids (TDS) 
and zinc to determine compliance under Sec. 143.3 may be conducted with 
the methods in the following Table. Criteria for analyzing aluminum, 
copper, iron, manganese, silver and zinc samples with digestion or 
directly without digestion, and other analytical test procedures are 
contained in Technical Notes on Drinking Water Methods, EPA-600/R-94-
173, October 1994, which is available at NTIS PB95-104766.

----------------------------------------------------------------------------------------------------------------
            Contaminant                  EPA             ASTM\3\                  SM4                 Other     
----------------------------------------------------------------------------------------------------------------
Aluminum...........................     \2\200.7  ....................  3120B.................                  
                                        \2\200.8  ....................  3113B.................                  
                                        \2\200.9  ....................  3111D.................                  
Chloride...........................     \1\300.0  D4327-91............  4110..................                  
                                                                        4500-Cl--D............                  
Color..............................  ...........  ....................  2120B.................                  
Foaming Agents.....................  ...........  ....................  5540C.................                  
Iron...............................     \2\200.7  ....................  3120B.................                  
                                        \2\200.9  ....................  3111B.................                  
                                                                        3113B.................                  
Manganese..........................     \2\200.7  ....................  3120B.................                  
                                        \2\200.8  ....................  3111B.................                  
                                        \2\200.9  ....................  3113B.................                  
Odor...............................  ...........  ....................  2150B.................                  
Silver.............................     \2\200.7  ....................  3120B.................  I-3720-85\5\    
                                        \2\200.8  ....................  3111B.................                  
                                        \2\200.9  ....................  3113B.................                  
Sulfate............................     \1\300.0  D4327-91............  4110..................                  
                                        \1\375.2  ....................  4500-SO4-F............                  
                                                                        4500-SO4-C,D..........                  
TDS................................  ...........  ....................  2540C.................                  
Zinc...............................     \2\200.7  ....................  3120B.................                  
                                        \2\200.8  ....................  3111B ................                  
----------------------------------------------------------------------------------------------------------------
Footnotes:                                                                                                      
\1\``Methods for the Determination of Inorganic Substances in Environmental Samples'', EPA-600/R-93-100, August 
  1993. Available at NTIS, PB94-121811.                                                                         
\2\``Methods for the Determination of Metals in Environmental Samples--Supplement I'', EPA-600/R-94-111, May    
  1994. Available at NTIS, PB94-184942.                                                                         
\3\The procedures shall be done in accordance with the Annual Book of ASTM Standards, 1994, Vols. 11.01 and     
  11.02, American Society for Testing and Materials. 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 obtained 
  from the American Society for Testing and Materials, 1916 Race Street, Philadelphia, PA 19103. Copies may be  
  inspected at EPA's Drinking Water Docket, 401 M Street, SW., Washington, DC 20460; or at the Office of the    
  Federal Register, 800 North Capitol Street, NW., Suite 700, Washington, DC.                                   
\4\The procedures shall be done in accordance with the 18th edition of Standard Methods for the Examination of  
  Water and Wastewater, 1992, American Public Health Association. 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   
  obtained from the American Public Health Association, 1015 Fifteenth Street NW., Washington, DC 20005. Copies 
  may be inspected at EPA's Drinking Water Docket, 401 M Street, SW., Washington, DC 20460; or at the Office of 
  the Federal Register, 800 North Capitol Street, NW., Suite 700, Washington, DC.                               
\5\Available from Books and Open-File Reports Section, U.S. Geological Survey, Federal Center, Box 25425,       
  Denver, CO 80225-0425.                                                                                        

[FR Doc. 94-29692 Filed 12-2-94; 8:45 am]
BILLING CODE 6560-50-P