[Federal Register Volume 62, Number 138 (Friday, July 18, 1997)]
[Rules and Regulations]
[Pages 38764-38854]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-18579]



[[Page 38763]]

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Part IV





Environmental Protection Agency





_______________________________________________________________________



40 CFR Parts 53 and 58



Revised Requirements for Designation of Reference and Equivalent 
Methods for PM2.5 and Ambient Air Quality Surveillance for 
Particulate Matter; Final Rule

  Federal Register / Vol. 62, No. 138 / Friday, July 18, 1997 / Rules 
and Regulations  

[[Page 38764]]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 53 and 58

[AD-FRL-5725-6]
RIN 2060-AE66


Revised Requirements for Designation of Reference and Equivalent 
Methods for PM2.5 and Ambient Air Quality Surveillance for 
Particulate Matter

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: This final rule revises the 40 CFR part 58 ambient air quality 
surveillance regulations to include provisions for PM2.5 
(particulate matter with an aerodynamic diameter less than or equal to 
a nominal 2.5 micrometers), as measured by a new reference method being 
published in 40 CFR part 50, Appendix L, elsewhere in this issue of the 
Federal Register or by an equivalent method designed in accordance with 
requirements being promulgated in 40 CFR part 53. In addition, this 
rule also revises existing ambient air quality monitoring requirements 
for PM10 (particles with an aerodynamic diameter less than 
or equal to 10 micrometers). These revisions address network design and 
siting, quality assurance (QA) and quality control (QC), operating 
schedule, network completion, system modifications, data reporting, and 
other monitoring subjects.

EFFECTIVE DATE: This regulation is effective September 16, 1997.

ADDRESSES: All comments received relative to this rule have been placed 
in Docket A-96-51, located in the Air Docket (LE-131), Environmental 
Protection Agency, 401 M St., SW., Washington, DC 20460. The docket may 
be inspected between 8 a.m. and 5:30 p.m., Monday through Friday, 
excluding legal holidays. A reasonable fee may be charged for copying.

FOR FURTHER INFORMATION CONTACT: For general information, contact 
Brenda Millar (MD-14), Monitoring and Quality Assurance Group, 
Emissions Monitoring, and Analysis Division, Environmental Protection 
Agency, Research Triangle Park, North Carolina 27711, Telephone: (919) 
541-5651, e-mail: [email protected]. For technical 
information, contact Neil Frank (MD-14), Monitoring and Quality 
Assurance Group, Emissions, Monitoring, and Analysis Division, 
Environmental Protection Agency, Research Triangle Park, North Carolina 
27711, Telephone: (919) 541-5560.

SUPPLEMENTARY INFORMATION:
Table of Contents
I. Authority
II. Introduction
    A. Revision to the Particulate Matter NAAQS
    B. Air Quality Monitoring Requirements
III. Discussion of Regulatory Revisions and Major Comments on 40 CFR 
Part 53
    A. Designation of Reference and Equivalent Methods for 
PM2.5
    B. Reference Method Designation Requirements
    C. Equivalent Method Designation Requirements
    D. Proposed Reference and Equivalent Method Requirements
    E. Changes to the Proposed Method Designation Requirements
IV. Discussion of Regulatory Revisions and Major Comments on 40 CFR 
Part 58
    A. Overview of Part 58 Regulatory Requirements
    B. Section 58.1 - Definitions
    C. Section 58.13 - Operating schedule
    D. Section 58.14 - Special purpose monitors
    E. Section 58.15 - Designation of monitoring sites
    F. Section 58.20 - Air quality surveillance: plan content
    G. Section 58.23 - Monitoring network completion
    H. Section 58.25 - System modification
    I. Section 58.26 - Annual State monitoring report
    J. Section 58.30 - NAMS network establishment
    K. Section 58.31 - NAMS network description
    L. Section 58.34 - NAMS network completion
    M. Section 58.35 - NAMS data submittal
    N. Appendix A - Quality Assurance Requirements for State and 
Local Air Monitoring Stations (SLAMS)
    O. Appendix C - Ambient Air Quality Monitoring Methodology
    P. Appendix D - Network Design for State and Local Air 
Monitoring Stations (SLAMS), National Air Monitoring Stations (NAMS) 
and Photochemical Assessment Monitoring Stations (PAMS)
    Q. Appendix E - Probe and Monitoring Path Siting Criteria for 
Ambient Air Quality Monitoring
    R. Appendix F - Annual Summary Statistics
    S. Review of Network Design and Siting Requirements for PM
    T. Resources and Cost Estimates for New PM Networks
V. Reference
VI. Regulatory Assessment Requirements
    A. Regulatory Impact Analysis
    B. Paperwork Reduction Act
    C. Impact on Small Entities
    D. Unfunded Mandates Reform Act of 1995

I. Authority

    Section 110, 301(a), 313, and 319 of the Clean Air Act (Act) as 
amended 42 U.S.C. 7410, 7601(a), 7613, 7619.

II. Introduction

A. Revision to the Particulate Matter NAAQS

    Elsewhere in this issue of the Federal Register, EPA announced 
revisions to the national ambient air quality standards (NAAQS) for 
particulate matter (PM). In that document EPA amends the current suite 
of PM standards by adding PM2.5 standards and by revising 
the form of the current 24-hour PM10 standard. Specifically, 
EPA is adding two primary PM2.5 standards set at 15 
g/m3, annual mean, and 65 g/m3, 
24-hour average. The annual PM2.5 standard would be met when 
the 3-year average of the annual arithmetic mean PM2.5 
concentrations is less than or equal to 15 g/m3 
from single or multiple community-oriented monitors in accordance with 
40 CFR part 50, Appendix K and requirements set forth in this final 
rule. The 24-hour PM2.5 standard would be met when the 3-
year average of the 98th percentile of 24-hour PM2.5 
concentrations at each population-oriented monitor within an area is 
less than or equal to 65 g/m3.
    EPA also retained the current annual PM10 standard at 
the level of 50 g/m3 which would be met when the 3-
year average of the annual arithmetic PM10 concentrations at 
each monitor within an area is less than or equal to 50 g/
m3. Further, EPA retained the current 24-hour 
PM10 standard at the level of 150 g/m3, 
but revised the form such that the standard would be met when the 3-
year average of the 99th percentile of the monitored concentrations at 
the highest monitor in an area is less than or equal to 150 g/
m3.
    In the part 50 final rule published elsewhere in this issue of the 
Federal Register, EPA is also revising the current secondary standards 
for PM by making them identical to the suite of primary standards. The 
suite of PM2.5 and PM10 standards, in conjunction 
with the establishment of a regional haze program under section 169A of 
the Clean Air Act (the Act), are intended to protect against PM-related 
welfare effects including soiling and materials damage and visibility 
impairment.
    As discussed in the part 50 final rule for the PM NAAQS, the 
PM2.5 standards are intended to protect against exposures to 
fine particulate pollution, while the PM10 standards are 
intended to protect against coarse fraction particles as measured by 
PM10.
    For PM2.5, the annual standard is intended to protect 
against both long- and short-term exposures to fine particle pollution. 
Under this approach, the PM2.5 24-hour standard would serve 
as a supplement to PM2.5 annual standard

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to provide additional protection against days with high 
PM2.5 concentrations, localized ``hot spots,'' and risks 
arising from seasonal emissions that would not be well controlled by a 
national annual standard.
    In specifying that the calculation of the annual arithmetic mean 
for an area (for purposes of comparison to level of PM2.5 
annual standard) should be accomplished by comparing the annual mean 
from a community-oriented monitor that is representative of average 
community-wide exposure, or averaging the annual arithmetic means 
derived from multiple, community-oriented monitoring sites, EPA took 
into account several factors. As discussed in the part 50 final rule, 
many of the community-oriented epidemiologic studies examined in this 
review used spatial averages, when multiple monitoring sites were 
available, to characterize area-wide PM exposure levels and associated 
public health risk. In those studies that used only one monitoring 
location, the selected site was chosen to represent community-wide 
exposures, not the highest value likely to be experienced within the 
community. Because the annual PM2.5 standard is intended to 
reduce aggregate population risk from both long- and short-term 
exposures by lowering the broad distribution of PM concentrations 
across the community, an annual standard based on monitoring data 
reflecting average community wide exposure would better reflect area-
wide PM2.5 exposure levels and associated health risks than 
would a standard based on concentrations from a single monitor with the 
highest measured values in the area. The concept of average community 
exposures is not appropriate for PM10 because the spatial 
distribution of coarse particles is different and tends to be more 
localized in its behavior.
    Finally, under the policy approach presented in the part 50 final 
rule, the 24-hour PM2.5 standard is intended to supplement 
an annual PM2.5 standard by providing protection against 
peak 24-hour concentrations arising from situations that would not be 
well-controlled by an annual standard. Accordingly, the 24-hour 
PM2.5 standard will be based on the single population-
oriented monitoring site within a monitoring planning area with the 
highest measured values.
    In EPA's judgment, an annual PM2.5 standard based on 
monitoring data representative of community average air quality, 
established in conjunction with a 24-hour standard based on the 
population-oriented monitoring site with the highest measured values, 
will provide the most appropriate target for reducing area-wide 
population exposure to fine particle pollution and will be most 
consistent with the underlying epidemiological data base.

B. Air Quality Monitoring Requirements

    A new Federal Reference Method (FRM) for PM2.5 is 
promulgated in a new Appendix L to 40 CFR part 50. Section 319 of the 
Act requires that uniform criteria be followed when measuring ambient 
air quality. To satisfy these requirements, EPA established procedures 
on February 10, 1975, in 40 CFR part 53 for the determination and 
designation of reference or equivalent monitoring methods (40 FR 7049). 
Accordingly, new provisions are added to 40 CFR part 53 so that each 
reference method for PM2.5, based on a particular sampler, 
will be formally designed as such by EPA. Similarly, samplers 
demonstrated as equivalent to the FRM can also be designated. 
Furthermore, section 110(a)(2)(C) of the Act requires ambient air 
quality monitoring for purposes of the State Implementation Plans 
(SIPs) and for reporting data quality to EPA. Uniform criteria to be 
followed when measuring air quality and provisions for daily air 
pollution index reporting are required by section 319 of the Act.1 
To satisfy these requirements, on May 10, 1979 (44 FR 27558), EPA 
established 40 CFR part 58 which provided detailed requirements for air 
quality monitoring, data reporting, and surveillance for all of the 
pollutants for which national ambient air quality standards have been 
established (criteria pollutants). Provisions were promulgated 
subsequently for PM measured as PM10 on July 1, 1987 (52 FR 
24740); provisions for PM2.5 are published in this final 
rule.
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    1EPA intends to develop and propose for public comment a revised 
Pollutant Standards Index that will address PM2.5 as well 
as PM10, at a later date.
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    On December 13, 1996, these rules were proposed in the Federal 
Register as amendments to 40 CFR parts 53 and 58. The intent of the 
monitoring method designations and air quality surveillance 
requirements being promulgated today are to establish a revised 
particulate matter monitoring network that will produce air quality 
data utilizing uniform criteria for the purpose of comparison to the 
revised primary and secondary PM NAAQS and to facilitate implementation 
of a forthcoming regional haze program. The effective date of today's 
monitoring regulation is September 16, 1997.

III. Discussion of Regulatory Revisions and Major Comments on 40 
CFR Part 53

A. Designation of Reference and Equivalent Methods for PM2.5

    Provisions for EPA designation of reference and equivalent methods 
for PM10 and gaseous criteria pollutants have been 
previously established and are set forth in 40 CFR part 53. On December 
13, 1996, EPA proposed to amend part 53 to add new provisions to govern 
designation of reference and equivalent method for PM2.5. 
The December 13th notice proposed new, detailed sampler testing and 
other requirements that would apply to candidate reference and 
equivalent PM2.5 methods and describes how EPA proposed to 
determine whether a candidate method should be designated as either a 
reference or equivalent method. The notice further solicited public 
comments on the proposed new provisions. Those provisions, modified 
somewhat based on the public comments received, are being promulgated 
today as amended part 53.
    As for the other criteria air pollutants, reference methods for 
PM2.5 are intended to provide for uniform, reproduceable 
measurements of PM2.5 concentrations in ambient air to serve 
as a measurement standard for the primary purpose of making comparisons 
to the NAAQS. Equivalent methods for PM2.5 allow for the 
consideration and introduction of new and innovative PM2.5 
measurement technologies for this same purpose, provided such new 
technologies can be shown to provide PM2.5 measurements 
comparable to reference measurements under a variety of typical 
monitoring conditions.

B. Reference Method Designation Requirements

    The new reference method for PM2.5, described in 40 CFR 
part 50, Appendix L contains a combination of design and performance 
specifications to define the reference method PM2.5 sampler. 
The performance-based specifications for the reference method sampler 
allow manufacturers to design and fabricate different samplers that 
would meet all reference method requirements. Accordingly, multiple 
PM2.5 reference methods are expected to become available 
from several manufacturers, as is the case for reference methods for 
PM10 and most gaseous criteria pollutants. Each reference 
method for PM2.5, based on a particular sampler, will be 
formally designated as such by EPA under the new provisions added to 40 
CFR part 53.

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    The requirements for designation of PM2.5 reference 
methods are set forth in subparts A and E of 40 CFR part 53. These 
requirements include specific tests to show conformance with all design 
and performance specifications, an operational field precision test, a 
comprehensive operation/instruction manual, and documentation of an 
adequate manufacturing and testing quality system. Subpart A, which has 
been amended to add provisions for PM2.5 methods, sets forth 
the general requirements for both reference and equivalent methods and 
for the process under which applications are submitted and reference 
and equivalent method are designated. New subpart E, which is devoted 
exclusively to PM2.5 methods, describes the test procedures 
and related requirements for candidate reference methods.

C. Equivalent Method Designation Requirements

    The requirements for designation of equivalent methods for 
PM2.5 are also set forth in amended part 53. The general 
requirements are set forth in subpart A. All candidate equivalent 
methods are subject to the field tests for operational precision and 
comparability to reference method measurements, which are specified in 
subpart C. Both subparts A and C have been amended to include the 
provisions for PM2.5 methods.
    To minimize the number and extent of performance tests to which 
candidate equivalent methods must be subjected, three classes of 
equivalent methods are defined.
    Class I equivalent methods are based on samplers that have 
relatively small deviations from the specifications for reference 
method samplers. Therefore, in addition to the tests and other 
requirements applicable reference method samplers, candidate Class I 
equivalent samplers must be tested only to make sure that the 
modifications do not significantly compromise sampler performance. The 
additional test requirements for most Class I candidate equivalent 
methods are a test for possible loss of PM2.5 in any new or 
modified components in the sampler inlet upstream of the sample filter, 
and the field testing for comparability to reference method samplers. 
These additional tests are described in subparts E and C, respectively.
    Class II equivalent methods include all other PM2.5 
methods that are based on a 24-hour integrated filter sample that is 
subjected to subsequent moisture equilibration and gravimetric mass 
analysis. A sampler associated with a Class II equivalent method will 
generally have one or more substantial deviations from the design or 
performance specifications of the reference method, such that it cannot 
qualify as a Class I equivalent method. These samplers may have a 
different inlet, a different particle size separator, a different 
volumetric flow rate, a different filter or filter face velocity, or 
other significant differences. More extensive performance testing is 
required for designation of Class II candidate equivalent methods, with 
the specific tests required depending on the nature and extent of the 
differences between the candidate sampler and the specifications for 
reference method samplers. These tests may include a full wind tunnel 
evaluation, a wind tunnel inlet aspiration test, a static fractionator 
test, a fractionator loading test, a volatility test, and field testing 
against reference method samplers. The tests and their specific 
applicability to various types of candidate Class II equivalent method 
samplers are set forth in the new subpart F.
    Finally, Class III equivalent methods include any candidate 
PM2.5 methods that cannot qualify as either Class I or Class 
II. This class includes any filter-based integrated sampling method 
having other than a 24-hour PM2.5 sample collection interval 
followed by moisture equilibration and gravimetric mass. More 
importantly, Class III also includes filter-based continuous or semi-
continuous methods, such as beta attenuation instruments, harmonic 
oscillating element instruments, and other complete in situ monitor 
types. Non-filter-based methods such as nephelometry or other optical 
instruments will also fall into the Class III category.
    The testing requirements for designation of Class III candidate 
methods are the most stringent, because quantitative comparability to 
the reference method will have to be shown under various potential 
particle size distributions and aerosol composition. However, because 
of the variety of measurement principles and types of methods possible 
for Class III candidate equivalent methods, the test requirements must 
be individually selected or specifically designed or adapted for each 
such type of method. Therefore, EPA has determined that it is not 
practical to attempt to develop and explicitly describe the test 
procedures and performance requirements for all of these potential 
Class III methods a priori. Rather, the specific test procedures and 
performance requirements applicable to each Class III candidate method 
will be determined by EPA on a case-by-case basis upon request, in 
connection with each proposed or anticipated application for a Class 
III equivalent method determination.

D. Proposed Reference and Equivalent Method Requirements

    The proposed changes to 40 CFR part 53 to provide for designation 
of reference and equivalent methods for PM2.5 consisted of 
revisions to subparts A and C, and new subparts E and F. The proposed 
revisions to subpart A included new definitions applicable to 
PM2.5 methods and clarifications of existing definitions, 
clarifications of the reference and equivalent method designation 
requirements for all pollutants including the new classes of equivalent 
methods for PM2.5, and requirements for PM2.5 
samplers to be manufactured in an International Organization for 
Standardization (ISO) 9001-registered facility (or equivalent). 
Additional proposed changes included clarifications of the test data 
and other information required to be submitted in applications for a 
reference or equivalent method determination, clarification of 
requirements for product warranty and content of operation or 
instruction manuals, an increased time limit for processing 
applications; and provisions for providing EPA with a candidate test 
PM2.5 sampler or analyzer to evaluate in connection with an 
application for reference or equivalent method determination.
    Revisions to subpart C included new procedures and specifications 
for comparing candidate equivalent methods for PM2.5 to 
reference method samplers. The entirely new subpart E described the 
technical procedures for testing the physical (design) and performance 
characteristics of reference methods and Class I equivalent candidate 
methods for PM2.5. The new subpart F described the 
procedures for testing the performance characteristics of Class II 
equivalent methods for PM2.5.

E. Changes to the Proposed Method Designation Requirements

    The tests of the design and performance characteristics of 
candidate samplers for designating reference methods as well as 
equivalent methods are intimately related to the specifications for 
reference methods in 40 CFR part 50, Appendix L. Many of the concerns 
expressed by commenters regarding the reference method for 
PM2.5 in 40 CFR part 50, Appendix L also apply to some of 
the provisions of part 53. Other comments were more directly concerned 
with the provisions of 40 CFR part 53, and these comments are 
summarized in this unit.

[[Page 38767]]

    Several commenters addressed the responsibilities of EPA and 
manufacturers in the method designation process. Specific comments 
included the suggestions that: (1) It would be more appropriate for EPA 
to conduct the necessary testing of a candidate method before 
designating a reference method; (2) that EPA should clarify how it will 
respond to possible poor sampler performance under extreme 
environmental conditions encountered in some areas of the United 
States, since the samplers are not required to meet such extreme 
conditions; (3) that EPA should clarify that specifications for 
completing sampler modifications or retrofits to work in nonstandard 
environments should be included as part of a sampler purchase contract; 
and (4) that EPA should clarify that the required method specifications 
must be met throughout the warranty period and that the applicant 
accepts responsibility and liability for ensuring conformance or 
resolving nonconformities, including all necessary components of the 
system, regardless of the original manufacturer.
    The new provisions contained in the modified 40 CFR part 53 require 
the applicant to submit information and documentation to demonstrate 
that the applicant's candidate reference method sampler meets all 
design specifications set forth in 40 CFR part 50, Appendix L. The 
provisions also require the applicant to carry out specific tests to 
demonstrate that the candidate reference or equivalent method meets all 
performance specifications. The nature of these tests and the 
requirement that they be carried out by the applicant rather than by 
EPA is consistent with the previously established requirements in 40 
CFR part 53 for designating reference or equivalent methods for other 
criteria pollutants. Section 53.9 clearly states that a sampler sold as 
part of a designated method must meet the applicable performance 
specifications for at least 1 year after delivery. Section 53.9 further 
requires that ISO 9001 registration of the manufacturing facility be 
maintained and that a Product Manufacturing Checklist signed by a 
certified ISO auditor be submitted annually to verify manufacturing 
quality control.
    In response to concerns about the performance of the sampler under 
extreme weather conditions, EPA has established sampler specifications 
that are intended to cover reasonably normal environmental conditions 
at about 95 percent of expected monitoring sites. The performance tests 
in subpart E address essentially all of these operational requirements. 
Specification of the sampler performance for sites with extreme 
environmental conditions would substantially raise the cost of the 
sampler for users, most of whom do not require the extra capability. 
EPA strongly recommends that users requiring operation of samplers 
under extreme environmental conditions develop supplemental 
specifications for modified samplers to cover those specific 
conditions. Sampler manufacturers have indicated a commitment to 
respond to such special operational needs.
    Documentation is required to demonstrate that samplers to be sold 
as reference or equivalent methods for PM2.5 will be 
manufactured under an effective quality control system. Although some 
commenters supported the general quality assurance concepts contained 
in the proposed method, several questioned the inclusion of the ISO 
9001-registration requirement. EPA believes that the ISO 9001-
registration requirement and related provisions are the most cost-
effective way to ensure that samplers are manufactured in a facility 
conforming to internationally recognized quality system standards.
    Several comments questioned the proposed requirement that each 
PM2.5 sampler model be subjected to a specific annual 
evaluation of performance and meet certain operating performance 
specifications. In response to these comments, this requirement has 
been deleted. However, EPA will review the performance of each 
PM2.5 sampler model on an annual basis, and if compelling 
evidence indicates a significant bias or other operational problem, the 
EPA Administrator may make a preliminary finding to cancel a reference 
or equivalent method designation in accordance with the provisions of 
Sec. 53.11 in subpart A.
    Otherwise, the provisions of 40 CFR part 53 have been retained to 
conform with the requirements described in 40 CFR part 50, Appendix L. 
The proposed revisions to subparts A and C have been retained with no 
substantive changes. However, minor technical and editorial changes 
have been made to subparts A and C to clarify or simplify proposed 
provisions. Subpart E has undergone extensive revision and 
reorganization. Although these changes do not affect the objectives and 
nature of the tests, they are intended to make the test requirements 
easier to understand and the tests easier to perform. The changes were 
based on EPA's own experience in performing tests of prototype 
candidate samplers and on comments from prospective sampler 
manufacturers. Subpart F has also been revised to some extent. The 
changes to subpart F are not substantive in nature, but numerous 
technical and editorial changes were made to clarify the test 
requirements and make the tests, particularly the volatility test, more 
straightforward to carry out.
    All testing related to an application for a PM2.5 
reference or equivalent method determination under 40 CFR part 53 must 
be carried out in accordance with American National Standards 
Institute/American Society for Quality Control (ANSI/ASQC) E4 
standards. These requirements are necessary to ensure that all samplers 
or analyzers sold as reference or equivalent methods are manufactured 
and tested to the high standards required to achieve the needed data 
quality. These procedures are in keeping with the developing 
international standards for manufacturing and testing in this and other 
industries.

IV. Discussion of Regulatory Revisions and Major Comments on Part 
58

    The following discussion presents an overview of the final part 58 
monitoring regulation. This is followed by a detailed discussion of the 
basic concepts outlined in the December 13, 1996 monitoring proposal 
and addresses those comments received on the proposed part 58 
regulations that EPA considered to be most relevant to the changes and 
additions adopted in the final rule. Comments not addressed in this 
preamble are found in a Summary and Response to Comment document that 
has been placed in Docket A-96-51. Those parts of the proposed 
regulations which were not commented on have not been changed. The 
items are discussed in the order in which they appear in the 
regulation.

A. Overview of Part 58 Regulatory Requirements

    The requirements set forth in this rule simultaneously preserve the 
underlying intent of the revised NAAQS and respond positively to the 
very substantial and reasoned comments received on the proposal. 
Specifically, the major monitoring requirements and principles set 
forth by the revised part 58 regulation include:
    1. PM2.5 network design. Community-oriented (core) 
monitors that represent community-wide average exposure, form the basis 
of PM2.5 network design. This approach is consistent with 
the data bases used to develop the NAAQS. While all population-oriented 
monitoring locations are eligible for comparison to the 24-hour 
PM2.5 NAAQS, only locations representative of neighborhood 
or larger spatial scales

[[Page 38768]]

are eligible for comparison to the annual NAAQS. Community monitoring 
zones with constrained criteria may be also used to define monitors 
acceptable for spatial averaging for comparison to the annual NAAQS. 
Monitoring for regional transport and regional background is required 
to assist with implementation of the air quality management program. 
The combination of emphasis on well-sited community-oriented monitors 
and the feasibility by the States to select the preferred community 
monitoring approach reduces complexity associated with network design 
and planning. The number of required core PM2.5 State and 
Local Air Monitoring Stations (SLAMS), and other PM2.5 SLAMS 
results in a minimum national requirement of approximately 850 
PM2.5 sites (compared to 629 proposed); the total 
PM2.5 network is projected to approach 1,500 
PM2.5 sites. Exceptions to the minimum number of required 
samplers may be approved by the EPA Regional Administrator. As 
proposed, the mature network of 1,500 PM2.5 sites would be 
in place within 3 years. The phase-in of the required network has been 
reduced from 3 to 2 years.
    2. PM10 monitoring networks. Requirements for 
PM10 network design and siting are unchanged. Reductions in 
PM10 networks are encouraged in areas of low concentrations 
where the PM10 NAAQS are not expected to be violated.
    3. Sampling frequencies. The sampling frequencies stipulated in 40 
CFR 58.13 for both PM2.5 and PM10, have been 
modified to reflect a one in 3-day minimum requirement. Required every 
day sampling at certain core sites may be reduced to one in 3-day 
sampling after at least 3 complete years of data collection with a 
reference or equivalent method or when collocated with a correlated 
acceptable continuous (CAC) fine particulate monitor; background and 
regional transport may also sample once every third day. Exceptions to 
the minimum requirement may be approved by the EPA Regional 
Administrator for seasonal or year-round sampling.
    4. Chemical speciation. A modest chemical speciation network of 50 
PM2.5 sites that provides a first order characterization of 
the metals, ions, and carbon constituents of PM2.5 is a 
requirement of this rule. These sites will be part of the National Air 
Monitoring Stations (NAMS) network and will provide national 
consistency for trends purposes and serve as a model for other chemical 
speciation efforts. This required network represents a small fraction 
of all the chemical speciation work that EPA expects to support with 
Federal funds. Additional efforts may be used to enhance the required 
network and tailor the collection and analysis of speciated data to the 
needs of individual areas.
    5. Quality assurance. The QA program is collectively based on a 
variety of QA tools resulting in a program which is more efficient, 
less costly, and relaxes the burden on State and local agencies. The 
key program requirements include:
    a. Independent field audits with a PM2.5 FRM are used to 
evaluate the bias of PM2.5 measurements. The number of 
PM2.5 audited sites compared to the proposal are reduced 
from all non-collocated sites to 25 percent of all SLAMS sites 
(including NAMS) and the audit frequency per site is reduced from 6 to 
4 visits per year.
    b. Flow checks will also be used to evaluate bias of 
PM2.5 and PM10 measurements and are conducted on 
a quarterly basis as proposed.
    c. Collocation with PM2.5 FRM and Federal Equivalent 
Methods (FEM) samplers at SLAMS sites is used to judge precision. The 
number of collocated sites per reporting organization is 25 percent of 
all PM2.5 SLAMS sites (20 percent were proposed) and 
approximately 20 percent of all PM10 SLAMS sites (which is 
current practice).
    d. Systems audits are used to evaluate an agency's QA system and 
will be performed by EPA every 3 years as originally proposed.
    In an effort to assist the State and local agencies in achieving 
the data quality objectives of the PM2.5 monitoring program, 
an incentive program has been established that is based on network 
performance and maturity that can reduce these QA requirements.
    6. Moratorium on the use of special purpose monitor (SPM) data. The 
moratorium on the use of PM2.5 data (Sec. 58.14) collected 
by SPMs, has been changed from the first 3 calendar years following the 
effective date of this rule to the first 2 complete calendar years of 
operation of a new SPM. If such monitors produce valid data for more 
than 2 years, then all historical data for that site may be used for 
regulatory purposes.
    7. Monitoring methodology. Appendix C has been revised to allow the 
use of Interagency Monitoring of Protected Visual Environments 
(IMPROVE) samplers at regional transport and regional background sites 
to satisfy the SLAMS requirements.
    8. PM monitoring network description. The State shall submit a PM 
monitoring network description to the EPA Regional Administrator by 
July 1, 1998, which describes the PM monitoring network, its intended 
community monitoring approach for comparison to the annual 
PM2.5 standard, use of non-population-oriented special 
purpose PM2.5 monitors or alternative samplers, and proposed 
exceptions to EPA's requirements for minimum number of monitors or 
sampling frequency. The description shall be available for pubic 
inspection and EPA shall review and approve/disapprove the document 
within 60 days. A State air monitoring report with proposed network 
revisions, if any, shall be submitted annually.
    EPA believes that the aforesaid revisions to the rule, as proposed, 
provide a firm basis for the uniform implementation of a national 
particulate monitoring network which is responsive to a revised NAAQS 
expressed as PM2.5. The following is a section-by-section 
discussion of comments received and any resulting modifications to the 
proposal.

B. Section 58.1 - Definitions

    EPA proposed to add several definitions applicable to PM 
monitoring. This consisted of revising the definition of the term 
traceable and definitions of the terms Consolidated Metropolitan 
Statistical Area (CMSA), core SLAMS, equivalent methods, Metropolitan 
Statistical Area (MSA), monitoring planning area (MPA), monitoring 
plan, PM2.5, Primary Metropolitan Statistical Area (PMSA), 
population-oriented, reference method, spatial averaging zone (SAZ), 
SPM fine monitors, and Annual State Monitoring Report. In response to 
comments, EPA is modifying the proposed approach and is introducing new 
terminology and definitions. First, EPA is changing the definition of 
core SLAMS monitors to describe community-oriented monitors that are 
representative of neighborhood or larger spatial scales and will be key 
monitoring entities in the new PM2.5 SLAMS network. As 
discussed later, a subset of these monitors will be required to sample 
everyday in the most populated metropolitan areas with the stated 
emphasis on community-oriented monitoring. Although very important, the 
background and regional transport monitors in the SLAMS network are no 
longer called core sites. Secondly, EPA is replacing the definition of 
spatial averaging zone with a definition of community monitoring zone 
(CMZ). This is consistent with the intent of the annual 
PM2.5 standard, that is to be judged at monitoring stations 
that are representative of community-wide air quality. EPA is also 
renaming the PM monitoring plan as the PM monitoring network 
description. EPA's rationale for

[[Page 38769]]

these changes, together with a more complete description of community 
monitoring zones, are discussed in 40 CFR part 58, Appendix D.
    In addition, several commenters addressed the definition of 
population-oriented monitoring, objecting to the narrowness of the 
definition with respect to industrial areas, and noting that if people 
are present in an area, the site should be considered population-
oriented.
    EPA assessed these comments and concluded that the definition of 
population-oriented monitoring or sites proposed in Sec. 58.1 is 
essentially appropriate and as such will provide monitoring agencies 
with the flexibility to design networks that are consistent with the 
population-oriented approach described by the PM2.5 
standards. Therefore EPA is retaining this definition in the final rule 
with a minor simplifying change as follows: population-oriented 
monitoring (or sites) applies to residential areas, commercial areas, 
recreational areas, industrial areas and other areas where a 
substantial number of people may spend a significant fraction of their 
day. The definition of population-oriented monitoring will be further 
deliniated in future EPA guidance. As proposed, the final rule states 
that all population-oriented PM2.5 monitoring locations 
shall be eligible for comparison to both the 24-hour PM10 
and PM2.5 standards. In order to make these concepts clearer 
for the final rule, however, several changes to the proposed language 
were made in the final rule regarding eligibility of monitoring sites 
for comparisons to the PM2.5 NAAQS. First, the new 
PM2.5 network will place emphasis on community-oriented 
monitoring for making comparisons to both the annual and 24-hour 
PM2.5 NAAQS. Secondly, as proposed, unique population-
oriented microscale and middle-scale monitoring sites shall only be 
used for comparisons to the 24-hour NAAQS. Furthermore, violations 
detected at rural background and regional transport sites are more 
appropriately addressed by the implementation program which EPA is 
developing.

C. Section 58.13 - Operating Schedule

    EPA proposed that core PM2.5 SLAMS (including NAMS and 
core SLAMS collocated at Photochemical Assessment Monitoring Stations 
(PAMS) sites) would be required to sample every day, unless an 
exception is approved by EPA during established seasons of low PM 
pollution during which time a minimum of one in 6-day sampling would be 
permitted. The proposal stated that non-core SLAMS sites would 
generally be required to sample a minimum of once every sixth day, 
although episodic or seasonal sampling could also be possible (e.g., in 
areas where significant violations of the 24-hour NAAQS are expected or 
at sites heavily influenced by regional transport or episodic 
conditions). The proposed and final rule state that special purpose 
monitors may sample on any sampling schedule. The proposal also 
recognized that although daily sampling with manual methods is labor 
intensive due to site visits and filter equilibration and weighing, 
semi-automatic sequential samplers are anticipated to be approvable as 
FRMs or Class I equivalent samplers (under the provisions of part 53) 
that will simplify the data collection process. Finally, EPA proposed 
that alternative PM2.5 operating schedules that combine 
intermittent sampling with the use of acceptable continuous fine 
particulate samplers are approvable at some core sites. This 
alternative was intended to give the States additional flexibility in 
designing their PM2.5 monitoring networks and to permit data 
from continuous instruments to be telemetered. This would facilitate 
public reporting of fine particulate concentrations, and allow air 
pollution alerts to be issued, and allow episodic controls to be 
implemented (as currently done in woodburning areas for 
PM10). Furthermore, this alternative would permit monitoring 
agencies to take advantage of new and improved monitoring technologies 
that should become available during the first few years following the 
promulgation of this rule. As proposed, applicability does not apply to 
areas with population greater than 1 million during the first 2 years 
of required sampling.
    Many commenters supported daily PM2.5 sampling, citing 
the need to target sources, aid enforcement, and provide exposure 
measurements for future community health studies. Additionally, 
commenters supported daily PM2.5 sampling to cover the most 
polluted and most populated areas and to capture all violations. Other 
commenters supported daily sampling but suggested limiting it to key 
locations or seasons (e.g., only the largest metropolitan areas or 
those areas with the highest PM2.5 concentrations, only 
during seasons when high values are likely). Other commenters suggested 
allowing a reduction in sampling frequency to one in 6 days under 
certain conditions; for example, at sites that have demonstrated 
attainment, at sites with CAC analyzers, following the third year of 
data collection, and during the portion of the year with low 
PM2.5 concentrations at a site with a district seasonal 
pattern.
    In addition, a number of commenters suggested a delay of everyday 
sampling until the Class I equivalent samplers are available. It was 
noted that over the short-term, only designated manual samplers capable 
of collecting single 24-hour samples, could be available. Consequently, 
to meet an everyday sampling schedule, several samplers would need to 
be installed at each everyday sampling site to satisfy the daily 
schedule, and cover weekend and holiday sampling periods.
    Based on its review of these comments, EPA is retaining its 
everyday sampling schedule for certain community-oriented (core) SLAMS 
(i.e., two monitoring sites in each MSA greater than 500,000 population 
and SLAMS collocated at PAMS for a total of 313 nationwide). The 
remaining SLAMS including NAMS and other core SLAMS are required to 
sample every third day.
    Because of concerns over the potential unavailability of Class I 
sequential samplers, EPA is allowing a waiver of the everyday or every 
third day sampling schedule, when appropriate, in those situations 
where such sampling is not needed. This waiver would expire 1 calendar 
year from the time a sequential sampler has been approved by EPA. When 
the waiver is granted for every day sampling, one in 3-day sampling 
would be required. As proposed, EPA encourages the use of a 
supplemental CAC analyzer as a means of facilitating a reduction of the 
reference or equivalent method everyday sampling schedule to once in 3 
days. The CAC monitoring option, however, will not be allowed in areas 
greater than 1 million population that have high PM2.5 
concentrations during the first 2 years of daily data collection. A 
minimum frequency of one in 6-day sampling is still required during 
periods for which exemptions to everyday or every third day sampling 
are allowed for PM2.5 SLAMS.
    For PM10, the EPA Administrator proposed that one in 6-
day sampling should be sufficient to support the proposed 
PM10 NAAQS and a less dense monitoring network would also be 
needed.
    A number of commenters supported the typical one in 6-day sampling 
frequency for PM10. On the other hand, a number of 
commenters opposed the proposed reduction in PM10 sampling 
frequency to one in 6 days, stating that one in 6-day sampling is 
inadequate to evaluate impacts on the 24-hour PM10

[[Page 38770]]

standard, especially in areas with episodic events or localized hot 
spots, and that extreme pollutant conditions could be missed.
    In response to the general concerns that sampling for 
PM10 is not sufficient and in accordance with the choice of 
the 99th percentile as the form of the 24-hour PM10 
standards as discussed in 40 CFR part 50, EPA has changed the minimum 
required sampling frequency from one sample every 6 days to one sample 
in every 3 days.
    The specified minimum sampling frequency of one in 3 days for 
PM2.5 and PM10 will provide for a more 
statistically stable representation of actual air quality at each 
monitor as discussed in 40 CFR part 50. Further, increasing the 
sampling frequency from one in 6- to one in 3-days will ensure that the 
24-hour NAAQS comparisons are not based on the highest measured values 
per year, and thus will significantly reduce the chances of incorrectly 
classifying a ``clean'' area as nonattainment, and at the same time 
provide enough information to confidently classify ``dirty'' areas as 
nonattainment without requiring those areas to sample every day.
    EPA believes that once in 6-day sampling is sufficient to estimate 
an annual mean concentration for PM2.5 or PM10. 
Furthermore, every day or every third day sampling is not generally 
needed during periods of the lowest ambient PM concentrations. 
Therefore, EPA is allowing exemptions to the every day or the one in 3-
day sampling requirement to individual areas with the approval of the 
EPA Regional Administrator, in accordance with forthcoming EPA 
guidance. In general, exemptions to the minimum one in 3-day sampling 
frequency will be approvable when existing information suggests that 
maximum 24-hour measurements are less than the level of the standard. 
In these cases, a minimum of one in 6-day sampling will be required to 
ensure that sufficient data are available to calculate an annual 
average concentration. Areas adopting less frequent sampling would be 
advised of the risks involved in such a choice; namely, that a single 
high value in 1 year could end up causing the area to be declared in 
violation of the 24-hour NAAQS. The guidance will also recommend that 
more frequent sampling be considered for those areas that are 
relatively close to the level of the standard. For example, areas whose 
PM2.5 or PM10 data indicate that they meet the 
annual PM NAAQS, but have the potential to not meet the 24-hour PM 
NAAQS will be encouraged to sample everyday for PM2.5 or 
PM10, as appropriate, during the high PM seasons in order to 
better assess their status to the standards. While such an option may 
be more costly for individual areas, the risk of inaccurately declaring 
an attainment area to be nonattainment would be reduced.

D. Section 58.14 - Special Purpose Monitors

    EPA proposed that special purpose monitoring (SPM) is needed in a 
new PM2.5 monitoring program to help identify potential 
problems, to help define boundaries of problem areas, to better define 
temporal (e.g., diurnal) patterns, to determine the spatial scale of 
high concentration areas, and to help characterize the chemical 
composition of PM (using alternative samplers and supplemental 
analyzers), especially on high concentration days or during special 
studies. It was proposed, however, that data from SPMs would not be 
used for attainment/nonattainment designations if the monitor is 
located in an unpopulated area, if the monitoring method is not a 
reference or equivalent method or does not meet the requirements of 
section 2.4 of 40 CFR part 58, Appendix C. Moreover, in order to 
encourage the deployment of SPMs, EPA proposed that nonattainment 
designations will not be based on data produced at an SPM site with any 
monitoring method for a period of 3 years following the promulgation 
date of the NAAQS.
    Numerous commenters opposed the proposed 3-year exclusion of SPM 
data as a basis for NAAQS violations, noting that all measured 
violations from all monitors should be used for nonattainment 
designations. Other commenters supported the exclusion, suggesting that 
SPM data should always be considered exploratory in nature and should 
remain exempt from inclusion in regulatory data bases.
    EPA has revisited its position on SPMs in light of these comments. 
In order to encourage the deployment of SPMs, EPA has decided to 
continue to provide States with the flexibility to exempt SPM data from 
regulatory use, but limit the period of the moratorium to the first 2 
complete calendar years of operation of a new SPM. Given the currently 
limited amount of PM2.5 data and the complexity of the 
PM2.5 air quality problem, the Agency feels that this 
approach still provides a significant incentive for States to engage in 
additional monitoring and thereby collect data that would supplement 
the data collected at SLAMS sites. This can be very helpful for 
establishing an optimum network design, for a better understanding of 
the impacts of specific emission sources, and for other planning 
purposes. If a monitoring site satisfies all applicable part 58 
requirements including use of reference or equivalent methods, meeting 
siting criteria, and other requirements as explained in Sec. 58.14 and 
it continues to collect data beyond the first 2 complete calendar years 
of its operation, the data from such SPM sites would then be generally 
eligible for comparisons to the NAAQS. One exception is when a 
monitoring agency intends to evaluate a special situation which is not 
representative of population-oriented monitoring. In this case, the 
data from the special purpose monitor would not be used for comparison 
to the PM2.5 standards. A second exception is when the 
agency intends to evaluate a unique impact area that represents a small 
spatial scale (micro or middle). In this case, the site would only be 
eligible for comparison to the 24-hour NAAQS. Although SPM data will be 
exempt from regulatory use during the 2-year moratorium, EPA emphasizes 
that SPM data should nevertheless be considered in the State's PM 
monitoring network description and in the design of its overall SLAMS 
network. Moreover, SPM sites reporting values greater than the level of 
a NAAQS should be considered during the annual network review in 
accordance with Sec. 58.25, and summary data from SPM sites must be 
included in the annual State Air Monitoring report described in 
Sec. 58.26.

E. Section 58.15 - Designation of Monitoring Sites

    The proposed monitoring regulations defined categories of sites 
that would be eligible for comparisons to the annual or 24-hour NAAQS. 
This included certain sites that could be used for comparison to both 
standards (B sites), to only the daily standard (D sites) and certain 
special purpose monitors (O sites) that potentially would not be used 
for comparison to any standard. Due to significant concern regarding 
the complexity of implementing those concepts to handle a small number 
of unique monitoring situations, the final rule has eliminated the 
coding of sites as type B, D, and O sites. Therefore, Sec. 58.15 has 
been deleted in its entirety. The principal reasons also include the 
emphasis on community-oriented monitors, the new terminology and 
modified approach associated with CMZs, and more precise descriptions 
of SLAMS and SPMs. The final rule provides a more streamlined and 
simplified monitoring approach that retains the basic community average 
air quality exposure tenets of the PM2.5 annual NAAQS and, 
as proposed,

[[Page 38771]]

recognizes that population-oriented hot spot monitoring may be more 
reflective of situations applicable to the purposes of the 24-hour 
PM2.5 standard.
    The changes to community monitoring and site categorization are 
well integrated. EPA agrees with public comment that the proposed 
spatial averaging approach may not have been properly communicated by 
suggesting that it allowed averaging of monitors across widely 
disparate areas not reflective of average community-oriented exposure 
and a homogeneous emission source mix. EPA believes that by clarifying 
the criteria that determine which monitors can be averaged together 
(i.e., monitors in areas affected by similar emission sources), along 
with emphasizing that well sited community-oriented monitors should be 
used, environmental equity concerns and related issues are effectively 
addressed. First, a single SLAMS or SPM that adequately represents a 
local area can reflect its own community monitoring area. If its annual 
average concentrations are more than 20 percent higher than the 
surrounding average PM2.5 air quality, it would not be 
eligible to be averaged in with the surrounding sites of the larger 
geographic domain. In addition, unique population-oriented hot spot 
impact sites are not eligible for comparison to the annual 
PM2.5 NAAQS and are only eligible for comparison to the 24-
hour NAAQS. Additional details about CMZs are provided later.

F. Section 58.20 - Air Quality Surveillance: Plan Content

    Although no comments were received on proposed changes to this 
section, the title was inadvertently stated as Plan Control; this title 
has been changed to Plan Content. In addition, the first sentence of 
paragraph (d) has been changed by deleting the words ``section 2.8 of'' 
and the words ``as well as the minimum requirements for networks of 
SLAMS stations for PM2.5 described in section 2.8.2 of 40 
CFR part 58, Appendix D.'' Since Sec. 58.20 requires an annual review 
of the air quality surveillance system for all SLAMS, these changes 
were instituted for clarity. The reference to PM2.5 in the 
third sentence of Sec. 58.20 was retained to ensure that the review 
includes the unique requirements of the PM2.5 monitoring 
network.
    The proposal indicated that a detailed Particulate Matter 
Monitoring Plan (see Sec. 58.1, as proposed) must be prepared by the 
affected air pollution control agency and submitted to EPA for 
approval. This plan was designed to comprehensively describe the 
Agency's PM2.5 and PM10 air quality surveillance 
networks. Comments received noted that the term PM monitoring plan 
could be confused with the network description required by Sec. 58.20. 
Accordingly, EPA has replaced references to the ``PM Monitoring Plan or 
monitoring plan'' in this final rule with references to the 
``particulate matter monitoring network description or PM monitoring 
network description.'' The Agency notes, however, that the rule 
published today requires a more expanded and comprehensive network 
description for PM than has previously been required for other 
networks. Therefore, a new paragraph (f) has been added to Sec. 58.20 
to delineate the requirements for PM monitoring network descriptions. 
According to Sec. 58.20(e), as amended, this network description must 
be submitted to the EPA Regional Administrator for approval.
    To ensure opportunities for public review and inspection of the 
monitoring network, States must maintain information and records on 
such items as the station location, monitoring objectives, spatial 
scale of representativeness, optional CMZs, and schedule for completion 
of the network. Such information and records are included in a State's 
PM monitoring network description. The PM monitoring network 
description prepared by States and submitted to EPA for approval should 
be viewed as a long-term network of SLAMS and NAMS sites that meet the 
variety of monitoring objectives specified in 40 CFR part 58, Appendix 
D of these regulations. These objectives include determining compliance 
with air quality standards, developing appropriate control strategies 
as required, and preparing short- and long-term air quality trends. 
However, modifications to the network can be made without a formal SIP 
revision thus encouraging States to make any needed yearly (or 
alternate schedule as determined by the EPA Regional Administrator) 
changes to the SLAMS network to make it more responsive to data needs 
and resource constraints. In order to avoid making major modifications 
to the PM monitoring network description during the annual review, the 
detailed network, including monitoring planning areas and CMZs, should 
be carefully planned and designed to provide a stable base of air 
quality data. Since no formal SIP revision (that entails Federal 
Register proposal and public comment) is required for the PM monitoring 
network description revisions, EPA encourages public involvement in the 
review of a State's PM monitoring network description particularly when 
the spatial averaging monitoring approach is selected for comparisons 
to the annual standard.

G. Section 58.23 - Monitoring Network Completion

    EPA proposed that the PM networks would be expected to be completed 
within 3 years of the effective date of promulgation. While new 
PM2.5 networks are developed, reductions in existing 
PM10 networks would be considered. The proposal stated that 
during the first year, a minimum of one monitoring planning area per 
State would be required to have core PM2.5 SLAMS. This area 
would be selected by the State according to the likelihood of observing 
high PM2.5 concentrations and according to the size of the 
affected population. In addition, one PM2.5 site was 
proposed to be collocated at one PAMS site in each of the PAMS areas. 
During the second year, all other core population-oriented 
PM2.5 SLAMS, and all core background and transport sites, 
were proposed to be fully operational. During the third year, any 
additional required PM2.5 (non-core) SLAMS was proposed to 
be fully deployed and all NAMS sites would be selected from core SLAMS 
and proposed to EPA for approval.
    Several commenters discussed the proposed phase-in schedule. One 
commenter supported an accelerated phase-in schedule, while other 
commenters supported a longer phase-in period. Several State commenters 
expressed reservations about their ability to meet the proposed phase-
in schedule, due to limited resources and the unavailability of 
monitoring equipment. One commenter felt that the phase-in should 
require one core monitor in each of a few geographically diverse areas 
per State, as this would provide more valuable information than only 
one per MPA.
    As noted in the comments on 40 CFR part 58, Appendix D, a large 
number of commenters cited the immediate need for an expansive 
PM2.5 monitoring network to provide adequate monitoring data 
to satisfy the monitoring objectives of the SLAMS network, in 
particular, to provide 3 years of PM2.5 data in order to 
make comparisons with the NAAQS. As noted in the discussion below on 
resources and costs, the Agency's grant allocations for fiscal years 
1997-1998 include significant resources to accelerate the 
implementation schedule and increase the number of monitoring sites 
included in today's final rule. In view of these actions, the Agency is 
accelerating the SLAMS monitoring

[[Page 38772]]

network completion schedule to require at least one core monitor in 
each MSA greater than 500,000 population plus one PM2.5 site 
to be collocated with a PAMS site in each PAMS area and at least 2 
additional SLAMS per State to be in operation by 1998; to require all 
other required SLAMS including required regional transport and regional 
background sites to be in operation by 1999; and to encourage all 
additional sites (to complete the network) to be in operation by 2000. 
In addition, the States should have at least one core SLAMS to be 
deployed in all areas expected to have the potential for high 
PM2.5 concentrations, in accordance with EPA guidance, to be 
in operation by 1998 which will be supported with funding from EPA's 
section 105 grant program.

H. Section 58.25 - System Modification

    The preamble to the proposal noted that although no changes to the 
regulatory language were proposed for this section, the annual 
monitoring system modifications review must include changes to 
PM2.5 site designations (e.g., NAAQS comparison sites), and 
the number or boundaries of monitoring planning areas and/or spatial 
averaging zones, now referred to as community monitoring zones. This 
information is included for explanatory purposes only and does not 
necessitate changes to the regulatory language.

I. Section 58.26 - Annual State Monitoring Report

    Under the current regulations, States are required to submit an 
annual SLAMS data summary report. EPA proposed that this report shall 
be expanded to: (1) Describe the proposed changes to the State's PM 
Monitoring Network Description, as defined in Sec. 58.20; (2) include a 
new brief narrative report to describe the findings of the annual SLAMS 
network review, reflecting within the year and proposed changes to the 
State air quality surveillance system; and (3) provide information on 
PM SPMs and other PM sites noted in the PM monitoring network 
description regardless of whether data from the stations are submitted 
to EPA (including number of monitoring stations, general locations, 
monitoring objective, scale of measurement, and appropriate 
concentration statistics to characterize PM air quality such as number 
of measurements, averaging time, and maximum, minimum, and average 
concentration). The latter is for EPA to ensure that a proper mix of 
permanent and temporary monitoring locations are used and that 
populated areas throughout the Nation are monitored, and to provide 
needed flexibility in the State monitoring program.
    In addition, the proposed changes to the PM monitoring network 
description included changes to existing PM networks. The proposed 
changes to existing PM networks included modifications to the number, 
size, or boundaries of MPAs or SAZ's, number and location of PM SLAMS; 
number or location of core PM2.5 SLAMS; alternative sampling 
frequencies proposed for PM2.5 SLAMS (including core 
PM2.5 SLAMS and PM2.5 NAMS); core 
PM2.5 SLAMS to be designated PM2.5 NAMS; and PM 
SLAMS to be designated PM NAMS. SPM's with measured values greater than 
the level of the NAAQS would become part of the SLAMS network. The 
proposed changes would be developed in close consultation with the 
appropriate EPA Regional Office and submitted to the appropriate 
Regional Office for approval. The portion of the document pertaining to 
NAMS would be submitted to the EPA Administrator (through the 
appropriate Regional Office).
    Finally, as a continuation of current regulations, the States would 
be required to submit the annual SLAMS summary report and to certify to 
the EPA Administrator that the SLAMS data submitted are accurate and in 
conformance with applicable part 58 requirements. Under the proposed 
revisions, States would also be required to submit annual summaries of 
SPM data to the EPA Regional Administrator for sites included in their 
PM monitoring network description and to certify that such data are 
similarly accurate and likewise in conformance with applicable part 58 
requirements or other requirements approved by the EPA Regional 
Administrator, if these data are intended to be used for SIP purposes. 
All of the proposed changes described above did not receive substantive 
comment and were retained in the final rule.
    During the first 3 years following promulgation, the proposal 
stated that the State's PM monitoring description (changed to PM 
monitoring network description) and any modifications of it would be 
submitted to EPA by July 1 (starting on the year following 
promulgation) or by alternate annual date to be negotiated between the 
State and EPA Regional Administrator, with review and approval/
disapproval by the EPA Regional Administrator was proposed to occur 
within 45 days. After the initial 3-year period or once an SAZ (now 
called CMZ) has been determined to be violating any PM2.5 
NAAQS, then changes to a MPA would require public review and 
notification to ensure that the appropriate monitoring locations and 
site types are included.
    Several commenters addressed the requirements for the Annual State 
Monitoring Report. Some commenters felt that the 45-day review was too 
restrictive and should be extended to 60 days. Other commenters felt 
that the annual review requirement was reasonable in the short-term, 
but should be reconsidered after 3 years.
    In response to these comments, the Agency is extending the Regional 
review period to 60 days. After the first 3 years, the required annual 
review can be reconsidered and its schedule revised as determined by 
the EPA Regional Administrator. As discussed earlier in this preamble, 
EPA will entertain suggestions for modifications to the published 
monitoring network requirements. States can request exemptions from 
specific required elements of the network design (e.g., required number 
of core SLAMS sites, other SLAMS sites, sampling frequency, etc.) 
through the Annual Monitoring Report.

J. Section 58.30 - NAMS Network Establishment

    The preamble to the proposal called for States to submit a NAMS 
network description (which is to be derived from the core 
PM2.5 SLAMS) of each State's SLAMS network to the EPA 
Administrator (through the appropriate EPA Regional Office) within 6 
months of the effective date of the final rule. At the same time, a 
State's NAMS PM10 network must be reaffirmed if no changes 
are made to the existing network and if changed must also be fully 
described and documented in a submittal to the EPA Administrator 
(through the appropriate EPA Regional Office). The proposed Sec. 58.34 
stated that the NAMS Network completion shall be by 3 years after the 
effective date of the final rule. This has not been changed in this 
final rule. However, the proposed revisions to this section 
inadvertently called for the PM2.5 network description to be 
submitted 3 years after the effective date of promulgation. The final 
rule has been changed to read July 1, 1998.

K. Section 58.31 - NAMS Network Description

    The term spatial averaging zone was used in the proposed revisions 
to this section. In the final rule, this term has been replaced by the 
term community monitoring zone (CMZ).

[[Page 38773]]

L. Section 58.34 - NAMS Network Completion

    The preamble to the proposal called for changes to the NAMS 
PM10 network to be completed by 1 year after the effective 
date of the final rule and to the NAMS PM2.5 network to be 
completed by 3 years after the effective date of the final rule. The 
proposed rule incorrectly stated 6 months instead of 1 year for the 
PM10 network to be completed. The final rule has been 
changed to read 1 year after the effective date of these regulations 
for PM10 and 3 years after the effective date of these 
regulations for PM2.5.

M. Section 58.35 - NAMS Data Submittal

    The proposed revision to this section added PM2.5 as an 
additional indicator of PM to the list of pollutants that must submit 
air quality data and associated information to the EPA Administrator as 
specified in the AIRS Users Guide. This section is promulgated as 
proposed.

N. Appendix A - Quality Assurance Requirements for SLAMS

    1. Summary of proposal. The proposal addressed the fact that 
enhanced QA and QC procedures were required in the areas of sampler 
operation, filter handling, data quality assessment, and other 
operator-related aspects of the PM2.5 measurement process. 
These enhanced QA/QC procedures were necessary for meeting the data 
quality objectives for ambient PM2.5 monitoring.
    Most operational QC aspects were specified in 40 CFR part 58, 
Appendix A in general terms. However, for PM2.5, explicit, 
more stringent, requirements were proposed for sample filter treatment-
-including the moisture equilibration protocol, weighing procedures, 
temperature limits for collected samples, and time limits for prompt 
analysis of samples. Details concerning these operator-related 
procedures were proposed to be published as a new section 2.12 of EPA's 
Quality Assurance Handbook for Air Pollution Measurement Systems, 
Volume II to assist monitoring personnel in maintaining high standards 
of data quality.
    Procedures were proposed for assessing the resulting quality of the 
monitoring data in 40 CFR part 58, Appendix A. Perhaps the most 
significant new data quality assessment requirement proposed for 
PM2.5 monitoring was the requirement that each 
PM2.5 SLAMS monitor was to be audited at least six times per 
year. This was the first time a requirement had been proposed to assess 
the relative accuracy of the mass concentration measured by a PM SLAMS 
monitor. Each of these six audits would have been performed by the 
monitoring agency and would have consisted of concurrent operation of a 
collocated reference method audit sampler along with the 
PM2.5 SLAMS monitor. The data from these collocated audits 
were proposed to have been used by EPA to assess the performance of the 
PM2.5 SLAMS monitor and to identify reporting organizations 
or individual sites that had abnormal bias or inadequate precision for 
the year.
    Other data assessment requirements proposed for PM2.5 
monitoring networks were patterned after the current requirements for 
PM10 networks and were intended to supplement the audit 
procedure. The proposal required PM2.5 network monitors to 
be subject to precision and accuracy assessments for both manual and 
automated methods, using procedures similar or identical to the current 
procedures required for PM10 monitoring networks. Results of 
the field tests performed by the monitoring agencies (including the 
field tests) would have been sent to EPA. EPA then would have carried 
out the specified calculations which would have become part of the 
annual assessment of the quality of the monitoring data.
    Although the proposed QA requirements for PM2.5 would 
have resulted in an increase in quality assessment requirement for PM 
monitoring, the additional QA/QC checks would have incurred more cost 
to the monitoring agency. Some of the proposed new QA/QC assessment 
requirements would have somewhat overlapped the information provided by 
other checks, such as the periodic flow rate checks and the use of 
collocated samplers in monitoring networks.
    A revision to 40 CFR part 58, Appendix A, was also proposed to 
provide for technical system audits to be performed by EPA at least 
every 3 years rather than every year. This change to a less frequent 
system audit schedule recognized the fact that for many well 
established agencies, an extensive system audit and rigorous inspection 
may not have been necessary every year. The determination of the extent 
and frequency of system audits at an even lower frequency than the 
proposed 3-year interval was being left up to the discretion of the 
appropriate EPA Regional Office, based on an evaluation of the Agency's 
data quality measures. This change would have afforded both EPA and the 
air monitoring agencies flexibility to manage their air monitoring 
resources to better address the most critical data quality issues.
    2. The PM2.5 QA system. Based upon public comments, the 
Agency has reviewed 40 CFR part 58, Appendix A and re-evaluated several 
aspects of the QA and QC quality control system used to assess the 
particulate monitoring data. The requirements associated with the 
PM10 QA system remained unchanged by these modifications. 
Specifically for PM2.5, the major modifications include 
focusing 80 percent of the QA resources to sites with concentrations of 
greater than or equal to 90 percent of the annual PM2.5 
NAAQS (or 24-hour NAAQS if that is affecting the area), increasing the 
amount of collocated monitors to 25 percent of the total number of 
SLAMS monitors within a reporting organization, and changing the FRM 
audit procedures to an independent assessment of the bias of the 
PM2.5 monitoring network. The FRM audits were reduced in 
number to 25 percent of the SLAMS monitors at a frequency of 4 times 
per year. All modifications are discussed in detail in the following 
paragraphs.
    In response to comments that the proposed QA requirements were 
inadequate, and in order to clarify the intent of the quality system, 
EPA is incorporating the concept and definition of a quality system 
into section 2, Quality System Requirements. EPA defines QA as an 
integrated system of management activities involving planning, 
implementation, assessment, reporting, and quality improvement to 
ensure that a process, item, or service is of the type and quality 
needed and expected by the customer. QC is defined as the overall 
system of technical activities that measures the attributes and 
performance of a process, item, or service against defined standards to 
verify that they meet the stated requirements established by the 
customer. A quality system is defined as a structured and documented 
management system describing the policies, objectives, principles, 
organizational authority, responsibilities, accountability, and 
implementation plan of an organization for ensuring quality in its work 
processes, products (items), and services. The quality system provides 
the framework for planning, implementing, and assessing work performed 
by the organization and for carrying out required QA and QC.
    The Agency used the data quality objective (DQO) process to 
specifically develop the QA system for the new PM2.5 
program. The DQO process is a systematic strategic planning tool based

[[Page 38774]]

on the scientific method that identifies and defines the type, quality, 
and quantity of data needed to satisfy a specific use. Meeting the new 
data quality objectives for ambient PM2.5 monitoring 
requires a combination of QA and QC procedures to evaluate and control 
data measurement uncertainty. For this reason, EPA has developed a 
quality system specifically for PM2.5 which incorporates 
procedures to quantify total measurement uncertainty, as it relates to 
total precision and total bias, within the PM2.5 monitoring 
network. In order to clarify the tools used in the QA system, the 
Agency has included definitions in 40 CFR part 58, Appendix A. Total 
bias is defined as the systematic or persistent distortion of a 
measurement process which causes errors in one direction (i.e., the 
expected sample measurement is different from the sample's true value). 
Total precision is defined as a measure of mutual agreement among 
individual measurements of the same property, usually under prescribed 
similar conditions, expressed generally in terms of the standard 
deviation. Accuracy is defined as the degree of agreement between an 
observed value and an accepted reference value, accuracy includes a 
combination of random error (precision) and systematic error (bias) 
components which are due to sampling and analytical operations. The 
Agency will use various QA tools to quantify this measurement 
uncertainty; this includes collocation of monitors at various 
PM2.5 sites, use of operational flow checks, and 
implementation of an independent FRM audit.
    The measurement system represents the entire data collection 
activity. This activity includes the initial equilibration, weighing, 
and transportation of the filters to the sampler; calibration, 
maintenance, and proper operation of the instrument; handling/placement 
of the filters; proper operation of the instrument (sample collection); 
removal/handling/transportation of the filter from the sampler to the 
laboratory; weighing, storage, and archival of the sampled filter; and 
finally, data analysis and reporting. Additional or supplemental 
detailed quality assurance procedures and guidance for all operator-
related aspects of the PM2.5 monitoring process will be 
published as a new section 2.12 of EPA's Quality Assurance Handbook for 
Air Pollution Measurement Systems, Volume II, Ambient Air Specific 
Methods to assist monitoring personnel in maintaining high standards of 
data quality.
    To clarify the requirements and guidance concerning the SLAMS 
ambient air network, the Agency has developed Quality Assurance 
Division (QAD) requirements documents, which are referenced in section 
2.2. For simplification, the Agency has removed the list of pertinent 
operational procedures from this section and has replaced the list with 
the updated reference. In response to comments about potential 
difficulties in following the requirements in ANSI E-4, EPA has instead 
required quality assurance and control programs to follow the 
requirements for quality assurance project plans contained in EPA 
requirements for quality assurance project plans for environmental data 
operations, EPA QA/R-5 an EPA QAD document.
    EPA received many comments on the proposed bimonthly audits for 
each PM2.5 site as proposed in section 6.0 of Appendix A. 
Commenters expressed concerns about the excessive burden the 
requirement would put on State and local air pollution control 
agencies, the length of time involved with the process, and the quality 
control, reliability, and logistical aspects of a portable audit 
device.
    Based upon these comments, the Agency re-assessed its position 
concerning the number of sites and the frequency of audits that the 
State and local agencies perform. The Agency feels that independent FRM 
audits are essential to reaching the goal of the data quality 
objectives for PM2.5 because these audits evaluate the total 
bias for each designated PM2.5 Federal Reference and 
Equivalent monitoring method within the monitoring network. Therefore, 
the Agency has modified the proposed audit program to make it 
independent and also to reduce the burden on State and local agencies. 
Section 6.0 as proposed has been deleted, with remaining data quality 
assessment requirements for PM2.5 included in section 3.5 of 
40 CFR part 58, Appendix A. The resulting data will be assessed at 
three distinct levels--single monitor level, reporting organization 
level, and at a national level. Details of the assessment process will 
be published in EPA's Quality Assurance Handbook for Air Pollution 
Measurement Systems, Volume II, Ambient Air Specific Methods.
    Commenters endorsed the reduction in the frequency of systems 
audits from every year to every 3 years as proposed in section 2.5. 
Therefore, the requirement for a 3-year schedule for system audits 
remains unchanged.
    3. Evaluation of measurement uncertainty. EPA received several 
comments on the procedures used to address the quality assurance of the 
data as proposed in section 3 of the Appendix. Commenters were 
concerned about the limited resources available to properly comply with 
all aspects of the proposed quality system. In the initial deployment 
of the SLAMS PM2.5 network, special QA emphasis should be 
placed on those sites likely to be involved in possible nonattainment 
decisions. Once the initial attainment/nonattainment designations have 
been made, the Agency recommends focusing 80 percent of the QA activity 
(collocated monitors and FRM audits) at sites with concentrations 
greater than or equal to 90 percent of the mean annual PM2.5 
NAAQS (or 24-hour NAAQS if that is affecting the area); this percentage 
will be 100 percent if all sites have concentrations above either 
NAAQS. The remaining 20 percent of the QA activity would be at sites 
with concentrations less than 90 percent of the PM2.5 NAAQS. 
If an organization has no sites at concentration ranges greater than or 
equal to 90 percent of the PM2.5 NAAQS, the Agency 
recommends 60 percent of the QA activity be at sites among the highest 
25 percent for all PM2.5 sites in the network. The Agency 
understands the initial selection of sites will likely be subjective 
and based upon the experience of State and local organizations.
    Other data assessment requirements for PM2.5 monitoring 
networks are patterned after the current requirements for 
PM10 networks and are intended to quantify the monitoring 
network's total precision and bias. PM2.5 network monitors 
will be subject to performance assessments for both manual and 
automated methods, using procedures similar or identical to the current 
procedures required for PM10 monitoring networks. The Agency 
received several comments describing incentives for acceptable 
performance in the QA field. In response to these concerns, EPA intends 
to reduce the QA burden in accordance with network monitoring and 
acceptable performance of the QA program. Based upon EPA's yearly data 
quality assessment, acceptable performance could result in a reduction 
in the frequencies of QA/QC requirements. Additional details for the 
incentive program will be provided in the Quality Assurance Handbook 
for Air Pollution Measurement Systems, Volume II, Ambient Air Specific 
Methods.
    The Agency believes that to develop a national, consistent 
monitoring network with quantifiable data quality, a quality system 
must be developed that permits maximum flexibility yet ensures that the 
measurement uncertainty is known and under control. For this

[[Page 38775]]

reason, the Agency has removed the requirement in section 3.3.5 that 
the paired monitors have the same FRM or equivalent sampler designation 
number, but now formalizes the 6-day sampling schedule for collocated 
monitors into the regulation; this was previously described in 
guidance.
    With regard to the requirements for evaluating measurement 
uncertainty, the estimates of bias within the monitoring network will 
be evaluated with flow audits (section 3.5.1) and independent FRM 
audits (see comments concerning section 3.5.3). An audit of the 
operational flow rate determines bias as performed by the local 
operators of manual methods for PM2.5 with each sampler each 
calendar quarter. Using a flow rate transfer standard, each sampler 
will be audited at its normal operating flow rate. The percent 
differences between the standard and sampler flow rates will be used to 
evaluate instrument-specific bias.
    Specifically, for Federal Reference and Equivalent automated 
methods, an additional assessment of the precision will consist of a 
one-point precision check performed at least once every 2 weeks on each 
automated analyzer used to measure PM2.5. This precision 
check is performed by checking the operational flow rate of the 
analyzer, using a procedure similar to that currently used for 
PM10 network assessments. In addition, an alternative 
procedure may be used where, under certain specific conditions, it is 
permissible to obtain the precision check flow rate data from the 
analyzer's internal flow meter without the use of an external flow rate 
transfer standard. This alternative procedure is also made applicable 
to PM10 methods.
    With regard to the proposed requirements in section 3.5.2, 
(Measurement of precision using collocated procedures for automated and 
manual methods of PM2.5) several commenters felt that 
invalid data or data of questionable quality should not be a part of 
the data base, since the general public and many end-users of the data 
such as consultants and modelers do not always make distinctions about 
data. Data reporting requirements specify that all valid monitoring 
data be reported to AIRS. EPA believes that the requirement contained 
in section 4.1 to report all QA/QC measurements including results from 
invalid tests is necessary to fully assess the performance of reporting 
organizations and to allow EPA to recommend appropriate corrective 
actions. Such data will be flagged so that it will not be utilized for 
quantitative assessments of precision, bias, and accuracy. EPA also 
received many comments on the use of collocated samplers to assess 
precision. Most of these comments advocated an increase in the number 
of collocated monitors as an alternative to reduce the burden of the 
independent audit system. Based upon these comments, EPA has reassessed 
its position on the number of collocated monitors and now requires 25 
percent of the total number of monitors for each designated Federal 
Rand Equivalent Method within a reporting organization to be 
collocated. To further assess the total precision and bias of the 
monitoring network, half of the collocated monitors for each designated 
Federal Reference and Equivalent Method must be collocated with a 
Federal Reference Method (FRM) designated monitor and half must be 
collocated with a monitor of the same designated method type as the 
primary monitor. An example is shown in Table A-2 in 40 CFR part 58, 
Appendix A.
    The Agency received numerous comments concerning the burden of the 
proposed FRM audit procedures for PM2.5 (section 3.5.3), 
which consisted of having every site audited six times each year with a 
portable FRM audit sampler. In response to these comments, EPA has 
reduced the number of audits to 25 percent of the total number of SLAMS 
PM2.5 sites to be audited 4 times each year. In addition, 
EPA has reduced the burden of the State and local agencies 
responsibility for implementing the audits by providing access to the 
existing EPA National Performance Audit Program (NPAP) or other 
comparable programs. The details concerning the assessment of the 
resulting data will be published in EPA's Quality Assurance Handbook 
for Air Pollution Measurement Systems, Volume II, Ambient Air Specific 
Methods.
    4. Reporting requirements. EPA received several comments concerning 
the adequacy of QA reporting requirements (section 4). The Agency has 
addressed these comments by strongly encouraging earlier QA data 
submittal in order to assist the State and local agencies in 
controlling and evaluating the quality of the ambient air SLAMS data.
    5. Data quality assessment. In response to several comments 
concerning the adequacy of the QA data assessment procedures for the 
PM2.5 program, including parts of proposed section 6.0, EPA 
developed a new section 5.5 to consolidate and simplify the procedures 
and calculations for the precision, accuracy, and bias measurements 
used to quantify PM2.5 data quality. The quality assurance 
system has been nested in such a manner that will allow for the 
assessment of total measurement bias and precision, as well as portions 
of the measurement system (i.e. field operations, laboratory 
operations, etc.). Four distinct quality control checks and audits are 
implemented to evaluate total measurement uncertainty: (1) Determine 
instrument accuracy and instrument bias from flow rate audits, (2) 
determine precision from collocated monitors where the duplicate 
monitor has the same method designation, (3) determine a portion of the 
measurement bias from collocated monitors where the duplicate sampler 
is an FRM device, and (4) determine total measurement bias from FRM 
audits. This design will allow for early identification of data quality 
issues in the measurement phases (field/laboratory operations) where 
they may be occurring and therefore, effective implementation of 
corrective actions.
    6. FRM audit requirements. The Agency received many comments 
concerned with the burden the proposed FRM audit system (the deleted 
Section 6: Annual Operational Evaluation of PM2.5 Methods) 
would put upon the individual State and local air pollution agencies. 
Based upon the numerous comments, the Agency has re-assessed its 
position concerning the audit system. The Agency reduced this burden by 
providing the State and local agencies the flexibility to access the 
existing NPAP program or comparable program, additionally reducing the 
burden to 25 percent of the total number of SLAMS PM2.5 
sites each year, and reducing the frequency of the audits to 4 per 
year. EPA has removed section 6.0 from the regulations and incorporated 
the appropriate information into other sections within 40 CFR part 58, 
Appendix A. Additional information will be provided in the Quality 
Assurance Handbook for Air Pollution Measurement Systems, Volume II, 
Ambient Air Specific Methods.

O. Appendix C - Ambient Air Quality Monitoring Methodology

    EPA proposed that 40 CFR part 53, subpart C, be amended to allow 
the use of certain PM10 monitors as surrogates for 
PM2.5 monitors for purposes of demonstrating compliance with 
the NAAQS. The proposal further stated however, following the 
measurement of a PM10 concentration higher than the 24-hour 
PM2.5 standard or an annual average concentration higher 
than the annual average PM2.5 standard, the PM10 
monitor would have to be replaced with a PM2.5 monitor. In 
the proposal of Appendix C, EPA also discussed the use of several types 
of PM2.5 samplers at a SLAMS that are not designated as a

[[Page 38776]]

reference or equivalent method under 40 CFR part 53. First, EPA 
proposed the use of certain nonreference/nonequivalent PM2.5 
methods that could be used at a particular SLAMS site to make 
comparisons to the NAAQS if it met the basic requirements of the test 
for comparability to a reference method sampler for PM2.5, 
as specified of 40 CFR part 53, subpart C in each of the four seasons 
of the year at the site at which it is intended to be used. A method 
that meets this test would then be further subjected to the operating 
precision and accuracy requirements specified in the proposed Appendix 
A to 40 CFR part 53, at twice the normal evaluation interval. A method 
that meets these proposed requirements would not become an equivalent 
method, but the method could be used at that particular SLAMS site for 
any regulatory purpose. Second, EPA discussed the use of CAC methods 
described in Sec. 58.13(f) which are intended to supplement a reference 
or equivalent manual method at certain SLAMS, so that the manual method 
could reduce its sampling frequency from every day to once in 3 days. 
In addition, the proposed Appendix C clarifies that the monitoring data 
obtained with CAC methods would be restricted to use for the purposes 
of the proposed Sec. 58.13(f) and would not be used for making 
comparisons to the NAAQS. Finally, the proposal also described samplers 
for fine particulate matter used in the IMPROVE network (hereafter 
termed IMPROVED samplers) and clarified that IMPROVE samplers, although 
not designated as equivalent methods, could be used in SLAMS for 
monitoring regional background concentrations of fine particulate 
matter.
    Some commenters questioned the proposed use of PM10 
samplers as substitutes for PM2.5 samplers to satisfy 
requirements for PM2.5 SLAMS monitoring. EPA reassessed the 
logic behind this proposal and agreed with commenters that substitute 
samplers should not be allowed. In order for a PM10 sampler 
to be a substitute PM2.5 sampler, the annual average 
PM10 would have to be less than 15 g/m3 
and the annual maximum 24-hour PM10 would have to be less 
than 65 g/m3. This situation would not be 
representative of community-oriented monitoring, would only exist at a 
few rural locations and would not even provide useful information about 
PM2.5 background concentrations; therefore EPA has deleted 
this provision from Appendix C.
    Appendix C is being amended to add a new section 2.4 continuing 
provisions that allow the use of a PM2.5 method that had not 
been designated as a reference or equivalent method under 40 CFR part 
53 at a SLAMS under special conditions. Such a method will be allowed 
to be used at a particular SLAMS site to make comparisons to the NAAQS 
if it meets the basic requirements of the test for comparability to a 
reference method sampler for PM2.5, as specified in 40 CFR 
part 53, subpart C, in each of the four seasons of the year at the site 
at which it is intended to be used. A method that meets this test will 
then be further subjected to the operating precision and accuracy 
requirements specified in 40 CFR part 53, Appendix A, at twice the 
normal evaluation interval. A method that meets these requirements will 
not become an equivalent method, but can be used at that particular 
SLAMS site for any regulatory purpose. The method will be assigned a 
special method code, and data obtained with the method will be accepted 
into AIRS as if they had been obtained with a reference or equivalent 
method. This provision will allow the use of non-conventional 
PM2.5 methods, such as optical or open path measurement 
methods, which would be difficult to test under the equivalent method 
test procedures proposed for 40 CFR part 53.
    In addition, Appendix C is being amended to add a new section 2.5 
to clarify that CAC methods for PM2.5 approved for use in a 
SLAMS under new provisions in Sec. 58.13(f) will not become de facto 
equivalent methods as proposed. This applies to methods that have not 
been designated equivalent or do not satisfy the requirements of 
section 2.4 previously described. In response to recommendations that 
IMPROVE samplers be allowed for use at core background and core 
transport sites, EPA is revising section 2.9 to define IMPROVE samplers 
for fine particulate matter and clarify that IMPROVE samplers, although 
not designated as equivalent methods, could be used in SLAMS for 
monitoring regional background and regional transport concentrations of 
fine particulate matter.
    Finally, minor changes are being made to section 2.7.1 to update 
the address to which requests for approval for the use of methods under 
the various provisions of Appendix C should be sent, and section 5 to 
add additional references.

P. Appendix D - Network Design For State and Local Air Monitoring 
Stations (SLAMS), National Air Monitoring Stations (NAMS) and 
Photochemical Assessment Monitoring Stations (PAMS)

    1. Section 2.8.1 - Specific design criteria for PM2.5. 
The proposed regulation contained language regarding the implementation 
of spatial averaging through the design of PM2.5 monitoring 
networks. MPAs and SAZs were introduced to conform to the population-
oriented, spatial averaging approach taken in the proposed 
PM2.5 NAAQS under 40 CFR part 50. While this proposed 
approach is more directly related to the epidemiological studies used 
as the basis for the proposed revisions to the particulate matter 
NAAQS, it recognized that the use of MPAs and SAZs introduced greater 
complexity into the network design process and the comparison of 
observed values to the level of the PM2.5 annual NAAQS.
    A great number of comments were received concerning the 
communication and complexity of spatial averaging, the selection of 
monitors, and the need for providing flexibility in specifying network 
designs and spatial averaging given that the nature and sources of fine 
particles vary from one area to another.
    In response to concerns about the implementation and communication 
of spatial averaging, EPA is clarifying the requirement for SAZs by 
changing some terminology. EPA is also making it clear that the annual 
mean PM2.5 from a single properly sited monitor that is 
representative of community-wide exposures or an average of annual mean 
PM2.5 concentrations produced by one or more of such 
monitors that meet siting requirements and other constraints as set 
forth in this rulemaking can be compared to the PM2.5 annual 
standard. Specifically, this rule indicates that comparisons to the 
annual PM2.5 standard can be made through the use of 
individual monitors or the annual average of monitors in specific CMZs. 
Community-oriented monitors should be used for these comparisons. This 
approach will provide State and local agencies with additional 
flexibility in defining community-wide air quality and in designing 
monitoring networks. The annual average PM2.5 concentration 
from one or more monitoring sites within a CMZ may be averaged to 
produce an alternative indicator of annual average community-wide air 
quality. However, the criteria for establishing CMZs have been modified 
(compared to the previous SAZs) so that initial monitors will be 
located in those

[[Page 38777]]

areas expected to have the highest community-oriented concentrations. 
It should be noted that many of the sites meeting the siting, 
monitoring methodology, and other monitoring requirements in 40 CFR 
part 58 include population-oriented SPMs and industrial monitors.
    The eligible core monitors in a CMZ still must be properly sited 
and meet the constraints specified in section 2.8.1.6 of 40 CFR part 
58, Appendix D. The term SAZ has been replaced with CMZ and zone 
throughout Appendix D. If the State chooses to make comparisons to the 
annual PM2.5 NAAQS directly with individual monitors that 
use the siting requirements of section 2.8.1.6.3 of 40 CFR part 58, 
Appendix D then it is not required to perform the analyses needed to 
establish a CMZ. A State still would be expected to justify that the 
site meets the specified siting requirements and is representative of 
community-wide exposures. Then it would not be expected, apriori, to 
define the boundaries of zones within which the monitoring data would 
be averaged. This section, that was proposed as ``Monitoring Planning 
Areas and Spatial Averaging Zones,'' has been retitled as ``Specific 
Design Criteria for PM2.5.''
    2. Section 2.8.1.3 - Core monitoring stations for PM2.5. 
The proposed regulations described requirements for the numbers of 
SLAMS sites including core SLAMS. To provide a minimal PM2.5 
network in all high population areas for protection of the annual and 
24-hour PM NAAQS, each required MPA was proposed to have at least two 
core monitors. The new core monitoring locations would be an important 
part of the basic PM-fine SLAMS regulatory network. These sites are 
intended to primarily reflect community-wide air pollution in 
residential areas or where people spend a substantial part of the day. 
In addition to the population-oriented monitoring sites, core monitors 
would also be established for regional background and regional 
transport monitoring.
    To permit interface with measurements of ozone precursors and 
related emission sources that may contribute to PM2.5, an 
additional core monitor collocated at a PAMS site was proposed to be 
required in those MSAs where both PAMS and PM2.5 monitoring 
are required. The core monitor to be collocated at a PAMS site would be 
considered to be part of the MPA PM2.5 SLAMS network and 
would not be considered to be a part of the PAMS network as described 
in section 4 of 40 CFR part 58, Appendix D. Each SAZ in a required MPA 
was proposed to have at least one core monitor; SAZs in optional MPAs 
were proposed to have at least one core monitor; and SAZs were proposed 
to have at least one core site for every four SLAMS.
    Several commenters addressed issues related to the number of core 
SLAMS, population-oriented SLAMS, and other SLAMS. Numerous commenters 
supported increasing the number of stations while few supported 
decreasing the number of stations. In addition, some commenters 
addressing the issue of spatial averaging also suggested that more 
monitors might be needed to address less populated areas and areas near 
hot spots. A few commenters suggested that large States or geographic 
areas might require several regional background or regional transport 
sites and that increased monitoring in rural or remote areas would be 
needed to establish naturally occurring concentrations produced by 
biogenic sources.
    EPA agrees with commenters that more monitors are needed to address 
smaller communities, larger MSAs with several source categories of fine 
particulate emissions, to address coverage for multiple sites in 
optional CMZs, regional transport monitoring upwind of the major 
population centers in the country, and additional sites near 
population-oriented pollution hot spots. Accordingly, EPA has revised 
the regulation to increase the number of required core SLAMS and other 
SLAMS. These changes result in approximately 220 more required sampling 
sites, nationally, as compared to the number proposed (850 versus 629). 
At least one core SLAMS is now required in any MSA with a population 
greater than 200,000. EPA is requiring additional sites in all MSAs 
with population greater than 1 million in accordance with the following 
table:

   Table 1.--Required Number of Core SLAMS According to MSA Population  
------------------------------------------------------------------------
                                            Minimum Required No. of Core
              MSA Population                           Sitesa           
------------------------------------------------------------------------
>1 M                                        3                           
------------------------------------------------------------------------
>2 M                                        4                           
------------------------------------------------------------------------
>4 M                                        6                           
------------------------------------------------------------------------
>6 M                                        8                           
------------------------------------------------------------------------
>8 M                                        10                          
------------------------------------------------------------------------
aCore SLAMS at PAMS are in addition to these numbers.                   

This section, which was proposed as section 2.8.2.1, has been 
renumbered as section 2.8.1.3.
    As discussed in Sec. 58.13, Operating Schedule, all 
PM2.5 SLAMS are required to have a minimum operating 
schedule of once every 3 days, except for a subset of at least two core 
PM2.5 sites per MSA with population greater than 500,000 and 
one site in each PAMS area that is required to conduct daily sampling 
as proposed.
    3. Section 2.8.1.4 - Other PM2.5 SLAMS locations. EPA is 
retaining the requirement to have a minimum of one regional background 
and one regional transport site per State and recognizing the need for 
exceptions when appropriate, particularly in small States; however, 
these sites are no longer designated as core SLAMS. EPA also is 
requiring additional SLAMS monitors based upon the State population 
less the population in all required MSA monitoring areas (i.e., MSAs 
greater than 200,000), to provide population coverage throughout the 
State, particularly in States with fewer urbanized areas. For this 
remaining population there should be one additional SLAMS per 200,000 
population. These additional sites may be used to satisfy any SLAMS 
objective anywhere in the State including population areas (large 
cities or small towns) or regional transport in rural areas. The 
requirement for the additional SLAMS is over and above the requirement 
for one regional background and regional transport site per State as 
mentioned above. This section, which was proposed as section 2.8.2.2, 
has been renumbered as section 2.8.1.4. For planning purposes, EPA 
expects that the total number of sites in a mature, fully-developed 
PM2.5 network will exceed these required minimums. The 
projected total number is 1,500 sites, as compared to the proposed 
1,200 sites. This is an increase of 25 percent compared to the number 
proposed and is based on the recognized need for more monitoring in 
smaller communities, more monitors in larger MSAs with several source 
categories of fine particulate emissions, the possible need for 
multiple sites in optional CMZs, the need to support regional transport 
monitoring upwind of the major population centers in the country, and 
the need for additional sites near pollution hot spots.
    4. Section 2.8.1.5 - Additional PM2.5 Analysis 
Requirements. EPA recognizes the need for chemical speciation of 
particulate matter. Such data are needed to characterize 
PM2.5 composition and to better understand the sources and 
processes leading to elevated PM2.5 concentrations. Because 
of the costs associated with conducting filter analysis on a routine 
basis, however the

[[Page 38778]]

proposal only required filters to be archived so they would be 
available for subsequent chemical analysis on an as needed basis. EPA 
recognizes that there is a need for speciation and other specialized 
monitoring efforts that were not specifically required by the proposed 
rule. Accordingly, EPA intended to give these PM monitoring efforts 
high priority in its section 105 grants program.
    Many commenters supported the concept of chemical speciation, 
noting that speciation was essential for identifying all of the 
components of fine particles and developing control strategies. Some 
commenters recommended that the program be conducted under national or 
regional supervision to ensure consistency and reduce costs, and that 
routine chemical analyses are conducted in a centralized laboratory. 
EPA also received several comments on the proposed archival 
requirements. Some commenters suggested that if chemical speciation was 
required, the filter archival requirement could be eliminated. Other 
commenters noted that the long-term archival requirements placed 
additional resource burdens on agencies, and that possible filter 
degradation and/or bias could result from archiving samples prior to 
analysis.
    Based on these comments, the Agency reassessed its position 
concerning chemical speciation as an optional part of the 
PM2.5 monitoring program. Although speciation is resource 
intensive, EPA believes that its overall value in satisfying control 
strategy and other data needs justifies the added expense. Chemical 
speciation is critically important for the implementation efforts 
associated with air quality programs. Specific subject areas supported 
by chemical speciation include source attribution analysis (i.e., 
determining the likely mix of sources impacting a site) and emission 
inventory and air quality model evaluation. Emission inventory and 
modeling tools are used to develop sound emission reduction strategies. 
Speciated data are especially critical for air quality model evaluation 
since resolved chemical measurements provide greater assurance that 
acceptable model behavior results from appropriate process 
characterization rather than through the collective effect of 
compensating errors. Speciated data provide greater ability to identify 
the causes of poor model performance and implement corrective actions. 
After strategies are developed and controls are implemented, chemically 
resolved PM2.5 data provide a tracking and feedback 
mechanism to assess the effectiveness of controls and, if necessary, 
provide a basis for adjustment. Chemical speciation provides an 
additional quality check on data consistency since a basis for 
comparing the sum of individual components (i.e., speciated data) with 
total mass measurement is available. Also, speciated data supports the 
forthcoming regional haze program by providing a basis for developing 
reliable estimates of seasonal and annual average visibility 
conditions. Chemically resolved data should provide more complete data 
for future health studies. EPA believes that speciation should be part 
of the final PM2.5 monitoring program due to the collective 
value of speciation. However, the Agency also believes that flexibility 
must be provided to the States to tailor efforts to the needs of 
specific areas. Based on public comments, a minimum chemical speciation 
trends network will be required to address the needs discussed above.
    Based on this requirement to collect speciated data at NAMS sites, 
EPA is eliminating the requirement to archive filters from NAMS. 
However, all other SLAMS sites will still be required to archive 
filters for a minimum of 1 year after collection. Access to these 
archived filters for chemical speciation would be helpful in cases 
where: (1) Exceedances or near exceedances of the standard have 
occurred and additional information and data are needed to determine 
more precisely possible sources contributing to the exceedances or high 
concentrations, and (2) certain sites may have shown marked differences 
in air quality trends at the local or national level for no apparent 
reason and analysis of filters from more than one site might be 
required to determine the reason(s) for the differences. EPA intends to 
assign a high priority to this program through its section 105 grant 
allocation program and will issue guidance describing the monitoring 
methods and scenarios under which speciation should be performed. The 
FRM described in 40 CFR part 50, Appendix L, is finalized as a single-
filter based method. Therefore, supplementary monitoring equipment 
that, for example, permits the use of additional filter media will be 
needed to perform the appropriate speciation. Additional details on the 
monitoring methodology for performing speciation and related 
information on filter handling and/or storage will be addressed in 
forthcoming EPA guidance.
    EPA is now instructing the States to initiate chemical speciation 
in accordance with forthcoming EPA guidance at PM2.5 core 
sites collocated at approximately 25 PAMS sites and at approximately 25 
other core sites for a total of approximately 50 sites nationwide. 
These sites would be selected as candidates for future NAMS 
designation. Depending on available resources, chemical speciation 
could be expanded to additional sites in the second and third years. 
The requirement to collect speciated data will be reexamined after 5 
years of data collection. Based on this review, the EPA Administrator 
may exempt some sites from collecting speciated data. At a minimum, 
chemical speciation will include analysis for metals and other 
elemental constituents, selected anions and cations, and carbon.
    EPA recognizes that advantages related to consistency, quality 
assurance and scales of economy would result from using centralized 
laboratories for conducting chemical analyses. However, EPA is 
concerned about the available laboratory capacity for meeting the needs 
of a national PM2.5 speciation network. Several options are 
under consideration that include developing new central and regional 
laboratories and exploring the use of existing federal and State 
facilities. This section, which was proposed as section 2.8.2.4, has 
been renumbered as section 2.8.1.5.
    5. Section 3.7.6 - NAMS speciation. Consistent with the previous 
discussion on speciation, the requirement to establish a subset of 
approximately 50 NAMS sites for routine speciation is described in a 
new section 3.7.6 of 40 CFR part 58, Appendix D. The approximately 50 
sites will include the ones collocated at PAMS and approximately 25 
other sites to be selected by the EPA Administrator, in consultation 
with the Regional Administrators and the States. After 5 years of data 
collection, the EPA Administrator may exempt some sites from collecting 
speciated data. The number of NAMS sites at which speciation will be 
performed each year and the number of samples per year will be 
determined in accordance with EPA guidance. The subsequent sections of 
section 3.7 have been renumbered accordingly.

Q. Appendix E - Probe and Monitoring Path Siting Criteria for Ambient 
Air Quality Monitoring

    The proposed revisions to this Appendix consisted of relatively 
minor changes in the siting criteria to expand the requirements to 
include PM2.5. Minor changes were made to the example 
monitoring location in section 8.1 of the proposed revisions to 40 CFR 
part 58, Appendix E, to replace ``mid-

[[Page 38779]]

 town Manhattan in New York City'' with ``central business district of 
a Metropolitan area.''

R. Appendix F - Annual Summary Statistics

    A new section was proposed to be added to 40 CFR part 58, Appendix 
F, to include annual summary statistics for PM2.5. No 
changes were made to the proposed revisions.

S. Review of Network Design and Siting Requirements for PM

    1. PM10. The network design and siting requirements for 
the annual and 24-hour PM10 NAAQS will continue to emphasize 
identification of locations at maximum concentrations. The 
PM10 network itself, however, will be revised because the 
new PM2.5 standards will likely be the controlling standards 
in most situations.
    The new network for PM10 will be derived from the 
existing network of SLAMS, NAMS, and other monitors generically 
classified as SPMs which include industrial and special study monitors. 
Population-oriented PM10 NAMS will generally be maintained 
as will other key sampling locations in existing nonattainment areas, 
and in areas whose concentrations are near the levels of the revised 
PM10 NAAQS. Currently approved reference or equivalent 
PM10 samplers can continue to be utilized. The revised 
network will ensure that analysis of national trends in PM10 
can be continued, that air surveillance in areas with established PM 
emission control programs can be maintained, and that the 
PM10 NAAQS will not be jeopardized by additional growth in 
PM10 emissions. PM10 sites should be collocated 
with new PM2.5 sites at key community-oriented monitoring 
stations so that better definition of fine and coarse contributions to 
PM10 can be determined to provide a better understanding of 
exposure, emission controls, and atmospheric processes. PM10 
sites not needed for trends or with maximum concentrations less than 60 
percent of the NAAQS should be discontinued in a longer-term 
PM10 network.2 The sampling frequency at all 
PM10 sites can be changed to a minimum of once in 3 days, 
which will be sufficient to make comparisons with the new 
PM10 standards at most locations. Locations without high 24-
hour concentrations of PM10 (e.g., 140 g/
m3) may be exempted from this provision, and their sampling 
frequency reduced to a minimum of once in 6 days.
---------------------------------------------------------------------------

    2Memorandum from William F. Hunt, Jr., Director, Emissions, 
Monitoring, and Analysis Division dated April 22, 1997, to EPA 
Regional Directors entitled Ambient Monitoring Reengineering (found 
in Docket A-96-51).
---------------------------------------------------------------------------

    2. PM2.5. Consistency with the new PM2.5 
NAAQS demands the adoption of new perspectives for identifying and 
establishing monitoring stations for the PM2.5 ambient air 
monitoring network. First, sites which are representative of community-
wide air quality shall be the principal focus of the new 
PM2.5 monitoring program; however, all eligible population-
oriented PM2.5 sites (including regional background and 
regional transport sites) will be used for comparisons to the new 
NAAQS. Second, eligible SLAMS and other eligible SPMs may be averaged 
within properly defined CMZs to better characterize exposure and air 
quality for comparison to the annual PM2.5 NAAQS. Third, 
population-oriented PM2.5 SLAMS and SPMs representative of 
unique microscale or middle scale impact sites would not be eligible 
for comparison to the annual PM2.5 NAAQS and would only be 
compared to the 24-hour PM2.5 NAAQS. The 24-hour 
PM2.5 NAAQS is intended to supplement the annual 
PM2.5 standard by providing additional protection at these 
small spatial scales. A violation of the annual PM2.5 NAAQS 
at localized hot spot and other areas of a small spatial scale (i.e., 
less than 0.5km in diameter) are not reflective of the data used to 
establish the annual PM2.5 NAAQS. It is also not indicative 
of a greater area-wide problem which would initiate the need for an 
area-wide implementation strategy. Clearly, the combination of careful 
network design, i.e., one that identifies the differences in monitor 
locations, and an implementation policy that strives to develop 
effective strategies optimizing regional and local efforts is required 
to address the intent of the PM2.5 NAAQS.
    The new network for PM2.5 consists of a core network of 
community-oriented SLAMS monitors (including certain SLAMS collocated 
at PAMS), other SLAMS monitors (including background and regional 
transport sites), a NAMS network for long-term monitoring for trends 
purposes, and a supplementary network of SPMs. Daily sampling is 
required at a subset of core SLAMS located in MSAs with population 
greater than 500,000 and at core SLAMS collocated at PAMS sites. This 
will provide more accurate and complete information on population 
exposure. One in 3-day sampling is required at NAMS and at all other 
SLAMS, except when exempted by the Regional Administrator, in which 
case one in 6-day sampling is required. Frequent measurements are 
important to characterize the day-to-day variability in 
PM2.5 concentrations, and to understand episodic behavior of 
PM2.5. Routine chemical speciation of PM2.5 will 
be required for a small subset of the core SLAMS. This is necessary to 
establish and track effective emission control strategies to assure 
protection of the NAAQS. These sites shall be part of the future 
PM2.5 NAMS network. Overall, many of the new 
PM2.5 sites are expected to be located at existing 
PM10 sites, that are representative of monitoring oriented 
exposures and would be collocated with some PAMS sites.
    The concepts that address the intent of PM2.5 network 
for making comparisons to the NAAQS are embodied through: (1) 
Monitoring planning areas; (2) specially coded sites including 
community-oriented (core) SLAMS, regional transport and regional 
background SLAMS, and other SLAMS or SPMs whose data would be used to 
compare to the levels of the annual and 24-hour PM2.5 NAAQS; 
(3) SLAMS or SPMs representative of unique population-oriented 
microscale or middle scale locations that are only eligible for 
comparison to the 24-hour PM2.5 NAAQS, and (4) individual 
community-oriented sites or CMZs to correspond to the spatial averaging 
approach defined by the annual PM2.5 NAAQS.
    Core sites are community-representative monitoring sites which are 
among the most important SLAMS for identifying areas that are in 
violation of the PM2.5 NAAQS and to be used for the 
associated SIP planning process. Because of their generally larger 
spatial scales of representativeness, the core sites are the sites most 
likely to be eligible for spatial averaging and are also vital in order 
to establish the boundaries of potential areas of violation of the 
NAAQS that would be reflective of the areas of highest population 
exposure to fine particles. Core sites are neighborhood scale in their 
spatial dimensions. Core SLAMS and specific SPM monitoring locations 
which are eligible for spatial averaging must be identified in the PM 
monitoring network description, satisfy criteria outlined in Appendix 
D, and be approved by EPA. In accordance with information to be 
specified by the AIRS guidance, the State shall assign the appropriate 
monitoring site code when reporting these data to EPA.
    Regional transport and regional background sites are located 
outside major metropolitan areas and would generally be upwind of one 
or more high concentration PM2.5 impact areas. These sites 
are expected to be in areas

[[Page 38780]]

of relatively low population density or in unpopulated regions. The 
collection of data at these sites is encouraged because they are 
critical for the complete understanding of potential pollutant 
transport and for the development and evaluation of emission control 
strategies. Although violations of the NAAQS may be observed at these 
sites, the interpretation and use of such data observed at regional 
transport and regional background locations will be addressed in the PM 
implementation program.
    SLAMS monitoring locations generally should reflect the population-
oriented emphasis of the new NAAQS' population risk management approach 
and its data would be used for NAAQS comparisons. SPMs, on the other 
hand, could represent a variety of monitoring situations, some of which 
are not appropriate for comparison to the PM2.5 standards. 
This includes monitoring at non-population-oriented hot spots or 
special emissions characterization sites that do not meet EPA siting 
criteria or required SLAMS monitoring methodology, but provide valuable 
planning information to support the SIP process. In addition, certain 
SLAMS and SPMs that represent small spatial scales (i.e., sites that 
are classified as microscale or middle scale, in accordance with 
Appendix D) would not represent average, community-oriented air 
quality. In general, such locations would be relatively close to a 
single PM emission source or a collection of small local sources. An 
example of such a location is a unique microscale site in a non-
residential part of an urban area and which may be zoned industrial. 
Clearly, such a site should not be called a SLAMS. There might also be 
SLAMS sites in residential districts which are representative of small 
maximum concentration impact areas. Due to the greater spatial 
homogeneity of fine particles, the existence of such small scale impact 
locations is expected to be much less than that for coarse particles. 
When SLAMS or SPMs do represent small, unique population-oriented 
impact areas, they should be used for comparison to the 24-hour 
PM2.5 standard but not for the annual standard. This is 
especially true when the site is dominated by a single emission source. 
In general, these types of small impact sites may be surrounded by 
broader areas of more homogeneous concentrations which are reflective 
of community-wide air quality. However, if the State chooses to monitor 
at a unique population-oriented microscale or middle scale location and 
the monitoring station meets all applicable 40 CFR part 58 requirements 
(including monitoring methodology), then the data shall be used only 
for comparison to the 24-hour PM2.5 standard. This is 
consistent with the underlying rationale of the PM2.5 NAAQS. 
Such monitors would require a special AIRS code when their data are 
submitted to EPA, as specified by AIRS guidance.
    Exceptions to the use of micro and middle scale PM2.5 
for comparison only to the 24-hour standard may exist when micro or 
middle scale PM2.5 sites represent several small areas in 
the monitoring domain which collectively identify a larger region of 
localized high concentration. For example, there may be two or more 
disjoint middle scale impact areas in a single residential district 
that are not predominantly influenced by a single PM2.5 
emission source. In this case, these small scale sites should be used 
for comparison to the annual NAAQS. This is because their annual 
average ambient air concentrations can be interpreted as if they 
collectively represent a larger scale. In a sense, this situation can 
be viewed as a neighborhood of small scale impact areas. These concepts 
and associated requirements are discussed in section 2.8.1 of 40 CFR 
part 58, Appendix D.
    The new network design and siting requirements encourage the 
placement of PM2.5 monitors both within and outside of 
population centers in order to: (1) Provide air quality data necessary 
to facilitate implementation of the PM2.5 NAAQS, and (2) 
augment the existing visibility fine particle monitoring network. The 
coordination of these two monitoring objectives will facilitate 
implementation of a regional haze program and lead to an integrated 
monitoring program for fine particles.
    To achieve the appropriate level of air quality surveillance in 
such areas, EPA believes it is important to coordinate and integrate 
the regional background and regional transport monitoring sites 
specified in this final rule with the existing IMPROVE monitors that 
have been in place in a number of locations around the country since 
the late 1980s to characterize fine particulate levels and visibility 
in mandatory Federal Class I areas (e.g., certain national parks and 
wilderness areas). The need for coordination and integration of 
visibility-oriented monitoring sites will increase when EPA proposes 
rules under section 169A of the Act to supplement the secondary NAAQS 
in addressing regional haze. More detailed guidance on monitoring and 
assessment requirements will be forthcoming to support this program. 
This will include details on topics such as monitor placement, 
monitoring methodology, duration of sampling and frequency of sampling. 
It is anticipated, however, that the existing IMPROVE network, together 
with sites established under this rule, would be an integral part of 
the network for determining reasonable progress under a regional haze 
program.
    In the meantime, EPA recommends that States, in conjunction with 
EPA and Federal land managers, explore opportunities for expanding and 
managing PM2.5 and visibility monitoring networks in the 
most efficient and effective ways to meet the collective goals of these 
programs. It is EPA's intent that monitoring conducted for purposes of 
the PM2.5 primary and secondary NAAQS (including regional 
background and regional transport sites), and for visibility protection 
be undertaken as one coordinated national PM2.5 monitoring 
program, rather than as a number of independent networks.
    Although the major emphasis of the new PM2.5 network is 
compliance monitoring in support of the NAAQS, the network is also 
intended to assist in reporting of data to the general public, 
especially during air pollution episodes and to assist in the SIP 
planning process. To these ends, additional monitoring and analyses are 
suggested concerning the location of nephelometers (or other continuous 
PM measuring devices) at some core monitoring sites and the collection 
of meteorological data at core SLAMS sites (including background and 
regional transport sites).

T. Resources and Cost Estimates for New PM Networks

    The proposed rules contained a discussion of the costs associated 
with the start-up and implementation of a PM2.5 network and 
the phase-down of the existing PM10 network.
    1. Resources and costs. Several commenters expressed concern about 
the costs of the proposed monitoring and QA/QC requirements. Most 
commenters wanted EPA to provide the funds to meet the increased effort 
and costs with new monies to the agencies, noting that implementing the 
network in a timely manner will depend heavily on timely grant 
assistance from EPA.
    Numerous commenters expressed concern that either not enough 
monitoring money was projected or that the program would be an unfunded 
mandate. Commenters felt that EPA should budget the funds necessary to 
develop an adequate PM2.5 network that will support all SIP 
obligations, including support for speciation. Funds to implement a new 
monitoring network should include one-time funding to

[[Page 38781]]

procure sampling, calibration, laboratory, and audit equipment, plus 
annual funding to support field and laboratory operations.
    Several commenters felt that EPA estimates were too low, citing 
underestimates for additional operational, analytical, and equipment 
costs including daily sampling; speciation; startup for new monitoring 
locations; laboratory modifications; operator training; travel; data 
collection and reporting; greater QA equipment and manpower needs; 
field testing of reference and equivalent methods; and continuous 
monitors. No commenter felt that EPA estimates were too high.
    A few commenters addressed the suggested portions of the total 
monitoring program cost for speciation. Several commenters suggested 
that the cost of requiring speciation could be reduced by limiting the 
requirement to a subset of the daily monitoring sites, or offset by 
eliminating the requirement for daily sampling, noting that any cost 
savings would be overwhelmed by the greater number of PM2.5 
sites and the number of sites conducting everyday sampling.
    EPA understands the complexities and resource demands required by 
State and local agencies in establishing and implementing the new 
regulations. In its review of the comments on the use of the proposed 
Federal reference sampler and associated quality assurance 
requirements, the Agency has published more cost-effective requirements 
with this final rule for monitoring network design, methodology, and 
quality assurance. Likewise, EPA recognizes the subsequent need for it 
to provide technical and financial assistance. In this regard, some 
control agencies have used FY-97 grant allocations to procure 
PM2.5 prototype instruments or upgrade their filter weighing 
facilities. Additionally, the Agency has designated approximately 
$10,935,000 in section 105 grant monies for distribution to States in 
FY-98. EPA intends to assign a high priority to the PM2.5 
monitoring program through its section 105 grants, and additional grant 
dollars have been earmarked by EPA for subsequent years which should 
ensure successful implementation of the PM2.5 monitoring 
program.
    2. Revised cost analysis. In response to comments on cost 
estimation and new requirements described earlier, EPA has revised its 
estimates for the projected PM10 and PM2.5 
networks. EPA believes that it has both improved its cost estimates and 
more adequately addressed the needs for the PM monitoring program. The 
net costs associated with the final PM rules promulgated today include 
the start-up and implementation costs associated with the new 
PM2.5 network and the cost savings associated with phase-
down of the existing PM10 network. The estimated costs in 
the preamble have been revised to reflect changes to the regulations 
based on comments received on the proposed changes in 40 CFR parts 50, 
53, and 58. In particular, PM2.5 network costs have been 
revised to reflect an increase in the number of sites to 1,500, newer 
cost estimates for prototype samplers, equipping many sites with 
sequential samplers to provide for greater operational flexibility, 
reducing the number and frequency of audits with federal reference 
method samplers, and providing for additional multi-filter sampling to 
determine PM2.5 constituent species. In addition, 
PM10 network costs have been revised to reflect an increase 
in the remaining number of PM10 sites to 900 and a sampling 
frequency of once every 3 days (instead of once every 6 days, as 
proposed) for those sites that previously had been sampling everyday, 
every 2 days, or every 6 days.
    Table 2 shows the PM2.5 network phase-in data including 
number of sites and samplers, costs for capital equipment, sampling and 
quality assurance, filter analyses, and special studies. Table 3 
provides a breakdown of the costs associated with the filter analyses. 
Table 4 provides a breakdown of the phase-down costs for the 
PM10 network. The costs are shown for a current network of 
approximately 1,650 sites in 1997 and the phase-down to a future 
projected network of 900 sites. Table 5 shows the cost of PM monitoring 
according to sampling frequency and the type of PM monitor. Details of 
this information can be found in the Information Collection Request for 
these requirements. Tables 2 through 5 follow.

                                          Table 2.--PM2.5 Network Costs                                         
                                          [Thousands of Actual Dollars]                                         
----------------------------------------------------------------------------------------------------------------
                                 Number of   Number of    Capital    Sampling     Filter     Special     Total  
              Year                 Sites      Samplers      Cost       & QA      Analysis    Studies      Cost  
------------------------------------------------\1\--------------------------------\2\--------------------------
1997...........................          0           0      $4,500  .........  ...........  .........     $4,500
1998...........................        724         861      $8,963    $10,216        $472      $1,426    $18,225
1999...........................      1,200       1,512     $14,877    $17,938      $2,325      $3,004    $38,143
2000...........................      1,500       1,887      $7,155    $26,697      $3,649   .........   $37,502 
----------------------------------------------------------------------------------------------------------------
\1\ The PM2.5 network includes a mature network of 332 collocated samplers for QA purposes.                     
\2\ Three different types of filter analyses are anticipated (exceedance analyses, screening analyses, and      
  detailed analyses).                                                                                           



                Table 3.--Cost for PM2.5 Filter Analyses                
------------------------------------------------------------------------
          Type of Filter Analysis             Estimated Cost per Sample 
------------------------------------------------------------------------
Exceedance Analysis                                                 $200
    High PM2.5 concentration events are                                 
     analyzed for particle size and                                     
     composition utilizing optical or                                   
     electron microscopy..................  ............................
Screening Analysis                                                  $150
    Multi-filter analyses including (1) x-                              
     ray fluorescence (XRF) for elemental                               
     composition (crustal material,                                     
     sulfur, and heavy metals); (2) ion                                 
     chromatography for ions such as                                    
     sulfate, nitrate, and chloride; (3)                                
     thermal-optical analysis for                                       
     elemental/organic/total carbon.......  ............................
Detailed Analysis                                                   $400
    Analysis for speciated organic                                      
     composition..........................  ............................
------------------------------------------------------------------------



[[Page 38782]]


                                          Table 4.--PM10 Network Costs                                          
                                          [Thousands of Actual Dollars]                                         
----------------------------------------------------------------------------------------------------------------
                                                                   Capital Cost     Operation &                 
              Year                   Number of       Number of       to Remove      Maintenance     Total Cost  
                                       Sites        Samplers\1\        Sites           Cost                     
----------------------------------------------------------------------------------------------------------------
1997............................           1,650           1,810  ..............         $15,861         $15,861
1998............................           1,450           1,610            $137         $13,358         $13,495
1999............................           1,250           1,410             $89         $11,946         $12,035
2000............................             900           1,060            $159          $9,134          $9,293
----------------------------------------------------------------------------------------------------------------
\1\ The PM10 network includes 160 collocated samplers for QA purposes.                                          



                                   Table 5.--Costs for Particulate Monitoring                                   
                                                [In 1997 Dollars]                                               
----------------------------------------------------------------------------------------------------------------
                                                                                Annual Operation & Maintenance  
    PM Monitor and Sampling Frequency            One-Time Capital Cost                       Cost               
----------------------------------------------------------------------------------------------------------------
PM10 1-in-6 day sampling schedule.......  $7,700 to $14,800.................  $8,000 to $8,900                  
PM10 1-in-3 day sampling schedule.......  $7,700 to $19,400.................  $12,400                           
PM2.5 1-in-6 day sampling schedule......  $9,300 to $20,700.................  $11,300 to $12,500                
PM2.5 1-in-3 day sampling schedule......  $12,800 to $20,700................  $17,000 to $18,600                
PM2.5 every day sampling................  $12,900 to $20,700................  $20,700 to $22,200                
Nephelometer (continuous)...............  $21,000...........................  $19,700                           
----------------------------------------------------------------------------------------------------------------

V. References

    (1) Information Collection Request, 40 CFR Part 58, Ambient Air 
Quality Surveillance, OMB #2060-0084, EPA ICR No. 0940.14, U.S. 
Environmental Protection Agency, Office of Air Quality Planning and 
Standards, Research Triangle Park, NC 27711.

VI. Regulatory Assessment Requirements

A. Regulatory Impact Analysis

    Under Executive Order 12866 (58 FR 51735, October 4, 1993), the 
Agency must determine whether the regulatory action is ``significant'' 
and therefore subject to Office of Management and Budget (OMB) review 
and to 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 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 or 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 the Executive Order 12866 and is 
therefore not subject to formal OMB review. However, this rule is being 
reviewed by OMB under Reporting and Recordkeeping Requirements.

B. Paperwork Reduction Act

    The information collection requirements contained in this rule have 
been submitted for approval to OMB under the Paperwork Reduction Act, 
44 U.S.C. 3501 et seq. An Information Collection Request document has 
been prepared by EPA (ICR No. 0940.14) and a copy may be obtained from 
Sandy Farmer, Information Policy Branch, EPA, 401 M St., SW., Mail Code 
2137, Washington, DC 20460; or by calling (202) 260-2740.
    1. Need and use of the collection. The main use for the collection 
of the data is to implement the air quality standards. The various 
parameters reported as part of this ICR are necessary to ensure that 
the information and data collected by State and local agencies to 
assess the nation's air quality are defensible, of known quality, and 
meet EPA's data quality goals of completeness, precision, and accuracy.
    The need and authority for this information collection is contained 
in section 110(a)(2)(C) of the Act, that requires ambient air quality 
monitoring for purposes of the SIP and reporting of the data to EPA, 
and section 319, that requires the reporting of a daily air pollution 
index. The legal authority for this requirement is the Ambient Air 
Quality Surveillance Regulations, 40 CFR 58.20, 58.21, 58.25, 58.26, 
58.28, 58.30, 58.31, 58.35, and 58.36.
    EPA's Office of Air Quality Planning and Standards uses ambient air 
monitoring data for a wide variety of purposes, including making NAAQS 
attainment/nonattainment decisions; determining the effectiveness of 
air pollution control programs; evaluating the effects of air pollution 
levels on public health; tracking the progress of SIPs; providing 
dispersion modeling support; developing responsible, cost-effective 
control strategies; reconciling emission inventories; and developing 
air quality trends. The collection of PM2.5 data is 
necessary to support the PM2.5 NAAQS, and the information 
collected will have practical utility as a data analysis tool.
    The State and local agencies with responsibility for reporting 
ambient air quality data and information as requested by these 
regulations will submit these data electronically to the U.S. EPA's 
Aerometric Information Retrieval System, Air Quality Subsystem (AIRS-
AQS). Quality assurance/quality control records and monitoring network 
documentation are also maintained by each State/local agency, in AIRS-
AQS electronic format where possible.
    2. Reporting and recordkeeping burden. The total annual collection 
and reporting burden associated with this rule is estimated to be 
785,430 hours. Of

[[Page 38783]]

this total, 778,826 hours are estimated to be for data reporting, or an 
average of 5,991 hours for the estimated 130 respondents. The remainder 
of 6,604 hours for recordkeeping burden averages 51 hours for the 
estimated 130 respondents. The capital operation/maintenance costs 
associated with this rule are estimated to be $32,463,626. These 
estimates include time for reviewing instructions, searching existing 
data sources, gathering and maintaining the data needed, and completing 
and reviewing the collection of information.
    The frequency of data reporting for the NAMS and the SLAMS air 
quality data as well as the associated precision and accuracy data are 
submitted to EPA according to the schedule defined in 40 CFR part 58. 
This regulation currently requires that State and local air quality 
management agencies report their data within 90 days after the end of 
the quarter during which the data were collected. The annual SLAMS 
report is submitted by July 1 of each year for data collected from 
January 1 through December 31 of the previous year in accordance with 
40 CFR part 58.26. This certification also implies that all SPM data to 
be used for regulatory purposes by the affected State or local air 
quality management agency have been submitted by July 1.
    3. Burden. Burden means the total time, effort, or financial 
resources expended by persons to generate, maintain, retain, or 
disclose or provide information to or for a Federal agency. This 
includes the time needed to review instructions; develop, acquire, 
install, and utilize technology and systems for the purpose of 
collecting, validating, and verifying information, processing and 
maintaining information, and disclosing and providing information; 
adjust the existing ways to comply with any previously applicable 
instructions and requirements; train personnel to be able to respond to 
a collection of information; search data sources; complete and review 
the collection of information; and transmit or otherwise disclose the 
information.
    An Agency may not conduct or sponsor, and a person is not required 
to respond to a collection of information unless it displays a 
currently valid OMB control number. The OMB control numbers for EPA's 
regulations are listed in 40 CFR part 9 and 48 CFR Chapter 15.

C. Impact on Small Entities

    Pursuant to section 605(b) of the Regulatory Flexibility Act, 5 
U.S.C. 605(b), the EPA Administrator certifies that this rule will not 
have a significant economic impact on a substantial number of small 
entities. This rulemaking package does not impose any additional 
requirements on small entities because it applies to governments whose 
jurisdictions cover more than 200,000 population. Under the Regulatory 
Flexibility Act, governments are small entities only if they have 
jurisdictions of less than 50,000 people. In addition, this rule 
imposes no enforceable duties on small businesses.

D. Unfunded Mandates Reform Act of 1995

    Under sections 202, 203, and 205 of the Unfunded Mandates Reform 
Act of 1995 signed into law on March 22, 1995, EPA must undertake 
various actions in association with proposed or final rules that 
include a Federal mandate that may result in estimated costs of $100 
million or more to the private sector, or to State or local governments 
in the aggregate.
    EPA has determined that this rule does not contain a Federal 
mandate that may result in an administrative burden of $100 million or 
more for State and local governments, in the aggregate, or the private 
sector in any one year. The Agency's economic analysis indicates that 
the total incremental administrative cost will be approximately 
$56,611,000 in 1997 dollars for the 3 years to phase in the network, or 
an average of $18,820,000 per year for the 3-year implementation 
period. Table 6 shows how this 3-year average was derived for the 
various cost elements of monitoring. While this table represents the 3-
year period 1998-2000, the total cost for PM2.5 monitoring 
include the initial capital costs anticipated in 1997. In addition, 
this rule imposes no enforceable duties on small businesses.

                                                        Table 6.--Cost Elements for PM Monitoring                                                       
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                    Administrative Cost Based on 3-year Average (thousands of constant 1997 dollars)*                                   
---------------------------------------------------------------------------------------------------------------------------------------------------------
                                             Current                                        Revised                                                     
            Cost/Element            ----------------------------------------------------------------------------------------------       Net Change     
                                              PM10                    PM10                   PM2.5                  Totals                              
--------------------------------------------------------------------------------------------------------------------------------------------------------
Network design                                               $0                      $1,174                 $1,174                 $1,174               
Site installation                                            $0                      $1,532                 $1,532                 $1,532               
Sampling & analysis                  $3,518                  $2,528                  $7,915                 $10,443                $6,926               
Maintenance                          $1,658                  $1,192                  $2,285                 $3,477                 $1,818               
Data management                      $2,098                  $1,508                  $3,370                 $4,878                 $2,780               
Quality assurance                    $2,940                  $2,113                  $3,342                 $5,455                 $2,515               
Supervision                          $3,350                  $2,408                  $3,068                 $5,476                 $2,125               
Summary                              $13,564                 $9,749                  $22,684                $32,433                $18,820              
*Totals are rounded                                                                                                                                     
--------------------------------------------------------------------------------------------------------------------------------------------------------


[[Page 38784]]

List of Subjects in 40 CFR Parts 53 and 58

    Environmental protection, Administrative practice and procedure, 
Air pollution control, Intergovernmental relations, Reporting and 
recordkeeping requirements.

    Dated: July 16, 1997.

Carol M. Browner,
Administrator.
    For the reasons set forth in the preamble, title 40, chapter I, 
parts 53 and 58 of the Code of Federal Regulations are amended as 
follows:

PART 53--[AMENDED]

    1. In part 53:
    a. The authority citation for part 53 continues to read as follows:

    Authority: Sec. 301(a) of the Clean Air Act (42 U.S.C. Sec. 
1857g(a)) as amended by sec. 15(c)(2) of Pub. L. 91-604, 84 Stat. 
1713, unless otherwise noted.

    b. Subpart A is revised to read as follows:
Subpart A--General Provisions
Sec.
53.1   Definitions.
53.2   General requirements for a reference method determination.
53.3   General requirements for an equivalent method determination.
53.4   Applications for reference or equivalent method 
determinations.
53.5   Processing of applications.
53.6   Right to witness conduct of tests.
53.7   Testing of methods at the initiative of the Administrator.
53.8   Designation of reference and equivalent methods.
53.9   Conditions of designation.
53.10   Appeal from rejection of application.
53.11   Cancellation of reference or equivalent method designation.
53.12   Request for hearing on cancellation.
53.13   Hearings.
53.14   Modification of a reference or equivalent method.
53.15   Trade secrets and confidential or privileged information.
53.16   Supersession of reference methods.
Tables to Subpart A of Part 53
Table A-1.--Summary of Applicable Requirements for Reference 
Equivalent Methods for Air Monitoring of Criteria Pollutants
Appendix A to Subpart A of Part 53--References

Subpart A--General Provisions


Sec. 53.1   Definitions.

    Terms used but not defined in this part shall have the meaning 
given them by the Act.
    Act means the Clean Air Act (42 U.S.C. 1857-1857l), as amended.
    Administrator means the Administrator of the Environmental 
Protection Agency or the Administrator's authorized representative.
    Agency means the Environmental Protection Agency.
    Applicant means a person or entity who submits an application for a 
reference or equivalent method determination under Sec. 53.4, or a 
person or entity who assumes the rights and obligations of an applicant 
under Sec.  53.7. Applicant may include a manufacturer, distributor, 
supplier, or vendor.
    Automated method or analyzer means a method for measuring 
concentrations of an ambient air pollutant in which sample collection 
(if necessary), analysis, and measurement are performed automatically 
by an instrument.
    Candidate method means a method for measuring the concentration of 
an air pollutant in the ambient air for which an application for a 
reference method determination or an equivalent method determination is 
submitted in accordance with Sec. 53.4, or a method tested at the 
initiative of the Administrator in accordance with Sec. 53.7.
    Class I equivalent method means an equivalent method for 
PM2.5 which is based on a sampler that is very similar to 
the sampler specified for reference methods in Appendix L of this part, 
with only minor deviations or modifications, as determined by EPA.
    Class II equivalent method means an equivalent method for 
PM2.5 that utilizes a PM2.5 sampler in which an 
integrated PM2.5 sample is obtained from the atmosphere by 
filtration and is subjected to a subsequent filter conditioning process 
followed by a gravimetric mass determination, but which is not a Class 
I equivalent method because of substantial deviations from the design 
specifications of the sampler specified for reference methods in 
Appendix L of part 50 of this chapter, as determined by EPA.
     Class III equivalent method means an equivalent method for 
PM2.5 that has been determined by EPA not to be a Class I or 
Class II equivalent method. This fourth type of PM2.5 method 
includes alternative equivalent method samplers and continuous 
analyzers, based on designs and measurement principles different from 
those specified for reference methods (e.g., a means for estimating 
aerosol mass concentration other than by conventional integrated 
filtration followed by equilibration and gravimetric analysis. These 
samplers (or monitors) are those deemed to be substantially different 
from reference method samplers and are likely to use components and 
methods other than those specified for reference method samplers.
    Collocated describes two or more air samplers, analyzers, or other 
instruments which sampler the ambient air that are operated 
silmultaneously while located side by side, separated by a distance 
that is large enough to preclude the air sampled by any of the devices 
from being affected by any of the other devices, but small enough so 
that all devices obtain identical or uniform ambient air samples that 
are equally representative of the general area in which the group of 
devices is located.
    Equivalent method means a method for measuring the concentration of 
an air pollutant in the ambient air that has been designated as an 
equivalent method in accordance with this part; it does not include a 
method for which an equivalent method designation has been canceled in 
accordance with Sec. 53.11 or Sec. 53.16.
    ISO 9001-registered facility means a manufacturing facility that is 
either:
    (1) An International Organization for Standardization (ISO) 9001-
registered manufacturing facility, registered to the ISO 9001 standard 
(by the Registrar Accreditation Board (RAB) of the American Society for 
Quality Control (ASQC) in the United States), with registration 
maintained continuously.
    (2) A facility that can be demonstrated, on the basis of 
information submitted to the EPA, to be operated according to an EPA-
approved and periodically audited quality system which meets, to the 
extent appropriate, the same general requirements as an ISO 9001-
registered facility for the design and manufacture of designated 
reference and equivalent method samplers and monitors.
    ISO-certified auditor means an auditor who is either certified by 
the Registrar Accreditation Board (in the United States) as being 
qualified to audit quality systems using the requirements of recognized 
standards such as ISO 9001, or who, based on information submitted to 
the EPA, meets the same general requirements as provided for ISO-
certified auditors.
    Manual method means a method for measuring concentrations of an 
ambient air pollutant in which sample collection, analysis, or 
measurement, or some combination therof, is performed manually. A 
method for PM10 or PM2.5 which utilizes a sampler 
that requires manual preparation, loading, and weighing of filter 
samples is considered a manual method even though the sampler may be 
capable of

[[Page 38785]]

 automatically collecting a series of sequential samples.
    PM2.5 sampler means a device, associated with a manual 
method for measuring PM2.5, designed to collect 
PM2.5 from an ambient air sample, but lacking the ability to 
automatically analyze or measure the collected sample to determine the 
mass concentrations of PM2.5 in the sampled air.
    PM10 sampler means a device, associated with a manual 
method for measuring PM10, designed to collect 
PM10 from an ambient air sample, but lacking the ability to 
automatically analyze or measure the collected sample to determine the 
mass concentrations of PM10 in the sampled air.
    Reference method means a method of sampling and analyzing the 
ambient air for an air pollutant that is specified as a reference 
method in an appendix to part 50 of this chapter, or a method that has 
been designated as a reference method in accordance with this part; it 
does not include a method for which a reference method designation has 
been canceled in accordance with Sec. 53.11 or Sec. 53.16.
    Sequential samples for PM samplers means two or more PM samples for 
sequential (but not necessarily contiguous) time periods that are 
collected automatically by the same sampler without the need for 
intervening operator service.
    Test analyzer means an analyzer subjected to testing as part of a 
candidate method in accordance with subparts B, C, D, E, or F of this 
part, as applicable. Test sampler means a PM10 sampler or a 
PM2.5 sampler subjected to testing as part of a candidate 
method in accordance with subparts C, D, E, or F of this part.
    Ultimate purchaser means the first person or entity who purchases a 
reference method or an equivalent method for purposes other than 
resale.


Sec. 53.2   General requirements for a reference method determination.

    The following general requirements for a reference method 
determination are summarized in Table A-1 of this subpart.
    (a) Manual methods. (1) For measuring sulfur dioxide 
(SO2) and lead, Appendices A and G of part 50 of this 
chapter specify unique manual reference methods for those pollutants. 
Except as provided in Sec. 53.16, other manual methods for 
SO2 and lead will not be considered for reference method 
determinations under this part.
    (2) A reference method for measuring PM10 must be a 
manual method that meets all requirements specified in Appendix J of 
part 50 of this chapter and must include a PM10 sampler that 
has been shown in accordance with this part to meet all requirements 
specified in subparts A and D of this part.
    (3) A reference method for measuring PM2.5 must be a 
manual method that meets all requirements specified in Appendix L of 
part 50 of this chapter and must include a PM2.5 sampler 
that has been shown in accordance with this part to meet the applicable 
requirements specified in subparts A and E of this part. Further, 
reference method samplers must be manufactured in an ISO 9001-
registered facility, as defined in Sec. 53.1 and as set forth in 
Sec. 53.51, and the Product Manufacturing Checklist set forth in 
subpart E of this part must be completed by an ISO-certified auditor, 
as defined in Sec. 53.1, and submitted to EPA annually to retain a 
PM2.5 reference method designation.
    (b) Automated methods. An automated reference method for measuring 
carbon monoxide (CO), ozone (O3), and nitrogen dioxide 
(NO2) must utilize the measurement principle and calibration 
procedure specified in the appropriate appendix to part 50 of this 
chapter and must have been shown in accordance with this part to meet 
the requirements specified in subpart B of this part.


Sec. 53.3   General requirements for an equivalent method 
determination.

    (a) Manual methods. A manual equivalent method must have been shown 
in accordance with this part to satisfy the applicable requirements 
specified in subpart C of this part. In addition, PM10 or 
PM2.5 samplers associated with manual equivalent methods for 
PM10 or PM2.5 must have been shown in accordance 
with this part to satisfy the following additional requirements:
    (1) A PM10 sampler associated with a manual method for 
PM10 must satisfy the requirements of subpart D of this 
part.
    (2) A PM2.5 Class I equivalent method sampler must 
satisfy all requirements of subparts C and E of this part, which 
include appropriate demonstration that each and every deviation or 
modification from the reference method sampler specifications does not 
significantly alter the performance of the sampler.
    (3) A PM2.5 Class II equivalent method sampler must 
satisfy the applicable requirements of subparts C, E, and F of this 
part.
    (4) Requirements for PM2.5 Class III equivalent method 
samplers are not provided in this part because of the wide range of 
non-filter-based measurement technologies that could be applied and the 
likelihood that these requirements will have to be specifically adapted 
for each such type of technology. Specific requirements will be 
developed as needed and may include selected requirements from subparts 
C, E, or F of this part or other requirements not contained in this 
part.
    (5) All designated equivalent methods for PM2.5 must be 
manufactured in an ISO 9001-registered facility, as defined in 
Sec. 53.1 and as set forth in Sec. 53.51, and the Product Manufacturing 
Checklist set forth in subpart E of this part must be completed by an 
ISO-certified auditor, as defined in Sec. 53.1, and submitted to EPA 
annually to retain a PM2.5 equivalent method designation.
    (b) Automated methods. (1) Automated equivalent methods for 
pollutants other than PM2.5 or PM10 must have 
been shown in accordance with this part to satisfy the requirements 
specified in subparts B and C of this part.
    (2) Automated equivalent methods for PM10 must have been 
shown in accordance with this part to satisfy the requirements of 
subparts C and D of this part.
    (3) Requirements for PM2.5 Class III automated 
equivalent methods for PM2.5 are not provided in this part 
because of the wide range of non-filter-based measurement technologies 
that could be applied and the likelihood that these requirements will 
have to be specifically adapted for each such type of technology. 
Specific requirements will be developed as needed and may include 
selected requirements from subparts C, E, or F of this part or other 
requirements not contained in this part.
    (4) All designated equivalent methods for PM2.5 must be 
manufactured in an ISO 9001-registered facility, as set forth in 
subpart E of this part, and the Product Manufacturing Checklist set 
forth in subpart E of this part must be completed by an ISO-certified 
auditor and submitted to EPA annually to retain a PM2.5 
equivalent method designation.
    (5) All designated equivalent methods for PM2.5 must 
also meet annual requirements for network operating performance 
determined as set forth in section 6 of Appendix A of part 58 of this 
chapter.


Sec. 53.4   Applications for reference or equivalent method 
determinations.

    (a) Applications for reference or equivalent method determinations 
shall be submitted in duplicate to: Director, National Exposure 
Research Laboratory, Department E (MD-77B), U.S. Environmental 
Protection Agency, Research Triangle Park, North Carolina 27711.

[[Page 38786]]

    (b) Each application shall be signed by an authorized 
representative of the applicant, shall be marked in accordance with 
Sec. 53.15 (if applicable), and shall contain the following:
    (1) A clear identification of the candidate method, which will 
distinguish it from all other methods such that the method may be 
referred to unambiguously. This identification must consist of a unique 
series of descriptors such as title, identification number, analyte, 
measurement principle, manufacturer, brand, model, etc., as necessary 
to distinguish the method from all other methods or method variations, 
both within and outside the applicant's organization.
    (2) A detailed description of the candidate method, including but 
not limited to the following: The measurement principle, manufacturer, 
name, model number and other forms of identification, a list of the 
significant components, schematic diagrams, design drawings, and a 
detailed description of the apparatus and measurement procedures. 
Drawings and descriptions pertaining to candidate methods or samplers 
for PM2.5 must meet all applicable requirements in Reference 
1 of Appendix A of this subpart, using appropriate graphical, 
nomenclature, and mathematical conventions such as those specified in 
References 3 and 4 of Appendix A of this subpart.
    (3) A copy of a comprehensive operation or instruction manual 
providing a complete and detailed description of the operational, 
maintenance, and calibration procedures prescribed for field use of the 
candidate method and all instruments utilized as part of that method 
(under Sec. 53.9(a)).
    (i) As a minimum this manual shall include:
    (A) Description of the method and associated instruments.
    (B) Explanation of all indicators, information displays, and 
controls.
    (C) Complete setup and installation instructions, including any 
additional materials or supplies required.
    (D) Details of all initial or startup checks or acceptance tests 
and any auxiliary equipment required.
    (E) Complete operational instructions.
    (F) Calibration procedures and required calibration equipment and 
standards.
    (G) Instructions for verification of correct or proper operation.
    (H) Trouble-shooting guidance and suggested corrective actions for 
abnormal operation.
    (I) Required or recommended routine, periodic, and preventative 
maintenance and maintenance schedules.
    (J) Any calculations required to derive final concentration 
measurements.
    (K) Appropriate references to Appendix L of part 50 of this 
chapter; Reference 6 of Appendix A of this subpart; and any other 
pertinent guidelines.
    (ii) The manual shall also include adequate warning of potential 
safety hazards that may result from normal use and/or malfunction of 
the method and a description of necessary safety precautions. (See 
Sec. 53.9(b).) However, the previous requirement shall not be 
interpreted to constitute or imply any warranty of safety of the method 
by EPA. For samplers and automated methods, the manual shall include a 
clear description of all procedures pertaining to installation, 
operation, preventive maintenance, and troubleshooting and shall also 
include parts identification diagrams. The manual may be used to 
satisfy the requirements of paragraphs (b)(1) and (b)(2) of this 
section to the extent that it includes information necessary to meet 
those requirements.
    (4) A statement that the candidate method has been tested in 
accordance with the procedures described in subparts B, C, D, E, and/or 
F of this part, as applicable.
    (5) Descriptions of test facilities and test configurations, test 
data, records, calculations, and test results as specified in subparts 
B, C, D, E, and/or F of this part, as applicable. Data must be 
sufficiently detailed to meet appropriate principles described in 
paragraphs 4 through 6 of Reference 2 of Appendix A of this subpart, 
Part b, sections 3.3.1 (paragraph 1) and 3.5.1 (paragraphs 2 and 3) and 
in paragraphs 1 through 3 of Reference 5 (section 4.8, Records) of 
Appendix A of this subpart. Salient requirements from these references 
include the following:
    (i) The applicant shall maintain and include records of all 
relevant measuring equipment, including the make, type, and serial 
number or other identification, and most recent calibration with 
identification of the measurement standard or standards used and their 
National Institute of Standards and Technology (NIST) traceability. 
These records shall demonstrate the measurement capability of each item 
of measuring equipment used for the application and include a 
description and justification (if needed) of the measurement setup or 
configuration in which it was used for the tests. The calibration 
results shall be recorded and identified in sufficient detail so that 
the traceability of all measurements can be determined and any 
measurement could be reproduced under conditions close to the original 
conditions, if necessary, to resolve any anomalies.
    (ii) Test data shall be collected according to the standards of 
good practice and by qualified personnel. Test anomalies or 
irregularities shall be documented and explained or justified. The 
impact and significance of the deviation on test results and 
conclusions shall be determined. Data collected shall correspond 
directly to the specified test requirement and be labeled and 
identified clearly so that results can be verified and evaluated 
against the test requirement. Calculations or data manipulations must 
be explained in detail so that they can be verified.
    (6) A statement that the method, analyzer, or sampler tested in 
accordance with this part is representative of the candidate method 
described in the application.
    (c) For candidate automated methods and candidate manual methods 
for PM10 and PM2.5, the application shall also 
contain the following:
    (1) A detailed description of the quality system that will be 
utilized, if the candidate method is designated as a reference or 
equivalent method, to ensure that all analyzers or samplers offered for 
sale under that designation will have essentially the same performance 
characteristics as the analyzer(s) or samplers tested in accordance 
with this part. In addition, the quality system requirements for 
candidate methods for PM2.5 must be described in sufficient 
detail, based on the elements described in section 4 of Reference 1 
(Quality System Requirements) of Appendix A of this subpart. Further 
clarification is provided in the following sections of Reference 2 of 
Appendix A of this subpart: Part A (Management Systems), sections 2.2 
(Quality System and Description), 2.3 (Personnel Qualification and 
Training), 2.4 (Procurement of Items and Services), 2.5 (Documents and 
Records), and 2.7 (Planning); Part B (Collection and Evaluation of 
Environmental Data), sections 3.1 (Planning and Scoping), 3.2 (Design 
of Data Collection Operations), and 3.5 (Assessment and Verification of 
Data Usability); and Part C (Operation of Environmental Technology), 
sections 4.1 (Planning), 4.2 (Design of Systems), and 4.4 (Operation of 
Systems).
    (2) A description of the durability characteristics of such 
analyzers or samplers (see Sec. 53.9(c)). For methods for 
PM2.5, the warranty program must

[[Page 38787]]

ensure that the required specifications (see Table A-1 of this subpart) 
will be met throughout the warranty period and that the applicant 
accepts responsibility and liability for ensuring this conformance or 
for resolving any nonconformities, including all necessary components 
of the system, regardless of the original manufacturer. The warranty 
program must be described in sufficient detail to meet appropriate 
provisions of the ANSI/ASQC and ISO 9001 standards (References 1 and 2 
in Appendix A of this subpart) for controlling conformance and 
resolving nonconformance, particularly sections 4.12, 4.13, and 4.14 of 
Reference 1 in Appendix A of this subpart.
    (i) Section 4.12 in Appendix A of this subpart requires the 
manufacturer to establish and maintain a system of procedures for 
identifying and maintaining the identification of inspection and test 
status throughout all phases of manufacturing to ensure that only 
instruments that have passed the required inspections and tests are 
released for sale.
    (ii) Section 4.13 in Appendix A of this subpart requires documented 
procedures for control of nonconforming product, including review and 
acceptable alternatives for disposition; section 4.14 in Appendix A of 
this subpart requires documented procedures for implementing corrective 
(4.14.2) and preventive (4.14.3) action to eliminate the causes of 
actual or potential nonconformities. In particular, section 4.14.3 
requires that potential causes of nonconformities be eliminated by 
using information such as service reports and customer complaints to 
eliminate potential causes of nonconformities.
    (d) For candidate reference or equivalent methods for 
PM2.5, the applicant shall provide to EPA for test purposes 
one sampler or analyzer that is representative of the sampler or 
analyzer associated with the candidate method. The sampler or analyzer 
shall be shipped FOB destination to Department E, (MD-77B), U.S. EPA, 
79 T.W. Alexander Drive, Research Triangle Park, NC 27711, scheduled to 
arrive concurrent with or within 30 days of the arrival of the other 
application materials. This analyzer or sampler may be subjected to 
various tests that EPA determines to be necessary or appropriate under 
Sec. 53.5(f), and such tests may include special tests not described in 
this part. If the instrument submitted under this paragraph 
malfunctions, becomes inoperative, or fails to perform as represented 
in the application before the necessary EPA testing is completed, the 
applicant shall be afforded an opportunity to repair or replace the 
device at no cost to EPA. Upon completion of EPA testing, the analyzer 
or sampler submitted under this paragraph shall be repacked by EPA for 
return shipment to the applicant, using the same packing materials used 
for shipping the instrument to EPA unless alternative packing is 
provided by the applicant. Arrangements for, and the cost of, return 
shipment shall be the responsibility of the applicant. EPA does not 
warrant or assume any liability for the condition of the analyzer or 
sampler upon return to the applicant.


Sec. 53.5   Processing of applications.

    After receiving an application for a reference or equivalent method 
determination, the Administrator will publish notice of the application 
in the Federal Register and, within 120 calendar days after receipt of 
the application, take one or more of the following actions:
    (a) Send notice to the applicant, in accordance with Sec. 53.8, 
that the candidate method has been determined to be a reference or 
equivalent method.
    (b) Send notice to the applicant that the application has been 
rejected, including a statement of reasons for rejection.
    (c) Send notice to the applicant that additional information must 
be submitted before a determination can be made and specify the 
additional information that is needed (in such cases, the 120-day 
period shall commence upon receipt of the additional information).
    (d) Send notice to the applicant that additional test data must be 
submitted and specify what tests are necessary and how the tests shall 
be interpreted (in such cases, the 120-day period shall commence upon 
receipt of the additional test data).
    (e) Send notice to the applicant that the application has been 
found to be substantially deficient or incomplete and cannot be 
processed until additional information is submitted to complete the 
application and specify the general areas of substantial deficiency.
    (f) Send notice to the applicant that additional tests will be 
conducted by the Administrator, specifying the nature of and reasons 
for the additional tests and the estimated time required (in such 
cases, the 120-day period shall commence 1 calendar day after the 
additional tests have been completed).


Sec. 53.6   Right to witness conduct of tests.

    (a) Submission of an application for a reference or equivalent 
method determination shall constitute consent for the Administrator or 
the Administrator's authorized representative, upon presentation of 
appropriate credentials, to witness or observe any tests required by 
this part in connection with the application or in connection with any 
modification or intended modification of the method by the applicant.
    (b) The applicant shall have the right to witness or observe any 
test conducted by the Administrator in connection with the application 
or in connection with any modification or intended modification of the 
method by the applicant.
    (c) Any tests by either party that are to be witnessed or observed 
by the other party shall be conducted at a time and place mutually 
agreeable to both parties.


Sec. 53.7   Testing of methods at the initiative of the Administrator.

    (a) In the absence of an application for a reference or equivalent 
method determination, the Administrator may conduct the tests required 
by this part for such a determination, may compile such other 
information as may be necessary in the judgment of the Administrator to 
make such a determination, and on the basis of the tests and 
information may determine that a method satisfies applicable 
requirements of this part.
    (b) In the absence of an application requesting the Administrator 
to consider revising an appendix to part 50 of this chapter in 
accordance with Sec. 53.16, the Administrator may conduct such tests 
and compile such information as may be necessary in the Administrator's 
judgment to make a determination under Sec. 53.16(d) and on the basis 
of the tests and information make such a determination.
    (c) If a method tested in accordance with this section is 
designated as a reference or equivalent method in accordance with 
Sec. 53.8 or is specified or designated as a reference method in 
accordance with Sec. 53.16, any person or entity who offers the method 
for sale as a reference or equivalent method thereafter shall assume 
the rights and obligations of an applicant for purposes of this part, 
with the exception of those pertaining to submission and processing of 
applications.


Sec. 53.8   Designation of reference and equivalent methods.

    (a) A candidate method determined by the Administrator to satisfy 
the applicable requirements of this part shall be designated as a 
reference method or equivalent method (as applicable), and a notice of 
the

[[Page 38788]]

designation shall be submitted for publication in the Federal Register 
not later than 15 days after the determination is made.
    (b) A notice indicating that the method has been determined to be a 
reference method or an equivalent method shall be sent to the 
applicant. This notice shall constitute proof of the determination 
until a notice of designation is published in accordance with paragraph 
(a) of this section.
    (c) The Administrator will maintain a current list of methods 
designated as reference or equivalent methods in accordance with this 
part and will send a copy of the list to any person or group upon 
request. A copy of the list will be available for inspection or copying 
at EPA Regional Offices.


Sec. 53.9   Conditions of designation.

    Designation of a candidate method as a reference method or 
equivalent method shall be conditioned to the applicant's compliance 
with the following requirements. Failure to comply with any of the 
requirements shall constitute a ground for cancellation of the 
designation in accordance with Sec. 53.11.
    (a) Any method offered for sale as a reference or equivalent method 
shall be accompanied by a copy of the manual referred to in 
Sec. 53.4(b)(3) when delivered to any ultimate purchaser.
    (b) Any method offered for sale as a reference or equivalent method 
shall generate no unreasonable hazard to operators or to the 
environment during normal use or when malfunctioning.
    (c) Any analyzer, PM10 sampler, or PM2.5 
sampler offered for sale as part of a reference or equivalent method 
shall function within the limits of the performance specifications 
referred to in Sec. 53.20(a), Sec. 53.30(a), Sec. 53.50, or Sec. 53.60, 
as applicable, for at least 1 year after delivery and acceptance when 
maintained and operated in accordance with the manual referred to in 
Sec. 53.4(b)(3).
    (d) Any analyzer, PM10 sampler, or PM2.5 
sampler offered for sale as a reference or equivalent method shall bear 
a prominent, permanently affixed label or sticker indicating that the 
analyzer or sampler has been designated by EPA as a reference method or 
as an equivalent method (as applicable) in accordance with this part 
and displaying any designated method identification number that may be 
assigned by EPA.
    (e) If an analyzer is offered for sale as a reference or equivalent 
method and has one or more selectable ranges, the label or sticker 
required by paragraph (d) of this section shall be placed in close 
proximity to the range selector and shall indicate clearly which range 
or ranges have been designated as parts of the reference or equivalent 
method.
    (f) An applicant who offers analyzers, PM10 samplers, or 
PM2.5 samplers for sale as reference or equivalent methods 
shall maintain an accurate and current list of the names and mailing 
addresses of all ultimate purchasers of such analyzers or samplers. For 
a period of 7 years after publication of the reference or equivalent 
method designation applicable to such an analyzer or sampler, the 
applicant shall notify all ultimate purchasers of the analyzer or 
PM2.5 or PM10 sampler within 30 days if the 
designation has been canceled in accordance with Sec. 53.11 or 
Sec. 53.16 or if adjustment of the analyzer or sampler is necessary 
under Sec. 53.11(b).
    (g) If an applicant modifies an analyzer, PM10 sampler, 
or PM2.5 sampler that has been designated as a reference or 
equivalent method, the applicant shall not sell the modified analyzer 
or sampler as a reference or equivalent method nor attach a label or 
sticker to the modified analyzer or sampler under paragraph (d) or (e) 
of this section until the applicant has received notice under 
Sec. 53.14(c) that the existing designation or a new designation will 
apply to the modified analyzer, PM10 sampler, or 
PM2.5 sampler or has applied for and received notice under 
Sec. 53.8(b) of a new reference or equivalent method determination for 
the modified analyzer or sampler.
    (h) An applicant who has offered PM2.5 samplers or 
analyzers for sale as part of a reference or equivalent method may 
continue to do so only so long as the facility in which the samplers or 
analyzers are manufactured continues to be an ISO 9001-registered 
facility, as set forth in subpart E of this part. In the event that the 
ISO 9001 registration for the facility is withdrawn, suspended, or 
otherwise becomes inapplicable, either permanently or for some 
specified time interval, such that the facility is no longer an ISO 
9001-registered facility, the applicant shall notify EPA within 30 days 
of the date the facility becomes other than an ISO 9001-registered 
facility, and upon such notification, EPA shall issue a preliminary 
finding and notification of possible cancellation of the reference or 
equivalent method designation under Sec. 53.11.
    (i) An applicant who has offered PM2.5 samplers or 
analyzers for sale as part of a reference or equivalent method may 
continue to do so only so long as updates of the Product Manufacturing 
Checklist set forth in subpart E of this part are submitted annually. 
In the event that an annual Checklist update is not received by EPA 
within 12 months of the date of the last such submitted Checklist or 
Checklist update, EPA shall notify the applicant within 30 days that 
the Checklist update has not been received and shall, within 30 days 
from the issuance of such notification, issue a preliminary finding and 
notification of possible cancellation of the reference or equivalent 
method designation under Sec. 53.11.


Sec. 53.10   Appeal from rejection of application.

    Any applicant whose application for a reference or equivalent 
method determination has been rejected may appeal the Administrator's 
decision by taking one or more of the following actions:
    (a) The applicant may submit new or additional information in 
support of the application.
    (b) The applicant may request that the Administrator reconsider the 
data and information already submitted.
    (c) The applicant may request that any test conducted by the 
Administrator that was a material factor in the decision to reject the 
application be repeated.


Sec. 53.11   Cancellation of reference or equivalent method 
designation.

    (a) Preliminary finding. If the Administrator makes a preliminary 
finding on the basis of any available information that a representative 
sample of a method designated as a reference or equivalent method and 
offered for sale as such does not fully satisfy the requirements of 
this part or that there is any violation of the requirements set forth 
in Sec. 53.9, the Administrator may initiate proceedings to cancel the 
designation in accordance with the following procedures.
    (b) Notification and opportunity to demonstrate or achieve 
compliance. (1) After making a preliminary finding in accordance with 
paragraph (a) of this section, the Administrator will send notice of 
the preliminary finding to the applicant, together with a statement of 
the facts and reasons on which the preliminary finding is based, and 
will publish notice of the preliminary finding in the Federal Register.
    (2) The applicant will be afforded an opportunity to demonstrate or 
to achieve compliance with the requirements of this part within 60 days 
after publication of notice in accordance with paragraph (b)(1) of this 
section or within such further period as the Administrator may allow, 
by demonstrating to the satisfaction of the Administrator that the 
method in question satisfies the requirements of this part, by 
commencing a program to

[[Page 38789]]

make any adjustments that are necessary to bring the method into 
compliance, or by taking such action as may be necessary to cure any 
violation of the requirements of Sec. 53.9. If adjustments are 
necessary to bring the method into compliance, all such adjustments 
shall be made within a reasonable time as determined by the 
Administrator. If the applicant demonstrates or achieves compliance in 
accordance with this paragraph (b)(2), the Administrator will publish 
notice of such demonstration or achievement in the Federal Register.
    (c) Request for hearing. Within 60 days after publication of a 
notice in accordance with paragraph (b)(1) of this section, the 
applicant or any interested person may request a hearing as provided in 
Sec. 53.12.
    (d) Notice of cancellation. If, at the end of the period referred 
to in paragraph (b)(2) of this section, the Administrator determines 
that the reference or equivalent method designation should be canceled, 
a notice of cancellation will be published in the Federal Register and 
the designation will be deleted from the list maintained under 
Sec. 53.8(c). If a hearing has been requested and granted in accordance 
with Sec. 53.12, action under this paragraph (d) will be taken only 
after completion of proceedings (including any administrative review) 
conducted in accordance with Sec. 53.13 and only if the decision of the 
Administrator reached in such proceedings is that the designation in 
question should be canceled.


Sec. 53.12   Request for hearing on cancellation.

    Within 60 days after publication of a notice in accordance with 
Sec. 53.11(b)(1), the applicant or any interested person may request a 
hearing on the Administrator's action. If, after reviewing the request 
and supporting data, the Administrator finds that the request raises a 
substantial issue of fact, a hearing will be granted in accordance with 
Sec. 53.13 with respect to such issue. The request shall be in writing, 
signed by an authorized representative of the applicant or interested 
person, and shall include a statement specifying:
     (a) Any objections to the Administrator's action.
     (b) Data or other information in support of such objections.


Sec. 53.13   Hearings.

    (a)(1) After granting a request for a hearing under Sec. 53.12, the 
Administrator will designate a presiding officer for the hearing.
    (2) If a time and place for the hearing have not been fixed by the 
Administrator, the hearing will be held as soon as practicable at a 
time and place fixed by the presiding officer, except that the hearing 
shall in no case be held sooner than 30 days after publication of a 
notice of hearing in the Federal Register.
    (3) For purposes of the hearing, the parties shall include EPA, the 
applicant or interested person(s) who requested the hearing, and any 
person permitted to intervene in accordance with paragraph (c) of this 
section.
    (4) The Deputy General Counsel or the Deputy General Counsel's 
representative will represent EPA in any hearing under this section.
    (5) Each party other than EPA may be represented by counsel or by 
any other duly authorized representative.
    (b)(1) Upon appointment, the presiding officer will establish a 
hearing file. The file shall contain copies of the notices issued by 
the Administrator pursuant to Sec. 53.11(b)(1), together with any 
accompanying material, the request for a hearing and supporting data 
submitted therewith, the notice of hearing published in accordance with 
paragraph (a)(2) of this section, and correspondence and other material 
data relevant to the hearing.
    (2) The hearing file shall be available for inspection by the 
parties or their representatives at the office of the presiding 
officer, except to the extent that it contains information identified 
in accordance with Sec. 53.15.
    (c) The presiding officer may permit any interested person to 
intervene in the hearing upon such a showing of interest as the 
presiding officer may require; provided that permission to intervene 
may be denied in the interest of expediting the hearing where it 
appears that the interests of the person seeking to intervene will be 
adequately represented by another party (or by other parties), 
including EPA.
    (d)(1) The presiding officer, upon the request of any party or at 
the officer's discretion, may arrange for a prehearing conference at a 
time and place specified by the officer to consider the following:
    (i) Simplification of the issues.
    (ii) Stipulations, admissions of fact, and the introduction of 
documents.
    (iii) Limitation of the number of expert witnesses.
    (iv) Possibility of agreement on disposing of all or any of the 
issues in dispute.
    (v) Such other matters as may aid in the disposition of the 
hearing, including such additional tests as may be agreed upon by the 
parties.
    (2) The results of the conference shall be reduced to writing by 
the presiding officer and made part of the record.
    (e)(1) Hearings shall be conducted by the presiding officer in an 
informal but orderly and expeditious manner. The parties may offer oral 
or written evidence, subject to exclusion by the presiding officer of 
irrelevant, immaterial, or repetitious evidence.
    (2) Witnesses shall be placed under oath.
    (3) Any witness may be examined or cross-examined by the presiding 
officer, the parties, or their representatives. The presiding officer 
may, at his/her discretion, limit cross-examination to relevant and 
material issues.
    (4) Hearings shall be reported verbatim. Copies of transcripts of 
proceedings may be purchased from the reporter.
    (5) All written statements, charts, tabulations, and data offered 
in evidence at the hearing shall, upon a showing satisfactory to the 
presiding officer of their authenticity, relevancy, and materiality, be 
received in evidence and shall constitute part of the record.
    (6) Oral argument shall be permitted. The presiding officer may 
limit oral presentations to relevant and material issues and designate 
the amount of time allowed for oral argument.
    (f)(1) The presiding officer shall make an initial decision which 
shall include written findings and conclusions and the reasons 
therefore on all the material issues of fact, law, or discretion 
presented on the record. The findings, conclusions, and written 
decision shall be provided to the parties and made part of the record. 
The initial decision shall become the decision of the Administrator 
without further proceedings unless there is an appeal to, or review on 
motion of, the Administrator within 30 calendar days after the initial 
decision is filed.
    (2) On appeal from or review of the initial decision, the 
Administrator will have all the powers consistent with making the 
initial decision, including the discretion to require or allow briefs, 
oral argument, the taking of additional evidence or the remanding to 
the presiding officer for additional proceedings. The decision by the 
Administrator will include written findings and conclusions and the 
reasons or basis therefore on all the material issues of fact, law, or 
discretion presented on the appeal or considered in the review.


Sec. 53.14   Modification of a reference or equivalent method.

    (a) An applicant who offers a method for sale as a reference or 
equivalent method shall report to the EPA Administrator prior to 
implementation any intended modification of the

[[Page 38790]]

method, including but not limited to modifications of design or 
construction or of operational and maintenance procedures specified in 
the operation manual (see Sec. 53.9(g)). The report shall be signed by 
an authorized representative of the applicant, marked in accordance 
with Sec. 53.15 (if applicable), and addressed as specified in 
Sec. 53.4(a).
    (b) A report submitted under paragraph (a) of this section shall 
include:
    (1) A description, in such detail as may be appropriate, of the 
intended modification.
    (2) A brief statement of the applicant's belief that the 
modification will, will not, or may affect the performance 
characteristics of the method.
    (3) A brief statement of the probable effect if the applicant 
believes the modification will or may affect the performance 
characteristics of the method.
    (4) Such further information, including test data, as may be 
necessary to explain and support any statement required by paragraphs 
(b)(2) and (b)(3) of this section.
    (c) Within 30 calendar days after receiving a report under 
paragraph (a) of this section, the Administrator will take one or more 
of the following actions:
    (1) Notify the applicant that the designation will continue to 
apply to the method if the modification is implemented.
    (2) Send notice to the applicant that a new designation will apply 
to the method (as modified) if the modification is implemented, submit 
notice of the determination for publication in the Federal Register, 
and revise or supplement the list referred to in Sec. 53.8(c) to 
reflect the determination.
    (3) Send notice to the applicant that the designation will not 
apply to the method (as modified) if the modification is implemented 
and submit notice of the determination for publication in the Federal 
Register.
    (4) Send notice to the applicant that additional information must 
be submitted before a determination can be made and specify the 
additional information that is needed (in such cases, the 30-day period 
shall commence upon receipt of the additional information).
    (5) Send notice to the applicant that additional tests are 
necessary and specify what tests are necessary and how they shall be 
interpreted (in such cases, the 30-day period shall commence upon 
receipt of the additional test data).
    (6) Send notice to the applicant that additional tests will be 
conducted by the Administrator and specify the reasons for and the 
nature of the additional tests (in such cases, the 30-day period shall 
commence 1 calendar day after the additional tests are completed).
    (d) An applicant who has received a notice under paragraph (c)(3) 
of this section may appeal the Administrator's action as follows:
    (1) The applicant may submit new or additional information 
pertinent to the intended modification.
    (2) The applicant may request the Administrator to reconsider data 
and information already submitted.
    (3) The applicant may request that the Administrator repeat any 
test conducted that was a material factor in the Administrator's 
determination. A representative of the applicant may be present during 
the performance of any such retest.


Sec. 53.15   Trade secrets and confidential or privileged information.

    Any information submitted under this part that is claimed to be a 
trade secret or confidential or privileged information shall be marked 
or otherwise clearly identified as such in the submittal. Information 
so identified will be treated in accordance with part 2 of this chapter 
(concerning public information).


Sec. 53.16   Supersession of reference methods.

    (a) This section prescribes procedures and criteria applicable to 
requests that the Administrator specify a new reference method, or a 
new measurement principle and calibration procedure on which reference 
methods shall be based, by revision of the appropriate appendix to part 
50 of this chapter. Such action will ordinarily be taken only if the 
Administrator determines that a candidate method or a variation thereof 
is substantially superior to the existing reference method(s).
    (b) In exercising discretion under this section, the Administrator 
will consider:
    (1) The benefits, in terms of the requirements and purposes of the 
Act, that would result from specifying a new reference method or a new 
measurement principle and calibration procedure.
    (2) The potential economic consequences of such action for State 
and local control agencies.
    (3) Any disruption of State and local air quality monitoring 
programs that might result from such action.
    (c) An applicant who wishes the Administrator to consider revising 
an appendix to part 50 of this chapter on the ground that the 
applicant's candidate method is substantially superior to the existing 
reference method(s) shall submit an application for a reference or 
equivalent method determination in accordance with Sec. 53.4 and shall 
indicate therein that such consideration is desired. The application 
shall include, in addition to the information required by Sec. 53.4, 
data and any other information supporting the applicant's claim that 
the candidate method is substantially superior to the existing 
reference method(s).
    (d) After receiving an application under paragraph (c) of this 
section, the Administrator will publish notice of its receipt in the 
Federal Register and, within 120 calendar days after receipt of the 
application, take one of the following actions:
    (1) Determine that it is appropriate to propose a revision of the 
appendix to part 50 of this chapter in question and send notice of the 
determination to the applicant.
    (2) Determine that it is inappropriate to propose a revision of the 
appendix to part 50 of this chapter in question, determine whether the 
candidate method is a reference or equivalent method, and send notice 
of the determinations, including a statement of reasons for the 
determination not to propose a revision, to the applicant.
    (3) Send notice to the applicant that additional information must 
be submitted before a determination can be made and specify the 
additional information that is needed (in such cases, the 120-day 
period shall commence upon receipt of the additional information).
    (4) Send notice to the applicant that additional tests are 
necessary, specifying what tests are necessary and how the test shall 
be interpreted (in such cases, the 120-day period shall commence upon 
receipt of the additional test data).
    (5) Send notice to the applicant that additional tests will be 
conducted by the Administrator, specifying the nature of and reasons 
for the additional tests and the estimated time required (in such 
cases, the 120-day period shall commence 1 calendar day after the 
additional tests have been completed).
    (e)(1)(i) After making a determination under paragraph (d)(1) of 
this section, the Administrator will publish a notice of proposed 
rulemaking in the Federal Register. The notice of proposed rulemaking 
will indicate that the Administrator proposes:
    (A) To revise the appendix to part 50 of this chapter in question.
    (B) Where the appendix specifies a measurement principle and 
calibration procedure, to cancel reference method designations based on 
the appendix.

[[Page 38791]]

    (C) To cancel equivalent method designations based on the existing 
reference method(s).
    (ii) The notice of proposed rulemaking will include the terms or 
substance of the proposed revision, will indicate what period(s) of 
time the Administrator proposes to allow for replacement of existing 
methods under section 2.3 of Appendix C to part 58 of this chapter, and 
will solicit public comments on the proposal with particular reference 
to the considerations set forth in paragraphs (a) and (b) of this 
section.
    (2)(i) If, after consideration of comments received, the 
Administrator determines that the appendix to part 50 in question 
should be revised, the Administrator will, by publication in the 
Federal Register:
    (A) Promulgate the proposed revision, with such modifications as 
may be appropriate in view of comments received.
    (B) Where the appendix to part 50 (prior to revision) specifies a 
measurement principle and calibration procedure, cancel reference 
method designations based on the appendix.
    (C) Cancel equivalent method designations based on the existing 
reference method(s).
    (D) Specify the period(s) that will be allowed for replacement of 
existing methods under section 2.3 of Appendix C to part 58 of this 
chapter, with such modifications from the proposed period(s) as may be 
appropriate in view of comments received.
    (3) Canceled designations will be deleted from the list maintained 
under Sec. 53.8(c). The requirements and procedures for cancellation 
set forth in Sec. 53.11 shall be inapplicable to cancellation of 
reference or equivalent method designations under this section.
    (4) If the appendix to part 50 of this chapter in question is 
revised to specify a new measurement principle and calibration 
procedure on which the applicant's candidate method is based, the 
Administrator will take appropriate action under Sec. 53.5 to determine 
whether the candidate method is a reference method.
    (5) Upon taking action under paragraph (e)(2) of this section, the 
Administrator will send notice of the action to all applicants for 
whose methods reference and equivalent method designations are canceled 
by such action.
    (f) An applicant who has received notice of a determination under 
paragraph (d)(2) of this section may appeal the determination by taking 
one or more of the following actions:
    (1) The applicant may submit new or additional information in 
support of the application.
    (2) The applicant may request that the Administrator reconsider the 
data and information already submitted.
    (3) The applicant may request that any test conducted by the 
Administrator that was a material factor in making the determination be 
repeated.

Tables to Subpart A of Part 53

              Table A-1.--Summary of Applicable Requirements for Reference and Equivalent Methods for Air Monitoring of Criteria Pollutants             
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                  Applicable Subparts of part 53        
              Pollutant                 Ref. or Equivalent      Manual or Automated   Applicable part 50 -----------------------------------------------
                                                                                           Appendix          A       B       C       D       E       F  
--------------------------------------------------------------------------------------------------------------------------------------------------------
SO2.................................  Reference.............  Manual................  A                   ......  ......  ......  ......  ......  ......
                                                              Manual................  ..................                 >                         
                                      Equivalent............  Automated.............  ..................         >       >                         
CO..................................  Reference.............  Automated.............  C                          >                                 
                                                              Manual................  ..................                 >                         
                                      Equivalent............  Automated.............  ..................         >       >                         
O3..................................  Reference.............  Automated.............  D                          >                                 
                                                              Manual................  ..................                 >                         
                                      Equivalent............  Automated.............  ..................         >       >                         
NO2.................................  Reference.............  Automated.............  F                          >                                 
                                                              Manual................  ..................                 >                         
                                      Equivalent............  Automated.............  ..................         >       >                         
Pb..................................  Reference.............  Manual................  G                   ......  ......  ......  ......  ......  ......
                                      Equivalent............  Manual................  ..................                 >                         
PM10................................  Reference.............  Manual................  J                                          >                 
                                                              Manual................  ..................                 >       >                 
                                      Equivalent............  Automated.............  ..................                 >       >                 
PM2.5...............................  Reference.............  Manual................  L                                                  >         
                                      Equivalent Class I....  Manual................  L                                  >               >         
                                      Equivalent Class II...  Manual................  L                                  >               >       > 
                                      Equivalent Class III..  Manual or Automated...  ..................             > \1\           > \1\   > \1\ 
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Note: Because of the wide variety of potential devices possible, the specific requirements applicable to a Class III candidate equivalent method for
  PM2.5 are not specified explicitly in this part but, instead, shall be determined on a case-by-case basis for each such candidiate method.            


Appendix A to Subpart A of Part 53--References
    (1) American National Standard Quality Systems-Model for Quality 
Assurance in Design, Development, Production, Installation, and 
Servicing, ANSI/ISO/ASQC Q9001-1994. Available from American Society 
for Quality Control, 611 East Wisconsin Avenue, Milwaukee, WI 53202.
    (2) American National Standard--Specifications and Guidelines 
for Quality Systems for Environmental Data Collection and 
Environmental Technology Programs, ANSI/ASQC E41994. Available from 
American Society for Quality Control, 611 East Wisconsin Avenue, 
Milwaukee, WI 53202.
    (3) Dimensioning and Tolerancing, ASME Y14.5M-1994. Available 
from the American Society of Mechanical Engineers, 345 East 47th 
Street, New York, NY 10017.
    (4) Mathematical Definition of Dimensioning and Tolerancing 
Principles, ASME Y14.5.1M-1994. Available from the American Society 
of Mechanical Engineers, 345 East 47th Street, New York, NY 10017.
    (5) ISO 10012, Quality Assurance Requirements for Measuring 
Equipment-Part 1: Meteorological confirmation system for measuring 
equipment):1992(E). Available from American Society for Quality 
Control, 611 East Wisconsin Avenue, Milwaukee, WI 53202.
    (6) Copies of section 2.12 of the Quality Assurance Handbook for 
Air Pollution

[[Page 38792]]

Measurement Systems, Volume II, Ambient Air Specific Methods, EPA/
600/R-94/038b, are available from Department E (MD-77B), U.S. EPA, 
Research Triangle Park, NC 27711.
    c. Subpart C is revised to read as follows:
Subpart C--Procedures for Determining Comparability Between Candidate 
Methods and Reference Methods
Sec.
53.30   General provisions.
53.31   Test conditions.
53.32   Test procedures for methods for SO2, CO, 
O3, and NO2.
53.33   Test procedure for methods for lead.
53.34   Test procedure for methods for PM10 and 
PM2.5.
Tables to Subpart C of Part 53
Table C-1.--Test Concentration Ranges, Number of Measurements 
Required, and Maximum Discrepancy Specification
Table C-2.--Sequence of Test Measurements
Table C-3.--Test Specifications for Lead Methods
Table C-4.--Test Specifications for PM10 and 
PM2.5 Methods
Figures to Subpart C of Part 53
Figure C-1.--Suggested Format for Reporting Test Results
Appendix A to Subpart C of Part 53--References

Subpart C--Procedures for Determining Comparability Between 
Candidate Methods and Reference Methods


Sec. 53.30   General provisions.

    (a) Determination of comparability. The test procedures prescribed 
in this subpart shall be used to determine if a candidate method is 
comparable to a reference method when both methods measure pollutant 
concentrations in ambient air.
    (1) Comparability is shown for SO2, CO, O3, 
and NO2 methods when the differences between:
    (i) Measurements made by a candidate manual method or by a test 
analyzer representative of a candidate automated method.
    (ii) Measurements made simultaneously by a reference method, are 
less than or equal to the values specified in the last column of Table 
C-1 of this subpart.
    (2) Comparability is shown for lead methods when the differences 
between:
    (i) Measurements made by a candidate method.
    (ii) Measurements made by the reference method on simultaneously 
collected lead samples (or the same sample, if applicable), are less 
than or equal to the value specified in Table C-3 of this subpart.
    (3) Comparability is shown for PM10 and PM2.5 
methods when the relationship between:
    (i) Measurements made by a candidate method.
    (ii) Measurements made by a reference method on simultaneously 
collected samples (or the same sample, if applicable) at each of two 
test sites, is such that the linear regression parameters (slope, 
intercept, and correlation coefficient) describing the relationship 
meet the values specified in Table C-4 of this subpart.
    (b) Selection of test sites--(1) All methods. Each test site shall 
be in a predominately urban area which can be shown to have at least 
moderate concentrations of various pollutants. The site shall be 
clearly identified and shall be justified as an appropriate test site 
with suitable supporting evidence such as maps, population density 
data, vehicular traffic data, emission inventories, pollutant 
measurements from previous years, concurrent pollutant measurements, 
and meteorological data. If approval of a proposed test site is desired 
prior to conducting the tests, a written request for approval of the 
test site or sites must be submitted prior to conducting the tests and 
must include the supporting and justification information required. The 
Administrator may exercise discretion in selecting a different site (or 
sites) for any additional tests the Administrator decides to conduct.
    (2) Methods for SO2, CO, O3, and 
NO2. All test measurements are to be made at the same test 
site. If necessary, the concentration of pollutant in the sampled 
ambient air may be augmented with artificially generated pollutant to 
facilitate measurements in the specified ranges described under 
paragraph (d)(2) of this section.
    (3) Methods for Pb. Test measurements may be made at any number of 
test sites. Augmentation of pollutant concentrations is not permitted, 
hence an appropriate test site or sites must be selected to provide 
lead concentrations in the specified range.
    (4) Methods for PM10. Test measurements must be made, or 
derived from particulate samples collected, at not less than two test 
sites, each of which must be located in a geographical area 
characterized by ambient particulate matter that is significantly 
different in nature and composition from that at the other test 
site(s). Augmentation of pollutant concentrations is not permitted, 
hence appropriate test sites must be selected to provide 
PM10 concentrations in the specified range. The tests at the 
two sites may be conducted in different calendar seasons, if 
appropriate, to provide PM10 concentrations in the specified 
ranges.
    (5) Methods for PM2.5. Augmentation of pollutant 
concentrations is not permitted, hence appropriate test sites must be 
selected to provide PM2.5 concentrations and 
PM2.5/PM10 ratios (if applicable) in the 
specified ranges.
    (i) Where only one test site is required, as specified in Table C-4 
of this subpart, the site need only meet the PM2.5 ambient 
concentration levels required by Sec. 53.34(c)(3).
    (ii) Where two sites are required, as specified in Table C-4 of 
this subpart, each site must be selected to provide the ambient 
concentration levels required by Sec. 53.34(c)(3). In addition, one 
site must be selected such that all acceptable test sample sets, as 
defined in Sec. 53.34(c)(3), have a PM2.5/PM10 
ratio of more than 0.75; the other site must be selected such that all 
acceptable test sample sets, as defined in Sec. 53.34(c)(3), have a 
PM2.5/PM10 ratio of less than 0.40. At least two 
reference method PM10 samplers shall be collocated with the 
candidate and reference method PM2.5 samplers and operated 
simultaneously with the other samplers at each test site to measure 
concurrent ambient concentrations of PM10 to determine the 
PM2.5/PM10 ratio for each sample set. The 
PM2.5/PM10 ratio for each sample set shall be the 
average of the PM2.5 concentration, as determined in 
Sec. 53.34(c)(1), divided by the average PM10 concentration, 
as measured by the PM10 samplers. The tests at the two sites 
may be conducted in different calendar seasons, if appropriate, to 
provide PM2.5 concentrations and PM2.5/
PM10 ratios in the specified ranges.
    (c) Test atmosphere. Ambient air sampled at an appropriate test 
site or sites shall be used for these tests. Simultaneous concentration 
measurements shall be made in each of the concentration ranges 
specified in Tables C-1, C-3, or C-4 of this subpart, as appropriate.
    (d) Sample collection--(1) All methods. All test concentration 
measurements or samples shall be taken in such a way that both the 
candidate method and the reference method receive air samples that are 
homogenous or as nearly identical as practical.
    (2) Methods for SO2, CO, O3, and 
NO2. Ambient air shall be sampled from a common intake and 
distribution manifold designed to deliver homogenous air samples to 
both methods. Precautions shall be taken in the design and construction 
of this manifold to minimize the removal of particulates and trace 
gases, and to ensure that identical samples reach the two methods. If 
necessary, the concentration of pollutant in the sampled ambient air 
may be augmented

[[Page 38793]]

with artificially-generated pollutant. However, at all times the air 
sample measured by the candidate and reference methods under test shall 
consist of not less than 80 percent ambient air by volume. Schematic 
drawings, physical illustrations, descriptions, and complete details of 
the manifold system and the augmentation system (if used) shall be 
submitted.
    (3) Methods for Pb, PM10 and PM2.5. The 
ambient air intake points of all the candidate and reference method 
collocated samplers for lead, PM10 or PM2.5 shall 
be positioned at the same height above the ground level, and between 2 
and 4 meters apart. The samplers shall be oriented in a manner that 
will minimize spatial and wind directional effects on sample 
collection.
    (4) PM10 methods employing the same sampling procedure 
as the reference method but a different analytical method. Candidate 
methods for PM10 which employ a sampler and sample 
collection procedure that are identical to the sampler and sample 
collection procedure specified in the reference method, but use a 
different analytical procedure, may be tested by analyzing common 
samples. The common samples shall be collected according to the sample 
collection procedure specified by the reference method and shall be 
analyzed in accordance with the analytical procedures of both the 
candidate method and the reference method.
    (e) Submission of test data and other information. All recorder 
charts, calibration data, records, test results, procedural 
descriptions and details, and other documentation obtained from (or 
pertinent to) these tests shall be identified, dated, signed by the 
analyst performing the test, and submitted. For candidate methods for 
PM2.5, all submitted information must meet the requirements 
of the ANSI/ASQC E4 Standard, sections 3.3.1, paragraphs 1 and 2 
(Reference 1 of Appendix A of this subpart).


Sec. 53.31   Test conditions.

    (a) All methods. All test measurements made or test samples 
collected by means of a sample manifold as specified in 
Sec. 53.30(d)(2) shall be at a room temperature between 20  deg.C and 
30  deg.C, and at a line voltage between 105 and 125 volts. All methods 
shall be calibrated as specified in paragraph (c) of this section prior 
to initiation of the tests.
    (b) Samplers and automated methods. (1) Setup and start-up of the 
test analyzer, test sampler(s), and reference method (if applicable) 
shall be in strict accordance with the applicable operation manual(s). 
If the test analyzer does not have an integral strip chart or digital 
data recorder, connect the analyzer output to a suitable strip chart or 
digital data recorder. This recorder shall have a chart width of at 
least 25 centimeters, a response time of 1 second or less, a deadband 
of not more than 0.25 percent of full scale, and capability of either 
reading measurements at least 5 percent below zero or offsetting the 
zero by at least 5 percent. Digital data shall be recorded at 
appropriate time intervals such that trend plots similar to a strip 
chart recording may be constructed with a similar or suitable level of 
detail.
    (2) Other data acquisition components may be used along with the 
chart recorder during the conduct of these tests. Use of the chart 
recorder is intended only to facilitate visual evaluation of data 
submitted.
    (3) Allow adequate warmup or stabilization time as indicated in the 
applicable operation manual(s) before beginning the tests.
    (c) Calibration. The reference method shall be calibrated according 
to the appropriate appendix to part 50 of this chapter (if it is a 
manual method) or according to the applicable operation manual(s) (if 
it is an automated method). A candidate manual method (or portion 
thereof) shall be calibrated, according to the applicable operation 
manual(s), if such calibration is a part of the method.
    (d) Range. (1) Except as provided in paragraph (d)(2) of this 
section, each method shall be operated in the range specified for the 
reference method in the appropriate appendix to part 50 of this chapter 
(for manual reference methods), or specified in Table B-1 of subpart B 
of this part (for automated reference methods).
    (2) For a candidate method having more than one selectable range, 
one range must be that specified in Table B-1 of subpart B of this part 
and a test analyzer representative of the method must pass the tests 
required by this subpart while operated on that range. The tests may be 
repeated for a broader range (i.e., one extending to higher 
concentrations) than the one specified in Table B-1 of subpart B of 
this part, provided that the range does not extend to concentrations 
more than two times the upper range limit specified in Table B-1 of 
subpart B of this part and that the test analyzer has passed the tests 
required by subpart B of this part (if applicable) for the broader 
range. If the tests required by this subpart are conducted or passed 
only for the range specified in Table B-1 of subpart B of this part, 
any equivalent method determination with respect to the method will be 
limited to that range. If the tests are passed for both the specified 
range and a broader range (or ranges), any such determination will 
include the broader range(s) as well as the specified range. 
Appropriate test data shall be submitted for each range sought to be 
included in such a determination.
    (e) Operation of automated methods. (1) Once the test analyzer has 
been set up and calibrated and tests started, manual adjustment or 
normal periodic maintenance as specified in the manual referred to in 
Sec. 53.4(b)(3) is permitted only every 3 days. Automatic adjustments 
which the test analyzer performs by itself are permitted at any time. 
The submitted records shall show clearly when manual adjustments were 
made and describe the operations performed.
    (2) All test measurements shall be made with the same test 
analyzer; use of multiple test analyzers is not permitted. The test 
analyzer shall be operated continuously during the entire series of 
test measurements.
    (3) If a test analyzer should malfunction during any of these 
tests, the entire set of measurements shall be repeated, and a detailed 
explanation of the malfunction, remedial action taken, and whether 
recalibration was necessary (along with all pertinent records and 
charts) shall be submitted.


Sec. 53.32   Test procedures for methods for SO2, CO, 
O3, and NO2.

    (a) Conduct the first set of simultaneous measurements with the 
candidate and reference methods:
    (1) Table C-1 of this subpart specifies the type (1- or 24-hour) 
and number of measurements to be made in each of the three test 
concentration ranges.
    (2) The pollutant concentration must fall within the specified 
range as measured by the reference method.
    (3) The measurements shall be made in the sequence specified in 
Table C-2 of this subpart, except for the 1-hour SO2 
measurements, which are all in the high range.
    (b) For each pair of measurements, determine the difference 
(discrepancy) between the candidate method measurement and reference 
method measurement. A discrepancy which exceeds the discrepancy 
specified in Table C-1 of this subpart constitutes a failure. Figure C-
1 of this subpart contains a suggested format for reporting the test 
results.
    (c) The results of the first set of measurements shall be 
interpreted as follows:

[[Page 38794]]

    (1) Zero failures. The candidate method passes the test for 
comparability.
    (2) Three or more failures. The candidate method fails the test for 
comparability.
    (3) One or two failures. Conduct a second set of simultaneous 
measurements as specified in Table C-1 of this subpart. The results of 
the combined total of first-set and second-set measurements shall be 
interpreted as follows:
    (i) One or two failures. The candidate method passes the test for 
comparability.
    (ii) Three or more failures. The candidate method fails the test 
for comparability.
    (4) For SO2, the 1-hour and 24-hour measurements shall 
be interpreted separately, and the candidate method must pass the tests 
for both 1- and 24-hour measurements to pass the test for 
comparability.
    (d) A 1-hour measurement consists of the integral of the 
instantaneous concentration over a 60-minute continuous period divided 
by the time period. Integration of the instantaneous concentration may 
be performed by any appropriate means such as chemical, electronic, 
mechanical, visual judgment, or by calculating the mean of not less 
than 12 equally spaced instantaneous readings. Appropriate allowances 
or corrections shall be made in cases where significant errors could 
occur due to characteristic lag time or rise/fall time differences 
between the candidate and reference methods. Details of the means of 
integration and any corrections shall be submitted.
    (e) A 24-hour measurement consists of the integral of the 
instantaneous concentration over a 24-hour continuous period divided by 
the time period. This integration may be performed by any appropriate 
means such as chemical, electronic, mechanical, or by calculating the 
mean of 24 sequential 1-hour measurements.
    (f) For ozone and carbon monoxide, no more than six 1-hour 
measurements shall be made per day. For sulfur dioxide, no more than 
four 1-hour measurements or one 24-hour measurement shall be made per 
day. One-hour measurements may be made concurrently with 24-hour 
measurements if appropriate.
    (g) For applicable methods, control or calibration checks may be 
performed once per day without adjusting the test analyzer or method. 
These checks may be used as a basis for a linear interpolation-type 
correction to be applied to the measurements to correct for drift. If 
such a correction is used, it shall be applied to all measurements made 
with the method, and the correction procedure shall become a part of 
the method.


Sec. 53.33   Test procedure for methods for lead.

    (a) Sample collection. Collect simultaneous 24-hour samples 
(filters) of lead at the test site or sites with both the reference and 
candidate methods until at least 10 filter pairs have been obtained. If 
the conditions of Sec. 53.30(d)(4) apply, collect at least 10 common 
samples (filters) in accordance with Sec. 53.30(d)(4) and divide each 
to form the filter pairs.
    (b) Audit samples. Three audit samples must be obtained from the 
address given in Sec. 53.4(a). The audit samples are 3/4 x 8-inch glass 
fiber strips containing known amounts of lead at the following nominal 
levels: 100 g/strip; 300 g/strip; 750 g/
strip. The true amount of lead, in total g/strip, will be 
provided with each audit sample.
    (c) Filter analysis. (1) For both the reference method samples and 
the audit samples, analyze each filter extract three times in 
accordance with the reference method analytical procedure. The analysis 
of replicates should not be performed sequentially, i.e., a single 
sample should not be analyzed three times in sequence. Calculate the 
indicated lead concentrations for the reference method samples in 
g/m3 for each analysis of each filter. Calculate 
the indicated total lead amount for the audit samples in g/
strip for each analysis of each strip. Label these test results as 
R1A, R1B, R1C, R2A, 
R2B, ..., Q1A, Q1B, Q1C, 
..., where R denotes results from the reference method samples; Q 
denotes results from the audit samples; 1, 2, 3 indicate the filter 
number, and A, B, C indicate the first, second, and third analysis of 
each filter, respectively.
    (2) For the candidate method samples, analyze each sample filter or 
filter extract three times and calculate, in accordance with the 
candidate method, the indicated lead concentrates in g/m3 
for each analysis of each filter. Label these test results as 
C1A, C1B, C2C, ..., where C denotes 
results from the candidate method. For candidate methods which provide 
a direct measurement of lead concentrations without a separable 
procedure, C1A=C1B=C1C, 
C2A=C2B=C2C, etc.
    (d) Average lead concentration. For the reference method, calculate 
the average lead concentration for each filter by averaging the 
concentrations calculated from the three analyses:

Equation 1
[GRAPHIC] [TIFF OMITTED] TR18JY97.052

where:
i is the filter number.

    (e) Acceptable filter pairs. Disregard all filter pairs for which 
the lead concentration as determined in the previous paragraph (d) of 
this section by the average of the three reference method 
determinations, falls outside the range of 0.5 to 4.0 g/
m3. All remaining filter pairs must be subjected to both of 
the following tests for precision and comparability. At least five 
filter pairs must be within the 0.5 to 4.0 g/m3 
range for the tests to be valid.
    (f) Test for precision. (1) Calculate the precision (P) of the 
analysis (in percent) for each filter and for each method, as the 
maximum minus the minimum divided by the average of the three 
concentration values, as follows:

Equation 2
[GRAPHIC] [TIFF OMITTED] TR18JY97.053

    or

Equation 3
[GRAPHIC] [TIFF OMITTED] TR18JY97.054

where:
i indicates the filter number.
    (2) If any reference method precision value (PRi) 
exceeds 15 percent, the precision of the reference method analytical 
procedure is out of control. Corrective action must be taken to 
determine the source(s) of imprecision and the reference method 
determinations must be repeated according to paragraph (c) of this 
section, or the entire test procedure (starting with paragraph (a) of 
this section) must be repeated.
    (3) If any candidate method precision value (PCi) 
exceeds 15 percent, the candidate method fails the precision test.
    (4) The candidate method passes this test if all precision values 
(i.e., all PRi's and all PCi's) are less than 15 
percent.
    (g) Test for accuracy. (1)(i) For the audit samples calculate the 
average lead concentration for each strip by averaging the 
concentrations calculated from the three analyses:

Equation 4
[GRAPHIC] [TIFF OMITTED] TR18JY97.055

where:
i is audit sample number.

[[Page 38795]]

    (ii) Calculate the percent difference (Dq) between the 
indicated lead concentration for each audit sample and the true lead 
concentration (Tq) as follows:

Equation 5
[GRAPHIC] [TIFF OMITTED] TR18JY97.056

    (2) If any difference value (Dqi) exceeds 5 
percent, the accuracy of the reference method analytical procedure is 
out of control. Corrective action must be taken to determine the source 
of the error(s) (e.g., calibration standard discrepancies, extraction 
problems, etc.) and the reference method and audit sample 
determinations must be repeated according to paragraph (c) of this 
section, or the entire test procedure (starting with paragraph (a) of 
this section) must be repeated.
    (h) Test for comparability. (1) For each filter pair, calculate all 
nine possible percent differences (D) between the reference and 
candidate methods, using all nine possible combinations of the three 
determinations (A, B, and C) for each method, as:

Equation 6
[GRAPHIC] [TIFF OMITTED] TR18JY97.057

where:
i is the filter number, and n numbers from 1 to 9 for the nine 
possible difference combinations for the three determinations for 
each method (j= A, B, C, candidate; k= A, B, C, reference).
    (2) If none of the percent differences (D) exceeds  20 
percent, the candidate method passes the test for comparability.
    (3) If one or more of the percent differences (D) exceeds 
 20 percent, the candidate method fails the test for 
comparability.
    (i) The candidate method must pass both the precision test 
(paragraph (f) of this section) and the comparability test (paragraph 
(h) of this section) to qualify for designation as an equivalent 
method.


Sec. 53.34   Test procedure for methods for PM10 and 
PM2.5.

    (a) Collocated measurements. Set up three reference method samplers 
collocated with three candidate method samplers or analyzers at each of 
the number of test sites specified in Table C-4 of this subpart. At 
each site, obtain as many sets of simultaneous PM10 or 
PM2.5 measurements as necessary (see paragraph (c)(3) of 
this section), each set consisting of three reference method and three 
candidate method measurements, all obtained simultaneously. For 
PM2.5 candidate Class II equivalent methods, at least two 
collocated PM10 reference method samplers are also required 
to obtain PM2.5/PM10 ratios for each sample set. 
Candidate PM10 method measurements shall be 24-hour 
integrated measurements; PM2.5 measurements may be either 
24- or 48-hour integrated measurements. All collocated measurements in 
a sample set must cover the same 24- or 48-hour time period. For 
samplers, retrieve the samples promptly after sample collection and 
analyze each sample according to the reference method or candidate 
method, as appropriate, and determine the PM10 or 
PM2.5 concentration in g/m3. If the 
conditions of Sec. 53.30(d)(4) apply, collect sample sets only with the 
three reference method samplers. Guidance for quality assurance 
procedures for PM2.5 methods is found in section 2.12 of the 
Quality Assurance Handbook (Reference 6 of Appendix A to subpart A of 
this part).
    (b) Sequential samplers. For sequential samplers, the sampler shall 
be configured for the maximum number of sequential samples and shall be 
set for automatic collection of all samples sequentially such that the 
test samples are collected equally, to the extent possible, among all 
available sequential channels or utilizing the full available 
sequential capability.
    (c) Test for comparability and precision. (1) For each of the 
measurement sets, calculate the average PM10 or 
PM2.5 concentration obtained with the reference method 
samplers:

Equation 7
[GRAPHIC] [TIFF OMITTED] TR18JY97.058

where:
R denotes results from the reference method;
i is the sampler number; and
j is the set.
    (2)(i)(A) For each of the measurement sets, calculate the precision 
of the reference method PM10 or PM2.5 
measurements as:

Equation 8
[GRAPHIC] [TIFF OMITTED] TR18JY97.059

    (B) If the corresponding j is below:
    80 g/m3 for PM10 methods.
    40 g/m3 for 24-hour PM2.5 at 
single test sites for Class I candidate methods.
    40 g/m3 for 24-hour PM2.5 at 
sites having PM2.5/PM10 ratios >0.75.
    30 g/m3 for 48-hour PM2.5 at 
single test sites for Class I candidate methods.
    30 g/m3 for 48-hour PM2.5 at 
sites having PM2.5/PM10 ratios >0.75.
    30 g/m3 for 24-hour PM2.5 at 
sites having PM2.5/PM10 ratios <0.40.
    20 g/m3 for 48-hour PM2.5 at 
sites having PM2.5/PM10 ratios >0.75.

    (ii) Otherwise, calculate the precision of the reference method 
PM10 or PM2.5 measurements as:

Equation 9
[GRAPHIC] [TIFF OMITTED] TR18JY97.060

    (3) If j falls outside the acceptable concentration range specified 
in Table C-4 of this subpart for any set, or if Pj or RPj, as 
applicable, exceeds the value specified in Table C-4 of this subpart 
for any set, that set of measurements shall be discarded. For each 
site, Table C-4 of this subpart specifies the minimum number of sample 
sets required for various conditions, and Sec. 53.30(b)(5) specifies 
the PM2.5/PM10 ratio requirements applicable to 
Class II candidate equivalent methods. Additional measurement sets 
shall be collected and analyzed, as necessary, to provide a minimum of 
10 acceptable measurement sets for each test site. If more than 10 
measurement sets are collected that meet the above criteria, all such 
measurement sets shall be used to demonstrate comparability.
    (4) For each of the acceptable measurement sets, calculate the 
average PM10 or PM2.5 concentration obtained with 
the candidate method samplers:

Equation 10
[GRAPHIC] [TIFF OMITTED] TR18JY97.061

where:
C denotes results from the candidate method;
i is the sampler number; and
j is the set.

    (5) For each site, plot the average PM10 or 
PM2.5 measurements obtained with the candidate method 
(Cj) against the corresponding average PM10 or 
PM2.5 measurements obtained with the reference method 
(Rj). For each site, calculate and record the linear 
regression slope and intercept, and the correlation coefficient.
    (6) If the linear regression parameters calculated under paragraph 
(c)(5) of this section meet the values specified in Table C-4 of this 
subpart for all test sites, the candidate method passes the test for 
comparability.

[[Page 38796]]

Tables to Subpart C of Part 53

                      Table C-1.--Test Concentration Ranges, Number of Measurements Required, and Maximum Discrepancy Specification                     
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                            Simultaneous Measurements Required               Maximum    
                                                                                   ----------------------------------------------------    Discrepancy  
               Pollutant                   Concentration Range Parts per Million              1-hr                      24-hr            Specification, 
                                                                                   ----------------------------------------------------     Parts per   
                                                                                     First Set    Second Set   First Set    Second Set       Million    
--------------------------------------------------------------------------------------------------------------------------------------------------------
Ozone.................................  Low 0.06 to 0.10..........................            5            6  ...........  ...........              0.02
                                        Med 0.15 to 0.25..........................            5            6  ...........  ...........               .03
                                        High 0.35 to 0.45.........................            4            6  ...........  ...........               .04
                                                                                   ---------------------------------------------------------------------
                                           Total..................................           14           18  ...........  ...........  ................
                                                                                   =====================================================================
Carbon Monoxide.......................  Low 7 to 11...............................            5            6  ...........  ...........               1.5
                                        Med 20 to 30..............................            5            6  ...........  ...........               2.0
                                        High 35 to 45.............................            4            6  ...........  ...........               3.0
                                                                                   ---------------------------------------------------------------------
                                           Total..................................           14           18  ...........  ...........  ................
                                                                                   =====================================================================
Sulfur Dioxide........................  Low 0.02 to 0.05..........................  ...........  ...........            3            3              0.02
                                        Med 0.10 to 0.15..........................  ...........  ...........            2            3               .03
                                        High 0.30 to 0.50.........................            7            8            2            2               .04
                                                                                   ---------------------------------------------------------------------
                                           Total..................................            7            8            7            8  ................
                                                                                   =====================================================================
Nitrogen Dioxide......................  Low 0.02 to 0.08..........................  ...........  ...........            3            3              0.02
                                        Med 0.10 to 0.20..........................  ...........  ...........            2            3               .03
                                        High 0.25 to 0.35.........................  ...........  ...........            2            2               .03
                                                                                   ---------------------------------------------------------------------
                                           Total..................................  ...........  ...........            7            8  ................
--------------------------------------------------------------------------------------------------------------------------------------------------------



                Table C-2.--Sequence of Test Measurements               
------------------------------------------------------------------------
                                           Concentration Range          
          Measurement           ----------------------------------------
                                      First Set           Second Set    
------------------------------------------------------------------------
1..............................  Low                 Medium             
2..............................  High                High               
3..............................  Medium              Low                
4..............................  High                High               
5..............................  Low                 Medium             
6..............................  Medium              Low                
7..............................  Low                 Medium             
8..............................  Medium              Low                
9..............................  High                High               
10.............................  Medium              Low                
11.............................  High                Medium             
12.............................  Low                 High               
13.............................  Medium              Medium             
14.............................  Low                 High               
15.............................                      Low                
16.............................                      Medium             
17.............................                      Low                
18.............................                      High               
------------------------------------------------------------------------



            Table C-3.--Test Specifications for Lead Methods            
------------------------------------------------------------------------
                                                                        
------------------------------------------------------------------------
Concentration range, g/m\3\..........................   0.5-4.0
Minimum number of 24-hr measurements..........................         5
Maximum analytical precision, percent.........................         5
Maximum analytical accuracy, percent..........................  10 and PM2.5 Methods                           
----------------------------------------------------------------------------------------------------------------
                                                                                    PM2.5                       
         Specification                      PM10           -----------------------------------------------------
                                                                     Class I                    Class II        
----------------------------------------------------------------------------------------------------------------
Acceptable concentration range   30-300...................  10-200...................  10-200                   
 (Rj), g/m3.                                                                                           
Minimum number of test sites...  2........................  1........................  2                        
Number of candidate method       3........................  3........................  3                        
 samplers per site.                                                                                             
Number of reference method       3........................  3........................  3                        
 samplers per site.                                                                                             
Minimum number of acceptable                                                                                    
 sample sets per site for PM10:                                                                                 
    Rj < 80 g/m3......  3........................  .........................  .........................
    Rj > 80 g/m3......  3........................  .........................  .........................
        Total..................  10.......................  .........................  .........................
Minimum number of acceptable                                                                                    
 sample sets per site for                                                                                       
 PM2.5:                                                                                                         
    Single test site for Class                                                                                  
     I candidate equivalent                                                                                     
     methods:                                                                                                   
        Rj < 40 g/m3      .......................  3........................  .........................
         for 24-hr or Rj < 30                                                                                   
         g/m3 for 48-                                                                                  
         hr samples.                                                                                            
        Rj > 40 g/m3      .......................  3........................  .........................
         for 24-hr or Rj > 30                                                                                   
         g/m3 for 48-                                                                                  
         hr samples.                                                                                            
    Sites at which the PM2.5/                                                                                   
     PM10 ratio must be > 0.75:                                                                                 
        Rj < 40 g/m3      .......................  .........................  3                        
         for 24-hr or Rj < 30                                                                                   
         g/m3 for 48-                                                                                  
         hr samples.                                                                                            
        Rj > 40 g/m3      .......................  .........................  3                        
         for 24-hr or Rj > 30                                                                                   
         g/m3 for 48-                                                                                  
         hr samples.                                                                                            
    Sites at which the PM2.5/                                                                                   
     PM10 ratio must be < 0.40:                                                                                 
        Rj < 30 g/m3      .......................  .........................  3                        
         for 24-hr or Rj < 20                                                                                   
         g/m3 for 48-                                                                                  
         hr samples.                                                                                            

[[Page 38797]]

                                                                                                                
        Rj > 30 g/m3      .......................  .........................  3                        
         for 24-hr or Rj > 20                                                                                   
         g/m3 for 48-                                                                                  
         hr samples.                                                                                            
Total, each site...............    .......................  10.......................  10                       
Precision of replicate           5 g/m3 or 7%....  2 g/m3 or 5%....  2 g/m3 or 5%    
 reference method measurements,                                                                                 
 Pj or RPj respectively,                                                                                        
 maximum.                                                                                                       
Slope of regression              10.1.........  10.05........  10.05        
 relationship.                                                                                                  
Intercept of regression          05...........  01...........  01           
 relationship, g/m3.                                                                                   
Correlation of reference method  0.97..........  0.97..........  0.97          
 and candidate method                                                                                           
 measurements.                                                                                                  
----------------------------------------------------------------------------------------------------------------


[[Page 38798]]

Figures to Subpart C of Part 53

                                                                    Figure C-1.--Suggested Format for Reporting Test Results                                                                    
                                                          Candidate Method------------------------------------------------------------                                                          
                                                          Reference Method------------------------------------------------------------                                                          
                                                         Applicant----------------------------------------------------------------------                                                        
                                                                    First Set      Second Set      Type     1 Hour      24 Hour                                                                 
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                        Concentration, ppm                                                                      
       Concentration Range                                   Date                Time        ----------------------------------------     Difference        Table C-1 Spec.      Pass or Fail   
                                                                                                   Candidate           Reference                                                                
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
               Low                1                                                                                                                                                             
         ---------- ppm                                                                                                                                                                         
         to -------- ppm                                                                                                                                                                        
                                 ---------------------------------------------------------------------------------------------------------------------------------------------------------------
                                  2                                                                                                                                                             
                                 ---------------------------------------------------------------------------------------------------------------------------------------------------------------
                                  3                                                                                                                                                             
                                 ---------------------------------------------------------------------------------------------------------------------------------------------------------------
                                  4                                                                                                                                                             
                                 ---------------------------------------------------------------------------------------------------------------------------------------------------------------
                                  5                                                                                                                                                             
                                 ---------------------------------------------------------------------------------------------------------------------------------------------------------------
                                  6                                                                                                                                                             
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
             Medium               1                                                                                                                                                             
         ---------- ppm                                                                                                                                                                         
         to -------- ppm                                                                                                                                                                        
                                 ---------------------------------------------------------------------------------------------------------------------------------------------------------------
                                  2                                                                                                                                                             
                                 ---------------------------------------------------------------------------------------------------------------------------------------------------------------
                                  3                                                                                                                                                             
                                 ---------------------------------------------------------------------------------------------------------------------------------------------------------------
                                  4                                                                                                                                                             
                                 ---------------------------------------------------------------------------------------------------------------------------------------------------------------
                                  5                                                                                                                                                             
                                 ---------------------------------------------------------------------------------------------------------------------------------------------------------------
                                  6                                                                                                                                                             
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
              High                1                                                                                                                                                             
         ---------- ppm                                                                                                                                                                         
         to -------- ppm                                                                                                                                                                        
                                 ---------------------------------------------------------------------------------------------------------------------------------------------------------------
                                  2                                                                                                                                                             
                                 ---------------------------------------------------------------------------------------------------------------------------------------------------------------
                                  3                                                                                                                                                             
                                 ---------------------------------------------------------------------------------------------------------------------------------------------------------------
                                  4                                                                                                                                                             
                                 ---------------------------------------------------------------------------------------------------------------------------------------------------------------
                                  5                                                                                                                                                             
                                 ---------------------------------------------------------------------------------------------------------------------------------------------------------------
                                  6                                                                                                                                                             
                                 ---------------------------------------------------------------------------------------------------------------------------------------------------------------
                                  7                                                                                                                                                             
                                 ---------------------------------------------------------------------------------------------------------------------------------------------------------------
                                  8                                                                                                                                                             
                                 ---------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                                          Total                                 
                                                                                                                                                          Failures:                             
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------


[[Page 38799]]

Appendix A to Subpart C of Part 53--References
    (1) American National Standard--Specifications and Guidelines 
for Quality Systems for Environmental Data Collection and 
Environmental Technology Programs, ANSI/ASQC E4-1994. Available from 
American Society for Quality Control, 611 East Wisconsin Avenue, 
Milwaukee, WI 53202.
    d. Subpart E is added to read as follows:
Subpart E--Procedures for Testing Physical (Design) and Performance 
Characteristics of Reference Methods and Class I Equivalent Methods for 
PM2.5
Sec.
53.50   General provisions.
53.51   Demonstration of compliance with design specifications and 
manufacturing and test requirements.
53.52   Leak check test.
53.53   Test for flow rate accuracy, regulation, measurement 
accuracy, and cut-off.
53.54   Test for proper sampler operation following power 
interruptions.
53.55   Test for effect of variations in power line voltage and 
ambient temperature.
53.56   Test for effect of variations in ambient pressure.
53.57   Test for filter temperature control during sampling and 
post-sampling periods.
53.58   Operational field precision and blank test.
53.59   Aerosol transport test for Class I equivalent method 
samplers.
Tables to Subpart E of Part 53
Table E-1.--Summary of Test Requirements for Reference and Class I 
Equivalent Methods for PM2.5.
Table E-2.--Spectral Energy Distribution and Permitted Tolerance for 
Conducting Radiative Tests.
Figures to Subpart E of Part 53
Figure E-1--Designation Testing Checklist
Figure E-2--Product Manufacturing Checklist
Appendix A to Subpart E of Part 53--References

Subpart E--Procedures for Testing Physical (Design) and Performance 
Characteristics of Reference Methods and Class I Equivalent Methods 
for PM2.5


Sec. 53.50   General provisions.

    (a) This subpart sets forth the specific tests that must be carried 
out and the test results, evidence, documentation, and other materials 
that must be provided to EPA to demonstrate that a PM2.5 
sampler associated with a candidate reference method or Class I 
equivalent method meets all design and performance specifications set 
forth in 40 CFR part 50, Appendix L, as well as additional requirements 
specified in this subpart E. Some of these tests may also be applicable 
to portions of a candidate Class II equivalent method sampler, as 
determined under subpart F of this part. Some or all of these tests may 
also be applicable to a candidate Class III equivalent method sampler, 
as may be determined under Sec. 53.3(a)(4) or Sec. 53.3(b)(3).
    (b) Samplers associated with candidate reference methods for 
PM2.5 shall be subject to the provisions, specifications, 
and test procedures prescribed in Secs. 53.51 through 53.58. Samplers 
associated with candidate Class I equivalent methods for 
PM2.5 shall be subject to the provisions, specifications, 
and test procedures prescribed in all sections of this subpart. 
Samplers associated with candidate Class II equivalent methods for 
PM2.5 shall be subject to the provisions, specifications, 
and test procedures prescribed in all applicable sections of this 
subpart, as specified in subpart F of this part.
    (c) The provisions of Sec. 53.51 pertain to test results and 
documentation required to demonstrate compliance of a candidate method 
sampler with the design specifications set forth in 40 CFR part 50, 
Appendix L. The test procedures prescribed in Secs. 53.52 through 53.59 
pertain to performance tests required to demonstrate compliance of a 
candidate method sampler with the performance specifications set forth 
in 40 CFR part 50, Appendix L, as well as additional requirements 
specified in this subpart E. These latter test procedures shall be used 
to test the performance of candidate samplers against the performance 
specifications and requirements specified in each procedure and 
summarized in Table E-1 of this subpart.
    (d) Test procedures prescribed in Sec. 53.59 do not apply to 
candidate reference method samplers. These procedures apply primarily 
to candidate Class I equivalent method samplers for PM2.5 
which have a sample air flow path configuration upstream of the sample 
filter that is modified with respect to that specified for the 
reference method sampler, as set forth in 40 CFR part 50, Appendix L, 
Figures L-1 to L-29, such as might be necessary to provide for 
sequential sample capability. The additional tests determine the 
adequacy of aerosol transport through any altered components or 
supplemental devices that are used in a candidate sampler upstream of 
the sample filter. In addition to the other test procedures in this 
subpart, these test procedures shall be used to further test the 
performance of such an equivalent method sampler against the 
performance specifications given in the procedure and summarized in 
Table E-1 of this subpart.
    (e) A 10-day operational field test of measurement precision is 
required under Sec. 53.58 for both candidate reference and equivalent 
method samplers. This test requires collocated operation of three 
candidate method samplers at a field test site. For candidate 
equivalent method samplers, this test may be combined and carried out 
concurrently with the test for comparability to the reference method 
specified under Sec. 53.34, which requires collocated operation of 
three reference method samplers and three candidate equivalent method 
samplers.
    (f) All tests and collection of test data shall be performed in 
accordance with the requirements of Reference 1, section 4.10.5 (ISO 
9001) and Reference 2, Part B, section 3.3.1, paragraphs 1 and 2 and 
Part C, section 4.6 (ANSI/ASQC E4) in Appendix A of this subpart. All 
test data and other documentation obtained specifically from or 
pertinent to these tests shall be identified, dated, signed by the 
analyst performing the test, and submitted to EPA in accordance with 
subpart A of this part.


Sec. 53.51   Demonstration of compliance with design specifications and 
manufacturing and test requirements.

    (a) Overview. (1) The subsequent paragraphs of this section specify 
certain documentation that must be submitted and tests that are 
required to demonstrate that samplers associated with a designated 
reference or equivalent method for PM2.5 are properly 
manufactured to meet all applicable design and performance 
specifications and have been properly tested according to all 
applicable test requirements for such designation. Documentation is 
required to show that instruments and components of a PM2.5 
sampler are manufactured in an ISO 9001-registered facility under a 
quality system that meets ISO-9001 requirements for manufacturing 
quality control and testing.
    (2) In addition, specific tests are required to verify that two 
critical features of reference method samplers impactor jet diameter 
and the surface finish of surfaces specified to be anodized meet the 
specifications of 40 CFR part 50, Appendix L. A checklist is required 
to provide certification by an ISO-certified auditor that all 
performance and other required tests have been properly and 
appropriately conducted, based on a reasonable and appropriate sample 
of the actual operations or their documented records. Following 
designation of the method, another checklist is required, initially

[[Page 38800]]

and annually, to provide an ISO-certified auditor's certification that 
the sampler manufacturing process is being implemented under an 
adequate and appropriate quality system.
    (3) For the purposes of this section, the definitions of ISO 9001-
registered facility and ISO-certified auditor are found in Sec. 53.1. 
An exception to the reliance by EPA on ISO affiliate audits is the 
requirement for the submission of the operation or instruction manual 
associated with the candidate method to EPA as part of the application. 
This manual is required under Sec. 53.4(b)(3). EPA has determined that 
acceptable technical judgment for review of this manual may not be 
assured by ISO affiliates, and approval of this manual will therefore 
be performed by EPA.
    (b) ISO registration of manufacturing facility. (1) The applicant 
must submit documentation verifying that the samplers identified and 
sold as part of a designated PM2.5 reference or equivalent 
method will be manufactured in an ISO 9001-registered facility and that 
the manufacturing facility is maintained in compliance with all 
applicable ISO 9001 requirements (Reference 1 in Appendix A of this 
subpart). The documentation shall indicate the date of the original ISO 
9001 registration for the facility and shall include a copy of the most 
recent certification of continued ISO 9001 facility registration. If 
the manufacturer does not wish to initiate or complete ISO 9001 
registration for the manufacturing facility, documentation must be 
included in the application to EPA describing an alternative method to 
demonstrate that the facility meets the same general requirements as 
required for registration to ISO-9001. In this case, the applicant must 
provide documentation in the application to demonstrate, by required 
ISO-certified auditor's inspections, that a quality system is in place 
which is adequate to document and monitor that the sampler system 
components and final assembled samplers all conform to the design, 
performance and other requirements specified in this part and in 40 CFR 
part 50, Appendix L.
    (2) Phase-in period. For a period of 1 year following the effective 
date of this subpart, a candidate reference or equivalent method for 
PM2.5 that utilizes a sampler manufactured in a facility 
that is not ISO 9001-registered or otherwise approved by EPA under 
paragraph (b)(1) of this section may be conditionally designated as a 
reference or equivalent method under this part. Such conditional 
designation will be considered on the basis of evidence submitted in 
association with the candidate method application showing that 
appropriate efforts are currently underway to seek ISO 9001 
registration or alternative approval of the facility's quality system 
under paragraph (b)(1) of this section within the next 12 months. Such 
conditional designation shall expire 1 year after the date of the 
Federal Register notice of the conditional designation unless 
documentation verifying successful ISO 9001 registration for the 
facility or other EPA-acceptable quality system review and approval 
process of the production facility that will manufacture the samplers 
is submitted at least 30 days prior to the expiration date.
    (c) Sampler manufacturing quality control. The manufacturer must 
ensure that all components used in the manufacture of PM2.5 
samplers to be sold as part of a reference or equivalent method and 
that are specified by design in 40 CFR part 50, Appendix L, are 
fabricated or manufactured exactly as specified. If the manufacturer's 
quality records show that its quality control (QC) and quality 
assurance (QA) system of standard process control inspections (of a set 
number and frequency of testing that is less than 100 percent) complies 
with the applicable QA provisions of section 4 of Reference 4 in 
Appendix A of this subpart and prevents nonconformances, 100 percent 
testing shall not be required until that conclusion is disproved by 
customer return or other independent manufacturer or customer test 
records. If problems are uncovered, inspection to verify conformance to 
the drawings, specifications, and tolerances shall be performed. Refer 
also to paragraph (e) of this section--final assembly and inspection 
requirements.
    (d) Specific tests and supporting documentation required to verify 
conformance to critical component specifications.--(1) Verification of 
PM2.5 impactor jet diameter. The diameter of the jet of each 
impactor manufactured for a PM2.5 sampler under the impactor 
design specifications set forth in 40 CFR part 50, Appendix L, shall be 
verified against the tolerance specified on the drawing, using 
standard, NIST-traceable ZZ go/no go plug gages. This test shall be a 
final check of the jet diameter following all fabrication operations, 
and a record shall be kept of this final check. The manufacturer shall 
submit evidence that this procedure is incorporated into the 
manufacturing procedure, that the test is or will be routinely 
implemented, and that an appropriate procedure is in place for the 
disposition of units that fail this tolerance test.
    (2) Verification of surface finish. The anodization process used to 
treat surfaces specified to be anodized shall be verified by testing 
treated specimen surfaces for weight and corrosion resistance to ensure 
that the coating obtained conforms to the coating specification. The 
specimen surfaces shall be finished in accordance with military 
standard specification 8625F, Type II, Class I (Reference 4 in Appendix 
A of this subpart) in the same way the sampler surfaces are finished, 
and tested, prior to sealing, as specified in section 4.5.2 of 
Reference 4 in Appendix A of this subpart.
    (e) Final assembly and inspection requirements. Each sampler shall 
be tested after manufacture and before delivery to the final user. Each 
manufacturer shall document its post-manufacturing test procedures. As 
a minimum, each test shall consist of the following: Tests of the 
overall integrity of the sampler, including leak tests; calibration or 
verification of the calibration of the flow measurement device, 
barometric pressure sensor, and temperature sensors; and operation of 
the sampler with a filter in place over a period of at least 48 hours. 
The results of each test shall be suitably documented and shall be 
subject to review by an ISO-certified auditor.
    (f) Manufacturer's audit checklists. Manufacturers shall require an 
ISO-certified auditor to sign and date a statement indicating that the 
auditor is aware of the appropriate manufacturing specifications 
contained in 40 CFR part 50, Appendix L, and the test or verification 
requirements in this subpart. Manufacturers shall also require an ISO-
certified auditor to complete the checklists, shown in Figures E-1 and 
E-2 of this subpart, which describe the manufacturer's ability to meet 
the requirements of the standard for both designation testing and 
product manufacture.
    (1) Designation testing checklist. The completed statement and 
checklist as shown in Figure E-1 of this subpart shall be submitted 
with the application for reference or equivalent method determination.
    (2) Product manufacturing checklist. Manufacturers shall require an 
ISO-certified auditor to complete a Product Manufacturing Checklist 
(Figure E-2 of this subpart), which evaluates the manufacturer on its 
ability to meet the requirements of the standard in maintaining quality 
control in the production of reference or equivalent devices. The 
initial completed checklist shall be submitted with the application for 
reference or equivalent method determination. Also, this checklist 
(Figure E-2 of this subpart) must be completed and submitted annually 
to

[[Page 38801]]

retain a reference or equivalent method designation for a 
PM2.5 method.
    (3) Phase-in period. If the conditions of paragraph (b)(2) of this 
section apply, a candidate reference or equivalent method for 
PM2.5 may be conditionally designated as a reference or 
equivalent method under this part 53 without the submission of the 
checklists described in paragraphs (f)(1) and (f)(2) of this section. 
Such conditional designation shall expire 1 year after the date of the 
Federal Register notice of the conditional designation unless the 
checklists are submitted at least 30 days prior to the expiration date.


Sec. 53.52   Leak check test.

    (a) Overview. In section 7.4.6 of 40 CFR part 50, Appendix L, the 
sampler is required to include the facility, including components, 
instruments, operator controls, a written procedure, and other 
capabilities as necessary, to allow the operator to carry out a leak 
test of the sampler at a field monitoring site without additional 
equipment. This test procedure is intended to test the adequacy and 
effectiveness of the sampler's leak check facility. Because of the 
variety of potential sampler configurations and leak check procedures 
possible, some adaptation of this procedure may be necessary to 
accommodate the specific sampler under test. The test conditions and 
performance specifications associated with this test are summarized in 
Table E-1 of this subpart. The candidate test sampler must meet all 
test parameters and test specifications to successfully pass this test.
    (b) Technical definitions. (1) External leakage includes the total 
flow rate of external ambient air which enters the sampler other than 
through the sampler inlet and which passes through any one or more of 
the impactor, filter, or flow rate measurement components.
    (2) Internal leakage is the total sample air flow rate that passes 
through the filter holder assembly without passing through the sample 
filter.
    (c) Required test equipment. (1) Flow rate measurement device, 
range 70 mL/min to 130 mL/min, 2 percent certified accuracy, NIST-
traceable.
    (2) Flow rate measurement adaptor (40 CFR part 50, Appendix L, 
Figure L-30) or equivalent adaptor to facilitate measurement of sampler 
flow rate at the top of the downtube.
    (3) Impermeable membrane or disk, 47 mm nominal diameter.
    (4) Means, such as a micro-valve, of providing a simulated leak 
flow rate through the sampler of approximately 80 mL/min under the 
conditions specified for the leak check in the sampler's leak check 
procedure.
    (5) Teflon sample filter, as specified in section 6 of 40 CFR part 
50, Appendix L.
    (d) Calibration of test measurement instruments. Submit 
documentation showing evidence of appropriately recent calibration, 
certification of calibration accuracy, and NIST-traceability (if 
required) of all measurement instruments used in the tests. The 
accuracy of flow rate meters shall be verified at the highest and 
lowest pressures and temperatures used in the tests and shall be 
checked at zero and one or more non-zero flow rates within 7 days of 
use for this test.
    (e) Test setup. (1) The test sampler shall be set up for testing as 
described in the sampler's operation or instruction manual referred to 
in Sec. 53.4(b)(3). The sampler shall be installed upright and set up 
in its normal configuration for collecting PM2.5 samples, 
except that the sample air inlet shall be removed and the flow rate 
measurement adaptor shall be installed on the sampler's downtube.
    (2) The flow rate control device shall be set up to provide a 
constant, controlled flow rate of 80 mL/min into the sampler downtube 
under the conditions specified for the leak check in the sampler's leak 
check procedure.
    (3) The flow rate measurement device shall be set up to measure the 
controlled flow rate of 80 mL/min into the sampler downtube under the 
conditions specified for the leak check in the sampler's leak check 
procedure.
    (f) Procedure. (1) Install the impermeable membrane in a filter 
cassette and install the cassette into the sampler. Carry out the 
internal leak check procedure as described in the sampler's operation/
instruction manual and verify that the leak check acceptance criterion 
specified in Table E-1 of this subpart is met.
    (2) Replace the impermeable membrane with a Teflon filter and 
install the cassette in the sampler. Remove the inlet from the sampler 
and install the flow measurement adaptor on the sampler's downtube. 
Close the valve of the adaptor to seal the flow system. Conduct the 
external leak check procedure as described in the sampler's operation/
instruction manual and verify that the leak check acceptance criteria 
specified in Table E-1 of this subpart are met.
    (3) Arrange the flow control device, flow rate measurement device, 
and other apparatus as necessary to provide a simulated leak flow rate 
of 80 mL/min into the test sampler through the downtube during the 
specified external leak check procedure. Carry out the external leak 
check procedure as described in the sampler's operation/instruction 
manual but with the simulated leak of 80 mL/min.
    (g) Test results. The requirements for successful passage of this 
test are:
    (1) That the leak check procedure indicates no significant external 
or internal leaks in the test sampler when no simulated leaks are 
introduced.
    (2) That the leak check procedure properly identifies the 
occurrence of the simulated external leak of 80 mL/min.


Sec. 53.53   Test for flow rate accuracy, regulation, measurement 
accuracy, and cut-off.

    (a) Overview. This test procedure is designed to evaluate a 
candidate sampler's flow rate accuracy with respect to the design flow 
rate, flow rate regulation, flow rate measurement accuracy, coefficient 
of variability measurement accuracy, and the flow rate cut-off 
function. The tests for the first four parameters shall be conducted 
over a 6-hour time period during which reference flow measurements are 
made at intervals not to exceed 5 minutes. The flow rate cut-off test, 
conducted separately, is intended to verify that the sampler carries 
out the required automatic sample flow rate cut-off function properly 
in the event of a low-flow condition. The test conditions and 
performance specifications associated with this test are summarized in 
Table E-1 of this subpart. The candidate test sampler must meet all 
test parameters and test specifications to successfully pass this test.
    (b) Technical definitions. (1) Sample flow rate means the 
quantitative volumetric flow rate of the air stream caused by the 
sampler to enter the sampler inlet and pass through the sample filter, 
measured in actual volume units at the temperature and pressure of the 
air as it enters the inlet.
    (2) The flow rate cut-off function requires the sampler to 
automatically stop sample flow and terminate the current sample 
collection if the sample flow rate deviates by more than the variation 
limits specified in Table E-1 of this subpart (10 percent 
from the nominal sample flow rate) for more than 60 seconds during a 
sample collection period. The sampler is also required to properly 
notify the operator with a flag warning indication of the out-of-
specification flow rate condition and if the flow rate cut-off results 
in an elapsed sample collection time of less than 23 hours.
    (c) Required test equipment. (1) Flow rate meter, suitable for 
measuring and recording the actual volumetric sample flow rate at the 
sampler downtube, with

[[Page 38802]]

a minimum range of 10 to 25 L/min, 2 percent certified, NIST-traceable 
accuracy. Optional capability for continuous (analog) recording 
capability or digital recording at intervals not to exceed 30 seconds 
is recommended. While a flow meter which provides a direct indication 
of volumetric flow rate is preferred for this test, an alternative 
certified flow measurement device may be used as long as appropriate 
volumetric flow rate corrections are made based on measurements of 
actual ambient temperature and pressure conditions.
    (2) Ambient air temperature sensor, with a resolution of 0.1  deg.C 
and certified to be accurate to within 0.5  deg.C (if needed). If the 
certified flow meter does not provide direct volumetric flow rate 
readings, ambient air temperature measurements must be made using 
continuous (analog) recording capability or digital recording at 
intervals not to exceed 5 minutes.
    (3) Barometer, range 600 mm Hg to 800 mm Hg, certified accurate to 
2 mm Hg (if needed). If the certified flow meter does not provide 
direct volumetric flow rate readings, ambient pressure measurements 
must be made using continuous (analog) recording capability or digital 
recording at intervals not to exceed 5 minutes.
    (4) Flow measurement adaptor (40 CFR part 50, Appendix L, Figure L-
30) or equivalent adaptor to facilitate measurement of sample flow rate 
at the sampler downtube.
    (5) Valve or other means to restrict or reduce the sample flow rate 
to a value at least 10 percent below the design flow rate (16.67 L/
min). If appropriate, the valve of the flow measurement adaptor may be 
used for this purpose.
    (6) Means for creating an additional pressure drop of 55 mm Hg in 
the sampler to simulate a heavily loaded filter, such as an orifice or 
flow restrictive plate installed in the filter holder or a valve or 
other flow restrictor temporarily installed in the flow path near the 
filter.
    (7) Teflon sample filter, as specified in section 6 of 40 CFR part 
50, Appendix L (if required).
    (d) Calibration of test measurement instruments. Submit 
documentation showing evidence of appropriately recent calibration, 
certification of calibration accuracy, and NIST-traceability (if 
required) of all measurement instruments used in the tests. The 
accuracy of flow-rate meters shall be verified at the highest and 
lowest pressures and temperatures used in the tests and shall be 
checked at zero and at least one flow rate within 3 percent 
of 16.7 L/min within 7 days prior to use for this test. Where an 
instrument's measurements are to be recorded with an analog recording 
device, the accuracy of the entire instrument-recorder system shall be 
calibrated or verified.
    (e) Test setup. (1) Setup of the sampler shall be as required in 
this paragraph (e) and otherwise as described in the sampler's 
operation or instruction manual referred to in Sec. 53.4(b)(3). The 
sampler shall be installed upright and set up in its normal 
configuration for collecting PM2.5 samples. A sample filter 
and (or) the device for creating an additional 55 mm Hg pressure drop 
shall be installed for the duration of these tests. The sampler's 
ambient temperature, ambient pressure, and flow rate measurement 
systems shall all be calibrated per the sampler's operation or 
instruction manual within 7 days prior to this test.
    (2) The inlet of the candidate sampler shall be removed and the 
flow measurement adaptor installed on the sampler's downtube. A leak 
check as described in the sampler's operation or instruction manual 
shall be conducted and must be properly passed before other tests are 
carried out.
    (3) The inlet of the flow measurement adaptor shall be connected to 
the outlet of the flow rate meter.
    (4) For the flow rate cut-off test, the valve or means for reducing 
sampler flow rate shall be installed between the flow measurement 
adaptor and the downtube or in another location within the sampler such 
that the sampler flow rate can be manually restricted during the test.
    (f) Procedure. (1) Set up the sampler as specified in paragraph (e) 
of this section and otherwise prepare the sampler for normal sample 
collection operation as directed in the sampler's operation or 
instruction manual. Set the sampler to automatically start a 6-hour 
sample collection period at a convenient time.
    (2) During the 6-hour operational flow rate portion of the test, 
measure and record the sample flow rate with the flow rate meter at 
intervals not to exceed 5 minutes. If ambient temperature and pressure 
corrections are necessary to calculate volumetric flow rate, ambient 
temperature and pressure shall be measured at the same frequency as 
that of the certified flow rate measurements. Note and record the 
actual start and stop times for the 6-hour flow rate test period.
    (3) Following completion of the 6-hour flow rate test period, 
install the flow rate reduction device and change the sampler flow rate 
recording frequency to intervals of not more than 30 seconds. Reset the 
sampler to start a new sample collection period. Manually restrict the 
sampler flow rate such that the sampler flow rate is decreased slowly 
over several minutes to a flow rate slightly less than the flow rate 
cut-off value (15.0 L/min). Maintain this flow rate for at least 2.0 
minutes or until the sampler stops the sample flow automatically. 
Manually terminate the sample period, if the sampler has not terminated 
it automatically.
    (g) Test results. At the completion of the test, validate the test 
conditions and determine the test results as follows:
    (1) Mean sample flow rate. (i) From the certified measurements 
(Qref) of the test sampler flow rate obtained by use of the 
flow rate meter, tabulate each flow rate measurement in units of L/min. 
If ambient temperature and pressure corrections are necessary to 
calculate volumetric flow rate, each measured flow rate shall be 
corrected using its corresponding temperature and pressure measurement 
values. Calculate the mean flow rate for the sample period 
(Qref,ave) as follows:

Equation 1
[GRAPHIC] [TIFF OMITTED] TR18JY97.063

where:
n equals the number of discrete certified flow rate measurements 
over the 6-hour test period.

    (ii)(A) Calculate the percent difference between this mean flow 
rate value and the design value of 16.67 L/min, as follows:

Equation 2
[GRAPHIC] [TIFF OMITTED] TR18JY97.064

    (B) To successfully pass the mean flow rate test, the percent 
difference calculated in Equation 2 of this paragraph (g)(1)(ii) must 
be within 5 percent.
    (2) Sample flow rate regulation. (i) From the certified 
measurements of the test sampler flow rate, calculate the sample 
coefficient of variation (CV) of the discrete measurements as follows:

Equation 3
[GRAPHIC] [TIFF OMITTED] TR18JY97.065

    (ii) To successfully pass the flow rate regulation test, the 
calculated coefficient of variation for the certified flow rates must 
not exceed 2 percent.

[[Page 38803]]

    (3) Flow rate measurement accuracy. (i) Using the mean volumetric 
flow rate reported by the candidate test sampler at the completion of 
the 6-hour test period (Qind,ave), determine the accuracy of 
the reported mean flow rate as:

Equation 4
[GRAPHIC] [TIFF OMITTED] TR18JY97.066

    (ii) To successfully pass the flow rate measurement accuracy test, 
the percent difference calculated in Equation 4 of this paragraph 
(g)(3) shall not exceed 2 percent.
    (4) Flow rate coefficient of variation measurement accuracy. (i) 
Using the flow rate coefficient of variation indicated by the candidate 
test sampler at the completion of the 6-hour test (%CVind), 
determine the accuracy of this reported coefficient of variation as:

Equation 5
[GRAPHIC] [TIFF OMITTED] TR18JY97.067

    (ii) To successfully pass the flow rate CV measurement accuracy 
test, the absolute difference in values calculated in Equation 5 of 
this paragraph (g)(4) must not exceed 0.3 (CV%).
    (5) Flow rate cut-off. (i) Inspect the measurements of the sample 
flow rate during the flow rate cut-off test and determine the time at 
which the sample flow rate decreased to a value less than the cut-off 
value specified in Table E-1 of this subpart. To pass this test, the 
sampler must have automatically stopped the sample flow at least 30 
seconds but not more than 90 seconds after the time at which the 
sampler flow rate was determined to have decreased to a value less than 
the cut-off value.
    (ii) At the completion of the flow rate cut-off test, download the 
archived data from the test sampler and verify that the sampler's 
required Flow-out-of-spec and Incorrect sample period flag indicators 
are properly set.


Sec. 53.54   Test for proper sampler operation following power 
interruptions.

    (a) Overview. (1) This test procedure is designed to test certain 
performance parameters of the candidate sampler during a test period in 
which power interruptions of various duration occur. The performance 
parameters tested are:
    (i) Proper flow rate performance of the sampler.
    (ii) Accuracy of the sampler's average flow rate, CV, and sample 
volume measurements.
    (iii) Accuracy of the sampler's reported elapsed sampling time.
    (iv) Accuracy of the reported time and duration of power 
interruptions.
    (2) This test shall be conducted during operation of the test 
sampler over a continuous 6-hour test period during which the sampler's 
flow rate shall be measured and recorded at intervals not to exceed 5 
minutes. The performance parameters tested under this procedure, the 
corresponding minimum performance specifications, and the applicable 
test conditions are summarized in Table E-1 of this subpart. Each 
performance parameter tested, as described or determined in the test 
procedure, must meet or exceed the associated performance specification 
to successfully pass this test.
    (b) Required test equipment. (1) Flow rate meter, suitable for 
measuring and recording the actual volumetric sample flow rate at the 
sampler downtube, with a minimum range of 10 to 25 L/min, 2 percent 
certified, NIST-traceable accuracy. Optional capability for continuous 
(analog) recording capability or digital recording at intervals not to 
exceed 5 minutes is recommended. While a flow meter which provides a 
direct indication of volumetric flow rate is preferred for this test, 
an alternative certified flow measurement device may be used as long as 
appropriate volumetric flow rate corrections are made based on 
measurements of actual ambient temperature and pressure conditions.
    (2) Ambient air temperature sensor (if needed for volumetric 
corrections to flow rate measurements), with a resolution of 0.1 
deg.C, certified accurate to within 0.5  deg.C, and continuous (analog) 
recording capability or digital recording at intervals not to exceed 5 
minutes.
    (3) Barometer (if needed for volumetric corrections to flow rate 
measurements), range 600 mm Hg to 800 mm Hg, certified accurate to 2 mm 
Hg, with continuous (analog) recording capability or digital recording 
at intervals not to exceed 5 minutes.
    (4) Flow measurement adaptor (40 CFR part 50, Appendix L, Figure L-
30) or equivalent adaptor to facilitate measurement of sample flow rate 
at the sampler downtube.
    (5) Means for creating an additional pressure drop of 55 mm Hg in 
the sampler to simulate a heavily loaded filter, such as an orifice or 
flow restrictive plate installed in the filter holder or a valve or 
other flow restrictor temporarily installed in the flow path near the 
filter.
    (6) Teflon sample filter, as specified in section 6 of 40 CFR part 
50, Appendix L (if required).
    (7) Time measurement system, accurate to within 10 seconds per day.
    (c) Calibration of test measurement instruments. Submit 
documentation showing evidence of appropriately recent calibration, 
certification of calibration accuracy, and NIST-traceability (if 
required) of all measurement instruments used in the tests. The 
accuracy of flow rate meters shall be verified at the highest and 
lowest pressures and temperatures used in the tests and shall be 
checked at zero and at least one flow rate within 3 percent 
of 16.7 L/min within 7 days prior to use for this test. Where an 
instrument's measurements are to be recorded with an analog recording 
device, the accuracy of the entire instrument-recorder system shall be 
calibrated or verified.
    (d) Test setup. (1) Setup of the sampler shall be performed as 
required in this paragraph (d) and otherwise as described in the 
sampler's operation or instruction manual referred to in 
Sec. 53.4(b)(3). The sampler shall be installed upright and set up in 
its normal configuration for collecting PM2.5 samples. A 
sample filter and (or) the device for creating an additional 55 mm Hg 
pressure drop shall be installed for the duration of these tests. The 
sampler's ambient temperature, ambient pressure, and flow measurement 
systems shall all be calibrated per the sampler's operating manual 
within 7 days prior to this test.
    (2) The inlet of the candidate sampler shall be removed and the 
flow measurement adaptor installed on the sample downtube. A leak check 
as described in the sampler's operation or instruction manual shall be 
conducted and must be properly passed before other tests are carried 
out.
    (3) The inlet of the flow measurement adaptor shall be connected to 
the outlet of the flow rate meter.
    (e) Procedure. (1) Set up the sampler as specified in paragraph (d) 
of this section and otherwise prepare the sampler for normal sample 
collection operation as directed in the sampler's operation or 
instruction manual. Set the sampler to automatically start a 6-hour 
sample collection period at a convenient time.
    (2) During the entire 6-hour operational flow rate portion of the 
test, measure and record the sample flow rate with the flow rate meter 
at intervals not to exceed 5 minutes. If ambient temperature and 
pressure corrections are necessary to calculate volumetric flow rate, 
ambient temperature and pressure shall be measured at the same 
frequency as that of the certified flow rate measurements. Note and 
record the actual start and stop times for the 6-hour flow rate test 
period.
    (3) During the 6-hour test period, interrupt the AC line electrical 
power to

[[Page 38804]]

the sampler 5 times, with durations of 20 seconds, 40 seconds, 2 
minutes, 7 minutes, and 20 minutes (respectively), with not less than 
10 minutes of normal electrical power supplied between each power 
interruption. Record the hour and minute and duration of each power 
interruption.
    (4) At the end of the test, terminate the sample period (if not 
automatically terminated by the sampler) and download all archived 
instrument data from the test sampler.
    (f) Test results. At the completion of the sampling period, 
validate the test conditions and determine the test results as follows:
    (1) Mean sample flow rate. (i) From the certified measurements 
(Qref) of the test sampler flow rate, tabulate each flow 
rate measurement in units of L/min. If ambient temperature and pressure 
corrections are necessary to calculate volumetric flow rate, each 
measured flow rate shall be corrected using its corresponding 
temperature and pressure measurement values. Calculate the mean flow 
rate for the sample period (Qref,ave) as follows:

Equation 6
[GRAPHIC] [TIFF OMITTED] TR18JY97.068

where:
n equals the number of discrete certified flow rate measurements 
over the 6-hour test period, excluding flow rate values obtained 
during periods of power interruption.

    (ii)(A) Calculate the percent difference between this mean flow 
rate value and the design value of 16.67 L/min, as follows:

Equation 7
[GRAPHIC] [TIFF OMITTED] TR18JY97.069

    (B) To successfully pass this test, the percent difference 
calculated in Equation 7 of this paragraph (f)(1)(ii) must be within 
5 percent.
    (2) Sample flow rate regulation. (i) From the certified 
measurements of the test sampler flow rate, calculate the sample 
coefficient of variation of the discrete measurements as follows:

Equation 8
[GRAPHIC] [TIFF OMITTED] TR18JY97.070

    (ii) To successfully pass this test, the calculated coefficient of 
variation for the certified flow rates must not exceed 2 percent.
    (3) Flow rate measurement accuracy. (i) Using the mean volumetric 
flow rate reported by the candidate test sampler at the completion of 
the 6-hour test (Qind,ave), determine the accuracy of the 
reported mean flow rate as:

Equation 9
[GRAPHIC] [TIFF OMITTED] TR18JY97.071

    (ii) To successfully pass this test, the percent difference 
calculated in Equation 9 of this paragraph (f)(3) shall not exceed 2 
percent.
    (4) Flow rate CV measurement accuracy. (i) Using the flow rate 
coefficient of variation indicated by the candidate test sampler at the 
completion of the 6-hour test (%CVind), determine the 
accuracy of the reported coefficient of variation as:

Equation 10
[GRAPHIC] [TIFF OMITTED] TR18JY97.072

    (ii) To successfully pass this test, the absolute difference in 
values calculated in Equation 10 of this paragraph (f)(4) must not 
exceed 0.3 (CV%).
    (5) Verify that the sampler properly provided a record and visual 
display of the correct year, month, day-of-month, hour, and minute with 
an accuracy of  2 minutes, of the start of each power 
interruption of duration greater than 60 seconds.
    (6) Calculate the actual elapsed sample time, excluding the periods 
of electrical power interruption. Verify that the elapsed sample time 
reported by the sampler is accurate to within  20 seconds 
for the 6-hour test run.
    (7) Calculate the sample volume as Qref,ave the sample 
time, excluding periods of power interruption. Verify that the sample 
volume reported by the sampler is within 2 percent of the calculated 
sample volume to successfully pass this test.
    (8) Inspect the downloaded instrument data from the test sampler 
and verify that all data are consistent with normal operation of the 
sampler.


Sec. 53.55   Test for effect of variations in power line voltage and 
ambient temperature.

    (a) Overview. (1) This test procedure is a combined procedure to 
test various performance parameters under variations in power line 
voltage and ambient temperature. Tests shall be conducted in a 
temperature controlled environment over four 6-hour time periods during 
which reference temperature and flow rate measurements shall be made at 
intervals not to exceed 5 minutes. Specific parameters to be evaluated 
at line voltages of 105 and 125 volts and temperatures of -20  deg.C 
and +40  deg.C are as follows:
    (i) Sample flow rate.
    (ii) Flow rate regulation.
    (iii) Flow rate measurement accuracy.
    (iv) Coefficient of variability measurement accuracy.
    (v) Ambient air temperature measurement accuracy.
    (vi) Proper operation of the sampler when exposed to power line 
voltage and ambient temperature extremes.
    (2) The performance parameters tested under this procedure, the 
corresponding minimum performance specifications, and the applicable 
test conditions are summarized in Table E-1 of this subpart. Each 
performance parameter tested, as described or determined in the test 
procedure, must meet or exceed the associated performance specification 
given. The candidate sampler must meet all specifications for the 
associated PM2.5 method to pass this test procedure.
    (b) Technical definition. Sample flow rate means the quantitative 
volumetric flow rate of the air stream caused by the sampler to enter 
the sampler inlet and pass through the sample filter, measured in 
actual volume units at the temperature and pressure of the air as it 
enters the inlet.
    (c) Required test equipment. (1) Environmental chamber or other 
temperature-controlled environment or environments, capable of 
obtaining and maintaining temperatures at -20  deg.C and +40  deg.C as 
required for the test with an accuracy of 2  deg.C. The 
test environment(s) must be capable of maintaining these temperatures 
within the specified limits continuously with the additional heat load 
of the operating test sampler in the environment. Henceforth, where the 
test procedures specify a test or environmental ``chamber,'' an 
alternative temperature-controlled environmental area or areas may be 
substituted, provided the required test temperatures and all other test 
requirements are met.
    (2) Variable voltage AC power transformer, range 100 Vac to 130 
Vac, with sufficient current capacity to operate the test sampler 
continuously under the test conditions.
    (3) Flow rate meter, suitable for measuring and recording the 
actual volumetric sample flow rate at the sampler downtube, with a 
minimum range of 10 to 25 actual L/min, 2 percent certified, NIST-
traceable accuracy. Optional capability for continuous (analog) 
recording capability or digital recording at intervals not to exceed 5 
minutes is recommended. While a flow

[[Page 38805]]

meter which provides a direct indication of volumetric flow rate is 
preferred for this test, an alternative certified flow measurement 
device may be used as long as appropriate volumetric flow rate 
corrections are made based on measurements of actual ambient 
temperature and pressure conditions.
    (4) Ambient air temperature recorder, range -30  deg.C to +50 
deg.C, with a resolution of 0.1  deg.C and certified accurate to within 
0.5  deg.C. Ambient air temperature measurements must be made using 
continuous (analog) recording capability or digital recording at 
intervals not to exceed 5 minutes.
    (5) Barometer, range 600 mm Hg to 800 mm Hg, certified accurate to 
2 mm Hg. If the certified flow rate meter does not provide direct 
volumetric flow rate readings, ambient pressure measurements must be 
made using continuous (analog) recording capability or digital 
recording at intervals not to exceed 5 minutes.
    (6) Flow measurement adaptor (40 CFR part 50, Appendix L, Figure L-
30) or equivalent adaptor to facilitate measurement of sampler flow 
rate at the sampler downtube.
    (7) Means for creating an additional pressure drop of 55 mm Hg in 
the sampler to simulate a heavily loaded filter, such as an orifice or 
flow restrictive plate installed in the filter holder or a valve or 
other flow restrictor temporarily installed in the flow path near the 
filter.
    (8) AC RMS voltmeter, accurate to 1.0 volt.
    (9) Teflon sample filter, as specified in section 6 of 40 CFR part 
50, Appendix L (if required).
    (d) Calibration of test measurement instruments. Submit 
documentation showing evidence of appropriately recent calibration, 
certification of calibration accuracy, and NIST-traceability (if 
required) of all measurement instruments used in the tests. The 
accuracy of flow rate meters shall be verified at the highest and 
lowest pressures and temperatures used in the tests and shall be 
checked at zero and at least one flow rate within 3 percent 
of 16.7 L/min within 7 days prior to use for this test. Where an 
instrument's measurements are to be recorded with an analog recording 
device, the accuracy of the entire instrument-recorder system shall be 
calibrated or verified.
    (e) Test setup. (1) Setup of the sampler shall be performed as 
required in this paragraph (e) and otherwise as described in the 
sampler's operation or instruction manual referred to in 
Sec. 53.4(b)(3). The sampler shall be installed upright and set up in 
the temperature-controlled chamber in its normal configuration for 
collecting PM2.5 samples. A sample filter and (or) the 
device for creating an additional 55 mm Hg pressure drop shall be 
installed for the duration of these tests. The sampler's ambient 
temperature, ambient pressure, and flow measurement systems shall all 
be calibrated per the sampler's operating manual within 7 days prior to 
this test.
    (2) The inlet of the candidate sampler shall be removed and the 
flow measurement adaptor installed on the sampler's downtube. A leak 
check as described in the sampler's operation or instruction manual 
shall be conducted and must be properly passed before other tests are 
carried out.
    (3) The inlet of the flow measurement adaptor shall be connected to 
the outlet of the flow rate meter.
    (4) The ambient air temperature recorder shall be installed in the 
test chamber such that it will accurately measure the temperature of 
the air in the vicinity of the candidate sampler without being unduly 
affected by the chamber's air temperature control system.
    (f) Procedure. (1) Set up the sampler as specified in paragraph (e) 
of this section and otherwise prepare the sampler for normal sample 
collection operation as directed in the sampler's operation or 
instruction manual.
    (2) The test shall consist of four test runs, one at each of the 
following conditions of chamber temperature and electrical power line 
voltage (respectively):
    (i) -20  deg.C 2  deg.C and 105 1 Vac.
    (ii) -20  deg.C 2  deg.C and 125 1 Vac.
    (iii) +40  deg.C 2  deg.C and 105 1 Vac.
    (iv) +40  deg.C 2  deg.C and 125 1 Vac.
    (3) For each of the four test runs, set the selected chamber 
temperature and power line voltage for the test run. Upon achieving 
each temperature setpoint in the chamber, the candidate sampler and 
flow meter shall be thermally equilibrated for a period of at least 2 
hours prior to the test run. Following the thermal conditioning time, 
set the sampler to automatically start a 6-hour sample collection 
period at a convenient time.
    (4) During each 6-hour test period:
    (i) Measure and record the sample flow rate with the flow rate 
meter at intervals not to exceed 5 minutes. If ambient temperature and 
pressure corrections are necessary to calculate volumetric flow rate, 
ambient temperature and pressure shall be measured at the same 
frequency as that of the certified flow rate measurements. Note and 
record the actual start and stop times for the 6-hour flow rate test 
period.
    (ii) Determine and record the ambient (chamber) temperature 
indicated by the sampler and the corresponding ambient (chamber) 
temperature measured by the ambient temperature recorder specified in 
paragraph (c)(4) of this section at intervals not to exceed 5 minutes.
    (iii) Measure the power line voltage to the sampler at intervals 
not greater than 1 hour.
    (5) At the end of each test run, terminate the sample period (if 
not automatically terminated by the sampler) and download all archived 
instrument data from the test sampler.
    (g) Test results. For each of the four test runs, examine the 
chamber temperature measurements and the power line voltage 
measurements. Verify that the temperature and line voltage met the 
requirements specified in paragraph (f) of this section at all times 
during the test run. If not, the test run is not valid and must be 
repeated. Determine the test results as follows:
    (1) Mean sample flow rate. (i) From the certified measurements 
(Qref) of the test sampler flow rate, tabulate each flow 
rate measurement in units of L/min. If ambient temperature and pressure 
corrections are necessary to calculate volumetric flow rate, each 
measured flow rate shall be corrected using its corresponding 
temperature and pressure measurement values. Calculate the mean flow 
rate for each sample period (Qref,ave) as follows:

Equation 11
[GRAPHIC] [TIFF OMITTED] TR18JY97.073

where:
n equals the number of discrete certified flow rate measurements 
over each 6-hour test period.

    (ii)(A) Calculate the percent difference between this mean flow 
rate value and the design value of 16.67 L/min, as follows:

Equation 12
[GRAPHIC] [TIFF OMITTED] TR18JY97.074

    (B) To successfully pass this test, the percent difference 
calculated in Equation 12 of this paragraph (g)(1)(ii) must be within 
5 percent for each test run.
    (2) Sample flow rate regulation. (i) From the certified 
measurements of the test sampler flow rate, calculate the sample 
coefficient of variation of the discrete measurements as follows:

[[Page 38806]]

Equation 13
[GRAPHIC] [TIFF OMITTED] TR18JY97.075

    (ii) To successfully pass this test, the calculated coefficient of 
variation for the certified flow rates must not exceed 2 percent.
    (3) Flow rate measurement accuracy. (i) Using the mean volumetric 
flow rate reported by the candidate test sampler at the completion of 
each 6-hour test (Qind,ave), determine the accuracy of the 
reported mean flow rate as:

Equation 14
[GRAPHIC] [TIFF OMITTED] TR18JY97.076

    (ii) To successfully pass this test, the percent difference 
calculated in Equation 14 of this paragraph (g)(3) shall not exceed 2 
percent for each test run.
    (4) Flow rate coefficient of variation measurement accuracy. (i) 
Using the flow rate coefficient of variation indicated by the candidate 
test sampler (%CVind), determine the accuracy of the 
reported coefficient of variation as:

Equation 15
[GRAPHIC] [TIFF OMITTED] TR18JY97.077

    (ii) To successfully pass this test, the absolute difference 
calculated in Equation 15 of this paragraph (g)(4) must not exceed 0.3 
(CV%) for each test run.
    (5) Ambient temperature measurement accuracy. (i) Calculate the 
absolute value of the difference between the mean ambient air 
temperature indicated by the test sampler and the mean ambient 
(chamber) air temperature measured with the ambient air temperature 
recorder as:

Equation 16
[GRAPHIC] [TIFF OMITTED] TR18JY97.078

where:
Tind,ave = mean ambient air temperature indicated by the 
test sampler,  deg.C; and
Tref,ave = mean ambient air temperature measured by the 
reference temperature instrument,  deg.C.

    (ii) The calculated temperature difference must be less than 2 
deg.C for each test run.
    (6) Sampler functionality. To pass the sampler functionality test, 
the following two conditions must both be met for each test run:
    (i) The sampler must not shutdown during any portion of the 6-hour 
test.
    (ii) An inspection of the downloaded data from the test sampler 
verifies that all the data are consistent with normal operation of the 
sampler.


Sec. 53.56   Test for effect of variations in ambient pressure.

    (a) Overview. (1) This test procedure is designed to test various 
sampler performance parameters under variations in ambient (barometric) 
pressure. Tests shall be conducted in a pressure-controlled environment 
over two 6-hour time periods during which reference pressure and flow 
rate measurements shall be made at intervals not to exceed 5 minutes. 
Specific parameters to be evaluated at operating pressures of 600 and 
800 mm Hg are as follows:
    (i) Sample flow rate.
    (ii) Flow rate regulation.
    (iii) Flow rate measurement accuracy.
    (iv) Coefficient of variability measurement accuracy.
    (v) Ambient pressure measurement accuracy.
    (vi) Proper operation of the sampler when exposed to ambient 
pressure extremes.
    (2) The performance parameters tested under this procedure, the 
corresponding minimum performance specifications, and the applicable 
test conditions are summarized in Table E-1 of this subpart. Each 
performance parameter tested, as described or determined in the test 
procedure, must meet or exceed the associated performance specification 
given. The candidate sampler must meet all specifications for the 
associated PM2.5 method to pass this test procedure.
    (b) Technical definition. Sample flow rate means the quantitative 
volumetric flow rate of the air stream caused by the sampler to enter 
the sampler inlet and pass through the sample filter, measured in 
actual volume units at the temperature and pressure of the air as it 
enters the inlet.
    (c) Required test equipment. (1) Hypobaric chamber or other 
pressure-controlled environment or environments, capable of obtaining 
and maintaining pressures at 600 mm Hg and 800 mm Hg required for the 
test with an accuracy of 5 mm Hg. Henceforth, where the test procedures 
specify a test or environmental chamber, an alternative pressure-
controlled environmental area or areas may be substituted, provided the 
test pressure requirements are met. Means for simulating ambient 
pressure using a closed-loop sample air system may also be approved for 
this test; such a proposed method for simulating the test pressure 
conditions may be described and submitted to EPA at the address given 
in Sec. 53.4(a) prior to conducting the test for a specific individual 
determination of acceptability.
    (2) Flow rate meter, suitable for measuring and recording the 
actual volumetric sampler flow rate at the sampler downtube, with a 
minimum range of 10 to 25 L/min, 2 percent certified, NIST-traceable 
accuracy. Optional capability for continuous (analog) recording 
capability or digital recording at intervals not to exceed 5 minutes is 
recommended. While a flow meter which provides a direct indication of 
volumetric flow rate is preferred for this test, an alternative 
certified flow measurement device may be used as long as appropriate 
volumetric flow rate corrections are made based on measurements of 
actual ambient temperature and pressure conditions.
    (3) Ambient air temperature recorder (if needed for volumetric 
corrections to flow rate measurements) with a range -30  deg.C to +50 
deg.C, certified accurate to within 0.5  deg.C. If the certified flow 
meter does not provide direct volumetric flow rate readings, ambient 
temperature measurements must be made using continuous (analog) 
recording capability or digital recording at intervals not to exceed 5 
minutes.
    (4) Barometer, range 600 mm Hg to 800 mm Hg, certified accurate to 
2 mm Hg. Ambient air pressure measurements must be made using 
continuous (analog) recording capability or digital recording at 
intervals not to exceed 5 minutes.
    (5) Flow measurement adaptor (40 CFR part 50, Appendix L, Figure L-
30) or equivalent adaptor to facilitate measurement of sampler flow 
rate at the sampler downtube.
    (6) Means for creating an additional pressure drop of 55 mm Hg in 
the sampler to simulate a heavily loaded filter, such as an orifice or 
flow restrictive plate installed in the filter holder or a valve or 
other flow restrictor temporarily installed in the flow path near the 
filter.
    (7) Teflon sample filter, as specified in section 6 of 40 CFR part 
50, Appendix L (if required).
    (d) Calibration of test measurement instruments. Submit 
documentation showing evidence of appropriately recent calibration, 
certification of calibration accuracy, and NIST-traceability (if 
required) of all measurement instruments used in the tests. The 
accuracy of flow rate meters shall be verified at the highest and 
lowest pressures and temperatures used in the tests and shall be 
checked at zero and at least one flow rate within 3 percent 
of 16.7 L/min within 7 days prior to use for this test. Where an 
instrument's measurements are to be

[[Page 38807]]

recorded with an analog recording device, the accuracy of the entire 
instrument-recorder system shall be calibrated or verified.
    (e) Test setup. (1) Setup of the sampler shall be performed as 
required in this paragraph (e) and otherwise as described in the 
sampler's operation or instruction manual referred to in 
Sec. 53.4(b)(3). The sampler shall be installed upright and set up in 
the pressure-controlled chamber in its normal configuration for 
collecting PM2.5 samples. A sample filter and (or) the 
device for creating an additional 55 mm Hg pressure drop shall be 
installed for the duration of these tests. The sampler's ambient 
temperature, ambient pressure, and flow measurement systems shall all 
be calibrated per the sampler's operating manual within 7 days prior to 
this test.
    (2) The inlet of the candidate sampler shall be removed and the 
flow measurement adaptor installed on the sampler's downtube. A leak 
check as described in the sampler's operation or instruction manual 
shall be conducted and must be properly passed before other tests are 
carried out.
    (3) The inlet of the flow measurement adaptor shall be connected to 
the outlet of the flow rate meter.
    (4) The barometer shall be installed in the test chamber such that 
it will accurately measure the air pressure to which the candidate 
sampler is subjected.
    (f) Procedure. (1) Set up the sampler as specified in paragraph (e) 
of this section and otherwise prepare the sampler for normal sample 
collection operation as directed in the sampler's operation or 
instruction manual.
    (2) The test shall consist of two test runs, one at each of the 
following conditions of chamber pressure:
    (i) 600 mm Hg.
    (ii) 800 mm Hg.
    (3) For each of the two test runs, set the selected chamber 
pressure for the test run. Upon achieving each pressure setpoint in the 
chamber, the candidate sampler shall be pressure-equilibrated for a 
period of at least 30 minutes prior to the test run. Following the 
conditioning time, set the sampler to automatically start a 6-hour 
sample collection period at a convenient time.
    (4) During each 6-hour test period:
    (i) Measure and record the sample flow rate with the flow rate 
meter at intervals not to exceed 5 minutes. If ambient temperature and 
pressure corrections are necessary to calculate volumetric flow rate, 
ambient temperature and pressure shall be measured at the same 
frequency as that of the certified flow rate measurements. Note and 
record the actual start and stop times for the 6-hour flow rate test 
period.
    (ii) Determine and record the ambient (chamber) pressure indicated 
by the sampler and the corresponding ambient (chamber) pressure 
measured by the barometer specified in paragraph (c)(4) of this section 
at intervals not to exceed 5 minutes.
    (5) At the end of each test period, terminate the sample period (if 
not automatically terminated by the sampler) and download all archived 
instrument data from the test sampler.
    (g) Test results. For each of the two test runs, examine the 
chamber pressure measurements. Verify that the pressure met the 
requirements specified in paragraph (f) of this section at all times 
during the test. If not, the test run is not valid and must be 
repeated. Determine the test results as follows:
    (1) Mean sample flow rate. (i) From the certified measurements 
(Qref) of the test sampler flow rate, tabulate each flow 
rate measurement in units of L/min. If ambient temperature and pressure 
corrections are necessary to calculate volumetric flow rate, each 
measured flow rate shall be corrected using its corresponding 
temperature and pressure measurement values. Calculate the mean flow 
rate for the sample period (Qref,ave) as follows:

Equation 17
[GRAPHIC] [TIFF OMITTED] TR18JY97.079

where:
n equals the number of discrete certified flow measurements over the 
6-hour test period.

    (ii)(A) Calculate the percent difference between this mean flow 
rate value and the design value of 16.67 L/min, as follows:

Equation 18
[GRAPHIC] [TIFF OMITTED] TR18JY97.080

    (B) To successfully pass this test, the percent difference 
calculated in Equation 18 of this paragraph (g)(1) must be within 
5 percent for each test run.
    (2) Sample flow rate regulation. (i) From the certified 
measurements of the test sampler flow rate, calculate the sample 
coefficient of variation of the discrete measurements as follows:

Equation 19
[GRAPHIC] [TIFF OMITTED] TR18JY97.081

    (ii) To successfully pass this test, the calculated coefficient of 
variation for the certified flow rates must not exceed 2 percent.
    (3) Flow rate measurement accuracy. (i) Using the mean volumetric 
flow rate reported by the candidate test sampler at the completion of 
each 6-hour test (Qind,ave), determine the accuracy of the 
reported mean flow rate as:

Equation 20
[GRAPHIC] [TIFF OMITTED] TR18JY97.082

    (ii) To successfully pass this test, the percent difference 
calculated in Equation 20 of this paragraph (g)(3) shall not exceed 2 
percent for each test run.
    (4) Flow rate CV measurement accuracy. (i) Using the flow rate 
coefficient of variation indicated by the candidate test sampler at the 
completion of the 6-hour test (%CVind), determine the 
accuracy of the reported coefficient of variation as:

Equation 21
[GRAPHIC] [TIFF OMITTED] TR18JY97.083

    (ii) To successfully pass this test, the absolute difference in 
values calculated in Equation 21 of this paragraph (g)(4) must not 
exceed 0.3 (CV%) for each test run.
    (5) Ambient pressure measurement accuracy. (i) Calculate the 
absolute difference between the mean ambient air pressure indicated by 
the test sampler and the ambient (chamber) air pressure measured with 
the reference barometer as:

Equation 22
[GRAPHIC] [TIFF OMITTED] TR18JY97.084


[[Page 38808]]


where:
Pind,ave = mean ambient pressure indicated by the test 
sampler, mm Hg; and
Pref,ave = mean barometric pressure measured by the 
reference barometer, mm Hg.

    (ii) The calculated pressure difference must be less than 10 mm Hg 
for each test run to pass the test.
    (6) Sampler functionality. To pass the sampler functionality test, 
the following two conditions must both be met for each test run:
    (i) The sampler must not shut down during any part of the 6-hour 
tests; and
    (ii) An inspection of the downloaded data from the test sampler 
verifies that all the data are consistent with normal operation of the 
sampler.


Sec. 53.57   Test for filter temperature control during sampling and 
post-sampling periods.

    (a) Overview. This test is intended to measure the candidate 
sampler's ability to prevent excessive overheating of the 
PM2.5 sample collection filter (or filters) under conditions 
of elevated solar insolation. The test evaluates radiative effects on 
filter temperature during a 4-hour period of active sampling as well as 
during a subsequent 4-hour non-sampling time period prior to filter 
retrieval. Tests shall be conducted in an environmental chamber which 
provides the proper radiant wavelengths and energies to adequately 
simulate the sun's radiant effects under clear conditions at sea level. 
For additional guidance on conducting solar radiative tests under 
controlled conditions, consult military standard specification 810-E 
(Reference 6 in Appendix A of this subpart). The performance parameters 
tested under this procedure, the corresponding minimum performance 
specifications, and the applicable test conditions are summarized in 
Table E-1 of this subpart. Each performance parameter tested, as 
described or determined in the test procedure, must meet or exceed the 
associated performance specification to successfully pass this test.
    (b) Technical definition. Filter temperature control during 
sampling is the ability of a sampler to maintain the temperature of the 
particulate matter sample filter within the specified deviation (5 
deg.C) from ambient temperature during any active sampling period. 
Post-sampling temperature control is the ability of a sampler to 
maintain the temperature of the particulate matter sample filter within 
the specified deviation from ambient temperature during the period from 
the end of active sample collection of the PM2.5 sample by 
the sampler until the filter is retrieved from the sampler for 
laboratory analysis.
    (c) Required test equipment. (1) Environmental chamber providing 
the means, such as a bank of solar-spectrum lamps, for generating or 
simulating thermal radiation in approximate spectral content and 
intensity equivalent to solar insolation of 1000  50 W/
m2 inside the environmental chamber. To properly simulate 
the sun's radiative effects on the sampler, the solar bank must provide 
the spectral energy distribution and permitted tolerances specified in 
Table E-2 of this subpart. The solar radiation source area shall be 
such that the width of the candidate sampler shall not exceed one-half 
the dimensions of the solar bank. The solar bank shall be located a 
minimum of 76 cm (30 inches) from any surface of the candidate sampler. 
To meet requirements of the solar radiation tests, the chamber's 
internal volume shall be a minimum of 10 times that of the volume of 
the candidate sampler. Air velocity in the region of the sampler must 
be maintained continuously during the radiative tests at 2.0 
 0.5 m/sec.
    (2) Ambient air temperature recorder, range -30  deg.C to +50 
deg.C, with a resolution of 0.1  deg.C and certified accurate to within 
0.5  deg.C. Ambient air temperature measurements must be made using 
continuous (analog) recording capability or digital recording at 
intervals not to exceed 5 minutes.
    (3) Flow measurement adaptor (40 CFR part 50, Appendix L, Figure L-
30) or equivalent adaptor to facilitate measurement of sampler flow 
rate at the sampler downtube.
    (4) Miniature temperature sensor(s), capable of being installed in 
the sampler without introducing air leakage and capable of measuring 
the sample air temperature within 1 cm of the center of the filter, 
downstream of the filter; with a resolution of 0.1  deg.C, certified 
accurate to within 0.5  deg.C, NIST-traceable, with continuous (analog) 
recording capability or digital recording at intervals of not more than 
5 minutes.
    (5) Solar radiometer, to measure the intensity of the simulated 
solar radiation in the test environment, range of 0 to approximately 
1500 W/m2. Optional capability for continuous (analog) 
recording or digital recording at intervals not to exceed 5 minutes is 
recommended.
    (6) Sample filter or filters, as specified in section 6 of 40 CFR 
part 50, Appendix L.
    (d) Calibration of test measurement instruments. Submit 
documentation showing evidence of appropriately recent calibration, 
certification of calibration accuracy, and NIST-traceability (if 
required) of all measurement instruments used in the tests. The 
accuracy of flow rate meters shall be verified at the highest and 
lowest pressures and temperatures used in the tests and shall be 
checked at zero and at least one flow rate within 3 percent 
of 16.7 L/min within 7 days prior to use for this test. Where an 
instrument's measurements are to be recorded with an analog recording 
device, the accuracy of the entire instrument-recorder system shall be 
calibrated or verified.
    (e) Test setup. (1) Setup of the sampler shall be performed as 
required in this paragraph (e) and otherwise as described in the 
sampler's operation or instruction manual referred to in 
Sec. 53.4(b)(3). The sampler shall be installed upright and set up in 
the solar radiation environmental chamber in its normal configuration 
for collecting PM2.5 samples (with the inlet installed). The 
sampler's ambient and filter temperature measurement systems shall be 
calibrated per the sampler's operating manual within 7 days prior to 
this test. A sample filter shall be installed for the duration of this 
test. For sequential samplers, a sample filter shall also be installed 
in each available sequential channel or station intended for collection 
of a sequential sample (or at least 5 additional filters for magazine-
type sequential samplers) as directed by the sampler's operation or 
instruction manual.
    (2) The miniature temperature sensor shall be temporarily installed 
in the test sampler such that it accurately measures the air 
temperature 1 cm from the center of the filter on the downstream side 
of the filter. The sensor shall be installed such that no external or 
internal air leakage is created by the sensor installation. The 
sensor's dimensions and installation shall be selected to minimize 
temperature measurement uncertainties due to thermal conduction along 
the sensor mounting structure or sensor conductors. For sequential 
samplers, similar temperature sensors shall also be temporarily 
installed in the test sampler to monitor the temperature 1 cm from the 
center of each filter stored in the sampler for sequential sample 
operation.
    (3) The solar radiant energy source shall be installed in the test 
chamber such that the entire test sampler is irradiated in a manner 
similar to the way it would be irradiated by solar radiation if it were 
located outdoors in an open area on a sunny day, with the radiation 
arriving at an angle of between 30 deg. and 45 deg. from vertical. The 
intensity of the radiation received by all sampler

[[Page 38809]]

surfaces that receive direct radiation shall average 1000  
50 W/m2, measured in a plane perpendicular to the incident 
radiation. The incident radiation shall be oriented with respect to the 
sampler such that the area of the sampler's ambient temperature sensor 
(or temperature shield) receives full, direct radiation as it would or 
could during normal outdoor installation. Also, the temperature sensor 
must not be shielded or shaded from the radiation by a sampler part in 
a way that would not occur at other normal insolation angles or 
directions.
    (4) The solar radiometer shall be installed in a location where it 
measures thermal radiation that is generally representative of the 
average thermal radiation intensity that the upper portion of the 
sampler and sampler inlet receive. The solar radiometer shall be 
oriented so that it measures the radiation in a plane perpendicular to 
its angle of incidence.
    (5) The ambient air temperature recorder shall be installed in the 
test chamber such that it will accurately measure the temperature of 
the air in the chamber without being unduly affected by the chamber's 
air temperature control system or by the radiant energy from the solar 
radiation source that may be present inside the test chamber.
    (f) Procedure. (1) Set up the sampler as specified in paragraph (e) 
of this section and otherwise prepare the sampler for normal sample 
collection operation as directed in the sampler's operation or 
instruction manual.
    (2) Remove the inlet of the candidate test sampler and install the 
flow measurement adaptor on the sampler's downtube. Conduct a leak 
check as described in the sampler's operation or instruction manual. 
The leak test must be properly passed before other tests are carried 
out.
    (3) Remove the flow measurement adaptor from the downtube and re-
install the sampling inlet.
    (4) Activate the solar radiation source and verify that the 
resulting energy distribution prescribed in Table E-2 of this subpart 
is achieved.
    (5) Program the test sampler to conduct a single sampling run of 4 
continuous hours. During the 4-hour sampling run, measure and record 
the radiant flux, ambient temperature, and filter temperature (all 
filter temperatures for sequential samplers) at intervals not to exceed 
5 minutes.
    (6) At the completion of the 4-hour sampling phase, terminate the 
sample period, if not terminated automatically by the sampler. Continue 
to measure and record the radiant flux, ambient temperature, and filter 
temperature or temperatures for 4 additional hours at intervals not to 
exceed 5 minutes. At the completion of the 4-hour post-sampling period, 
discontinue the measurements and turn off the solar source.
    (7) Download all archived sampler data from the test run.
    (g) Test results. Chamber temperature control. Examine the 
continuous record of the chamber radiant flux and verify that the flux 
met the requirements specified in Table E-2 of this subpart at all 
times during the test. If not, the entire test is not valid and must be 
repeated.
    (1) Filter temperature measurement accuracy. (i) For each 4-hour 
test period, calculate the absolute value of the difference between the 
mean filter temperature indicated by the sampler (active filter) and 
the mean filter temperature measured by the reference temperature 
sensor installed within 1 cm downstream of the (active) filter as:

Equation 23
[GRAPHIC] [TIFF OMITTED] TR18JY97.085

where:
Tind,filter = mean filter temperature indicated by the 
test sampler,  deg.C; and
Tref,filter = mean filter temperature measured by the 
reference temperature sensor,  deg.C.

    (ii) To successfully pass the indicated filter temperature accuracy 
test, the calculated difference between the measured means 
(Tdiff,filter) must not exceed 2  deg.C for each 4-hour test 
period.
    (2) Ambient temperature measurement accuracy. (i) For each 4-hour 
test period, calculate the absolute value of the difference between the 
mean ambient air temperature indicated by the test sampler and the mean 
ambient air temperature measured by the reference ambient air 
temperature recorder as:

Equation 24
[GRAPHIC] [TIFF OMITTED] TR18JY97.086

where:
Tind,ambient = mean ambient air temperature indicated by 
the test sampler,  deg.C; and
Tref,ambient = mean ambient air temperature measured by 
the reference ambient air temperature recorder,  deg.C.

    (ii) To successfully pass the indicated ambient temperature 
accuracy test, the calculated difference between the measured means 
(Tdiff,ambient) must not exceed 2  deg.C for each 4-hour 
test period.
    (3) Filter temperature control accuracy. (i) For each temperature 
measurement interval over each 4-hour test period, calculate the 
difference between the filter temperature indicated by the reference 
temperature sensor and the ambient temperature indicated by the test 
sampler as:

Equation 25
[GRAPHIC] [TIFF OMITTED] TR18JY97.087

    (ii) Tabulate and inspect the calculated differences as a function 
of time. To successfully pass the indicated filter temperature control 
test, the calculated difference between the measured values must not 
exceed 5  deg.C for any consecutive intervals covering more than a 30-
minute time period.
    (iii) For sequential samplers, repeat the test calculations for 
each of the stored sequential sample filters. All stored filters must 
also meet the 5  deg.C temperature control test.


Sec. 53.58   Operational field precision and blank test.

    (a) Overview. This test is intended to determine the operational 
precision of the candidate sampler during a minimum of 10 days of field 
operation, using three collocated test samplers. Measurements of 
PM2.5 are made at a test site with all of the samplers and 
then compared to determine replicate precision. Candidate sequential 
samplers are also subject to a test for possible deposition of 
particulate matter on inactive filters during a period of storage in 
the sampler. This procedure is applicable to both reference and 
equivalent methods. In the case of equivalent methods, this test may be 
combined and conducted concurrently with the comparability test for 
equivalent methods (described in subpart C of this part), using three 
reference method samplers collocated with three candidate equivalent 
method samplers and meeting the applicable site and other requirements 
of subpart C of this part.
    (b) Technical definition. (1) Field precision is defined as the 
standard deviation or relative standard deviation of a set of 
PM2.5 measurements obtained concurrently with three or more 
collocated samplers in actual ambient air field operation.
    (2) Storage deposition is defined as the mass of material 
inadvertently deposited on a sample filter that is stored in a 
sequential sampler either prior to or subsequent to the active sample 
collection period.
    (c) Test site. Any outdoor test site having PM2.5 
concentrations that are reasonably uniform over the test area and that 
meet the minimum level requirement of paragraph (g)(2) of this section 
is acceptable for this test.
    (d) Required facilities and equipment. (1) An appropriate test site 
and suitable

[[Page 38810]]

electrical power to accommodate three test samplers are required.
    (2) Teflon sample filters, as specified in section 6 of 40 CFR part 
50, Appendix L, conditioned and preweighed as required by section 8 of 
40 CFR part 50, Appendix L, as needed for the test samples.
    (e) Test setup. (1) Three identical test samplers shall be 
installed at the test site in their normal configuration for collecting 
PM2.5 samples in accordance with the instructions in the 
associated manual referred to in Sec. 53.4(b)(3) and should be in 
accordance with applicable supplemental guidance provided in Reference 
3 in Appendix A of this subpart. The test samplers' inlet openings 
shall be located at the same height above ground and between 2 and 4 
meters apart horizontally. The samplers shall be arranged or oriented 
in a manner that will minimize the spatial and wind directional effects 
on sample collection of one sampler on any other sampler.
    (2) Each test sampler shall be successfully leak checked, 
calibrated, and set up for normal operation in accordance with the 
instruction manual and with any applicable supplemental guidance 
provided in Reference 3 in Appendix A of this subpart.
    (f) Test procedure. (1) Install a conditioned, preweighed filter in 
each test sampler and otherwise prepare each sampler for normal sample 
collection. Set identical sample collection start and stop times for 
each sampler. For sequential samplers, install a conditioned, 
preweighed specified filter in each available channel or station 
intended for automatic sequential sample filter collection (or at least 
5 additional filters for magazine-type sequential samplers), as 
directed by the sampler's operation or instruction manual. Since the 
inactive sequential channels are used for the storage deposition part 
of the test, they may not be used to collect the active 
PM2.5 test samples.
    (2) Collect either a 24-hour or a 48-hour atmospheric 
PM2.5 sample simultaneously with each of the three test 
samplers.
    (3) Following sample collection, retrieve the collected sample from 
each sampler. For sequential samplers, retrieve the additional stored 
(blank, unsampled) filters after at least 5 days (120 hours) storage in 
the sampler if the active samples are 24-hour samples, or after at 
least 10 days (240 hours) if the active samples are 48-hour samples.
    (4) Determine the measured PM2.5 mass concentration for 
each sample in accordance with the applicable procedures prescribed for 
the candidate method in Appendix L, 40 CFR part 50 of this chapter, in 
the associated manual referred to in Sec. 53.4(b)(3) and in accordance 
with supplemental guidance in Reference 2 in Appendix A of this 
subpart. For sequential samplers, also similarly determine the storage 
deposition as the net weight gain of each blank, unsampled filter after 
the 5-day (or 10-day) period of storage in the sampler.
    (5) Repeat this procedure to obtain a total of 10 sets of any 
combination of 24-hour or 48-hour PM2.5 measurements over 10 
test periods. For sequential samplers, repeat the 5-day (or 10-day) 
storage test of additional blank filters once for a total of two sets 
of blank filters.
    (g) Calculations. (1) Record the PM2.5 concentration for 
each test sampler for each test period as Ci,j, where i is 
the sampler number (i=1,2,3) and j is the test period (j=1,2, . . . 
10).
    (2)(i) For each test period, calculate and record the average of 
the three measured PM2.5 concentrations as Cj 
where j is the test period:

Equation 26
[GRAPHIC] [TIFF OMITTED] TR18JY97.088

    (ii) If Cave,j < 10 g/m3 for any 
test period, data from that test period are unacceptable, and an 
additional sample collection set must be obtained to replace the 
unacceptable data.
    (3)(i) Calculate and record the precision for each of the 10 test 
days as:

Equation 27
[GRAPHIC] [TIFF OMITTED] TR18JY97.089

    (ii) If Cave,j is below 40 g/m3 for 
24-hour measurements or below 30 g/m3 for 48-hour 
measurements; or

Equation 28
[GRAPHIC] [TIFF OMITTED] TR18JY97.090

    (iii) If Cave,j is above 40 g/m3 for 
24-hour measurements or above 30 g/m3 for 48-hour 
measurements.

    (h) Test results. (1) The candidate method passes the precision 
test if all 10 Pj or RPj values meet the 
specifications in Table E-1 of this subpart.
    (2) The candidate sequential sampler passes the blank filter 
storage deposition test if the average net storage deposition weight 
gain of each set of blank filters (total of the net weight gain of each 
blank filter divided by the number of filters in the set) from each 
test sampler (six sets in all) is less than 50 g.


Sec. 53.59   Aerosol transport test for Class I equivalent method 
samplers.

    (a) Overview. This test is intended to verify adequate aerosol 
transport through any modified or air flow splitting components that 
may be used in a Class I candidate equivalent method sampler such as 
may be necessary to achieve sequential sampling capability. This test 
is applicable to all Class I candidate samplers in which the aerosol 
flow path (the flow path through which sample air passes upstream of 
sample collection filter) differs from that specified for reference 
method samplers as specified in 40 CFR part 50, Appendix L. The test 
requirements and performance specifications for this test are 
summarized in Table E-1 of this subpart.
    (b) Technical definitions. (1) Aerosol transport is the percentage 
of a laboratory challenge aerosol which penetrates to the active sample 
filter of the candidate equivalent method sampler.
    (2) The active sample filter is the exclusive filter through which 
sample air is flowing during performance of this test.
    (3) A no-flow filter is a sample filter through which no sample air 
is intended to flow during performance of this test.
    (4) A channel is any of two or more flow paths that the aerosol may 
take, only one of which may be active at a time.
    (5) An added component is any physical part of the sampler which is 
different in some way from that specified for a reference method 
sampler in 40 CFR part 50, Appendix L, such as a device or means to 
allow or cause the aerosol to be routed to one of several channels.
    (c) Required facilities and test equipment. (1) Aerosol generation 
system, as specified in Sec. 53.62(c)(2).
    (2) Aerosol delivery system, as specified in Sec. 53.64(c)(2).
    (3) Particle size verification equipment, as specified in 
Sec. 53.62(c)(3).
    (4) Fluorometer, as specified in Sec. 53.62(c)(7).
    (5) Candidate test sampler, with the inlet and impactor or 
impactors removed, and with all internal surfaces of added components 
electroless nickel coated as specified in Sec. 53.64(d)(2).
    (6) Filters that are appropriate for use with fluorometric methods 
(e.g., glass fiber).

[[Page 38811]]

    (d) Calibration of test measurement instruments. Submit 
documentation showing evidence of appropriately recent calibration, 
certification of calibration accuracy, and NIST-traceability (if 
required) of all measurement instruments used in the tests. The 
accuracy of flow rate meters shall be verified at the highest and 
lowest pressures and temperatures used in the tests and shall be 
checked at zero and at least one flow rate within 3 percent 
of 16.7 L/min within 7 days prior to use for this test. Where an 
instrument's measurements are to be recorded with an analog recording 
device, the accuracy of the entire instrument-recorder system shall be 
calibrated or verified.
    (e) Test setup. (1) The candidate test sampler shall have its inlet 
and impactor or impactors removed. The lower end of the down tube shall 
be reconnected to the filter holder, using an extension of the 
downtube, if necessary. If the candidate sampler has a separate 
impactor for each channel, then for this test, the filter holder 
assemblies must be connected to the physical location on the sampler 
where the impactors would normally connect.
    (2) The test particle delivery system shall be connected to the 
sampler downtube so that the test aerosol is introduced at the top of 
the downtube.
    (f) Test procedure. (1) All surfaces of the added or modified 
component or components which come in contact with the aerosol flow 
shall be thoroughly washed with 0.01 N NaOH and then dried.
    (2) Generate aerosol. (i) Generate aerosol composed of oleic acid 
with a uranine fluorometric tag of 3  0.25 m 
aerodynamic diameter using a vibrating orifice aerosol generator 
according to conventions specified in Sec. 53.61(g).
    (ii) Check for the presence of satellites and adjust the generator 
to minimize their production.
    (iii) Calculate the aerodynamic particle size using the operating 
parameters of the vibrating orifice aerosol generator. The calculated 
aerodynamic diameter must be 3  0.25 m aerodynamic 
diameter.
    (3) Verify the particle size according to procedures specified in 
Sec. 53.62(d)(4)(i).
    (4) Collect particles on filters for a time period such that the 
relative error of the resulting measured fluorometric concentration for 
the active filter is less than 5 percent.
    (5) Determine the quantity of material collected on the active 
filter using a calibrated fluorometer. Record the mass of fluorometric 
material for the active filter as Mactive (i) where i = the 
active channel number.
    (6) Determine the quantity of material collected on each no-flow 
filter using a calibrated fluorometer. Record the mass of fluorometric 
material on each no-flow filter as Mno-flow.
    (7) Using 0.01 N NaOH, wash the surfaces of the added component or 
components which contact the aerosol flow. Determine the quantity of 
material collected using a calibrated fluorometer. Record the mass of 
fluorometric material collected in the wash as Mwash.
    (8) Calculate the aerosol transport as:

Equation 29
[GRAPHIC] [TIFF OMITTED] TR18JY97.091

where:
i = the active channel number.

    (9) Repeat paragraphs (f)(1) through (8) of this section for each 
channel, making each channel in turn the exclusive active channel.
    (g) Test results. The candidate Class I sampler passes the aerosol 
transport test if T(i) is at least 97 percent for each 
channel.
Tables to Subpart E of Part 53

         Table E-1.--Summary of Test Requirements for Reference and Class I Equivalent Methods for PM2.5        
----------------------------------------------------------------------------------------------------------------
                                                          Performance                          Part 50, Appendix
       Subpart E Procedure         Performance Test      Specification      Test Conditions       L Reference   
----------------------------------------------------------------------------------------------------------------
Sec.  53.52 Sampler leak check    Sampler leak check  External leakage:   Controlled leak     Sec. 7.4.6        
 test                              facility            80 mL/min, max      flow rate of 80                      
                                                      Internal leakage:    mL/min                               
                                                       80 mL/min, max                                           
----------------------------------------------------------------------------------------------------------------
Sec.  53.53 Base flow rate test   Sample flow rate:   1. 16.67 plus-      (a) 6-hour normal   Sec. 7.4.1        
                                  1. Mean              minus 5%, L/min     operational test   Sec. 7.4.2        
                                  2. Regulation       2. 2%, max           plus flow rate     Sec. 7.4.3        
                                  3. Meas. accuracy   3. 2%, max           cut-off test       Sec. 7.4.4        
                                  4. CV accuracy      4. 0.3%, max        (b) Nominal         Sec. 7.4.5        
                                  5. Cut-off          5. Flow rate cut-    conditions                           
                                                       off if flow rate   (c) Additional 55                     
                                                       deviates more       mm Hg pressure                       
                                                       than 10% from       drop to simulate                     
                                                       design flow rate    loaded filter                        
                                                       for >60 plus-      (d) Variable flow                     
                                                       minus 30 seconds    restriction used                     
                                                                           for cut-off test                     
----------------------------------------------------------------------------------------------------------------
Sec.  53.54 Power interruption    Sample flow rate:   1. 16.67 plus-      (a) 6-hour normal   Sec. 7.4.1        
 test                             1. Mean              minus 5%, L/min     operational test   Sec. 7.4.2        
                                  2. Regulation       2. 2%, max          (b) Nominal         Sec. 7.4.3        
                                  3. Meas. accuracy   3. 2%, max           conditions         Sec. 7.4.5        
                                  4. CV accuracy      4. 0.3%, max        (c) Additional 55   Sec. 7.4.12       
                                  5. Occurrence time  5. plus-minus2 min   mm Hg pressure     Sec. 7.4.13       
                                   of power            if >60 seconds      drop to simulate   Sec. 7.4.15.4     
                                   interruptions      6. plus-minus20      loaded filter      Sec. 7.4.15.5     
                                  6. Elapsed sample    seconds            (d) 6 power                           
                                   time               7. plus-minus2%,     interruptions of                     
                                  7. Sample volume     max                 various durations                    
----------------------------------------------------------------------------------------------------------------

[[Page 38812]]

                                                                                                                
Sec.  53.55 Temperature and line  Sample flow rate:   1. 16.67 plus-      (a) 6-hour normal   Sec. 7.4.1        
 voltage effect test              1. Mean              minus 5%, L/min     operational test   Sec. 7.4.2        
                                  2. Regulation       2. 2 %, max         (b) Nominal         Sec. 7.4.3        
                                  3. Meas. accuracy   3. 2 %, max          conditions         Sec. 7.4.5        
                                  4. CV accuracy      4. 0.3 %, max       (c) Additional 55   Sec. 7.4.8        
                                  5. Temperature      5. 2  deg.C          mm Hg pressure     Sec. 7.4.15.1     
                                   meas. accuracy                          drop to simulate                     
                                  6. Proper                                loaded filter                        
                                   operation                              (d) Ambient                           
                                                                           temperature at -                     
                                                                           20 and +40  deg.C                    
                                                                          (e) Line voltage:                     
                                                                           105 Vac to 125                       
                                                                           Vac                                  
----------------------------------------------------------------------------------------------------------------
Sec.  53.56 Barometric pressure   Sample flow rate:   1. 16.67 plus-      (a) 6-hour normal   Sec. 7.4.1        
 effect test                      1. Mean              minus 5%, L/min     operational test   Sec. 7.4.2        
                                  2. Regulation       2. 2%, max          (b) Nominal         Sec. 7.4.3        
                                  3. Meas. accuracy   3. 2%, max           conditions         Sec. 7.4.5        
                                  4. CV accuracy      4. 0.3%, max        (c) Additional 55   Sec. 7.4.9        
                                  5. Pressure meas.   5. 10 mm Hg          mm Hg pressure                       
                                   accuracy                                drop to simulate                     
                                  6. Proper                                loaded filter                        
                                   operation                              (d) Barometric                        
                                                                           pressure at 600                      
                                                                           and 800 mm Hg.                       
----------------------------------------------------------------------------------------------------------------
Sec.  53.57 Filter temperature    1. Filter temp      1. 2  deg.C         (a) 4-hour          Sec. 7.4.8        
 control test                      meas. accuracy     2. 2  deg.C          simulated solar    Sec. 7.4.10       
                                  2. Ambient temp.    3. Not more than 5   radiation,         Sec. 7.4.11       
                                   meas. accuracy       deg.C above        sampling                             
                                  3. Filter temp       ambient temp. for  (b) 4-hour                            
                                   control accuracy,   more than 30 min    simulated solar                      
                                   sampling and non-                       radiation, non-                      
                                   sampling                                sampling                             
                                                                          (c) Solar flux of                     
                                                                           1000 W/m2                            
----------------------------------------------------------------------------------------------------------------
Sec.  53.58 Field precision test  1. Measurement      1. Pj <2 g/m3 for conc.    samplers at 1      Sec. 7.3.5        
                                  2. Storage           <40 g/m3   site for at least  Sec. 8            
                                   deposition test     (24-hr) or <30      10 days            Sec. 9            
                                   for sequential      g/m3 (48- (b) PM2.5 conc.10 j < 5% for conc.   m>g/m3                               
                                                       >40 g/m3  (c) 24- or 48-hour                    
                                                       (24-hr) or >30      samples                              
                                                       g/m3 (48- (d) 5- or 10-day                      
                                                       hr)                 storage period                       
                                                      2. 50 g,    for inactive                         
                                                       max weight gain     stored filters                       
----------------------------------------------------------------------------------------------------------------
                                                                                                                
                  The Following Requirement is Applicable to Candidate Equivalent Methods Only                  
                                                                                                                
----------------------------------------------------------------------------------------------------------------
Sec.  53.59 Aerosol transport     Aerosol transport   97%, min, for all   Determine aerosol                     
 test                                                  channels            transport through                    
                                                                           any new or                           
                                                                           modified                             
                                                                           components with                      
                                                                           respect to the                       
                                                                           reference method                     
                                                                           sampler before                       
                                                                           the filter for                       
                                                                           each channel.                        
----------------------------------------------------------------------------------------------------------------


         Table E-2.--Spectral Energy Distribution and Permitted Tolerance for Conducting Radiative Tests        
----------------------------------------------------------------------------------------------------------------
                                                                    Spectral Region                             
             Chacteristic             --------------------------------------------------------------------------
                                             Ultraviolet                Visible                  Infrared       
----------------------------------------------------------------------------------------------------------------
Bandwidth (m)                 0.28 to 0.32      10.32  0.40 to 0.78             0.78 to 3.00           
                                        to 0.40                                                                 
Irradiance (W/m2)                      5                    56  450 to 550               439                    
Allowed Tolerance                      2 35%        2 10%        2 10%      
                                              2                                                     
                                        25%                                                                     
----------------------------------------------------------------------------------------------------------------


[[Page 38813]]

Figures to Subpart E of Part 53


Figure E-1.--Designation Testing Checklist

DESIGNATION TESTING CHECKLIST

____________________      ____________________      
____________________
Auditee                 Auditor signature                 Date

----------------------------------------------------------------------------------------------------------------
       Compliance Status:    Y = Yes     N = No     NA = Not applicable/Not available                           
---------------------------------------------------------------------------------------------                   
                              Verification                                Verified by Direct                    
-------------------------------------------------------------------------   Observation of                      
                                                                             Process or of       Verification   
                                                                              Documented      Comments (Includes
                                                                               Evidence:       documentation of 
                                                                             Performance,      who, what, where,
                                                                               Design or       when, why) (Doc. 
                Y                          N                  NA           Application Spec.    #, Rev. #, Rev. 
                                                                           Corresponding to          Date)      
                                                                          Sections of 40 CFR                    
                                                                           Part 53 or 40 CFR                    
                                                                           Part 50, Appendix                    
                                                                                   L                            
----------------------------------------------------------------------------------------------------------------
                                                                          Performance                           
                                                                           Specification                        
                                                                           Tests                                
                                                                          Sample flow rate                      
                                                                           coefficient of                       
                                                                           variation (Sec.                      
                                                                           53.53) (L 7.4.3)                     
----------------------------------------------------------------------------------------------------------------
                                                                          Filter temperature                    
                                                                           control                              
                                                                           (sampling) (Sec.                     
                                                                           53.57) (L 7.4.10)                    
----------------------------------------------------------------------------------------------------------------
                                                                          Elapsed sample                        
                                                                           time accuracy                        
                                                                           (Sec.  53.54) (L                     
                                                                           7.4.13)                              
----------------------------------------------------------------------------------------------------------------
                                                                          Filter temperature                    
                                                                           control (post                        
                                                                           sampling) (Sec.                      
                                                                           53.57) (L 7.4.10)                    
----------------------------------------------------------------------------------------------------------------
                                                                          Application                           
                                                                           Specification                        
                                                                           Tests                                
----------------------------------------------------------------------------------------------------------------
                                                                          Field Precision                       
                                                                           (Sec.  53.58) (L                     
                                                                           5.1)                                 
----------------------------------------------------------------------------------------------------------------
                                                                          Meets all Appendix                    
                                                                           L requirements                       
                                                                           (part 53, subpart                    
                                                                           A, Sec.                              
                                                                           53.2(a)(3)) (part                    
                                                                           53, subpart E,                       
                                                                           Sec.  53.51(a),(d                    
                                                                           ))                                   
----------------------------------------------------------------------------------------------------------------
                                                                          Filter Weighing (L-                   
                                                                           8)                                   
----------------------------------------------------------------------------------------------------------------
                                                                          Field Sampling                        
                                                                           Procedure (Sec.                      
                                                                           53.30, .31, .34)                     
----------------------------------------------------------------------------------------------------------------
                                                                          Design                                
                                                                           Specification                        
                                                                           Tests                                
----------------------------------------------------------------------------------------------------------------
                                                                          Filter ( L-6)                         
----------------------------------------------------------------------------------------------------------------
                                                                          Range of                              
                                                                           Operational                          
                                                                           Conditions (L-                       
                                                                           7.4.7)                               
----------------------------------------------------------------------------------------------------------------
                                                                                                                
                  The Following Requirements Apply Only to Class I Candidate Equivalent Methods                 
                                                                                                                
----------------------------------------------------------------------------------------------------------------
                                                                          Aerosol Transport                     
                                                                           (Sec.  53.59)                        
----------------------------------------------------------------------------------------------------------------


[[Page 38814]]

Figure E-2.--Product Manufacturing Checklist

PRODUCT MANUFACTURING CHECKLIST

____________________      ____________________      
____________________
Auditee                 Auditor signature                 Date

                                                                                                                
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       Compliance Status:    Y = Yes     N = No     NA = Not applicable/Not available                           
---------------------------------------------------------------------------------------------                   
                              Verification                                Verified by Direct                    
-------------------------------------------------------------------------   Observation of                      
                                                                             Process or of       Verification   
                                                                              Documented      Comments (Includes
                                                                               Evidence:       documentation of 
                                                                             Performance,      who, what, where,
                                                                               Design or       when, why) (Doc. 
                Y                          N                  NA           Application Spec.    #, Rev. #, Rev. 
                                                                           Corresponding to          Date)      
                                                                          Sections of 40 CFR                    
                                                                           Part 53 or 40 CFR                    
                                                                           Part 50, Appendix                    
                                                                                   L                            
----------------------------------------------------------------------------------------------------------------
                                                                          Performance                           
                                                                           Specification                        
                                                                           Tests                                
----------------------------------------------------------------------------------------------------------------
                                                                            Assembled                           
                                                                           operational                          
                                                                           performance (Burn-                   
                                                                           in test) (Sec.                       
                                                                           53.53)                               
----------------------------------------------------------------------------------------------------------------
                                                                            Sample flow rate                    
                                                                           (Sec.  53.53) (L                     
                                                                           7.4.1, L 7.4.2)                      
----------------------------------------------------------------------------------------------------------------
                                                                            Sample flow rate                    
                                                                           regulation (Sec.                     
                                                                           53.53) (L 7.4.3)                     
----------------------------------------------------------------------------------------------------------------
                                                                            Flow rate and                       
                                                                           average flow rate                    
                                                                           measurement                          
                                                                           accuracy (Sec.                       
                                                                           53.53) (L 7.4.5)                     
----------------------------------------------------------------------------------------------------------------
                                                                            Ambient air                         
                                                                           temperature                          
                                                                           measurement                          
                                                                           accuracy (Sec.                       
                                                                           53.55) (L 7.4.8)                     
----------------------------------------------------------------------------------------------------------------
                                                                            Ambient                             
                                                                           barometric                           
                                                                           pressure                             
                                                                           measurement                          
                                                                           accuracy (Sec.                       
                                                                           53.56) (L 7.4.9)                     
----------------------------------------------------------------------------------------------------------------
                                                                            Sample flow rate                    
                                                                           cut-off (Sec.                        
                                                                           53.53) (L 7.4.4)                     
----------------------------------------------------------------------------------------------------------------
                                                                            Sampler leak                        
                                                                           check facility                       
                                                                           (Sec.  53.52) (L                     
                                                                           7.4.6)                               
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                                                                            Application                         
                                                                           Specification                        
                                                                           Tests                                
----------------------------------------------------------------------------------------------------------------
                                                                            Flow rate                           
                                                                           calibration                          
                                                                           transfer standard                    
                                                                           (L-9.2)                              
----------------------------------------------------------------------------------------------------------------
                                                                            Operational /                       
                                                                           Instructional                        
                                                                           manual (L-7.4.18)                    
----------------------------------------------------------------------------------------------------------------
                                                                            Design                              
                                                                           Specification                        
                                                                           Tests                                
----------------------------------------------------------------------------------------------------------------
                                                                            Impactor (jet                       
                                                                           width) (Sec.                         
                                                                           53.51(d)(1)) (L-                     
                                                                           7.3.4.1)                             
----------------------------------------------------------------------------------------------------------------
                                                                            Surface finish                      
                                                                           (Sec.  53.51(                        
                                                                           d)(2)) (L-7.3.7)                     
----------------------------------------------------------------------------------------------------------------

Appendix A to Subpart E of Part 53--References
    (1) Quality systems--Model for quality assurance in design, 
development, production, installation and servicing, ISO 9001. July 
1994. Available from American Society for Quality Control, 611 East 
Wisconsin Avenue, Milwaukee, WI 53202.
    (2) American National Standard--Specifications and Guidelines 
for Quality Systems for Environmental Data Collection and 
Environmental Technology Programs. ANSI/ASQC E4-1994. January 1995. 
Available from American Society for Quality Control, 611 East 
Wisconsin Avenue, Milwaukee, WI 53202.
    (3) Copies of section 2.12 of the Quality Assurance Handbook for 
Air Pollution Measurement Systems, Volume II, Ambient Air Specific 
Methods, EPA/600/R-94/038b, are available from Department E (MD-
77B), U.S. EPA, Research Triangle Park, NC 27711.
    (4) Military standard specification (mil. spec.) 8625F, Type II, 
Class 1 as listed in Department of Defense Index of Specifications 
and Standards (DODISS), available from DODSSP-Customer Service, 
Standardization Documents Order Desk, 700 Robbins Avenue, Building 
4D, Philadelphia, PA 1911-5094.
    (5) Quality Assurance Handbook for Air Pollution Measurement 
Systems, Volume IV: Meteorological Measurements. Revised March, 
1995. EPA-600/R-94-038d. Available from U.S. EPA, ORD Publications 
Office, Center for Environmental Research Information (CERI), 26 
West Martin Luther King Drive, Cincinnati, Ohio 45268-1072 (513-569-
7562).
    (6) Military standard specification (mil. spec.) 810-E as listed in 
Department of Defense Index of Specifications and Standards (DODISS), 
available from DODSSP-Customer Service, Standardization Documents Order 
Desk, 700 Robbins Avenue, Building 4D, Philadelphia, PA 1911-5094.
    e. Subpart F is added to read as follows:
Subpart F--Procedures for Testing Performance Characteristics of Class 
II Equivalent Methods for PM2.5
Sec.

53.60   General provisions.
53.61   Test conditions for PM2.5 reference method 
equivalency.
53.62   Test procedure: Full wind tunnel test.
53.63   Test procedure: Wind tunnel inlet aspiration test.
53.64   Test procedure: Static fractionator test.
53.65   Test procedure: Loading test.
53.66   Test procedure: Volatility test.
Tables to Subpart F of Part 53
Table F-1--Performance Specifications for PM2.5 Class II 
Equivalent Samplers
Table F-2--Particle Sizes and Wind Speeds for Full Wind Tunnel Test, 
Wind Tunnel

[[Page 38815]]

Inlet Aspiration Test, and Static Chamber Test
Table F-3--Critical Parameters of Idealized Ambient Particle Size 
Distributions
Table F-4--Estimated Mass Concentration Measurement of 
PM2.5 for Idealized Coarse Aerosol Size Distribution
Table F-5--Estimated Mass Concentration Measurement of 
PM2.5 for Idealized ``Typical'' Coarse Aerosol Size 
Distribution
Table F-6 Estimated Mass Concentration Measurement of 
PM2.5 for Idealized Fine Aerosol Size Distribution
Figures to Subpart F of Part 53
Figure F-1--Designation Testing Checklist
Appendix A to Subpart F of Part 53--References

Subpart F--Procedures for Testing Performance Characteristics of 
Class II Equivalent Methods for PM2.5


Sec. 53.60   General provisions.

    (a) This subpart sets forth the specific requirements that a 
PM2.5 sampler associated with a candidate Class II 
equivalent method must meet to be designated as an equivalent method 
for PM2.5. This subpart also sets forth the explicit test 
procedures that must be carried out and the test results, evidence, 
documentation, and other materials that must be provided to EPA to 
demonstrate that a sampler meets all specified requirements for 
designation as an equivalent method.
    (b) A candidate method described in an application for a reference 
or equivalent method application submitted under Sec. 53.4 shall be 
determined by the EPA to be a Class II candidate equivalent method on 
the basis of the definition of a Class II equivalent method given in 
Sec. 53.1.
    (c) Any sampler associated with a Class II candidate equivalent 
method (Class II sampler) must meet all requirements for reference 
method samplers and Class I equivalent method samplers specified in 
subpart E of this part, as appropriate. In addition, a Class II sampler 
must meet the additional requirements as specified in paragraph (d) of 
this section.
    (d) Except as provided in paragraphs (d)(1), (2), and (3) of this 
section, all Class II samplers are subject to the additional tests and 
performance requirements specified in Sec. 53.62 (full wind tunnel 
test), Sec. 53.65 (loading test), and Sec. 53.66 (volatility test). 
Alternative tests and performance requirements, as described in 
paragraphs (d)(1), (2), and (3) of this section, are optionally 
available for certain Class II samplers which meet the requirements for 
reference method or Class I samplers given in 40 CFR part 50, Appendix 
L, and in subpart E of this part, except for specific deviations of the 
inlet, fractionator, or filter.
    (1) Inlet deviation. A sampler which has been determined to be a 
Class II sampler solely because the design or construction of its inlet 
deviates from the design or construction of the inlet specified in 40 
CFR part 50, Appendix L, for reference method samplers shall not be 
subject to the requirements of Sec. 53.62 (full wind tunnel test), 
provided that it meets all requirements of Sec. 53.63 (wind tunnel 
inlet aspiration test), Sec. 53.65 (loading test), and Sec. 53.66 
(volatility test).
    (2) Fractionator deviation. A sampler which has been determined to 
be a Class II sampler solely because the design or construction of its 
particle size fractionator deviates from the design or construction of 
the particle size fractionator specified in 40 CFR part 50, Appendix L 
for reference method samplers shall not be subject to the requirements 
of Sec. 53.62 (full wind tunnel test), provided that it meets all 
requirements of Sec. 53.64 (static fractionator test), Sec. 53.65 
(loading test), and Sec. 53.66 (volatility test).
    (3) Filter size deviation. A sampler which has been determined to 
be a Class II sampler solely because its effective filtration area 
deviates from that of the reference method filter specified in 40 CFR 
part 50, Appendix L, for reference method samplers shall not be subject 
to the requirements of Sec. 53.62 (full wind tunnel test) nor 
Sec. 53.65 (loading test), provided it meets all requirements of 
Sec. 53.66 (volatility test).
    (e) The test specifications and acceptance criteria for each test 
are summarized in Table F-1 of this subpart. The candidate sampler must 
demonstrate performance that meets the acceptance criteria for each 
applicable test to be designated as an equivalent method.
    (f) Overview of various test procedures for Class II samplers--(1) 
Full wind tunnel test. This test procedure is designed to ensure that 
the candidate sampler's effectiveness (aspiration of an ambient aerosol 
and penetration of the sub 2.5-micron fraction to its sample filter) 
will be comparable to that of a reference method sampler. The candidate 
sampler is challenged at wind speeds of 2 and 24 km/hr with 
monodisperse aerosols of the size specified in Table F-2 of this 
subpart. The experimental test results are then integrated with three 
idealized ambient distributions (typical, fine, and coarse) to yield 
the expected mass concentration measurement for each. The acceptance 
criteria are based on the results of this numerical analysis and the 
particle diameter for which the sampler effectiveness is 50 percent.
    (2) Wind tunnel inlet aspiration test. The wind tunnel inlet 
aspiration test directly compares the inlet of the candidate sampler to 
the inlet of a reference method sampler with the single-sized, liquid, 
monodisperse challenge aerosol specified in Table F-2 of this subpart 
at wind speeds of 2 km/hr and 24 km/hr. The acceptance criteria, 
presented in Table F-1 of this subpart, is based on the relative 
aspiration between the candidate inlet and the reference method inlet.
    (3) Static fractionator test. The static fractionator test 
determines the effectiveness of the candidate sampler's 2.5-micron 
fractionator under static conditions for aerosols of the size specified 
in Table F-2 of this subpart. The numerical analysis procedures and 
acceptance criteria are identical to those in the full wind tunnel 
test.
    (4) Loading test. The loading test is conducted to ensure that the 
performance of a candidate sampler is not significantly affected by the 
amount of particulate deposited on its interior surfaces between 
periodic cleanings. The candidate sampler is artificially loaded by 
sampling a test environment containing aerosolized, standard test dust. 
The duration of the loading phase is dependent on both the time between 
cleaning as specified by the candidate method and the aerosol mass 
concentration in the test environment. After loading, the candidate's 
performance must then be evaluated by Sec. 53.62 (full wind tunnel 
evaluation), Sec. 53.64 (wind tunnel inlet aspiration test), or 
Sec. 53.64 (static fractionator test). If the results of the 
appropriate test meet the criteria presented in Table F-1 of this 
subpart, then the candidate sampler passes the loading test under the 
condition that it be cleaned at least as often as the cleaning 
frequency proposed by the candidate method and that has been 
demonstrated to be acceptable by this test.
    (5) Volatility test. The volatility test challenges the candidate 
sampler with a polydisperse, semi-volatile liquid aerosol. This aerosol 
is simultaneously sampled by the candidate method sampler and a 
reference method sampler for a specified time period. Clean air is then 
passed through the samplers during a blow-off time period. Residual 
mass is then calculated as the weight of the filter after the blow-off 
phase is subtracted from the initial weight of the filter. Acceptance 
criteria are based on a comparison of the residual mass measured by the 
candidate sampler (corrected for flow rate variations from that of the 
reference method) to the

[[Page 38816]]

residual mass measured by the reference method sampler for several 
specified clean air sampling time periods.
    (g) Test data. All test data and other documentation obtained from 
or pertinent to these tests shall be identified, dated, signed by the 
analyst performing the test, and submitted to EPA as part of the 
equivalent method application. Schematic drawings of each particle 
delivery system and other information showing complete procedural 
details of the test atmosphere generation, verification, and delivery 
techniques for each test performed shall be submitted to EPA. All 
pertinent calculations shall be clearly presented. In addition, 
manufacturers are required to submit as part of the application, a 
Designation Testing Checklist (Figure F-1 of this subpart) which has 
been completed and signed by an ISO-certified auditor.


Sec. 53.61   Test conditions for PM2.5 reference method 
equivalency.

    (a) Sampler surface preparation. Internal surfaces of the candidate 
sampler shall be cleaned and dried prior to performing any Class II 
sampler test in this subpart. The internal collection surfaces of the 
sampler shall then be prepared in strict accordance with the operating 
instructions specified in the sampler's operating manual referred to in 
section 7.4.18 of 40 CFR part 50, Appendix L.
    (b) Sampler setup. Set up and start up of all test samplers shall 
be in strict accordance with the operating instructions specified in 
the manual referred to in section 7.4.18 of 40 CFR part 50, Appendix L, 
unless otherwise specified within this subpart.
    (c) Sampler adjustments. Once the test sampler or samplers have 
been set up and the performance tests started, manual adjustment shall 
be permitted only between test points for all applicable tests. Manual 
adjustments and any periodic maintenance shall be limited to only those 
procedures prescribed in the manual referred to in section 7.4.18 of 40 
CFR part 50, Appendix L. The submitted records shall clearly indicate 
when any manual adjustment or periodic maintenance was made and shall 
describe the operations performed.
    (d) Sampler malfunctions. If a test sampler malfunctions during any 
of the applicable tests, that test run shall be repeated. A detailed 
explanation of all malfunctions and the remedial actions taken shall be 
submitted as part of the equivalent method application.
    (e) Particle concentration measurements. All measurements of 
particle concentration must be made such that the relative error in 
measurement is less than 5.0 percent. Relative error is defined as (s 
x  100 percent)/(X), where s is the sample standard deviation of the 
particle concentration detector, X is the measured concentration, and 
the units of s and X are identical.
    (f) Operation of test measurement equipment. All test measurement 
equipment shall be set up, calibrated, and maintained by qualified 
personnel according to the manufacturer's instructions. All appropriate 
calibration information and manuals for this equipment shall be kept on 
file.
    (g) Vibrating orifice aerosol generator conventions. This section 
prescribes conventions regarding the use of the vibrating orifice 
aerosol generator (VOAG) for the size-selective performance tests 
outlined in Secs. 53.62, 53.63, 53.64, and 53.65.
    (1) Particle aerodynamic diameter. The VOAG produces near-
monodisperse droplets through the controlled breakup of a liquid jet. 
When the liquid solution consists of a non-volatile solute dissolved in 
a volatile solvent, the droplets dry to form particles of near-
monodisperse size.
    (i) The physical diameter of a generated spherical particle can be 
calculated from the operating parameters of the VOAG as:

Equation 1
[GRAPHIC] [TIFF OMITTED] TR18JY97.094

where:
Dp = particle physical diameter, m;
Q = liquid volumetric flow rate, m3/sec;
Cvol = volume concentration (particle volume produced per 
drop volume), dimensionless; and
f = frequency of applied vibrational signal, 1/sec.

    (ii) A given particle's aerodynamic behavior is a function of its 
physical particle size, particle shape, and density. Aerodynamic 
diameter is defined as the diameter of a unit density 
(o = 1 g/m3) sphere having the same 
settling velocity as the particle under consideration. For converting a 
spherical particle of known density to aerodynamic diameter, the 
governing relationship is:

Equation 2
[GRAPHIC] [TIFF OMITTED] TR18JY97.095

where:
Dae = particle aerodynamic diameter, m;
p = particle density, g/cm3;
o = aerodynamic particle density = 1 g/
m3;
CDp = Cunningham's slip correction factor for physical 
particle diameter, dimensionless; and
CDae = Cunningham's slip correction factor for 
aerodynamic particle diameter, dimensionless.

    (iii) At room temperature and standard pressure, the Cunningham's 
slip correction factor is solely a function of particle diameter:

Equation 3
[GRAPHIC] [TIFF OMITTED] TR18JY97.096

or

Equation 4
[GRAPHIC] [TIFF OMITTED] TR18JY97.097

    (iv) Since the slip correction factor is itself a function of 
particle diameter, the aerodynamic diameter in Equation 2 of paragraph 
(g)(1)(ii) of this section cannot be solved directly but must be 
determined by iteration.
    (2) Solid particle generation. (i) Solid particle tests performed 
in this subpart shall be conducted using particles composed of ammonium 
fluorescein. For use in the VOAG, liquid solutions of known volumetric 
concentration can be prepared by diluting fluorescein powder 
(C20H12O5, FW = 332.31, CAS 2321-07-5) 
with aqueous ammonia. Guidelines for preparation of fluorescein 
solutions of the desired volume concentration (Cvol) are 
presented by Vanderpool and Rubow (1988) (Reference 2 in Appendix A of 
this subpart). For purposes of converting particle physical diameter to 
aerodynamic diameter, an ammonium fluorescein density of 1.35 g/
cm3 shall be used.
    (ii) Mass deposits of ammonium fluorescein shall be extracted and 
analyzed using solutions of 0.01 N ammonium hydroxide.
    (3) Liquid particle generation. (i) Tests prescribed in Sec. 53.63 
for inlet aspiration require the use of liquid particle tests composed 
of oleic acid tagged with uranine to enable subsequent fluorometric 
quantitation of collected aerosol mass deposits. Oleic acid 
(C18H34O2, FW = 282.47, CAS 112-80-1) 
has a density of 0.8935 g/cm3. Because the viscosity of 
oleic acid is relatively high, significant errors can occur when 
dispensing oleic acid using volumetric pipettes. For this reason, it is 
recommended that oleic acid solutions be prepared by quantifying 
dispensed oleic acid gravimetrically. The volume of oleic acid 
dispensed can then be calculated simply by dividing the

[[Page 38817]]

dispensed mass by the oleic acid density.
    (ii) Oleic acid solutions tagged with uranine shall be prepared as 
follows. A known mass of oleic acid shall first be diluted using 
absolute ethanol. The desired mass of the uranine tag should then be 
diluted in a separate container using absolute ethanol. Uranine 
(C20H10O5Na2, FW = 376.3, 
CAS 518-47-8) is the disodium salt of fluorescein and has a density of 
1.53 g/cm3. In preparing uranine tagged oleic acid 
particles, the uranine content shall not exceed 20 percent on a mass 
basis. Once both oleic acid and uranine solutions are properly 
prepared, they can then be combined and diluted to final volume using 
absolute ethanol.
    (iii) Calculation of the physical diameter of the particles 
produced by the VOAG requires knowledge of the liquid solution's volume 
concentration (Cvol). Because uranine is essentially 
insoluble in oleic acid, the total particle volume is the sum of the 
oleic acid volume and the uranine volume. The volume concentration of 
the liquid solution shall be calculated as:

Equation 5
[GRAPHIC] [TIFF OMITTED] TR18JY97.098

where:
Vu = uranine volume, ml;
Voleic = oleic acid volume, ml;
Vsol = total solution volume, ml;
Mu = uranine mass, g;
u = uranine density, g/cm3;
Moleic = oleic acid mass, g; and
oleic = oleic acid density, g/cm3.

    (iv) For purposes of converting the particles' physical diameter to 
aerodynamic diameter, the density of the generated particles shall be 
calculated as:

Equation 6
[GRAPHIC] [TIFF OMITTED] TR18JY97.099

    (v) Mass deposits of oleic acid shall be extracted and analyzed 
using solutions of 0.01 N sodium hydroxide.


Sec. 53.62   Test procedure: Full wind tunnel test.

    (a) Overview. The full wind tunnel test evaluates the effectiveness 
of the candidate sampler at 2 km/hr and 24 km/hr for aerosols of the 
size specified in Table F-2 of this subpart (under the heading, ``Full 
Wind Tunnel Test''). For each wind speed, a smooth curve is fit to the 
effectiveness data and corrected for the presence of multiplets in the 
wind tunnel calibration aerosol. The cutpoint diameter 
(Dp50) at each wind speed is then determined from the 
corrected effectiveness curves. The two resultant penetration curves 
are then each numerically integrated with three idealized ambient 
particle size distributions to provide six estimates of measured mass 
concentration. Critical parameters for these idealized distributions 
are presented in Table F-3 of this subpart.
    (b) Technical definitions. Effectiveness is the ratio (expressed as 
a percentage) of the mass concentration of particles of a specific size 
reaching the sampler filter or filters to the mass concentration of 
particles of the same size approaching the sampler.
    (c) Facilities and equipment required--(1) Wind tunnel. The 
particle delivery system shall consist of a blower system and a wind 
tunnel having a test section of sufficiently large cross-sectional area 
such that the test sampler, or portion thereof, as installed in the 
test section for testing, blocks no more than 15 percent of the test 
section area. The wind tunnel blower system must be capable of 
maintaining uniform wind speeds at the 2 km/hr and 24 km/hr in the test 
section.
    (2) Aerosol generation system. A vibrating orifice aerosol 
generator shall be used to produce monodisperse solid particles of 
ammonium fluorescein with equivalent aerodynamic diameters as specified 
in Table F-2 of this subpart. The geometric standard deviation for each 
particle size generated shall not exceed 1.1 (for primary particles) 
and the proportion of multiplets (doublets and triplets) in all test 
particle atmosphere shall not exceed 10 percent of the particle 
population. The aerodynamic particle diameter, as established by the 
operating parameters of the vibrating orifice aerosol generator, shall 
be within the tolerance specified in Table F-2 of this subpart.
    (3) Particle size verification equipment. The size of the test 
particles shall be verified during this test by use of a suitable 
instrument (e.g., scanning electron microscope, optical particle sizer, 
time-of-flight apparatus). The instrument must be capable of measuring 
solid and liquid test particles with a size resolution of 0.1 
m or less. The accuracy of the particle size verification 
technique shall be 0.15 m or better.
    (4) Wind speed measurement. The wind speed in the wind tunnel shall 
be determined during the tests using an appropriate technique capable 
of a precision of 2 percent and an accuracy of 5 percent or better 
(e.g., hot-wire anemometry). For the wind speeds specified in Table F-2 
of this subpart, the wind speed shall be measured at a minimum of 12 
test points in a cross-sectional area of the test section of the wind 
tunnel. The mean wind speed in the test section must be within 
 10 percent of the value specified in Table F-2 of this 
subpart, and the variation at any test point in the test section may 
not exceed 10 percent of the measured mean.
    (5) Aerosol rake. The cross-sectional uniformity of the particle 
concentration in the sampling zone of the test section shall be 
established during the tests using an array of isokinetic samplers, 
referred to as a rake. Not less than five evenly spaced isokinetic 
samplers shall be used to determine the particle concentration spatial 
uniformity in the sampling zone. The sampling zone shall be a 
rectangular area having a horizontal dimension not less than 1.2 times 
the width of the test sampler at its inlet opening and a vertical 
dimension not less than 25 centimeters.
    (6) Total aerosol isokinetic sampler. After cross-sectional 
uniformity has been confirmed, a single isokinetic sampler may be used 
in place of the array of isokinetic samplers for the determination of 
particle mass concentration used in the calculation of sampling 
effectiveness of the test sampler in paragraph (d)(5) of this section. 
In this case, the array of isokinetic samplers must be used to 
demonstrate particle concentration uniformity prior to the replicate 
measurements of sampling effectiveness.
    (7) Fluorometer. A fluorometer used for quantifying extracted 
aerosol mass deposits shall be set up, maintained, and calibrated 
according to the manufacturer's instructions. A series of calibration 
standards shall be prepared to encompass the minimum and maximum 
concentrations measured during size-selective tests. Prior to each 
calibration and measurement, the fluorometer shall be zeroed using an 
aliquot of the same solvent used for extracting aerosol mass deposits.
    (8) Sampler flow rate measurements. All flow rate measurements used 
to calculate the test atmosphere concentrations and the test results 
must be accurate to within  2 percent, referenced to a 
NIST-traceable primary standard. Any necessary flow rate measurement 
corrections shall be clearly documented. All flow rate measurements 
shall be performed and reported in actual volumetric units.
    (d) Test procedures--(1) Establish and verify wind speed. (i) 
Establish a wind speed specified in Table F-2 of this subpart.

[[Page 38818]]

    (ii) Measure the wind speed at a minimum of 12 test points in a 
cross-sectional area of the test section of the wind tunnel using a 
device as described in paragraph (c)(4) of this section.
    (iii) Verify that the mean wind speed in the test section of the 
wind tunnel during the tests is within 10 percent of the value 
specified in Table F-2 of this subpart. The wind speed measured at any 
test point in the test section shall not differ by more than 10 percent 
from the mean wind speed in the test section.
    (2) Generate aerosol. (i) Generate particles of a size specified in 
Table F-2 of this subpart using a vibrating orifice aerosol generator.
    (ii) Check for the presence of satellites and adjust the generator 
as necessary.
    (iii) Calculate the physical particle size using the operating 
parameters of the vibrating orifice aerosol generator and record.
    (iv) Determine the particle's aerodynamic diameter from the 
calculated physical diameter and the known density of the generated 
particle. The calculated aerodynamic diameter must be within the 
tolerance specified in Table F-2 of this subpart.
    (3) Introduce particles into the wind tunnel. Introduce the 
generated particles into the wind tunnel and allow the particle 
concentration to stabilize.
    (4) Verify the quality of the test aerosol. (i) Extract a 
representative sample of the aerosol from the sampling test zone and 
measure the size distribution of the collected particles using an 
appropriate sizing technique. If the measurement technique does not 
provide a direct measure of aerodynamic diameter, the geometric mean 
aerodynamic diameter of the challenge aerosol must be calculated using 
the known density of the particle and the measured mean physical 
diameter. The determined geometric mean aerodynamic diameter of the 
test aerosol must be within 0.15 m of the aerodynamic diameter 
calculated from the operating parameters of the vibrating orifice 
aerosol generator. The geometric standard deviation of the primary 
particles must not exceed 1.1.
    (ii) Determine the population of multiplets in the collected 
sample. The multiplet population of the particle test atmosphere must 
not exceed 10 percent of the total particle population.
    (5) Aerosol uniformity and concentration measurement. (i) Install 
an array of five or more evenly spaced isokinetic samplers in the 
sampling zone (paragraph (c)(5) of this section). Collect particles on 
appropriate filters over a time period such that the relative error of 
the measured particle concentration is less than 5.0 percent.
    (ii) Determine the quantity of material collected with each 
isokinetic sampler in the array using a calibrated fluorometer. 
Calculate and record the mass concentration for each isokinetic sampler 
as:

Equation 7
[GRAPHIC] [TIFF OMITTED] TR18JY97.100

where:
i = replicate number;
j = isokinetic sampler number;
Miso = mass of material collected with the isokinetic 
sampler;
Q = isokinetic sampler volumetric flow rate; and
t = sampling time.

    (iii) Calculate and record the mean mass concentration as:

Equation 8
[GRAPHIC] [TIFF OMITTED] TR18JY97.101

where:
i = replicate number;
j = isokinetic sampler number; and
n = total number of isokinetic samplers.

    (iv) Precision calculation. (A) Calculate the coefficient of 
variation of the mass concentration measurements as:

Equation 9
[GRAPHIC] [TIFF OMITTED] TR18JY97.102

where:
i = replicate number;
j = isokinetic sampler number; and
n = total number of isokinetic samplers.

    (B) If the value of CViso(i) for any replicate exceeds 
10 percent, the particle concentration uniformity is unacceptable and 
step 5 must be repeated. If adjustment of the vibrating orifice aerosol 
generator or changes in the particle delivery system are necessary to 
achieve uniformity, steps 1 through 5 must be repeated. When an 
acceptable aerosol spatial uniformity is achieved, remove the array of 
isokinetic samplers from the wind tunnel.
    (6) Alternative measure of wind tunnel total concentration. If a 
single isokinetic sampler is used to determine the mean aerosol 
concentration in the wind tunnel, install the sampler in the wind 
tunnel with the sampler nozzle centered in the sampling zone (paragraph 
(c)(6) of this section).
    (i) Collect particles on an appropriate filter over a time period 
such that the relative error of the measured concentration is less than 
5.0 percent.
    (ii) Determine the quantity of material collected with the 
isokinetic sampler using a calibrated fluorometer.
    (iii) Calculate and record the mass concentration as 
Ciso(i) as in paragraph (d)(5)(ii) of this section.
    (iv) Remove the isokinetic sampler from the wind tunnel.
    (7) Measure the aerosol with the candidate sampler. (i) Install the 
test sampler (or portion thereof) in the wind tunnel with the sampler 
inlet opening centered in the sampling zone. To meet the maximum 
blockage limit of paragraph (c)(1) of this section or for convenience, 
part of the test sampler may be positioned external to the wind tunnel 
provided that neither the geometry of the sampler nor the length of any 
connecting tube or pipe is altered. Collect particles for a time period 
such that the relative error of the measured concentration is less than 
5.0 percent.
    (ii) Remove the test sampler from the wind tunnel.
    (iii) Determine the quantity of material collected with the test 
sampler using a calibrated fluorometer. Calculate and record the mass 
concentration for each replicate as:

Equation 10
[GRAPHIC] [TIFF OMITTED] TR18JY97.103

where:
i = replicate number;
Mcand = mass of material collected with the candidate 
sampler;
Q = candidate sampler volumetric flow rate; and
t = sampling time.


[[Page 38819]]


    (iv)(A) Calculate and record the sampling effectiveness of the 
candidate sampler as:

Equation 11
[GRAPHIC] [TIFF OMITTED] TR18JY97.104

where:
i = replicate number.

    (B) If a single isokinetic sampler is used for the determination of 
particle mass concentration, replace Ciso(i) with 
Ciso.
    (8) Replicate measurements and calculation of mean sampling 
effectiveness. (i) Repeat steps in paragraphs (d)(5) through (d)(7) of 
this section, as appropriate, to obtain a minimum of three valid 
replicate measurements of sampling effectiveness.
    (ii) Calculate and record the average sampling effectiveness of the 
test sampler for the particle size as:

Equation 12
[GRAPHIC] [TIFF OMITTED] TR18JY97.105

where:
i = replicate number; and
n = number of replicates.

    (iii) Sampling effectiveness precision. (A) Calculate and record 
the coefficient of variation for the replicate sampling effectiveness 
measurements of the test sampler as:

Equation 13
[GRAPHIC] [TIFF OMITTED] TR18JY97.106

where:
i = replicate number, and
n = number of replicates.

    (B) If the value of CVE exceeds 10 percent, the test run 
(steps in paragraphs (d)(2) through (d)(8) of this section) must be 
repeated until an acceptable value is obtained.
    (9) Repeat steps in paragraphs (d)(2) through (d)(8) of this 
section until the sampling effectiveness has been measured for all 
particle sizes specified in Table F-2 of this subpart.
    (10) Repeat steps in paragraphs (d)(1) through (d)(9) of this 
section until tests have been successfully conducted for both wind 
speeds of 2 km/hr and 24 km/hr.
    (e) Calculations--(1) Graphical treatment of effectiveness data. 
For each wind speed given in Table F-2 of this subpart, plot the 
particle average sampling effectiveness of the candidate sampler as a 
function of aerodynamic particle diameter (Dae) on semi-
logarithmic graph paper where the aerodynamic particle diameter is the 
particle size established by the parameters of the VOAG in conjunction 
with the known particle density. Construct a best-fit, smooth curve 
through the data by extrapolating the sampling effectiveness curve 
through 100 percent at an aerodynamic particle size of 0.5 m 
and 0 percent at an aerodynamic particle size of 10 m. 
Correction for the presence of multiplets shall be performed using the 
techniques presented by Marple, et al (1987). This multiplet-corrected 
effectiveness curve shall be used for all remaining calculations in 
this paragraph (e).
    (2) Cutpoint determination. For each wind speed determine the 
sampler Dp50 cutpoint defined as the aerodynamic particle 
size corresponding to 50 percent effectiveness from the multiplet 
corrected smooth curve.
    (3) Expected mass concentration calculation. For each wind speed, 
calculate the estimated mass concentration measurement for the test 
sampler under each particle size distribution (Tables F-4, F-5, and F-6 
of this subpart) and compare it to the mass concentration predicted for 
the reference sampler as follows:
    (i) Determine the value of corrected effectiveness using the best-
fit, multiplet-corrected curve at each of the particle sizes specified 
in the first column of Table F-4 of this subpart. Record each corrected 
effectiveness value as a decimal between 0 and 1 in column 2 of Table 
F-4 of this subpart.
    (ii) Calculate the interval estimated mass concentration 
measurement by multiplying the values of corrected effectiveness in 
column 2 by the interval mass concentration values in column 3 and 
enter the products in column 4 of Table F-4 of this subpart.
    (iii) Calculate the estimated mass concentration measurement by 
summing the values in column 4 and entering the total as the estimated 
mass concentration measurement for the test sampler at the bottom of 
column 4 of Table F-4 of this subpart.
    (iv) Calculate the estimated mass concentration ratio between the 
candidate method and the reference method as:

Equation 14
[GRAPHIC] [TIFF OMITTED] TR18JY97.107

where:
Ccand(est) = estimated mass concentration measurement for 
the test sampler, g/m3; and
Cref(est) = estimated mass concentration measurement for 
the reference sampler, g/m3 (calculated for the 
reference sampler and specified at the bottom of column 7 of Table 
F-4 of this subpart).

    (v) Repeat steps in paragraphs (e) (1) through (e)(3) of this 
section for Tables F-5 and F-6 of this subpart.
    (f) Evaluation of test results. The candidate method passes the 
wind tunnel effectiveness test if the Rc value for each wind 
speed meets the specification in Table F-1 of this subpart for each of 
the three particle size distributions.


Sec. 53.63   Test procedure: Wind tunnel inlet aspiration test.

    (a) Overview. This test applies to a candidate sampler which 
differs from the reference method sampler only with respect to the 
design of the inlet. The purpose of this test is to ensure that the 
aspiration of a Class II candidate sampler is such that it 
representatively extracts an ambient aerosol at elevated wind speeds. 
This wind tunnel test uses a single-sized, liquid aerosol in 
conjunction with wind speeds of 2 km/hr and 24 km/hr. The test 
atmosphere concentration is alternately measured with the candidate 
sampler and a reference method device, both of which are operated 
without the 2.5-micron fractionation device installed. The test 
conditions are summarized in Table F-2 of this subpart (under the 
heading of ``wind tunnel inlet aspiration test''). The candidate 
sampler must meet or exceed the acceptance criteria given in Table F-1 
of this subpart.
    (b) Technical definition. Relative aspiration is the ratio 
(expressed as a percentage) of the aerosol mass concentration measured 
by the candidate sampler to that measured by a reference method 
sampler.
    (c) Facilities and equipment required. The facilities and equipment 
are identical to those required for the full wind tunnel test 
(Sec. 53.62(c)).
    (d) Setup. The candidate and reference method samplers shall be 
operated with the PM2.5 fractionation device removed from 
the flow path throughout this entire test procedure. Modifications to 
accommodate this requirement shall be limited to removal of the 
fractionator and insertion of the filter holder directly into the 
downtube of the inlet.
    (e) Test procedure--(1) Establish the wind tunnel test atmosphere. 
Follow the procedures in Sec. 53.62(d)(1) through (d)(4) to establish a 
test atmosphere for one of the two wind speeds specified in Table F-2 
of this subpart.

[[Page 38820]]

    (2) Measure the aerosol concentration with the reference sampler. 
(i) Install the reference sampler (or portion thereof) in the wind 
tunnel with the sampler inlet opening centered in the sampling zone. To 
meet the maximum blockage limit of Sec. 53.62(c)(1) or for convenience, 
part of the test sampler may be positioned external to the wind tunnel 
provided that neither the geometry of the sampler nor the length of any 
connecting tube or pipe is altered. Collect particles for a time period 
such that the relative error of the measured concentration is less than 
5.0 percent.
    (ii) Determine the quantity of material collected with the 
reference method sampler using a calibrated fluorometer. Calculate and 
record the mass concentration as:

Equation 15
[GRAPHIC] [TIFF OMITTED] TR18JY97.108

where:
i = replicate number;
Mref = mass of material collected with the reference 
method sampler;
Q = reference method sampler volumetric flow rate; and
t = sampling time.

    (iii) Remove the reference method sampler from the tunnel.
    (3) Measure the aerosol concentration with the candidate sampler. 
(i) Install the candidate sampler (or portion thereof) in the wind 
tunnel with the sampler inlet centered in the sampling zone. To meet 
the maximum blockage limit of Sec. 53.62(c)(1) or for convenience, part 
of the test sampler may be positioned external to the wind tunnel 
provided that neither the geometry of the sampler nor the length of any 
connecting tube or pipe is altered. Collect particles for a time period 
such that the relative error of the measured concentration is less than 
5.0 percent.
    (ii) Determine the quantity of material collected with the 
candidate sampler using a calibrated fluorometer. Calculate and record 
the mass concentration as:

Equation 16
[GRAPHIC] [TIFF OMITTED] TR18JY97.109

where:
i = replicate number;
Mcand = mass of material collected with the candidate 
sampler;
Q = candidate sampler volumetric flow rate; and
t = sampling time.

    (iii) Remove the candidate sampler from the wind tunnel.
    (4) Repeat steps in paragraphs (d) (2) and (d)(3) of this section. 
Alternately measure the tunnel concentration with the reference sampler 
and the candidate sampler until four reference sampler and three 
candidate sampler measurements of the wind tunnel concentration are 
obtained.
    (5) Calculations. (i) Calculate and record aspiration ratio for 
each candidate sampler run as:

Equation 17
[GRAPHIC] [TIFF OMITTED] TR18JY97.110

where:
i = replicate number.

    (ii) Calculate and record the mean aspiration ratio as:

Equation 18
[GRAPHIC] [TIFF OMITTED] TR18JY97.111

where:
i = replicate number; and
n = total number of measurements of aspiration ratio.

    (iii) Precision of the aspiration ratio. (A) Calculate and record 
the precision of the aspiration ratio measurements as the coefficient 
of variation as:

Equation 19
[GRAPHIC] [TIFF OMITTED] TR18JY97.112

where:
i = replicate number; and
n = total number of measurements of aspiration ratio.

    (B) If the value of CVA exceeds 10 percent, the entire 
test procedure must be repeated.
    (f) Evaluation of test results. The candidate method passes the 
inlet aspiration test if all values of A meet the acceptance criteria 
specified in Table F-1 of this subpart.


Sec. 53.64   Test procedure: Static fractionator test.

    (a) Overview. This test applies only to those candidate methods in 
which the sole deviation from the reference method is in the design of 
the 2.5-micron fractionation device. The purpose of this test is to 
ensure that the fractionation characteristics of the candidate 
fractionator are acceptably similar to that of the reference method 
sampler. It is recognized that various methodologies exist for 
quantifying fractionator effectiveness. The following commonly-employed 
techniques are provided for purposes of guidance. Other methodologies 
for determining sampler effectiveness may be used contingent upon prior 
approval by the Agency.
    (1) Wash-off method. Effectiveness is determined by measuring the 
aerosol mass deposited on the candidate sampler's after filter versus 
the aerosol mass deposited in the fractionator. The material deposited 
in the fractionator is recovered by washing its internal surfaces. For 
these wash-off tests, a fluorometer must be used to quantitate the 
aerosol concentration. Note that if this technique is chosen, the 
candidate must be reloaded with coarse aerosol prior to each test point 
when reevaluating the curve as specified in the loading test.
    (2) Static chamber method. Effectiveness is determined by measuring 
the aerosol mass concentration sampled by the candidate sampler's after 
filter versus that which exists in a static chamber. A calibrated 
fluorometer shall be used to quantify the collected aerosol deposits. 
The aerosol concentration is calculated as the measured aerosol mass 
divided by the sampled air volume.
    (3) Divided flow method. Effectiveness is determined by comparing 
the aerosol concentration upstream of the candidate sampler's 
fractionator versus that concentration which exists downstream of the 
candidate fractionator. These tests may utilize either fluorometry or a 
real-time aerosol measuring device to determine the aerosol 
concentration.
    (b) Technical definition. Effectiveness under static conditions is 
the ratio (expressed as a percentage) of the mass concentration of 
particles of a given size reaching the sampler filter to the mass 
concentration of particles of the same size existing in the test 
atmosphere.
    (c) Facilities and equipment required--(1) Aerosol generation. 
Methods for generating aerosols shall be identical to those prescribed 
in Sec. 53.62(c)(2).
    (2) Particle delivery system. Acceptable apparatus for delivering 
the generated aerosols to the candidate fractionator is dependent on 
the effectiveness measurement methodology and shall be defined as 
follows:
    (i) Wash-off test apparatus. The aerosol may be delivered to the 
candidate fractionator through direct piping (with or without an in-
line mixing chamber). Validation particle size and quality shall be 
conducted at a point directly upstream of the fractionator.

[[Page 38821]]

    (ii) Static chamber test apparatus. The aerosol shall be introduced 
into a chamber and sufficiently mixed such that the aerosol 
concentration within the chamber is spatially uniform. The chamber must 
be of sufficient size to house at least four total filter samplers in 
addition to the inlet of the candidate method size fractionator. 
Validation of particle size and quality shall be conducted on 
representative aerosol samples extracted from the chamber.
    (iii) Divided flow test apparatus. The apparatus shall allow the 
aerosol concentration to be measured upstream and downstream of the 
fractionator. The aerosol shall be delivered to a manifold with two 
symmetrical branching legs. One of the legs, referred to as the bypass 
leg, shall allow the challenge aerosol to pass unfractionated to the 
detector. The other leg shall accommodate the fractionation device.
    (3) Particle concentration measurement--(i) Fluorometry. Refer to 
Sec. 53.62(c)(7).
    (ii) Number concentration measurement. A number counting particle 
sizer may be used in conjunction with the divided flow test apparatus 
in lieu of fluorometric measurement. This device must have a minimum 
range of 1 to 10 m, a resolution of 0.1 m, and an 
accuracy of 0.15 m such that primary particles may be 
distinguished from multiplets for all test aerosols. The measurement of 
number concentration shall be accomplished by integrating the primary 
particle peak.
    (d) Setup--(1) Remove the inlet and downtube from the candidate 
fractionator. All tests procedures shall be conducted with the inlet 
and downtube removed from the candidate sampler.
    (2) Surface treatment of the fractionator. Rinsing aluminum 
surfaces with alkaline solutions has been found to adversely affect 
subsequent fluorometric quantitation of aerosol mass deposits. If wash-
off tests are to be used for quantifying aerosol penetration, internal 
surfaces of the fractionator must first be plated with electroless 
nickel. Specifications for this plating are specified in Society of 
Automotive Engineers Aerospace Material Specification (SAE AMS) 2404C, 
Electroless Nickel Plating (Reference 3 in Appendix A of Subpart F).
    (e) Test procedure: Wash-off method--(1) Clean the candidate 
sampler. Note: The procedures in this step may be omitted if this test 
is being used to evaluate the fractionator after being loaded as 
specified in Sec. 53.65.
    (i) Clean and dry the internal surfaces of the candidate sampler.
    (ii) Prepare the internal fractionator surfaces in strict 
accordance with the operating instructions specified in the sampler's 
operating manual referred to in section 7.4.18 of 40 CFR part 50, 
Appendix L.
    (2) Generate aerosol. Follow the procedures for aerosol generation 
prescribed in Sec. 53.62(d)(2).
    (3) Verify the quality of the test aerosol. Follow the procedures 
for verification of test aerosol size and quality prescribed in 
Sec. 53.62(d)(4).
    (4) Determine effectiveness for the particle size being produced. 
(i) Collect particles downstream of the fractionator on an appropriate 
filter over a time period such that the relative error of the 
fluorometric measurement is less than 5.0 percent.
    (ii) Determine the quantity of material collected on the after 
filter of the candidate method using a calibrated fluorometer. 
Calculate and record the aerosol mass concentration for the sampler 
filter as:

Equation 20
[GRAPHIC] [TIFF OMITTED] TR18JY97.113

where:
i = replicate number;
Mcand = mass of material collected with the candidate 
sampler;
Q = candidate sampler volumetric flowrate; and
t = sampling time.

    (iii) Wash all interior surfaces upstream of the filter and 
determine the quantity of material collected using a calibrated 
fluorometer. Calculate and record the fluorometric mass concentration 
of the sampler wash as:

Equation 21
[GRAPHIC] [TIFF OMITTED] TR18JY97.114

where:
i = replicate number;
Mwash = mass of material washed from the interior 
surfaces of the fractionator;
Q = candidate sampler volumetric flowrate; and
t = sampling time.

(iv) Calculate and record the sampling effectiveness of the test 
sampler for this particle size as:

Equation 22
[GRAPHIC] [TIFF OMITTED] TR18JY97.115

where:
i = replicate number.

    (v) Repeat steps in paragraphs (e)(4) of this section, as 
appropriate, to obtain a minimum of three replicate measurements of 
sampling effectiveness. Note: The procedures for loading the candidate 
in Sec. 53.65 must be repeated between repetitions if this test is 
being used to evaluate the fractionator after being loaded as specified 
in Sec. 53.65.
    (vi) Calculate and record the average sampling effectiveness of the 
test sampler as:

Equation 23
[GRAPHIC] [TIFF OMITTED] TR18JY97.116

where:
i = replicate number; and
n = number of replicates.

    (vii)(A) Calculate and record the coefficient of variation for the 
replicate sampling effectiveness measurements of the test sampler as:

Equation 24
[GRAPHIC] [TIFF OMITTED] TR18JY97.117

where:
i = replicate number; and
n = total number of measurements.
    (B) If the value of CVE exceeds 10 percent, then steps 
in paragraphs (e) (2) through (e)(4) of this section must be repeated.
    (5) Repeat steps in paragraphs (e) (1) through (e)(4) of this 
section for each particle size specified in Table F-2 of this subpart.
    (f) Test procedure: Static chamber method--(1) Generate aerosol. 
Follow the procedures for aerosol generation prescribed in 
Sec. 53.62(d)(2).
    (2) Verify the quality of the test aerosol. Follow the procedures 
for verification of test aerosol size and quality prescribed in 
Sec. 53.62(d)(4).
    (3) Introduce particles into chamber. Introduce the particles into 
the static chamber and allow the particle concentration to stabilize.
    (4) Install and operate the candidate sampler's fractionator and 
its after-filter and at least four total filters. (i) Install the 
fractionator and an array of four or more equally spaced total filter 
samplers such that the total filters surround and are in the same plane 
as the inlet of the fractionator.
    (ii) Simultaneously collect particles onto appropriate filters with 
the total filter samplers and the fractionator for a time period such 
that the relative error

[[Page 38822]]

of the measured concentration is less than 5.0 percent.
    (5) Calculate the aerosol spatial uniformity in the chamber. (i) 
Determine the quantity of material collected with each total filter 
sampler in the array using a calibrated fluorometer. Calculate and 
record the mass concentration for each total filter sampler as:

Equation 25
[GRAPHIC] [TIFF OMITTED] TR18JY97.118

where:
i = replicate number;
j = total filter sampler number;
Mtotal = mass of material collected with the total filter 
sampler;
Q = total filter sampler volumetric flowrate; and
t = sample time.

    (ii) Calculate and record the mean mass concentration as:

Equation 26
[GRAPHIC] [TIFF OMITTED] TR18JY97.119

where:
n = total number of samplers;
i = replicate number; and
j = filter sampler number.

    (iii) (A) Calculate and record the coefficient of variation of the 
total mass concentration as:

Equation 27
[GRAPHIC] [TIFF OMITTED] TR18JY97.120

where:
i = replicate number;
j = total filter sampler number; and
n = number of total filter samplers.

    (B) If the value of CVtotal exceeds 10 percent, then the 
particle concentration uniformity is unacceptable, alterations to the 
static chamber test apparatus must be made, and steps in paragraphs 
(f)(1) through (f)(5) of this section must be repeated.
    (6) Determine the effectiveness of the candidate sampler. (i) 
Determine the quantity of material collected on the candidate sampler's 
after filter using a calibrated fluorometer. Calculate and record the 
mass concentration for the candidate sampler as:

Equation 28
[GRAPHIC] [TIFF OMITTED] TR18JY97.121

where:
i = replicate number;
Mcand = mass of material collected with the candidate 
sampler;
Q = candidate sampler volumetric flowrate; and
t = sample time.

    (ii) Calculate and record the sampling effectiveness of the 
candidate sampler as:

Equation 29
[GRAPHIC] [TIFF OMITTED] TR18JY97.122

where:
i = replicate number.

    (iii) Repeat step in paragraph (f)(4) through (f)(6) of this 
section, as appropriate, to obtain a minimum of three replicate 
measurements of sampling effectiveness.
    (iv) Calculate and record the average sampling effectiveness of the 
test sampler as:

Equation 30
[GRAPHIC] [TIFF OMITTED] TR18JY97.123

where:
i= replicate number.

    (v)(A) Calculate and record the coefficient of variation for the 
replicate sampling effectiveness measurements of the test sampler as:

Equation 31
[GRAPHIC] [TIFF OMITTED] TR18JY97.124

where:
i = replicate number; and
n = number of measurements of effectiveness.

    (B) If the value of CVE exceeds 10 percent, then the 
test run (steps in paragraphs (f)(2) through (f)(6) of this section) is 
unacceptable and must be repeated.
    (7) Repeat steps in paragraphs (f)(1) through (f)(6) of this 
section for each particle size specified in Table F-2 of this subpart.
    (g) Test procedure: Divided flow method--(1) Generate calibration 
aerosol. Follow the procedures for aerosol generation prescribed in 
Sec. 53.62(d)(2).
    (2) Verify the quality of the calibration aerosol. Follow the 
procedures for verification of calibration aerosol size and quality 
prescribed in Sec. 53.62(d)(4).
    (3) Introduce aerosol. Introduce the calibration aerosol into the 
static chamber and allow the particle concentration to stabilize.
    (4) Validate that transport is equal for the divided flow option. 
(i) With fluorometry as a detector:
    (A) Install a total filter on each leg of the divided flow 
apparatus.
    (B) Collect particles simultaneously through both legs at 16.7 L/
min onto an appropriate filter for a time period such that the relative 
error of the measured concentration is less than 5.0 percent.
    (C) Determine the quantity of material collected on each filter 
using a calibrated fluorometer. Calculate and record the mass 
concentration measured in each leg as:

Equation 32
[GRAPHIC] [TIFF OMITTED] TR18JY97.125

where:
i = replicate number,
M = mass of material collected with the total filter; and
Q = candidate sampler volumetric flowrate.

    (D) Repeat steps in paragraphs (g)(4)(i)(A) through (g)(4)(i)(C) of 
this section until a minimum of three replicate measurements are 
performed.
    (ii) With a number counting device such as an aerosol detector:
    (A) Remove all flow obstructions from the flow paths of the two 
legs.

[[Page 38823]]

    (B) Quantify the aerosol concentration of the primary particles in 
each leg of the apparatus.
    (C) Repeat steps in paragraphs (g)(4)(ii)(A) through (g)(4)(ii)(B) 
of this section until a minimum of three replicate measurements are 
performed.
    (iii) (A) Calculate the mean concentration and coefficient of 
variation as:

Equation 33
[GRAPHIC] [TIFF OMITTED] TR18JY97.126

Equation 34
[GRAPHIC] [TIFF OMITTED] TR18JY97.127

where:
i = replicate number; and
n = number of replicates.

    (B) If the measured mean concentrations through the two legs do not 
agree within 5 percent, then adjustments may be made in the setup, and 
this step must be repeated.
    (5) Determine effectiveness. Determine the sampling effectiveness 
of the test sampler with the inlet removed by one of the following 
procedures:
    (i) With fluorometry as a detector:
    (A) Prepare the divided flow apparatus for particle collection. 
Install a total filter into the bypass leg of the divided flow 
apparatus. Install the particle size fractionator with a total filter 
placed immediately downstream of it into the other leg.
    (B) Collect particles simultaneously through both legs at 16.7 L/
min onto appropriate filters for a time period such that the relative 
error of the measured concentration is less than 5.0 percent.
    (C) Determine the quantity of material collected on each filter 
using a calibrated fluorometer. Calculate and record the mass 
concentration measured by the total filter and that measured after 
penetrating through the candidate fractionator as follows:

Equation 35
[GRAPHIC] [TIFF OMITTED] TR18JY97.128

Equation 36
[GRAPHIC] [TIFF OMITTED] TR18JY97.129

where:
i = replicate number.

    (ii) With a number counting device as a detector:
    (A) Install the particle size fractionator into one of the legs of 
the divided flow apparatus.
    (B) Quantify and record the aerosol number concentration of the 
primary particles passing through the fractionator as 
Ccand(i).
    (C) Divert the flow from the leg containing the candidate 
fractionator to the bypass leg. Allow sufficient time for the aerosol 
concentration to stabilize.
    (D) Quantify and record the aerosol number concentration of the 
primary particles passing through the bypass leg as 
Ctotal(i).
    (iii) Calculate and record sampling effectiveness of the candidate 
sampler as:

Equation 37
[GRAPHIC] [TIFF OMITTED] TR18JY97.130

where:
i = replicate number.

    (6) Repeat step in paragraph (g)(5) of this section, as 
appropriate, to obtain a minimum of three replicate measurements of 
sampling effectiveness.
    (7) Calculate the mean and coefficient of variation for replicate 
measurements of effectiveness. (i) Calculate and record the mean 
sampling effectiveness of the candidate sampler as:

Equation 38
[GRAPHIC] [TIFF OMITTED] TR18JY97.131

where:
i = replicate number.

    (ii)(A) Calculate and record the coefficient of variation for the 
replicate sampling effectiveness measurements of the candidate sampler 
as:

Equation 39
[GRAPHIC] [TIFF OMITTED] TR18JY97.132

where:
i = replicate number; and
n = number of replicates.

    (B) If the coefficient of variation is not less than 10 percent, 
then the test run must be repeated (steps in paragraphs (g)(1) through 
(g)(7) of this section).
    (8) Repeat steps in paragraphs (g)(1) through (g)(7) of this 
section for each particle size specified in Table F-2 of this subpart.
    (h) Calculations--(1) Treatment of multiplets. For all measurements 
made by fluorometric analysis, data shall be corrected for the presence 
of multiplets as described in Sec. 53.62(f)(1). Data collected using a 
real-time device (as described in paragraph (c)(3)(ii)) of this section 
will not require multiplet correction.
    (2) Cutpoint determination. For each wind speed determine the 
sampler Dp50 cutpoint defined as the aerodynamic particle 
size corresponding to 50 percent effectiveness from the multiplet 
corrected smooth curve.
    (3) Graphical analysis and numerical integration with ambient 
distributions. Follow the steps outlined in Sec. 53.62(e)(3) through 
(e)(4) to calculate the estimated concentration measurement ratio 
between the candidate sampler and a reference method sampler.
    (i) Test evaluation. The candidate method passes the static 
fractionator test if the values of Rc and Dp50 for each 
distribution meets the specifications in Table F-1 of this subpart.


Sec. 53.65   Test procedure: Loading test.

    (a) Overview. (1) The loading tests are designed to quantify any 
appreciable changes in a candidate method sampler's performance as a 
function of coarse aerosol collection. The candidate sampler is exposed 
to a mass of coarse aerosol equivalent to sampling a mass concentration 
of 150 g/m3 over the time period that the 
manufacturer has specified between periodic cleaning. After loading, 
the candidate sampler is then evaluated by performing the test in 
Sec. 53.62 (full wind tunnel test), Sec. 53.63 (wind tunnel inlet 
aspiration test), or Sec. 53.64 (static fractionator test). If the 
acceptance criteria are met for this evaluation test, then the 
candidate sampler is approved for multi-day sampling with the periodic 
maintenance schedule as specified by the candidate method. For example, 
if the candidate sampler passes the reevaluation tests following 
loading with an aerosol mass equivalent to sampling a 150 g/
m3 aerosol continuously for 7 days, then the sampler is 
approved for 7 day field operation before cleaning is required.
    (b) Technical definition. Effectiveness after loading is the ratio 
(expressed as a percentage) of the mass concentration of particles of a 
given size reaching the sampler filter to the mass concentration of 
particles of the same size approaching the sampler.
    (c) Facilities and equipment required--(1) Particle delivery 
system. The particle delivery system shall consist of a static chamber 
or a low velocity wind tunnel having a

[[Page 38824]]

sufficiently large cross-sectional area such that the test sampler, or 
portion thereof, may be installed in the test section. At a minimum, 
the system must have a sufficiently large cross section to house the 
candidate sampler inlet as well as a collocated isokinetic nozzle for 
measuring total aerosol concentration. The mean velocity in the test 
section of the static chamber or wind tunnel shall not exceed 2 km/hr.
    (2) Aerosol generation equipment. For purposes of these tests, the 
test aerosol shall be produced from commercially available, bulk 
Arizona road dust. To provide direct interlaboratory comparability of 
sampler loading characteristics, the bulk dust is specified as 0-10 
m ATD available from Powder Technology Incorporated 
(Burnsville, MN). A fluidized bed aerosol generator, Wright dust 
feeder, or sonic nozzle shall be used to efficiently deagglomerate the 
bulk test dust and transform it into an aerosol cloud. Other dust 
generators may be used contingent upon prior approval by the Agency.
    (3) Isokinetic sampler. Mean aerosol concentration within the 
static chamber or wind tunnel shall be established using a single 
isokinetic sampler containing a preweighed high-efficiency total 
filter.
    (4) Analytic balance. An analytical balance shall be used to 
determine the weight of the total filter in the isokinetic sampler. The 
precision and accuracy of this device shall be such that the relative 
measurement error is less than 5.0 percent for the difference between 
the initial and final weight of the total filter. The identical 
analytic balance shall be used to perform both initial and final 
weighing of the total filter.
    (d) Test procedure. (1) Calculate and record the target time 
weighted concentration of Arizona road dust which is equivalent to 
exposing the sampler to an environment of 150 g/m3 
over the time between cleaning specified by the candidate sampler's 
operations manual as:

Equation 40
[GRAPHIC] [TIFF OMITTED] TR18JY97.133

where:
t = the number of hours specified by the candidate method prior to 
periodic cleaning.

    (2) Clean the candidate sampler. (i) Clean and dry the internal 
surfaces of the candidate sampler.
    (ii) Prepare the internal surfaces in strict accordance with the 
operating manual referred to in section 7.4.18 of 40 CFR part 50, 
Appendix L.
    (3) Determine the preweight of the filter that shall be used in the 
isokinetic sampler. Record this value as InitWt.
    (4) Install the candidate sampler's inlet and the isokinetic 
sampler within the test chamber or wind tunnel.
    (5) Generate a dust cloud. (i) Generate a dust cloud composed of 
Arizona test dust.
    (ii) Introduce the dust cloud into the chamber.
    (iii) Allow sufficient time for the particle concentration to 
become steady within the chamber.
    (6) Sample aerosol with a total filter and the candidate sampler. 
(i) Sample the aerosol for a time sufficient to produce an equivalent 
TWC equal to that of the target TWC  15 percent.
    (ii) Record the sampling time as t.
    (7) Determine the time weighted concentration. (i) Determine the 
postweight of the isokinetic sampler's total filter.
    (ii) Record this value as FinalWt.
    (iii) Calculate and record the TWC as:

Equation 41
[GRAPHIC] [TIFF OMITTED] TR18JY97.134

where:
Q = the flow rate of the candidate method.

    (iv) If the value of TWC deviates from the target TWC  
15 percent, then the loaded mass is unacceptable and the entire test 
procedure must be repeated.
    (8) Determine the candidate sampler's effectiveness after loading. 
The candidate sampler's effectiveness as a function of particle 
aerodynamic diameter must then be evaluated by performing the test in 
Sec. 53.62 (full wind tunnel test). A sampler which fits the category 
of inlet deviation in Sec. 53.60(e)(1) may opt to perform the test in 
Sec. 53.63 (inlet aspiration test) in lieu of the full wind tunnel 
test. A sampler which fits the category of fractionator deviation in 
Sec. 53.60(e)(2) may opt to perform the test in Sec. 53.64 (static 
fractionator test) in lieu of the full wind tunnel test.
    (e) Test results. If the candidate sampler meets the acceptance 
criteria for the evaluation test performed in paragraph (d)(8) of this 
section, then the candidate sampler passes this test with the 
stipulation that the sampling train be cleaned as directed by and as 
frequently as that specified by the candidate sampler's operations 
manual.


Sec. 53.66   Test procedure: Volatility test.

    (a) Overview. This test is designed to ensure that the candidate 
method's losses due to volatility when sampling semi-volatile ambient 
aerosol will be comparable to that of a federal reference method 
sampler. This is accomplished by challenging the candidate sampler with 
a polydisperse, semi-volatile liquid aerosol in three distinct phases. 
During phase A of this test, the aerosol is elevated to a steady-state, 
test-specified mass concentration and the sample filters are 
conditioned and preweighed. In phase B, the challenge aerosol is 
simultaneously sampled by the candidate method sampler and a reference 
method sampler onto the preweighed filters for a specified time period. 
In phase C (the blow-off phase), aerosol and aerosol-vapor free air is 
sampled by the samplers for an additional time period to partially 
volatilize the aerosol on the filters. The candidate sampler passes the 
volatility test if the acceptance criteria presented in Table F-1 of 
this subpart are met or exceeded.
    (b) Technical definitions. (1) Residual mass (RM) is defined as the 
weight of the filter after the blow-off phase subtracted from the 
initial weight of the filter.
    (2) Corrected residual mass (CRM) is defined as the residual mass 
of the filter from the candidate sampler multiplied by the ratio of the 
reference method flow rate to the candidate method flow rate.
    (c) Facilities and equipment required--(1) Environmental chamber. 
Because the nature of a volatile aerosol is greatly dependent upon 
environmental conditions, all phases of this test shall be conducted at 
a temperature of 22.0  0.5  deg.C and a relative humidity 
of 40  3 percent. For this reason, it is strongly advised 
that all weighing and experimental apparatus be housed in an 
environmental chamber capable of this level of control.
    (2) Aerosol generator. The aerosol generator shall be a pressure 
nebulizer operated at 20 to 30 psig (140 to 207 kPa) to produce a 
polydisperse, semi-voltile aerosol with a mass median diameter larger 
than 1 m and smaller than 2.5 m. The nebulized liquid 
shall be A.C.S. reagent grade glycerol 
(C3H8O, FW = 92.09, CAS 56-81-5) of 
99.5 percent minimum purity. For the purpose of this test the accepted 
mass median diameter is predicated on the stable aerosol inside the 
internal chamber and not on the aerosol emerging from the nebulizer 
nozzle. Aerosol monitoring and its stability are described in (c)(3) 
and (c)(4) of this section.
    (3) Aerosol monitoring equipment. The evaporation and condensation 
dynamics of a volatile aerosol is greatly dependent upon the vapor 
pressure of the volatile component in the carrier gas. The size of an 
aerosol becomes fixed only when an equilibrium is established between 
the aerosol and the surrounding vapor; therefore, aerosol

[[Page 38825]]

size measurement shall be used as a surrogate measure of this 
equilibrium. A suitable instrument with a range of 0.3 to 10 
m, an accuracy of 0.5 m, and a resolution of 0.2 
m (e.g., an optical particle sizer, or a time-of-flight 
instrument) shall be used for this purpose. The parameter monitored for 
stability shall be the mass median instrument measured diameter (i.e. 
optical diameter if an optical particle counter is used). A stable 
aerosol shall be defined as an aerosol with a mass median diameter that 
has changed less than 0.25 m over a 4 hour time period.
    (4) Internal chamber. The time required to achieve a stable aerosol 
depends upon the time during which the aerosol is resident with the 
surrounding air. This is a function of the internal volume of the 
aerosol transport system and may be facilitated by recirculating the 
challenge aerosol. A chamber with a volume of 0.5 m3 and a 
recirculating loop (airflow of approximately 500 cfm) is recommended 
for this purpose. In addition, a baffle is recommended to dissipate the 
jet of air that the recirculating loop can create. Furthermore, a HEPA 
filtered hole in the wall of the chamber is suggested to allow makeup 
air to enter the chamber or excess air to exit the chamber to maintain 
a system flow balance. The concentration inside the chamber shall be 
maintained at 1 mg/m3  20 percent to obtain 
consistent and significant filter loading.
    (5) Aerosol sampling manifold. A manifold shall be used to extract 
the aerosol from the area in which it is equilibrated and transport it 
to the candidate method sampler, the reference method sampler, and the 
aerosol monitor. The losses in each leg of the manifold shall be 
equivalent such that the three devices will be exposed to an identical 
aerosol.
    (6) Chamber air temperature recorders. Minimum range 15-25  deg.C, 
certified accuracy to within 0.2  deg.C, resolution of 0.1  deg.C. 
Measurement shall be made at the intake to the sampling manifold and 
adjacent to the weighing location.
    (7) Chamber air relative humidity recorders. Minimum range 30 - 50 
percent, certified accuracy to within 1 percent, resolution of 0.5 
percent. Measurement shall be made at the intake to the sampling 
manifold and adjacent to the weighing location.
    (8) Clean air generation system. A source of aerosol and aerosol-
vapor free air is required for phase C of this test. This clean air 
shall be produced by filtering air through an absolute (HEPA) filter.
    (9) Balance. Minimum range 0 - 200 mg, certified accuracy to within 
10 g, resolution of 1 g.
    (d) Additional filter handling conditions. (1) Filter handling. 
Careful handling of the filter during sampling, conditioning, and 
weighing is necessary to avoid errors due to damaged filters or loss of 
collected particles from the filters. All filters must be weighed 
immediately after phase A dynamic conditioning and phase C.
    (2) Dynamic conditioning of filters. Total dynamic conditioning is 
required prior to the initial weight determined in phase A. Dynamic 
conditioning refers to pulling clean air from the clean air generation 
system through the filters. Total dynamic conditioning can be 
established by sequential filter weighing every 30 minutes following 
repetitive dynamic conditioning. The filters are considered 
sufficiently conditioned if the sequential weights are repeatable to 
 3 g.
    (3) Static charge. The following procedure is suggested for 
minimizing charge effects. Place six or more Polonium static control 
devices (PSCD) inside the microbalance weighing chamber, (MWC). Two of 
them must be placed horizontally on the floor of the MWC and the 
remainder placed vertically on the back wall of the MWC. Taping two 
PSCD's together or using double-sided tape will help to keep them from 
falling. Place the filter that is to be weighed on the horizontal PSCDs 
facing aerosol coated surface up. Close the MWC and wait 1 minute. Open 
the MWC and place the filter on the balance dish. Wait 1 minute. If the 
charges have been neutralized the weight will stabilize within 30-60 
seconds. Repeat the procedure of neutralizing charges and weighing as 
prescribed above several times (typically 2-4 times) until consecutive 
weights will differ by no more than 3 micrograms. Record the last 
measured weight and use this value for all subsequent calculations.
    (e) Test procedure--(1) Phase A - Preliminary steps. (i) Generate a 
polydisperse glycerol test aerosol.
    (ii) Introduce the aerosol into the transport system.
    (iii) Monitor the aerosol size and concentration until stability 
and level have been achieved.
    (iv) Condition the candidate method sampler and reference method 
sampler filters until total dynamic conditioning is achieved as 
specified in paragraph (d)(2) of this section.
    (v) Record the dynamically conditioned weight as InitWtc 
and InitWtr where c is the candidate method sampler and r is 
the reference method sampler.
    (2) Phase B - Aerosol loading. (i) Install the dynamically 
conditioned filters into the appropriate samplers.
    (ii) Attach the samplers to the manifold.
    (iii) Operate the candidate and the reference samplers such that 
they simultaneously sample the test aerosol for 30 minutes.
    (3) Phase C - Blow-off. (i) Alter the intake of the samplers to 
sample air from the clean air generation system.
    (ii) Sample clean air for one of the required blow-off time 
durations (1, 2, 3, and 4 hours).
    (iii) Remove the filters from the samplers.
    (iv) Weigh the filters immediately and record this weight, 
FinalWtc and FinalWtr, where c is the candidate 
method sampler and r is the reference method sampler.
    (v) Calculate the residual mass for the reference method sampler:

Equation 41a
[GRAPHIC] [TIFF OMITTED] TR18JY97.135

where:
i = repetition number; and
j = blow-off time period.

    (vi) Calculate the corrected residual mass for the candidate method 
sampler as:

Equation 41b
[GRAPHIC] [TIFF OMITTED] TR18JY97.136

where:
i = repetition number;
j = blow-off time period;
Qc = candidate method sampler flow rate, and
Qr = reference method sampler flow rate.

    (4) Repeat steps in paragraph (e)(1) through (e)(3) of this section 
until three repetitions have been completed for each of the required 
blow-off time durations (1, 2, 3, and 4 hours).
    (f) Calculations and analysis. (1) Perform a linear regression with 
the candidate method CRM as the dependent variable and the reference 
method RM as the independent variable.
    (2) Determine the following regression parameters: slope, 
intercept, and correlation coefficient (r).
    (g) Test results. The candidate method passes the volatility test 
if the regression parameters meet the acceptance criteria specified in 
Table F-1 of this subpart.

Tables to Subpart F of Part 53

[[Page 38826]]



  Table F-1.--Performance Specifications for PM2.5 Class II Equivalent  
                                Samplers                                
------------------------------------------------------------------------
                                                          Acceptance    
        Performance Test            Specifications         Criteria     
------------------------------------------------------------------------
Sec.  53.62 Full Wind Tunnel     Solid VOAG produced  Dp50 = 2.5 m  
                                  and 24 km/hr.        0.2 m;  
                                                       Numerical        
                                                       Analysis Results:
                                                       95% Rc1
                                                       05%              
Sec.  53.63 Wind Tunnel Inlet    Liquid VOAG          Relative          
 Aspiration Test.                 produced aerosol     Aspiration: 95%  
                                  at 2 km/hr and 24    A50 = 2.5 m  
                                  static conditions    0.2 m;  
                                                       Numerical        
                                                       Analysis Results:
                                                       95% Rc1
                                                       05%              
Sec.  53.65 Loading Test.......  Loading of the       Acceptance        
                                  clean candidate      criteria as      
                                  under laboratory     specified in the 
                                  conditions           post-loading     
                                                       evaluation test  
                                                       (Sec.  53.62,    
                                                       Sec.  53.63, or  
                                                       Sec.  53.64)     
Sec.  53.66 Volatility Test....  Polydisperse liquid  Regression        
                                  aerosol produced     Parameters Slope 
                                  by air               = 1  
                                  nebulization of      0.1, Intercept = 
                                  A.C.S. reagent       0    
                                  grade glycerol,      0.15 r  0.97     
                                  99.5% minimum                         
                                  purity                                
------------------------------------------------------------------------


  Table F-2.--Particle Sizes and Wind Speeds for Full Wind Tunnel Test, Wind Tunnel Inlet Aspiration Test, and  
                                               Static Chamber Test                                              
----------------------------------------------------------------------------------------------------------------
                                         Full Wind Tunnel Test   Inlet Aspiration Test     Static               
 Primary Partical Mean Size a (m)                     2 km/hr    24 km/hr     2 km/hr    24 km/hr       Test         Test   
----------------------------------------------------------------------------------------------------------------
1.50.25...................          S           S                                    S              
2.00.25...................          S           S                                    S              
2.20.25...................          S           S                                    S              
2.50.25...................          S           S                                    S              
2.80.25...................          S           S                                    S              
3.00.25...................                                  L           L                           
3.50.25...................          S           S                                    S              
4.00.5....................          S           S                                    S              
Polydisperse Glycerol Aerosol.........                                                                        L 
----------------------------------------------------------------------------------------------------------------
a Aerodynamic diameter.                                                                                         
S=Solid particles.                                                                                              
L=Liquid particles.                                                                                             


                                    Table F-3.--Critical Parameters of Idealized Ambient Particle Size Distributions                                    
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                             Fine Particle Mode                    Coarse Particle Mode                      FRM Sampler
                                                  ------------------------------------------------------------------------------   PM2.5/     Expected  
              Idealized Distribution                                            Conc.                                  Conc.        PM10     Mass Conc. 
                                                   MMD (g/  MMD (g/    Ratio    (g/
                                                       m>m)         Dev.         m3)          m>m)         Dev.         m3)                      m3)    
--------------------------------------------------------------------------------------------------------------------------------------------------------
Coarse...........................................         0.50           2         12.0            10           2         88.0        0.27       13.814 
``Typical''......................................         0.50           2         33.3            10           2         66.7        0.55       34.284 
Fine.............................................         0.85           2         85.0            15           2         15.0        0.94       78.539 
--------------------------------------------------------------------------------------------------------------------------------------------------------



                      Table F-4.--Estimated Mass Concentration Measurement of PM2.5 for Idealized Coarse Aerosol Size Distribution                      
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                         Test Sampler                                                Ideal Sampler                      
                                 -----------------------------------------------------------------------------------------------------------------------
  Particle Aerodynamic Diameter                                             Estimated Mass                                              Estimated Mass  
          (m)                Fractional         Interval Mass       Concentration        Fractional         Interval Mass       Concentration  
                                       Sampling          Concentration        Measurement          Sampling          Concentration        Measurement   
                                     Effectiveness      (g/m3)     (g/m3)      Effectiveness      (g/m3)     (g/m3) 
--------------------------------------------------------------------------------------------------------------------------------------------------------
               (1)                        (2)                 (3)                 (4)                 (5)                 (6)                 (7)       
--------------------------------------------------------------------------------------------------------------------------------------------------------
<0.500                            1.000               6.001                                   1.000               6.001               6.001             
0.625                                                 2.129                                   0.999               2.129               2.127             
0.750                                                 0.982                                   0.998               0.982               0.980             
0.875                                                 0.730                                   0.997               0.730               0.728             
1.000                                                 0.551                                   0.995               0.551               0.548             
1.125                                                 0.428                                   0.991               0.428               0.424             
1.250                                                 0.346                                   0.987               0.346               0.342             
1.375                                                 0.294                                   0.980               0.294               0.288             
1.500                                                 0.264                                   0.969               0.264               0.256             
1.675                                                 0.251                                   0.954               0.251               0.239             
1.750                                                 0.250                                   0.932               0.250               0.233             
1.875                                                 0.258                                   0.899               0.258               0.232             

[[Page 38827]]

                                                                                                                                                        
2.000                                                 0.272                                   0.854               0.272               0.232             
2.125                                                 0.292                                   0.791               0.292               0.231             
2.250                                                 0.314                                   0.707               0.314               0.222             
2.375                                                 0.339                                   0.602               0.339               0.204             
2.500                                                 0.366                                   0.480               0.366               0.176             
2.625                                                 0.394                                   0.351               0.394               0.138             
2.750                                                 0.422                                   0.230               0.422               0.097             
2.875                                                 0.449                                   0.133               0.449               0.060             
3.000                                                 0.477                                   0.067               0.477               0.032             
3.125                                                 0.504                                   0.030               0.504               0.015             
3.250                                                 0.530                                   0.012               0.530               0.006             
3.375                                                 0.555                                   0.004               0.555               0.002             
3.500                                                 0.579                                   0.001               0.579               0.001             
3.625                                                 0.602                                   0.000000            0.602               0.000000          
3.750                                                 0.624                                   0.000000            0.624               0.000000          
3.875                                                 0.644                                   0.000000            0.644               0.000000          
4.000                                                 0.663                                   0.000000            0.663               0.000000          
4.125                                                 0.681                                   0.000000            0.681               0.000000          
4.250                                                 0.697                                   0.000000            0.697               0.000000          
4.375                                                 0.712                                   0.000000            0.712               0.000000          
4.500                                                 0.726                                   0.000000            0.726               0.000000          
4.625                                                 0.738                                   0.000000            0.738               0.000000          
4.750                                                 0.750                                   0.000000            0.750               0.000000          
4.875                                                 0.760                                   0.000000            0.760               0.000000          
5.000                                                 0.769                                   0.000000            0.769               0.000000          
5.125                                                 0.777                                   0.000000            0.777               0.000000          
5.250                                                 0.783                                   0.000000            0.783               0.000000          
5.375                                                 0.789                                   0.000000            0.789               0.000000          
5.500                                                 0.794                                   0.000000            0.794               0.000000          
5.625                                                 0.798                                   0.000000            0.798               0.000000          
5.75                                                  0.801                                   0.000000            0.801               0.000000          
                                                      Csam(exp)=                                                  Cideal(exp)=        13.814            
--------------------------------------------------------------------------------------------------------------------------------------------------------


[[Page 38828]]


                Table F-5.--Estimated Mass Concentration Measurement of PM2.5 for Idealized ``Typical'' Coarse Aerosol Size Distribution                
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                         Test Sampler                                                Ideal Sampler                      
                                 -----------------------------------------------------------------------------------------------------------------------
  Particle Aerodynamic Diameter                                             Estimated Mass                                              Estimated Mass  
          (m)                Fractional         Interval Mass       Concentration        Fractional         Interval Mass       Concentration  
                                       Sampling          Concentration        Measurement          Sampling          Concentration        Measurement   
                                     Effectiveness      (g/m3)     (g/m3)      Effectiveness      (g/m3)     (g/m3) 
--------------------------------------------------------------------------------------------------------------------------------------------------------
               (1)                        (2)                 (3)                 (4)                 (5)                 (6)                 (7)       
--------------------------------------------------------------------------------------------------------------------------------------------------------
<0.500                            1.000               16.651                                  1.000               16.651              16.651            
0.625                                                 5.899                                   0.999               5.899               5.893             
0.750                                                 2.708                                   0.998               2.708               2.703             
0.875                                                 1.996                                   0.997               1.996               1.990             
1.000                                                 1.478                                   0.995               1.478               1.471             
1.125                                                 1.108                                   0.991               1.108               1.098             
1.250                                                 0.846                                   0.987               0.846               0.835             
1.375                                                 0.661                                   0.980               0.661               0.648             
1.500                                                 0.532                                   0.969               0.532               0.516             
1.675                                                 0.444                                   0.954               0.444               0.424             
1.750                                                 0.384                                   0.932               0.384               0.358             
1.875                                                 0.347                                   0.899               0.347               0.312             
2.000                                                 0.325                                   0.854               0.325               0.277             
2.125                                                 0.314                                   0.791               0.314               0.248             
2.250                                                 0.312                                   0.707               0.312               0.221             
2.375                                                 0.316                                   0.602               0.316               0.190             
2.500                                                 0.325                                   0.480               0.325               0.156             
2.625                                                 0.336                                   0.351               0.336               0.118             
2.750                                                 0.350                                   0.230               0.350               0.081             
2.875                                                 0.366                                   0.133               0.366               0.049             
3.000                                                 0.382                                   0.067               0.382               0.026             
3.125                                                 0.399                                   0.030               0.399               0.012             
3.250                                                 0.416                                   0.012               0.416               0.005             
3.375                                                 0.432                                   0.004               0.432               0.002             
3.500                                                 0.449                                   0.001               0.449               0.000000          
3.625                                                 0.464                                   0.000000            0.464               0.000000          
3.750                                                 0.480                                   0.000000            0.480               0.000000          
3.875                                                 0.494                                   0.000000            0.494               0.000000          
4.000                                                 0.507                                   0.000000            0.507               0.000000          
4.125                                                 0.520                                   0.000000            0.520               0.000000          
4.250                                                                                         0.000000            0.532               0.000000          
4.375                                                                                         0.000000            0.543               0.000000          
4.500                                                                                         0.000000            0.553               0.000000          
4.625                                                                                         0.000000            0.562               0.000000          
4.750                                                                                         0.000000            0.570               0.000000          
4.875                                                                                         0.000000            0.577               0.000000          
5.000                                                                                         0.000000            0.584               0.000000          
5.125                                                                                         0.000000            0.590               0.000000          
5.250                                                                                         0.000000            0.595               0.000000          
5.375                                                                                         0.000000            0.599               0.000000          
5.500                                                                                         0.000000            0.603               0.000000          
5.625                                                                                         0.000000            0.605               0.000000          
5.75                                                                                          0.000000            0.608               0.000000          
                                                      Csam(exp)=                                                  Cideal(exp)=        34.284            
--------------------------------------------------------------------------------------------------------------------------------------------------------


[[Page 38829]]


                       Table F-6.--Estimated Mass Concentration Measurement of PM2.5 for Idealized Fine Aerosol Size Distribution                       
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                         Test Sampler                                                Ideal Sampler                      
                                 -----------------------------------------------------------------------------------------------------------------------
  Particle Aerodynamic Diameter                                             Estimated Mass                                              Estimated Mass  
          (m)                Fractional         Interval Mass       Concentration        Fractional         Interval Mass       Concentration  
                                       Sampling          Concentration        Measurement          Sampling          Concentration        Measurement   
                                     Effectiveness      (g/m3)     (g/m3)      Effectiveness      (g/m3)     (g/m3) 
--------------------------------------------------------------------------------------------------------------------------------------------------------
               (1)                        (2)                 (3)                 (4)                 (5)                 (6)                 (7)       
--------------------------------------------------------------------------------------------------------------------------------------------------------
<0.500                            1.000               18.868                                  1.000               18.868              18.868            
0.625                                                 13.412                                  0.999               13.412              13.399            
0.750                                                 8.014                                   0.998               8.014               7.998             
0.875                                                 6.984                                   0.997               6.984               6.963             
1.000                                                 5.954                                   0.995               5.954               5.924             
1.125                                                 5.015                                   0.991               5.015               4.970             
1.250                                                 4.197                                   0.987               4.197               4.142             
1.375                                                 3.503                                   0.980               3.503               3.433             
1.500                                                 2.921                                   0.969               2.921               2.830             
1.675                                                 2.438                                   0.954               2.438               2.326             
1.750                                                 2.039                                   0.932               2.039               1.900             
1.875                                                 1.709                                   0.899               1.709               1.536             
2.000                                                 1.437                                   0.854               1.437               1.227             
2.125                                                 1.212                                   0.791               1.212               0.959             
2.250                                                 1.026                                   0.707               1.026               0.725             
2.375                                                 0.873                                   0.602               0.873               0.526             
2.500                                                 0.745                                   0.480               0.745               0.358             
2.625                                                 0.638                                   0.351               0.638               0.224             
2.750                                                 0.550                                   0.230               0.550               0.127             
2.875                                                 0.476                                   0.133               0.476               0.063             
3.000                                                 0.414                                   0.067               0.414               0.028             
3.125                                                 0.362                                   0.030               0.362               0.011             
3.250                                                 0.319                                   0.012               0.319               0.004             
3.375                                                 0.282                                   0.004               0.282               0.001             
3.500                                                 0.252                                   0.001               0.252               0.000000          
3.625                                                 0.226                                   0.000000            0.226               0.000000          
3.750                                                 0.204                                   0.000000            0.204               0.000000          
3.875                                                 0.185                                   0.000000            0.185               0.000000          
4.000                                                 0.170                                   0.000000            0.170               0.000000          
4.125                                                 0.157                                   0.000000            0.157               0.000000          
4.250                                                 0.146                                   0.000000            0.146               0.000000          
4.375                                                 0.136                                   0.000000            0.136               0.000000          
4.500                                                 0.129                                   0.000000            0.129               0.000000          
4.625                                                 0.122                                   0.000000            0.122               0.000000          
4.750                                                 0.117                                   0.000000            0.117               0.000000          
4.875                                                 0.112                                   0.000000            0.112               0.000000          
5.000                                                 0.108                                   0.000000            0.108               0.000000          
5.125                                                 0.105                                   0.000000            0.105               0.000000          
5.250                                                 0.102                                   0.000000            0.102               0.000000          
5.375                                                 0.100                                   0.000000            0.100               0.000000          
5.500                                                 0.098                                   0.000000            0.098               0.000000          
5.625                                                 0.097                                   0.000000            0.097               0.000000          
5.75                                                  0.096                                   0.000000            0.096               0.000000          
                                                      Csam(exp)=                                                  Cideal(exp)=        78.539            
--------------------------------------------------------------------------------------------------------------------------------------------------------


[[Page 38830]]

Figures to Subpart F of Part 53


Figure E-1.--Designation Testing Checklist

DESIGNATION TESTING CHECKLIST FOR CLASS II

____________________      ____________________      
____________________
Auditee                 Auditor signature                 Date

                                                                                                                
----------------------------------------------------------------------------------------------------------------
       Compliance Status:    Y = Yes     N = No     NA = Not applicable/Not available                           
---------------------------------------------------------------------------------------------                   
                              Verification                                Verified by Direct                    
-------------------------------------------------------------------------   Observation of                      
                                                                             Process or of       Verification   
                                                                              Documented      Comments (Includes
                                                                               Evidence:       documentation of 
                                                                             Performance,      who, what, where,
                                                                               Design or       when, why) (Doc. 
                Y                          N                  NA           Application Spec.    #, Rev. #, Rev. 
                                                                           Corresponding to          Date)      
                                                                          Sections of 40 CFR                    
                                                                           Part 53, Subparts                    
                                                                                E and F                         
----------------------------------------------------------------------------------------------------------------
                                                                          Subpart E:                            
                                                                           Performance                          
                                                                           Specification                        
                                                                           Tests                                
----------------------------------------------------------------------------------------------------------------
                                                                            Evaluation                          
                                                                           completed                            
                                                                           according to                         
                                                                           Subpart E Sec.                       
                                                                           53.50 to Sec.                        
                                                                           53.56                                
----------------------------------------------------------------------------------------------------------------
                                                                          Subpart E: Class I                    
                                                                           Sequential Tests                     
----------------------------------------------------------------------------------------------------------------
                                                                          Class II samplers                     
                                                                           that are also                        
                                                                           Class I                              
                                                                           (sequentialized)                     
                                                                           have passed the                      
                                                                           tests in Sec.                        
                                                                           53.57                                
----------------------------------------------------------------------------------------------------------------
                                                                          Subpart F:                            
                                                                           Performance Spec/                    
                                                                           Test                                 
----------------------------------------------------------------------------------------------------------------
                                                                          Evaluation of                         
                                                                           Physical                             
                                                                           Characteristics                      
                                                                           of Clean Sampler -                   
                                                                            One of these                        
                                                                           tests must be                        
                                                                           performed:                           
                                                                          Sec.  53.62 - Full                    
                                                                           Wind Tunnel                          
                                                                          Sec.  53.63 -                         
                                                                           Inlet Aspiration                     
                                                                          Sec.  53.64 -                         
                                                                           Static                               
                                                                           Fractionator                         
----------------------------------------------------------------------------------------------------------------
                                                                          Evaluation of                         
                                                                           Physical                             
                                                                           Characteristics                      
                                                                           of Loaded Sampler                    
                                                                                                                
                                                                                                                
----------------------------------------------------------------------------------------------------------------
                                                                            Evaluation of                       
                                                                           the Volatile                         
                                                                           Characteristics                      
                                                                           of the Class II                      
                                                                           Sampler Sec.                         
                                                                           53.66                                
----------------------------------------------------------------------------------------------------------------

Appendix A to Subpart F of Part 53--References

    (1) Marple, V.A., K.L. Rubow, W. Turner, and J.D. Spangler, Low 
Flow Rate Sharp Cut Impactors for Indoor Air Sampling: Design and 
Calibration., JAPCA, 37: 1303-1307 (1987).
    (2) Vanderpool, R.W. and K.L. Rubow, Generation of Large, Solid 
Calibration Aerosols, J. of Aer. Sci. and Tech., 9:65-69 (1988).
    (3) Society of Automotive Engineers Aerospace Material 
Specification (SAE AMS) 2404C, Electroless Nickel Planting, SAE, 400 
Commonwealth Drive, Warrendale PA-15096, Revised 7-1-84, pp. 1-6.

PART 58--[AMENDED]

    2. In part 58:
    a. The authority citation for part 58 continues to read as follows:

    Authority: 42 U.S.C. 7410, 7601(a), 7613, 7619.

    b. Section 58.1 is amended by removing the existing alphabetic 
paragraph designations, by alphabetizing the existing definitions, by 
revising the definition Traceable and by adding in alphabetical order 
the following definitions to read as follows:


Sec. 58.1   Definitions.

    *    *    *    *    *
    Annual State air monitoring report is an annual report, prepared by 
control agencies and submitted to EPA for approval, that consists of an 
annual data summary report for all pollutants and a detailed report 
describing any proposed changes to their air quality surveillance 
network.
    *    *    *    *    *
    Community Monitoring Zone (CMZ) means an optional averaging area 
with established, well defined boundaries, such as county or census 
block, within a MPA that has relatively uniform concentrations of 
annual PM2.5 as defined by Appendix D of this part. Two or 
more core SLAMS and other monitors within a CMZ that meet certain 
requirements as set forth in Appendix D of this part may be averaged 
for making comparisons to the annual PM2.5 NAAQS.
    Consolidated Metropolitan Statistical Area (CMSA) means the most 
recent area as designated by the U.S. Office of Management and Budget 
and population figures from the Bureau of the Census. The Department of 
Commerce provides that within metropolitan complexes of 1 million or 
more population, separate component areas are defined if specific 
criteria are met. Such areas are designated primary metropolitan 
statistical areas (PMSAs; and any area containing PMSAs is designated 
CMSA.
    Core PM2.5 SLAMS means community-oriented monitoring 
sites representative of community-wide exposures that are the basic 
component sites of the PM2.5 SLAMS regulatory network. Core 
PM2.5 SLAMS include community-oriented

[[Page 38831]]

SLAMS monitors, and sites collocated at PAMS.
    *    *    *    *    *
    Correlated acceptable continuous (CAC) PM analyzer means an 
optional fine particulate matter analyzer that can be used to 
supplement a PM2.5 reference or equivalent sampler, in 
accordance with the provisions of Sec. 58.13(f).
    *    *    *    *    *
    Equivalent method means a method of sampling and analyzing the 
ambient air for an air pollutant that has been designated as an 
equivalent method in accordance with part 53 of this chapter; it does 
not include a method for which an equivalent method designation has 
been canceled in accordance with Sec. 53.11 or Sec. 53.16 of this 
chapter.
    *    *    *    *    *
    Metropolitan Statistical Area (MSA) means the most recent area as 
designated by the U.S. Office of Management and Budget and population 
figures from the U.S. Bureau of the Census. The Department of Commerce 
defines a metropolitan area as one of a large population nucleus, 
together with adjacent communities that have a high degree of economic 
and social integration with that nucleus.
    *    *    *    *    *
    Monitoring Planning Area (MPA) means a contiguous geographic area 
with established, well defined boundaries, such as a metropolitan 
statistical area, county or State, having a common area that is used 
for planning monitoring locations for PM2.5. MPAs may cross 
State boundaries, such as the Philadelphia PA-NJ MSA, and be further 
subdivided into community monitoring zones. MPAs are generally oriented 
toward areas with populations greater than 200,000, but for 
convenience, those portions of a State that are not associated with 
MSAs can be considered as a single MPA. MPAs must be defined, where 
applicable, in a State PM monitoring network description.
    *    *    *    *    *
    Particulate matter monitoring network description, required by 
Sec. 58.20(f), means a detailed plan, prepared by control agencies and 
submitted to EPA for approval, that describes their PM2.5 
and PM10 air quality surveillance network.
    *    *    *    *    *
    PM2.5 means particulate matter with an aerodynamic 
diameter less than or equal to a nominal 2.5 micrometers as measured by 
a reference method based on 40 CFR part 50, Appendix L, and designated 
in accordance with part 53 of this chapter or by an equivalent method 
designated in accordance with part 53 of this chapter.
    *    *    *    *    *
    Population-oriented monitoring (or sites) applies to residential 
areas, commercial areas, recreational areas, industrial areas, and 
other areas where a substantial number of people may spend a 
significant fraction of their day.
    Primary Metropolitan Statistical Area (PMSA) is a separate 
component of a consolidated metropolitan statistical area. For the 
purposes of this part, PMSA is used interchangeably with MSA.
    *    *    *    *    *
    Reference method means a method of sampling and analyzing the 
ambient air for an air pollutant that will be specified as a reference 
method in an appendix to part 50 of this chapter, or a method that has 
been designated as a reference method in accordance with this part; it 
does not include a method for which a reference method designation has 
been canceled in accordance with Sec. 53.11 or Sec. 53.16 of this 
chapter.
    *    *    *    *    *
    Special Purpose Monitor (SPM) is a generic term used for all 
monitors other than SLAMS, NAMS, PAMS, and PSD monitors included in an 
agency's monitoring network for monitors used in a special study whose 
data are officially reported to EPA.
    *    *    *    *    *
    Traceable means that a local standard has been compared and 
certified, either directly or via not more than one intermediate 
standard, to a National Institute of Standards and Technology (NIST)-
certified primary standard such as a NIST-Traceable Reference Material 
(NTRM) or a NIST-certified Gas Manufacturer's Internal Standard (GMIS).
    *    *    *    *    *
    c. Section 58.13 is amended by revising paragraphs (b) and (d) and 
adding new paragraphs (e) and (f) to read as follows:


Sec. 58.13   Operating schedule.

    *    *    *    *    *
    (b) For manual methods (excluding PM10 samplers, 
PM2.5 samplers, and PAMS VOC samplers), at least one 24-hour 
sample must be obtained every sixth day except during periods or 
seasons exempted by the Regional Administrator.
    *    *    *    *    *
    (d) For PM10 samplers--a 24-hour sample must be taken a 
minimum of every third day.
    (e) For PM2.5 samplers, a 24-hour sample is required 
everyday for certain core SLAMS, including certain PAMS, as described 
in section 2.8.1.3 of Appendix D of this part, except during seasons or 
periods of low PM2.5 as otherwise exempted by the Regional 
Administrator. A waiver of the everyday sampling schedule for SLAMS may 
be granted by the Regional Administrator or designee, and for NAMS by 
the Administrator or designee, for 1 calendar year from the time a 
PM2.5 sequential sampler (FRM or Class I equivalent) has 
been approved by EPA. A 24-hour sample must be taken a minimum of every 
third day for all other SLAMS, including NAMS, as described in section 
2.8.1.3 of Appendix D of this part, except when exempted by the 
Regional Administrator in accordance with forthcoming EPA guidance. 
During periods for which exemptions to every third day or every day 
sampling are allowed for core PM2.5 SLAMS, a minimum 
frequency of one in 6-day sampling is still required. However, 
alternative sampling frequencies are allowed for SLAMS sites that are 
principally intended for comparisons to the 24-hour NAAQS. Such 
modifications must be approved by the Regional Administrator.
    (f) Alternatives to everyday sampling at sites with correlated 
acceptable continuous analyzers. (1) Certain PM2.5 core 
SLAMS sites located in monitoring planning areas (as described in 
section 2.8 of Appendix D of this part) are required to sample every 
day with a reference or equivalent method operating in accordance with 
part 53 of this chapter and section 2 of Appendix C of this part. 
However, in accordance with the monitoring priority as defined in 
paragraph (f)(2) of this section, established by the control agency and 
approved by EPA, a core SLAMS monitor may operate with a reference or 
equivalent method on a 1 in 3-day schedule and produce data that may be 
compared to the NAAQS, provided that it is collocated with an 
acceptable continuous fine particulate PM analyzer that is correlated 
with the reference or equivalent method. If the alternative sampling 
schedule is selected by the control agency and approved by EPA, the 
alternative schedule shall be implemented on January 1 of the year in 
which everyday sampling is required. The selection of correlated 
acceptable continuous PM analyzers and procedures for correlation with 
the intermittent reference or equivalent method shall be in accordance 
with procedures approved by the Regional Administrator. Unless the 
continuous fine particulate analyzer satisfies the requirements of 
section 2 of Appendix C of this part, however, the data derived from 
the correlated acceptable continuous monitor are not eligible for 
direct comparisons to the NAAQS in accordance with part 50 of this 
chapter.

[[Page 38832]]

    (2) A Metropolitan Statistical Area (MSA) (or primary metropolitan 
statistical area) with greater than 1 million population and high 
concentrations of PM2.5 (greater than or equal to 80 percent 
of the NAAQS) shall be a Priority 1 PM monitoring area. Other 
monitoring planning areas may be designated as Priority 2 PM monitoring 
areas.
    (3) Core SLAMS having a correlated acceptable continuous analyzer 
collocated with a reference or equivalent method in a Priority 1 PM 
monitoring area may operate on the 1 in 3 sampling frequency only after 
reference or equivalent data are collected for at least 2 complete 
years.
    (4) In all monitoring situations, with a correlated acceptable 
continuous alternative, FRM samplers or filter-based equivalent 
analyzers should preferably accompany the correlated acceptable 
continuous monitor.
    d. Section 58.14 is revised to read as follows:


Sec. 58.14   Special purpose monitors.

    (a) Except as specified in paragraph (b) of this section, any 
ambient air quality monitoring station other than a SLAMS or PSD 
station from which the State intends to use the data as part of a 
demonstration of attainment or nonattainment or in computing a design 
value for control purposes of the National Ambient Air Quality 
Standards (NAAQS) must meet the requirements for SLAMS as described in 
Sec. 58.22 and, after January 1, 1983, must also meet the requirements 
for SLAMS described in Sec. 58.13 and Appendices A and E of this part.
    (b) Based on the need, in transitioning to a PM2.5 
standard that newly addresses the ambient impacts of fine particles, to 
encourage a sufficiently extensive geographical deployment of 
PM2.5 monitors and thus hasten the development of an 
adequate PM2.5 ambient air quality monitoring 
infrastructure, PM2.5 NAAQS violation determinations shall 
not be exclusively made based on data produced at a population-oriented 
SPM site during the first 2 complete calendar years of its operation. 
However, a notice of NAAQS violations resulting from population-
oriented SPMs shall be reported to EPA in the State's annual monitoring 
report and be considered by the State in the design of its overall 
SLAMS network; these population-oriented SPMs should be considered to 
become a permanent SLAMS during the annual network review in accordance 
with Sec. 58.25.
    (c) Any ambient air quality monitoring station other than a SLAMS 
or PSD station from which the State intends to use the data for SIP-
related functions other than as described in paragraph (a) of this 
section is not necessarily required to comply with the requirements for 
a SLAMS station under paragraph (a) of this section but must be 
operated in accordance with a monitoring schedule, methodology, quality 
assurance procedures, and probe or instrument-siting specifications 
approved by the Regional Administrator.
    e. Section 58.20 is amended by revising the section heading, 
paragraph (d), and the introductory text of paragraph (e), by 
designating the flush text at the end of the section as paragraph (i) 
and amending the third sentence by removing the words ``(a) through 
(f)'' and adding in their place, ``(a) through (h)'', by redesignating 
paragraph (f) as paragraph (h), and adding new paragraphs (f) and (g) 
to read as follows:


Sec. 58.20   Air quality surveillance: plan content.

    *    *    *    *    *
    (d) Provide for the review of the air quality surveillance system 
on an annual basis to determine if the system meets the monitoring 
objectives defined in Appendix D of this part. Such review must 
identify needed modifications to the network such as termination or 
relocation of unnecessary stations or establishment of new stations 
that are necessary. For PM2.5, the review must identify 
needed changes to core SLAMS, monitoring planning areas, the chosen 
community monitoring approach including optional community monitoring 
zones, SLAMS, or SPMs.
    (e) Provide for having a SLAMS network description available for 
public inspection and submission to the Administrator upon request. The 
network description must be available at the time of plan revision 
submittal and must contain the following information for each SLAMS:
    *    *    *    *    *
    (f) Provide for having a PM monitoring network description 
available for public inspection which must provide for monitoring 
planning areas, and the community monitoring approach involving core 
monitors and optional community monitoring zones for PM2.5. 
The PM monitoring network description for PM10 and 
PM2.5 must be submitted to the Regional Administrator for 
approval by July 1, 1998, and must contain the following information 
for each PM SLAMS and PM2.5 SPM:
    (1) The AIRS site identification form for existing stations.
    (2) The proposed location for scheduled stations.
    (3) The sampling and analysis method.
    (4) The operating schedule.
    (5) The monitoring objective, spatial scale of representativeness, 
and additionally for PM2.5, the monitoring planning area, 
optional community monitoring zone, and the site code designation to 
identify which site will be identified as core SLAMS; and SLAMS or 
population-oriented SPMs, if any, that are microscale or middle scale 
in their representativeness as defined in Appendix D of this part.
    (6) A schedule for:
    (i) Locating, placing into operation, and making available the AIRS 
site identification form for each SLAMS which is not located and 
operating at the time of plan revision submittal.
    (ii) Implementing quality assurance procedures of Appendix A of 
this part for each SLAMS for which such procedures are not implemented 
at the time of plan revision submittal.
    (iii) Resiting each SLAMS which does not meet the requirements of 
Appendix E of this part at the time of plan revision submittal.
    (g) Provide for having a list of all PM2.5 monitoring 
locations including SLAMS, NAMS, PAMS and population-oriented SPMs, 
that are included in the State's PM monitoring network description and 
are intended for comparison to the NAAQS, available for public 
inspection.
    *    *    *    *    *
    f. Section 58.23 is amended by revising the introductory text and 
adding a new paragraph (c) to read as follows:


Sec. 58.23   Monitoring network completion.

    With the exception of the PM10 monitoring networks that 
shall be in place by March 16, 1998 and with the exception of the 
PM2.5 monitoring networks as described in paragraph (c) of 
this section:
    *    *    *    *    *
    (c) Each PM2.5 station in the SLAMS network must be in 
operation in accordance with the minimum requirements of Appendix D of 
this part, be sited in accordance with the criteria in Appendix E of 
this part, and be located as described on the station's AIRS site 
identification form, according to the following schedule:
    (1) Within 1 year after September 16, 1997, at least one required 
core PM2.5 SLAMS site in each MSA with population greater 
than 500,000, plus one site in each PAMS area, (plus at least two 
additional SLAMS sites per State) must be in operation.
    (2) Within 2 years after September 16, 1997, all other required 
SLAMS,

[[Page 38833]]

including all required core SLAMS, required regional background and 
regional transport SLAMS, continuous PM monitors in areas with greater 
than 1 million population, and all additional required PM2.5 
SLAMS must be in operation.
    (3) Within 3 years after September 16, 1997, all additional sites 
(e.g., sites classified as SLAMS/SPM to complete the mature network) 
must be in operation.
    g. Section 58.26 is amended by revising the section heading and the 
introductory text of paragraph (b), and adding paragraphs (d) and (e) 
to read as follows:


Sec. 58.26   Annual state air monitoring report.

    *    *    *    *    *
    (b) The SLAMS annual data summary report must contain:
    *    *    *    *    *
    (d) For PM monitoring and data--(1) The State shall submit a 
summary to the appropriate Regional Office (for SLAMS) or Administrator 
(through the Regional Office) (for NAMS) that details proposed changes 
to the PM Monitoring Network Description and to be in accordance with 
the annual network review requirements in Sec. 58.25. This shall 
discuss the existing PM networks, including modifications to the 
number, size or boundaries of monitoring planning areas and optional 
community monitoring zones; number and location of PM10 and 
PM2.5 SLAMS; number and location of core PM2.5 
SLAMS; alternative sampling frequencies proposed for PM2.5 
SLAMS (including core PM2.5 SLAMS and PM2.5 
NAMS), core PM2.5 SLAMS to be designated PM2.5 
NAMS; and PM10 and PM2.5 SLAMS to be designated 
PM10 and PM2.5 NAMS respectively.
    (2) The State shall submit an annual summary to the appropriate 
Regional Office of all the ambient air quality monitoring PM data from 
all special purpose monitors that are described in the State's PM 
monitoring network description and are intended for SIP purposes. These 
include those population-oriented SPMs that are eligible for comparison 
to the PM NAAQS. The State shall certify the data in accordance with 
paragraph (c) of this section.
    (e) The Annual State Air Monitoring Report shall be submitted to 
the Regional Administrator by July 1 or by an alternative annual date 
to be negotiated between the State and Regional Administrator. The 
Region shall provide review and approval/disapproval within 60 days. 
After 3 years following September 16, 1997, the schedule for submitting 
the required annual revised PM2.5 monitoring network 
description may be altered based on a new schedule determined by the 
Regional Administrator. States may submit an alternative PM monitoring 
network description in which it requests exemptions from specific 
required elements of the network design (e.g., required number of core 
sites, other SLAMS, sampling frequency, etc.). After 3 years following 
September 16, 1997 or once a CMZ monitoring area has been determined to 
violate the NAAQS, then changes to an MPA monitoring network affecting 
the violating locations shall require public review and notification.
    h. Section 58.30 is amended by revising the introductory text of 
paragraph (a) to read as follows:


Sec. 58.30   NAMS network establishment.

    (a) By January 1, 1980, with the exception of PM10 and 
PM2.5 samplers, which shall be by July 1, 1998, the State 
shall:
    *    *    *    *    *
    i. In Sec. 58.31, paragraph (f) is revised to read as follows:


Sec. 58.31   NAMS network description.

    *    *    *    *    *
    (f) The monitoring objective, spatial scale of representativeness, 
and for PM2.5, the monitoring planning area and community 
monitoring zone, as defined in Appendix D of this part.
    *    *    *    *    *
    j. In Sec. 58.34, the introductory text is revised to read as 
follows:


Sec. 58.34   NAMS network completion.

    With the exception of PM10 samplers, which shall be by 1 
year after September 16, 1997, and PM2.5, which shall be by 
3 years after September 16, 1997:
    *    *    *    *    *
    k. In Sec. 58.35, the first sentence of paragraph (b) is revised to 
read as follows:


Sec. 58.35   NAMS data submittal.

    *    *    *    *    *
    (b) The State shall report to the Administrator all ambient air 
quality data for SO2, CO, O3, NO2, Pb, 
PM10, and PM2.5, and information specified by the 
AIRS Users Guide (Volume II, Air Quality Data Coding, and Volume III, 
Air Quality Data Storage) to be coded into the AIRS-AQS format. *  *  *
    *    *    *    *    *
    l. Revise Appendix A of part 58 to read as follows:
Appendix A--Quality Assurance Requirements for State and Local Air 
Monitoring Stations (SLAMS)
1. General Information.
    1.1 This Appendix specifies the minimum quality assurance/
quality control (QA/QC) requirements applicable to SLAMS air 
monitoring data submitted to EPA. State and local agencies are 
encouraged to develop and maintain quality assurance programs more 
extensive than the required minimum.
    1.2 To assure the quality of data from air monitoring 
measurements, two distinct and important interrelated functions must 
be performed. One function is the control of the measurement process 
through broad quality assurance activities, such as establishing 
policies and procedures, developing data quality objectives, 
assigning roles and responsibilities, conducting oversight and 
reviews, and implementing corrective actions. The other function is 
the control of the measurement process through the implementation of 
specific quality control procedures, such as audits, calibrations, 
checks, replicates, routine self-assessments, etc. In general, the 
greater the control of a given monitoring system, the better will be 
the resulting quality of the monitoring data. The results of quality 
assurance reviews and assessments indicate whether the control 
efforts are adequate or need to be improved.
    1.3 Documentation of all quality assurance and quality control 
efforts implemented during the data collection, analysis, and 
reporting phases is important to data users, who can then consider 
the impact of these control efforts on the data quality (see 
Reference 1 of this Appendix). Both qualitative and quantitative 
assessments of the effectiveness of these control efforts should 
identify those areas most likely to impact the data quality and to 
what extent.
    1.4 Periodic assessments of SLAMS data quality are required to 
be reported to EPA. To provide national uniformity in this 
assessment and reporting of data quality for all SLAMS networks, 
specific assessment and reporting procedures are prescribed in 
detail in sections 3, 4, and 5 of this Appendix. On the other hand, 
the selection and extent of the QA and QC activities used by a 
monitoring agency depend on a number of local factors such as the 
field and laboratory conditions, the objectives for monitoring, the 
level of the data quality needed, the expertise of assigned 
personnel, the cost of control procedures, pollutant concentration 
levels, etc. Therefore, the quality system requirements, in section 
2 of this Appendix, are specified in general terms to allow each 
State to develop a quality assurance program that is most efficient 
and effective for its own circumstances while achieving the Ambient 
Air Quality Programs data quality objectives.
2. Quality System Requirements.
    2.1 Each State and local agency must develop a quality system 
(Reference 2 of this Appendix) to ensure that the monitoring 
results:
    (a) Meet a well-defined need, use, or purpose.
    (b) Satisfy customers' expectations.
    (c) Comply with applicable standards specifications.
    (d) Comply with statutory (and other) requirements of society.
    (e) Reflect consideration of cost and economics.
    (f) Implement a quality assurance program consisting of 
policies, procedures, specifications, standards, and documentation 
necessary to:

[[Page 38834]]

    (1) Provide data of adequate quality to meet monitoring 
objectives, and
    (2) Minimize loss of air quality data due to malfunctions or 
out-of-control conditions. This quality assurance program must be 
described in detail, suitably documented in accordance with Agency 
requirements (Reference 4 of this Appendix), and approved by the 
appropriate Regional Administrator, or the Regional Administrator's 
designee. The Quality Assurance Program will be reviewed during the 
systems audits described in section 2.5 of this Appendix.
    2.2 Primary requirements and guidance documents for developing 
the quality assurance program are contained in References 2 through 
7 of this Appendix, which also contain many suggested and required 
procedures, checks, and control specifications. Reference 7 of this 
Appendix describes specific guidance for the development of a QA 
Program for SLAMS. Many specific quality control checks and 
specifications for methods are included in the respective reference 
methods described in part 50 of this chapter or in the respective 
equivalent method descriptions available from EPA (Reference 8 of 
this Appendix). Similarly, quality control procedures related to 
specifically designated reference and equivalent method analyzers 
are contained in the respective operation or instruction manuals 
associated with those analyzers. Quality assurance guidance for 
meteorological systems at PAMS is contained in Reference 9 of this 
Appendix. Quality assurance procedures for VOC, NOx 
(including NO and NO2), O3, and carbonyl 
measurements at PAMS must be consistent with Reference 15 of this 
Appendix. Reference 4 of this Appendix includes requirements for the 
development of quality assurance project plans, and quality 
assurance and control programs, and systems audits demonstrating 
attainment of the requirements.
    2.3 Pollutant Concentration and Flow Rate Standards.
    2.3.1 Gaseous pollutant concentration standards (permeation 
devices or cylinders of compressed gas) used to obtain test 
concentrations for CO, SO2, NO, and NO2 must 
be traceable to either a National Institute of Standards and 
Technology (NIST) NIST-Traceable Reference Material (NTRM) or a 
NIST-certified Gas Manufacturer's Internal Standard (GMIS), 
certified in accordance with one of the procedures given in 
Reference 10 of this Appendix.
    2.3.2 Test concentrations for O3 must be obtained in 
accordance with the UV photometric calibration procedure specified 
in 40 CFR part 50, Appendix D, or by means of a certified ozone 
transfer standard. Consult References 11 and 12 of this Appendix for 
guidance on primary and transfer standards for O3.
    2.3.3 Flow rate measurements must be made by a flow measuring 
instrument that is traceable to an authoritative volume or other 
applicable standard. Guidance for certifying some types of 
flowmeters is provided in Reference 7 of this Appendix.
    2.4 National Performance Audit Program (NPAP). Agencies 
operating SLAMS are required to participate in EPA's NPAP. These 
audits are described in Reference 7 of this Appendix. For further 
instructions, agencies should contact either the appropriate EPA 
Regional QA Coordinator at the appropriate EPA Regional Office 
location, or the NPAP Coordinator, Emissions Monitoring and Analysis 
Division (MD-14), U.S. Environmental Protection Agency, Research 
Triangle Park, NC 27711.
    2.5 Systems Audit Programs. Systems audits of the ambient air 
monitoring programs of agencies operating SLAMS shall be conducted 
at least every 3 years by the appropriate EPA Regional Office. 
Systems audit programs are described in Reference 7 of this 
Appendix. For further instructions, agencies should contact either 
the appropriate EPA Regional QA Coordinator or the Systems Audit QA 
Coordinator, Office of Air Quality Planning and Standards, Emissions 
Monitoring and Analysis Division (MD-14), U.S. Environmental 
Protection Agency, Research Triangle Park, NC 27711.
3. Data Quality Assessment Requirements.
    3.0.1 All ambient monitoring methods or analyzers used in SLAMS 
shall be tested periodically, as described in this section, to 
quantitatively assess the quality of the SLAMS data. Measurement 
uncertainty is estimated for both automated and manual methods. 
Terminology associated with measurement uncertainty are found within 
this Appendix and includes:
    (a) Precision. A measurement of mutual agreement among 
individual measurements of the same property usually under 
prescribed similar conditions, expressed generally in terms of the 
standard deviation;
    (b) Accuracy. The degree of agreement between an observed value 
and an accepted reference value, accuracy includes a combination of 
random error (precision) and systematic error (bias) components 
which are due to sampling and analytical operations;
    (c) Bias. The systematic or persistent distortion of a 
measurement process which causes errors in one direction. The 
individual results of these tests for each method or analyzer shall 
be reported to EPA as specified in section 4 of this Appendix. EPA 
will then calculate quarterly assessments of measurement uncertainty 
applicable to the SLAMS data as described in section 5 of this 
Appendix. Data assessment results should be reported to EPA only for 
methods and analyzers approved for use in SLAMS monitoring under 
Appendix C of this part.
    3.0.2 Estimates of the data quality will be calculated on the 
basis of single monitors and reporting organizations and may also be 
calculated for each region and for the entire Nation. A reporting 
organization is defined as a State, subordinate organization within 
a State, or other organization that is responsible for a set of 
stations that monitors the same pollutant and for which data quality 
assessments can be pooled. States must define one or more reporting 
organizations for each pollutant such that each monitoring station 
in the State SLAMS network is included in one, and only one, 
reporting organization.
    3.0.3 Each reporting organization shall be defined such that 
measurement uncertainty among all stations in the organization can 
be expected to be reasonably homogeneous, as a result of common 
factors.
    (a) Common factors that should be considered by States in 
defining reporting organizations include:
    (1) Operation by a common team of field operators.
    (2) Common calibration facilities.
    (3) Oversight by a common quality assurance organization.
    (4) Support by a common laboratory or headquarters.
    (b) Where there is uncertainty in defining the reporting 
organizations or in assigning specific sites to reporting 
organizations, States shall consult with the appropriate EPA 
Regional Office. All definitions of reporting organizations shall be 
subject to final approval by the appropriate EPA Regional Office.
    3.0.4 Assessment results shall be reported as specified in 
section 4 of this Appendix. Table A-1 of this Appendix provides a 
summary of the minimum data quality assessment requirements, which 
are described in more detail in the following sections.
    3.1 Precision of Automated Methods Excluding PM2.5.
    3.1.1 Methods for SO2, NO2, O3 
and CO. A one- point precision check must be performed at least once 
every 2 weeks on each automated analyzer used to measure 
SO2, NO2, O3 and CO. The precision 
check is made by challenging the analyzer with a precision check gas 
of known concentration (effective concentration for open path 
analyzers) between 0.08 and 0.10 ppm for SO2, 
NO2, and O3 analyzers, and between 8 and 10 
ppm for CO analyzers. To check the precision of SLAMS analyzers 
operating on ranges higher than 0 to 1.0 ppm SO2, 
NO2, and O3, or 0 to 100 ppm for CO, use 
precision check gases of appropriately higher concentration as 
approved by the appropriate Regional Administrator or their 
designee. However, the results of precision checks at concentration 
levels other than those specified above need not be reported to EPA. 
The standards from which precision check test concentrations are 
obtained must meet the specifications of section 2.3 of this 
Appendix.
    3.1.1.1 Except for certain CO analyzers described below, point 
analyzers must operate in their normal sampling mode during the 
precision check, and the test atmosphere must pass through all 
filters, scrubbers, conditioners and other components used during 
normal ambient sampling and as much of the ambient air inlet system 
as is practicable. If permitted by the associated operation or 
instruction manual, a CO point analyzer may be temporarily modified 
during the precision check to reduce vent or purge flows, or the 
test atmosphere may enter the analyzer at a point other than the 
normal sample inlet, provided that the analyzer's response is not 
likely to be altered by these deviations from the normal operational 
mode. If a precision check is made in conjunction with a zero or 
span adjustment, it must be made prior to such zero or span 
adjustments. Randomization of the precision check with respect to 
time of day, day of week, and routine service and adjustments is 
encouraged where possible.

[[Page 38835]]

    3.1.1.2 Open path analyzers are tested by inserting a test cell 
containing a precision check gas concentration into the optical 
measurement beam of the instrument. If possible, the normally used 
transmitter, receiver, and as appropriate, reflecting devices should 
be used during the test, and the normal monitoring configuration of 
the instrument should be altered as little as possible to 
accommodate the test cell for the test. However, if permitted by the 
associated operation or instruction manual, an alternate local light 
source or an alternate optical path that does not include the normal 
atmospheric monitoring path may be used. The actual concentration of 
the precision check gas in the test cell must be selected to produce 
an effective concentration in the range specified in section 3.1.1. 
Generally, the precision test concentration measurement will be the 
sum of the atmospheric pollutant concentration and the precision 
test concentration. If so, the result must be corrected to remove 
the atmospheric concentration contribution. The corrected 
concentration is obtained by subtracting the average of the 
atmospheric concentrations measured by the open path instrument 
under test immediately before and immediately after the precision 
check test from the precision test concentration measurement. If the 
difference between these before and after measurements is greater 
than 20 percent of the effective concentration of the test gas, 
discard the test result and repeat the test. If possible, open path 
analyzers should be tested during periods when the atmospheric 
pollutant concentrations are relatively low and steady.
    3.1.1.3 Report the actual concentration (effective concentration 
for open path analyzers) of the precision check gas and the 
corresponding concentration measurement (corrected concentration, if 
applicable, for open path analyzers) indicated by the analyzer. The 
percent differences between these concentrations are used to assess 
the precision of the monitoring data as described in section 5.1. of 
this Appendix.
    3.1.2 Methods for Particulate Matter Excluding PM2.5. 
A one-point precision check must be performed at least once every 2 
weeks on each automated analyzer used to measure PM10. 
The precision check is made by checking the operational flow rate of 
the analyzer. If a precision flow rate check is made in conjunction 
with a flow rate adjustment, it must be made prior to such flow rate 
adjustment. Randomization of the precision check with respect to 
time of day, day of week, and routine service and adjustments is 
encouraged where possible.
    3.1.2.1 Standard procedure: Use a flow rate transfer standard 
certified in accordance with section 2.3.3 of this Appendix to check 
the analyzer's normal flow rate. Care should be used in selecting 
and using the flow rate measurement device such that it does not 
alter the normal operating flow rate of the analyzer. Report the 
actual analyzer flow rate measured by the transfer standard and the 
corresponding flow rate measured, indicated, or assumed by the 
analyzer.
    3.1.2.2 Alternative procedure:
    3.1.2.2.1 It is permissible to obtain the precision check flow 
rate data from the analyzer's internal flow meter without the use of 
an external flow rate transfer standard, provided that:
    3.1.2.2.1.1 The flow meter is audited with an external flow rate 
transfer standard at least every 6 months.
    3.1.2.2.1.2 Records of at least the three most recent flow 
audits of the instrument's internal flow meter over at least several 
weeks confirm that the flow meter is stable, verifiable and accurate 
to 4%.
    3.1.2.2.1.3 The instrument and flow meter give no indication of 
improper operation.
    3.1.2.2.2 With suitable communication capability, the precision 
check may thus be carried out remotely. For this procedure, report 
the set-point flow rate as the actual flow rate along with the flow 
rate measured or indicated by the analyzer flow meter.
    3.1.2.2.3 For either procedure, the percent differences between 
the actual and indicated flow rates are used to assess the precision 
of the monitoring data as described in section 5.1 of this Appendix 
(using flow rates in lieu of concentrations). The percent 
differences between these concentrations are used to assess the 
precision of the monitoring data as described in section 5.1. of 
this Appendix.
    3.2 Accuracy of Automated Methods Excluding PM2.5.
    3.2.1 Methods for SO2, NO2, O3, 
or CO.
    3.2.1.1 Each calendar quarter (during which analyzers are 
operated), audit at least 25 percent of the SLAMS analyzers that 
monitor for SO2, NO2, O3, or CO 
such that each analyzer is audited at least once per year. If there 
are fewer than four analyzers for a pollutant within a reporting 
organization, randomly reaudit one or more analyzers so that at 
least one analyzer for that pollutant is audited each calendar 
quarter. Where possible, EPA strongly encourages more frequent 
auditing, up to an audit frequency of once per quarter for each 
SLAMS analyzer.
    3.2.1.2 (a) The audit is made by challenging the analyzer with 
at least one audit gas of known concentration (effective 
concentration for open path analyzers) from each of the following 
ranges applicable to the analyzer being audited:

------------------------------------------------------------------------
                                          Concentration Range, PPM      
            Audit Level           --------------------------------------
                                     SO2, O3        NO2           CO    
------------------------------------------------------------------------
1................................    0.03-0.08    0.03-0.08          3-8
2................................    0.15-0.20    0.15-0.20        15-20
3................................    0.35-0.45    0.35-0.45        35-45
4................................    0.80-0.90  ...........        80-90
------------------------------------------------------------------------

    (b) NO2 audit gas for chemiluminescence-type 
NO2 analyzers must also contain at least 0.08 ppm NO.
    3.2.1.3 NO concentrations substantially higher than 0.08 ppm, as 
may occur when using some gas phase titration (GPT) techniques, may 
lead to audit errors in chemiluminescence analyzers due to 
inevitable minor NO-NOx channel imbalance. Such errors 
may be atypical of routine monitoring errors to the extent that such 
NO concentrations exceed typical ambient NO concentrations at the 
site. These errors may be minimized by modifying the GPT technique 
to lower the NO concentrations remaining in the NO2 audit 
gas to levels closer to typical ambient NO concentrations at the 
site.
    3.2.1.4 To audit SLAMS analyzers operating on ranges higher than 
0 to 1.0 ppm for SO2, NO2, and O3 
or 0 to 100 ppm for CO, use audit gases of appropriately higher 
concentration as approved by the appropriate Regional Administrator 
or the Administrators's designee. The results of audits at 
concentration levels other than those shown in the above table need 
not be reported to EPA.
    3.2.1.5 The standards from which audit gas test concentrations 
are obtained must meet the specifications of section 2.3 of this 
Appendix. The gas standards and equipment used for auditing must not 
be the same as the standards and equipment used for calibration or 
calibration span adjustments. The auditor should not be the operator 
or analyst who conducts the routine monitoring, calibration, and 
analysis.
    3.2.1.6 For point analyzers, the audit shall be carried out by 
allowing the analyzer to analyze the audit test atmosphere in its 
normal sampling mode such that the test atmosphere passes through 
all filters, scrubbers, conditioners, and other sample inlet 
components used during normal ambient sampling and as much of the 
ambient air inlet system as is practicable. The exception provided 
in section 3.1 of this Appendix for certain CO analyzers does not 
apply for audits.
    3.2.1.7 Open path analyzers are audited by inserting a test cell 
containing the various audit gas concentrations into the optical 
measurement beam of the instrument. If possible, the normally used 
transmitter, receiver, and, as appropriate, reflecting devices 
should be used during the audit, and the normal monitoring 
configuration of the instrument should be modified as little as 
possible to accommodate the test cell for the audit. However, if 
permitted by the associated operation or instruction manual, an 
alternate local light source or an alternate optical path that does 
not include the normal atmospheric monitoring path may be used. The 
actual concentrations of the audit gas in the test cell must be 
selected to produce effective concentrations in the ranges specified 
in this section 3.2 of this Appendix.

[[Page 38836]]

Generally, each audit concentration measurement result will be the 
sum of the atmospheric pollutant concentration and the audit test 
concentration. If so, the result must be corrected to remove the 
atmospheric concentration contribution. The corrected concentration 
is obtained by subtracting the average of the atmospheric 
concentrations measured by the open path instrument under test 
immediately before and immediately after the audit test (or 
preferably before and after each audit concentration level) from the 
audit concentration measurement. If the difference between the 
before and after measurements is greater than 20 percent of the 
effective concentration of the test gas standard, discard the test 
result for that concentration level and repeat the test for that 
level. If possible, open path analyzers should be audited during 
periods when the atmospheric pollutant concentrations are relatively 
low and steady. Also, the monitoring path length must be reverified 
to within 3 percent to validate the audit, since the 
monitoring path length is critical to the determination of the 
effective concentration.
    3.2.1.8 Report both the actual concentrations (effective 
concentrations for open path analyzers) of the audit gases and the 
corresponding concentration measurements (corrected concentrations, 
if applicable, for open path analyzers) indicated or produced by the 
analyzer being tested. The percent differences between these 
concentrations are used to assess the accuracy of the monitoring 
data as described in section 5.2 of this Appendix.
    3.2.2 Methods for Particulate Matter Excluding PM2.5.
    3.2.2.1 Each calendar quarter, audit the flow rate of at least 
25 percent of the SLAMS PM10 analyzers such that each 
PM10 analyzer is audited at least once per year. If there 
are fewer than four PM10 analyzers within a reporting 
organization, randomly re-audit one or more analyzers so that at 
least one analyzer is audited each calendar quarter. Where possible, 
EPA strongly encourages more frequent auditing, up to an audit 
frequency of once per quarter for each SLAMS analyzer.
    3.2.2.2 The audit is made by measuring the analyzer's normal 
operating flow rate, using a flow rate transfer standard certified 
in accordance with section 2.3.3 of this Appendix. The flow rate 
standard used for auditing must not be the same flow rate standard 
used to calibrate the analyzer. However, both the calibration 
standard and the audit standard may be referenced to the same 
primary flow rate or volume standard. Great care must be used in 
auditing the flow rate to be certain that the flow measurement 
device does not alter the normal operating flow rate of the 
analyzer. Report the audit (actual) flow rate and the corresponding 
flow rate indicated or assumed by the sampler. The percent 
differences between these flow rates are used to calculate accuracy 
(PM10) as described in section 5.2 of this Appendix.
    3.3 Precision of Manual Methods Excluding PM2.5.
    3.3.1 For each network of manual methods other than for 
PM2.5, select one or more monitoring sites within the 
reporting organization for duplicate, collocated sampling as 
follows: for 1 to 5 sites, select 1 site; for 6 to 20 sites, select 
2 sites; and for over 20 sites, select 3 sites. Where possible, 
additional collocated sampling is encouraged. For purposes of 
precision assessment, networks for measuring TSP and PM10 
shall be considered separately from one another. PM10 and 
TSP sites having annual mean particulate matter concentrations among 
the highest 25 percent of the annual mean concentrations for all the 
sites in the network must be selected or, if such sites are 
impractical, alternative sites approved by the Regional 
Administrator may be selected.
    3.3.2 In determining the number of collocated sites required for 
PM10, monitoring networks for lead should be treated 
independently from networks for particulate matter, even though the 
separate networks may share one or more common samplers. However, a 
single pair of samplers collocated at a common-sampler monitoring 
site that meets the requirements for both a collocated lead site and 
a collocated particulate matter site may serve as a collocated site 
for both networks.
    3.3.3 The two collocated samplers must be within 4 meters of 
each other, and particulate matter samplers must be at least 2 
meters apart to preclude airflow interference. Calibration, 
sampling, and analysis must be the same for both collocated samplers 
and the same as for all other samplers in the network.
    3.3.4 For each pair of collocated samplers, designate one 
sampler as the primary sampler whose samples will be used to report 
air quality for the site, and designate the other as the duplicate 
sampler. Each duplicate sampler must be operated concurrently with 
its associated routine sampler at least once per week. The operation 
schedule should be selected so that the sampling days are 
distributed evenly over the year and over the seven days of the 
week. A six-day sampling schedule is required. Report the 
measurements from both samplers at each collocated sampling site. 
The calculations for evaluating precision between the two collocated 
samplers are described in section 5.3 of this Appendix.
    3.4 Accuracy of Manual Methods Excluding PM2.5. The 
accuracy of manual sampling methods is assessed by auditing a 
portion of the measurement process.
    3.4.1 Procedures for PM10 and TSP.
    3.4.1.1 Procedures for flow rate audits for PM10. 
Each calendar quarter, audit the flow rate of at least 25 percent of 
the PM10 samplers such that each PM10 sampler 
is audited at least once per year. If there are fewer than four 
PM10 samplers within a reporting organization, randomly 
reaudit one or more samplers so that one sampler is audited each 
calendar quarter. Audit each sampler at its normal operating flow 
rate, using a flow rate transfer standard certified in accordance 
with section 2.3.3 of this Appendix. The flow rate standard used for 
auditing must not be the same flow rate standard used to calibrate 
the sampler. However, both the calibration standard and the audit 
standard may be referenced to the same primary flow rate standard. 
The flow audit should be scheduled so as to avoid interference with 
a scheduled sampling period. Report the audit (actual) flow rate and 
the corresponding flow rate indicated by the sampler's normally used 
flow indicator. The percent differences between these flow rates are 
used to calculate accuracy and bias as described in section 5.4.1 of 
this Appendix.
    3.4.1.2 Great care must be used in auditing high-volume 
particulate matter samplers having flow regulators because the 
introduction of resistance plates in the audit flow standard device 
can cause abnormal flow patterns at the point of flow sensing. For 
this reason, the flow audit standard should be used with a normal 
filter in place and without resistance plates in auditing flow-
regulated high-volume samplers, or other steps should be taken to 
assure that flow patterns are not perturbed at the point of flow 
sensing.
    3.4.2 SO2 Methods.
    3.4.2.1 Prepare audit solutions from a working sulfite-
tetrachloromercurate (TCM) solution as described in section 10.2 of 
the SO2 Reference Method (40 CFR part 50, Appendix A). 
These audit samples must be prepared independently from the 
standardized sulfite solutions used in the routine calibration 
procedure. Sulfite-TCM audit samples must be stored between 0 and 5 
deg.C and expire 30 days after preparation.
    3.4.2.2 Prepare audit samples in each of the concentration 
ranges of 0.2-0.3, 0.5-0.6, and 0.8-0.9 g SO2/
ml. Analyze an audit sample in each of the three ranges at least 
once each day that samples are analyzed and at least twice per 
calendar quarter. Report the audit concentrations (in g 
SO2/ml) and the corresponding indicated concentrations 
(in g SO2/ml). The percent differences between 
these concentrations are used to calculate accuracy as described in 
section 5.4.2 of this Appendix.
    3.4.3 NO2 Methods. Prepare audit solutions from a 
working sodium nitrite solution as described in the appropriate 
equivalent method (see Reference 8 of this Appendix). These audit 
samples must be prepared independently from the standardized nitrite 
solutions used in the routine calibration procedure. Sodium nitrite 
audit samples expire in 3 months after preparation. Prepare audit 
samples in each of the concentration ranges of 0.2-0.3, 0.5-0.6, and 
0.8-0.9 g NO2/ml. Analyze an audit sample in 
each of the three ranges at least once each day that samples are 
analyzed and at least twice per calendar quarter. Report the audit 
concentrations (in g NO2/ml) and the 
corresponding indicated concentrations (in g 
NO2/ml). The percent differences between these 
concentrations are used to calculate accuracy as described in 
section 5.4.2 of this Appendix.
    3.4.4 Pb Methods.
    3.4.4.1 For the Pb Reference Method (40 CFR part 50, Appendix 
G), the flow rates of the high-volume Pb samplers shall be audited 
as part of the TSP network using the same procedures described in 
section 3.4.1 of this Appendix. For agencies operating both TSP and 
Pb networks, 25 percent of the total number of high-volume samplers 
are to be audited each quarter.
    3.4.4.2 Each calendar quarter, audit the Pb Reference Method 
analytical procedure using

[[Page 38837]]

glass fiber filter strips containing a known quantity of Pb. These 
audit sample strips are prepared by depositing a Pb solution on 
unexposed glass fiber filter strips of dimensions 1.9 cm by 20.3 cm 
(3/4 inch by 8 inch) and allowing them to dry thoroughly. The audit 
samples must be prepared using batches of reagents different from 
those used to calibrate the Pb analytical equipment being audited. 
Prepare audit samples in the following concentration ranges:

------------------------------------------------------------------------
                                                           Equivalent   
                                             Pb            Ambient Pb   
                Range                  Concentration,    Concentration, 
                                      g/Strip    g/m3 
---------------------------------------------------------------\1\------
1...................................           100-300           0.5-1.5
2...................................          600-1000          3.0-5.0 
------------------------------------------------------------------------
\1\ Equivalent ambient Pb concentration in g/m3 is based on    
  sampling at 1.7 m3/min for 24 hours on a 20.3 cm x 25.4 cm (8 inch x  
  10 inch) glass fiber filter.                                          

    3.4.4.3 Audit samples must be extracted using the same 
extraction procedure used for exposed filters.
    3.4.4.4 Analyze three audit samples in each of the two ranges 
each quarter samples are analyzed. The audit sample analyses shall 
be distributed as much as possible over the entire calendar quarter. 
Report the audit concentrations (in g Pb/strip) and the 
corresponding measured concentrations (in g Pb/strip) using 
unit code 77. The percent differences between the concentrations are 
used to calculate analytical accuracy as described in section 5.4.2 
of this Appendix.
    3.4.4.5 The accuracy of an equivalent Pb method is assessed in 
the same manner as for the reference method. The flow auditing 
device and Pb analysis audit samples must be compatible with the 
specific requirements of the equivalent method.
    3.5 Measurement Uncertainty for Automated and Manual 
PM2.5 Methods. The goal for acceptable measurement 
uncertainty has been defined as 10 percent coefficient of variation 
(CV) for total precision and  10 percent for total bias 
(Reference 14 of this Appendix).
    3.5.1 Flow Rate Audits.
    3.5.1.1 Automated methods for PM2.5. A one-point 
precision check must be performed at least once every 2 weeks on 
each automated analyzer used to measure PM2.5. The 
precision check is made by checking the operational flow rate of the 
analyzer. If a precision flow rate check is made in conjunction with 
a flow rate adjustment, it must be made prior to such flow rate 
adjustment. Randomization of the precision check with respect to 
time of day, day of week, and routine service and adjustments is 
encouraged where possible.
    3.5.1.1.1 Standard procedure: Use a flow rate transfer standard 
certified in accordance with section 2.3.3 of this Appendix to check 
the analyzer's normal flow rate. Care should be used in selecting 
and using the flow rate measurement device such that it does not 
alter the normal operating flow rate of the analyzer. Report the 
actual analyzer flow rate measured by the transfer standard and the 
corresponding flow rate measured, indicated, or assumed by the 
analyzer.
    3.5.1.1.2 Alternative procedure: It is permissible to obtain the 
precision check flow rate data from the analyzer's internal flow 
meter without the use of an external flow rate transfer standard, 
provided that the flow meter is audited with an external flow rate 
transfer standard at least every 6 months; records of at least the 
three most recent flow audits of the instrument's internal flow 
meter over at least several weeks confirm that the flow meter is 
stable, verifiable and accurate to 4%; and the 
instrument and flow meter give no indication of improper operation. 
With suitable communication capability, the precision check may thus 
be carried out remotely. For this procedure, report the set-point 
flow rate as the actual flow rate along with the flow rate measured 
or indicated by the analyzer flow meter.
    3.5.1.1.3 For either procedure, the differences between the 
actual and indicated flow rates are used to assess the precision of 
the monitoring data as described in section 5.5 of this Appendix.
    3.5.1.2 Manual methods for PM2.5. Each calendar 
quarter, audit the flow rate of each SLAMS PM2.5 
analyzer. The audit is made by measuring the analyzer's normal 
operating flow rate, using a flow rate transfer standard certified 
in accordance with section 2.3.3 of this Appendix. The flow rate 
standard used for auditing must not be the same flow rate standard 
used to calibrate the analyzer. However, both the calibration 
standard and the audit standard may be referenced to the same 
primary flow rate or volume standard. Great care must be used in 
auditing the flow rate to be certain that the flow measurement 
device does not alter the normal operating flow rate of the 
analyzer. Report the audit (actual) flow rate and the corresponding 
flow rate indicated or assumed by the sampler. The procedures used 
to calculate measurement uncertainty PM2.5 are described 
in section 5.5 of this Appendix.
    3.5.2 Measurement of Precision using Collocated Procedures for 
Automated and Manual Methods of PM2.5.
    (a) For PM2.5 sites within a reporting organization 
each EPA designated Federal reference method (FRM) or Federal 
equivalent method (FEM) must:
    (1) Have 25 percent of the monitors collocated (values of .5 and 
greater round up).
    (2) Have at least 1 collocated monitor (if the total number of 
monitors is less than 4). The first collocated monitor must be a 
designated FRM monitor.
    (b) In addition, monitors selected must also meet the following 
requirements:
    (1) A monitor designated as an EPA FRM shall be collocated with 
a monitor having the same EPA FRM designation.
    (2) For each monitor designated as an EPA FEM, 50 percent of the 
designated monitors shall be collocated with a monitor having the 
same method designation and 50 percent of the monitors shall be 
collocated with an FRM monitor. If there are an odd number of 
collocated monitors required, the additional monitor shall be an 
FRM. An example of this procedure is found in Table A-2 of this 
Appendix.
    (c) For PM2.5 sites during the initial deployment of 
the SLAMS network, special emphasis should be placed on those sites 
in areas likely to be in violation of the NAAQS. Once areas are 
initially determined to be in violation, the collocated monitors 
should be deployed according to the following protocol:
    (1) Eighty percent of the collocated monitors should be deployed 
at sites with concentrations  ninety percent of the 
annual PM2.5 NAAQS (or 24-hour NAAQS if that is affecting 
the area); one hundred percent if all sites have concentrations 
above either NAAQS, and each area determined to be in violation 
should be represented by at least one collocated monitor.
    (2) The remaining 20 percent of the collocated monitors should 
be deployed at sites with concentrations < ninety percent of the 
annual PM2.5 NAAQS (or 24-hour NAAQS if that is affecting 
the area)
    (3) If an organization has no sites at concentration ranges 
 ninety percent of the annual PM2.5 NAAQS (or 
24-hour NAAQS if that is affecting the area), 60 percent of the 
collocated monitors should be deployed at those sites with the 
annual mean PM2.5 concentrations (or 24-hour NAAQS if 
that is affecting the area) among the highest 25 percent for all 
PM2.5 sites in the network.
    3.5.2.1 In determining the number of collocated sites required 
for PM2.5, monitoring networks for visibility should not 
be treated independently from networks for particulate matter, as 
the separate networks may share one or more common samplers. 
However, for class I visibility areas, EPA will accept visibility 
aerosol mass measurement instead of a PM2.5 measurement 
if the latter measurement is unavailable. Any PM2.5 
monitoring site which does not have a monitor which is an EPA 
federal reference or equivalent method is not required to be 
included in the number of sites which are used to determine the 
number of collocated monitors.
    3.5.2.2 The two collocated samplers must be within 4 meters of 
each other, and particulate matter samplers must be at least 2 
meters apart to preclude airflow interference. Calibration, 
sampling, and analysis must be the same for both collocated samplers 
and the same as for all other samplers in the network.
    3.5.2.3 For each pair of collocated samplers, designate one 
sampler as the primary sampler whose samples will be used to report 
air quality for the site, and designate the other as the duplicate 
sampler. Each duplicate sampler must be operated concurrently with 
its associated primary sampler. The operation schedule should be 
selected so that the sampling days are distributed evenly over the 
year and over the 7 days of the week and therefore, a 6-day sampling 
schedule is required. Report the measurements from both samplers at 
each collocated sampling site. The calculations for evaluating 
precision between the two collocated samplers are described in 
section 5.5 of this Appendix.
    3.5.3 Measurement of Bias using the FRM Audit Procedures for 
Automated and Manual Methods of PM2.5.
    3.5.3.1 The FRM audit is an independent assessment of the total 
measurement system bias. These audits will be performed under the 
National Performance Audit Program

[[Page 38838]]

(section 2.4 of this Appendix) or a comparable program. Twenty-five 
percent of the SLAMS monitors within each reporting organization 
will be assessed with an FRM audit each year. Additionally, every 
designated FRM or FEM within a reporting organization must:
    (a) Have at least 25 percent of each method designation audited, 
including collocated sites (even those collocated with FRM 
instruments), (values of .5 and greater round up).
    (b) Have at least one monitor audited.
    (c) Be audited at a frequency of four audits per year.
    (d) Have all FRM or FEM samples subject to an FRM audit at least 
once every 4 years. Table A-2 illustrates the procedure mentioned 
above.
    3.5.3.2 For PM2.5 sites during the initial deployment 
of the SLAMS network, special emphasis should be placed on those 
sites in areas likely to be in violation of the NAAQS. Once areas 
are initially determined to be in violation, the FRM audit program 
should be implemented according to the following protocol:
    (a) Eighty percent of the FRM audits should be deployed at sites 
with concentrations  ninety percent of the annual 
PM2.5 NAAQS (or 24-hour NAAQS if that is affecting the 
area); one hundred percent if all sites have concentrations above 
either NAAQS, and each area determined to be in violation should 
implement an FRM audit at a minimum of one monitor within that area.
    (b) The remaining 20 percent of the FRM audits should be 
implemented at sites with concentrations < ninety percent of the 
annual PM2.5 NAAQS (or 24-hour NAAQS if that is affecting 
the area).
    (c) If an organization has no sites at concentration ranges 
 ninety percent of the annual PM2.5 NAAQS (or 
24-hour NAAQS if that is affecting the area), 60 percent of the FRM 
audits should be implemented at those sites with the annual mean 
PM2.5 concentrations (or 24-hour NAAQS if that is 
affecting the area) among the highest 25 percent for all 
PM2.5 sites in the network. Additional information 
concerning the FRM audit program is contained in Reference 7 of this 
Appendix. The calculations for evaluating bias between the primary 
monitor and the FRM audit are described in section 5.5.
4. Reporting Requirements.
    (a) For each pollutant, prepare a list of all monitoring sites 
and their AIRS site identification codes in each reporting 
organization and submit the list to the appropriate EPA Regional 
Office, with a copy to AIRS-AQS. Whenever there is a change in this 
list of monitoring sites in a reporting organization, report this 
change to the Regional Office and to AIRS-AQS.
    4.1 Quarterly Reports. For each quarter, each reporting 
organization shall report to AIRS-AQS directly (or via the 
appropriate EPA Regional Office for organizations not direct users 
of AIRS) the results of all valid precision, bias and accuracy tests 
it has carried out during the quarter. The quarterly reports of 
precision, bias and accuracy data must be submitted consistent with 
the data reporting requirements specified for air quality data as 
set forth in Sec. 58.35(c). EPA strongly encourages early submittal 
of the QA data in order to assist the State and Local agencies in 
controlling and evaluating the quality of the ambient air SLAMS 
data. Each organization shall report all QA/QC measurements. Report 
results from invalid tests, from tests carried out during a time 
period for which ambient data immediately prior or subsequent to the 
tests were invalidated for appropriate reasons, and from tests of 
methods or analyzers not approved for use in SLAMS monitoring 
networks under Appendix C of this part. Such data should be flagged 
so that it will not be utilized for quantitative assessment of 
precision, bias and accuracy.
    4.2 Annual Reports.
    4.2.1 When precision, bias and accuracy estimates for a 
reporting organization have been calculated for all four quarters of 
the calendar year, EPA will calculate and report the measurement 
uncertainty for the entire calendar year. These limits will then be 
associated with the data submitted in the annual SLAMS report 
required by Sec.  58.26.
    4.2.2 Each reporting organization shall submit, along with its 
annual SLAMS report, a listing by pollutant of all monitoring sites 
in the reporting organization.
5. Calculations for Data Quality Assessment.
    (a) Calculations of measurement uncertainty are carried out by 
EPA according to the following procedures. Reporting organizations 
should report the data for individual precision, bias and accuracy 
tests as specified in sections 3 and 4 of this Appendix even though 
they may elect to perform some or all of the calculations in this 
section on their own.
    5.1 Precision of Automated Methods Excluding PM2.5. 
Estimates of the precision of automated methods are calculated from 
the results of biweekly precision checks as specified in section 3.1 
of this Appendix. At the end of each calendar quarter, an integrated 
precision probability interval for all SLAMS analyzers in the 
organization is calculated for each pollutant.
    5.1.1 Single Analyzer Precision.
    5.1.1.1 The percent difference (di) for each 
precision check is calculated using equation 1, where Yi 
is the concentration indicated by the analyzer for the I-th 
precision check and Xi is the known concentration for the 
I-th precision check, as follows:

Equation 1
[GRAPHIC] [TIFF OMITTED] TR18JY97.138

    5.1.1.2 For each analyzer, the quarterly average (dj) 
is calculated with equation 2, and the standard deviation 
(Sj) with equation 3, where n is the number of precision 
checks on the instrument made during the calendar quarter. For 
example, n should be 6 or 7 if precision checks are made biweekly 
during a quarter. Equation 2 and 3 follow:

Equation 2
[GRAPHIC] [TIFF OMITTED] TR18JY97.139

Equation 3
[GRAPHIC] [TIFF OMITTED] TR18JY97.140

    5.1.2 Precision for Reporting Organization.
    5.1.2.1 For each pollutant, the average of averages (D) and the 
pooled standard deviation (Sa) are calculated for all 
analyzers audited for the pollutant during the quarter, using either 
equations 4 and 5 or 4a and 5a, where k is the number of analyzers 
audited within the reporting organization for a single pollutant, as 
follows:

Equation 4
[GRAPHIC] [TIFF OMITTED] TR18JY97.141

Equation 4a
[GRAPHIC] [TIFF OMITTED] TR18JY97.142

Equation 5
[GRAPHIC] [TIFF OMITTED] TR18JY97.143

Equation 5a
[GRAPHIC] [TIFF OMITTED] TR18JY97.144

    5.1.2.2 Equations 4 and 5 are used when the same number of 
precision checks are made for each analyzer. Equations 4a and 5a are 
used to obtain a weighted average and a weighted standard deviation 
when different numbers of precision checks are made for the 
analyzers.
    5.1.2.3 For each pollutant, the 95 Percent Probability Limits 
for the precision of a reporting organization are calculated using 
equations 6 and 7, as follows:

[[Page 38839]]

Equation 6
[GRAPHIC] [TIFF OMITTED] TR18JY97.145

Equation 7
[GRAPHIC] [TIFF OMITTED] TR18JY97.146

    5.2 Accuracy of Automated Methods Excluding PM2.5. 
Estimates of the accuracy of automated methods are calculated from 
the results of independent audits as described in section 3.2 of 
this Appendix. At the end of each calendar quarter, an integrated 
accuracy probability interval for all SLAMS analyzers audited in the 
reporting organization is calculated for each pollutant. Separate 
probability limits are calculated for each audit concentration level 
in section 3.2 of this Appendix.
    5.2.1 Single Analyzer Accuracy. The percentage difference 
(di) for each audit concentration is calculated using 
equation 1, where Yi is the analyzer's indicated 
concentration measurement from the I-th audit check and 
Xi is the actual concentration of the audit gas used for 
the I-th audit check.
    5.2.2 Accuracy for Reporting Organization.
    5.2.2.1 For each audit concentration level of a particular 
pollutant, the average (D) of the individual percentage differences 
(di) for all n analyzers audited during the quarter is 
calculated using equation 8, as follows:

Equation 8
[GRAPHIC] [TIFF OMITTED] TR18JY97.147

    5.2.2.2 For each concentration level of a particular pollutant, 
the standard deviation (Sa) of all the individual 
percentage differences for all n analyzers audited during the 
quarter is calculated, using equation 9, as follows:

Equation 9
[GRAPHIC] [TIFF OMITTED] TR18JY97.148

    5.2.2.3 For reporting organizations having four or fewer 
analyzers for a particular pollutant, only one audit is required 
each quarter. For such reporting organizations, the audit results of 
two consecutive quarters are required to calculate an average and a 
standard deviation, using equations 8 and 9. Therefore, the 
reporting of probability limits shall be on a semiannual (instead of 
a quarterly) basis.
    5.2.2.4 For each pollutant, the 95 Percent Probability Limits 
for the accuracy of a reporting organization are calculated at each 
audit concentration level using equations 6 and 7.
    5.3 Precision of Manual Methods Excluding PM2.5. 
Estimates of precision of manual methods are calculated from the 
results obtained from collocated samplers as described in section 
3.3 of this Appendix. At the end of each calendar quarter, an 
integrated precision probability interval for all collocated 
samplers operating in the reporting organization is calculated for 
each manual method network.
    5.3.1 Single Sampler Precision.
    5.3.1.1 At low concentrations, agreement between the 
measurements of collocated samplers, expressed as percent 
differences, may be relatively poor. For this reason, collocated 
measurement pairs are selected for use in the precision calculations 
only when both measurements are above the following limits:
    (a) TSP: 20 g/m3.
    (b) SO2: 45 g/m3.
    (c) NO2: 30 g/m3.
    (d) Pb: 0.15 g/m3.
    (e) PM10: 20 g/m3.
    5.3.1.2 For each selected measurement pair, the percent 
difference (di) is calculated, using equation 10, as 
follows:

Equation 10
[GRAPHIC] [TIFF OMITTED] TR18JY97.149

where:
Yi is the pollutant concentration measurement obtained 
from the duplicate sampler; and
Xi is the concentration measurement obtained from the 
primary sampler designated for reporting air quality for the site.
    (a) For each site, the quarterly average percent difference 
(dj) is calculated from equation 2 and the standard 
deviation (Sj) is calculated from equation 3, where n= 
the number of selected measurement pairs at the site.
    5.3.2 Precision for Reporting Organization.
    5.3.2.1 For each pollutant, the average percentage difference 
(D) and the pooled standard deviation (Sa) are 
calculated, using equations 4 and 5, or using equations 4a and 5a if 
different numbers of paired measurements are obtained at the 
collocated sites. For these calculations, the k of equations 4, 4a, 
5 and 5a is the number of collocated sites.
    5.3.2.2 The 95 Percent Probability Limits for the integrated 
precision for a reporting organization are calculated using 
equations 11 and 12, as follows:

Equation 11
[GRAPHIC] [TIFF OMITTED] TR18JY97.150

Equation 12
[GRAPHIC] [TIFF OMITTED] TR18JY97.151

    5.4 Accuracy of Manual Methods Excluding PM2.5. 
Estimates of the accuracy of manual methods are calculated from the 
results of independent audits as described in section 3.4 of this 
Appendix. At the end of each calendar quarter, an integrated 
accuracy probability interval is calculated for each manual method 
network operated by the reporting organization.
    5.4.1 Particulate Matter Samplers other than PM2.5 
(including reference method Pb samplers).
    5.4.1.1 Single Sampler Accuracy. For the flow rate audit 
described in section 3.4.1 of this Appendix, the percentage 
difference (di) for each audit is calculated using 
equation 1, where Xi represents the known flow rate and 
Yi represents the flow rate indicated by the sampler.
    5.4.1.2 Accuracy for Reporting Organization. For each type of 
particulate matter measured (e.g., TSP/Pb), the average (D) of the 
individual percent differences for all similar particulate matter 
samplers audited during the calendar quarter is calculated using 
equation 8. The standard deviation (Sa) of the percentage 
differences for all of the similar particulate matter samplers 
audited during the calendar quarter is calculated using equation 9. 
The 95 Percent Probability Limits for the integrated accuracy for 
the reporting organization are calculated using equations 6 and 7. 
For reporting organizations having four or fewer particulate matter 
samplers of one type, only one audit is required each quarter, and 
the audit results of two consecutive quarters are required to 
calculate an average and a standard deviation. In that case, 
probability limits shall be reported semi-annually rather than 
quarterly.
    5.4.2 Analytical Methods for SO2, NO2, and 
Pb.
    5.4.2.1 Single Analysis-Day Accuracy. For each of the audits of 
the analytical methods for SO2, NO2, and Pb 
described in sections 3.4.2, 3.4.3, and 3.4.4 of this Appendix, the 
percentage difference (dj) at each concentration level is 
calculated using equation 1, where Xj represents the 
known value of the audit sample and Yj represents the 
value of SO2, NO2, or Pb indicated by the 
analytical method.
    5.4.2.2 Accuracy for Reporting Organization. For each analytical 
method, the average (D) of the individual percent differences at 
each concentration level for all audits during the calendar quarter 
is calculated using equation 8. The standard deviation 
(Sa) of the percentage differences at each concentration 
level for all audits during the calendar quarter is calculated using 
equation 9. The 95 Percent Probability Limits for the accuracy for 
the reporting organization are calculated using equations 6 and 7.
    5.5 Precision, Accuracy and Bias for Automated and Manual 
PM2.5 Methods.
    (a) Reporting organizations are required to report the data that 
will allow assessments of the following individual quality control 
checks and audits:
    (1) Flow rate audit.
    (2) Collocated samplers, where the duplicate sampler is not an 
FRM device.
    (3) Collocated samplers, where the duplicate sampler is an FRM 
device.
    (4) FRM audits.
    (b) EPA uses the reported results to derive precision, accuracy 
and bias estimates according to the following procedures.
    5.5.1 Flow Rate Audits. The reporting organization shall report 
both the audit standard flow rate and the flow rate indicated by the 
sampling instrument. These results are

[[Page 38840]]

used by EPA to calculate flow rate accuracy and bias estimates.
    5.5.1.1 Accuracy of a Single Sampler - Single Check (Quarterly) 
Basis (di). The percentage difference (di) for 
a single flow rate audit di is calculated using Equation 
13, where Xi represents the audit standard flow rate 
(known) and Yi represents the indicated flow rate, as 
follows:

Equation 13
[GRAPHIC] [TIFF OMITTED] TR18JY97.152

    5.5.1.2 Bias of a Single Sampler - Annual Basis (Dj). 
For an individual particulate sampler j, the average (Dj) 
of the individual percentage differences (di) during the 
calendar year is calculated using Equation 14, where nj 
is the number of individual percentage differences produced for 
sampler j during the calendar year, as follows:

Equation 14
[GRAPHIC] [TIFF OMITTED] TR18JY97.153

    5.5.1.3 Bias for Each EPA Federal Reference and Equivalent 
Method Designation Employed by Each Reporting Organization - 
Quarterly Basis (Dk,q). For method designation k used by 
the reporting organization, quarter q's single sampler percentage 
differences (di) are averaged using Equation 16, where 
nk,q is the number of individual percentage differences 
produced for method designation k in quarter q, as follows:

Equation 15
[GRAPHIC] [TIFF OMITTED] TR18JY97.154

    5.5.1.4 Bias for Each Reporting Organization - Quarterly Basis 
(Dq). For each reporting organization, quarter q's single 
sampler percentage differences (di) are averaged using 
Equation 16, to produce a single average for each reporting 
organization, where nq is the total number of single 
sampler percentage differences for all federal reference or 
equivalent methods of samplers in quarter q, as follows:

Equation 16
[GRAPHIC] [TIFF OMITTED] TR18JY97.155

    5.5.1.5 Bias for Each EPA Federal Reference and Equivalent 
Method Designation Employed by Each Reporting Organization - Annual 
Basis (Dk). For method designation k used by the 
reporting organization, the annual average percentage difference, 
Dk, is derived using Equation 17, where Dk,q 
is the average reported for method designation k during the qth 
quarter, and nk,q is the number of the method designation 
k's monitors that were deployed during the qth quarter, as follows:

Equation 17
[GRAPHIC] [TIFF OMITTED] TR18JY97.156

    5.5.1.6 Bias for Each Reporting Organization - Annual Basis (D). 
For each reporting organization, the annual average percentage 
difference, D, is derived using Equation 18, where Dq is 
the average reported for the reporting organization during the qth 
quarter, and nq is the total number monitors that were 
deployed during the qth quarter. A single annual average is produced 
for each reporting organization. Equation 18 follows:

Equation 18
[GRAPHIC] [TIFF OMITTED] TR18JY97.157

    5.5.2 Collocated Samplers, Where the Duplicate Sampler is not an 
FRM Device. (a) At low concentrations, agreement between the 
measurements of collocated samplers may be relatively poor. For this 
reason, collocated measurement pairs are selected for use in the 
precision calculations only when both measurements are above the 
following limits:
              PM2.5 : 6 g/m3
(b) Collocated sampler results are used to assess measurement 
system precision. A collocated sampler pair consists of a primary 
sampler (used for routine monitoring) and a duplicate sampler (used 
as a quality control check). Quarterly precision estimates are 
calculated by EPA for each pair of collocated samplers and for each 
method designation employed by each reporting organization. Annual 
precision estimates are calculated by EPA for each primary sampler, 
for each EPA Federal reference method and equivalent method 
designation employed by each reporting organization, and nationally 
for each EPA Federal reference method and equivalent method 
designation.
    5.5.2.1 Percent Difference for a Single Check (di). 
The percentage difference, di, for each check is 
calculated by EPA using Equation 19, where Xi represents 
the concentration produced from the primary sampler and 
Yi represents concentration reported for the duplicate 
sampler, as follows:

Equation 19
[GRAPHIC] [TIFF OMITTED] TR18JY97.158

    5.5.2.2 Coefficient of Variation (CV) for a Single Check 
(CVi). The coefficient of variation, CVi, for 
each check is calculated by EPA by dividing the absolute value of 
the percentage difference, di, by the square root of two 
as shown in Equation 20, as follows:

Equation 20
[GRAPHIC] [TIFF OMITTED] TR18JY97.159

    5.5.2.3 Precision of a Single Sampler - Quarterly Basis 
(CVj,q).
    (a) For particulate sampler j, the individual coefficients of 
variation (CVj,q) during the quarter are pooled using 
Equation 21, where nj,q is the number of pairs of 
measurements from collocated samplers during the quarter, as 
follows:

Equation 21
[GRAPHIC] [TIFF OMITTED] TR18JY97.160

    (b) The 90 percent confidence limits for the single sampler's CV 
are calculated by EPA using Equations 22 and 23, where X2 
0.05,df and X2 0.95,df are the 0.05 
and 0.95 quantiles of the chi-square (X2) distribution 
with nj,q degrees of freedom, as follows:

Equation 22
[GRAPHIC] [TIFF OMITTED] TR18JY97.161

Equation 23
[GRAPHIC] [TIFF OMITTED] TR18JY97.162

    5.5.2.4 Precision of a Single Sampler - Annual Basis. For 
particulate sampler j, the individual coefficients of variation, 
CVi, produced during the calendar year are pooled using 
Equation 21, where nj is the number of checks made during 
the calendar year. The 90 percent confidence limits for the single 
sampler's CV are calculated by EPA using Equations 22 and 23, where 
X2 0.05,df and X2 
0.95,df are the 0.05 and 0.95 quantiles of the chi-square 
(X2) distribution with nj degrees of freedom.
    5.5.2.5 Precision for Each EPA Federal Reference Method and 
Equivalent Method Designation Employed by Each Reporting 
Organization - Quarterly Basis (CVk,q).
    (a) For each method designation k used by the reporting 
organization, the quarter's single sampler coefficients of 
variation, CVj,qs, obtained from Equation 21, are pooled 
using Equation 24, where nk,q is the number of collocated 
primary monitors for the designated method (but not collocated with 
FRM samplers) and nj,q is the number of degrees of 
freedom associated with CVj,q, as follows:

[[Page 38841]]

Equation 24
[GRAPHIC] [TIFF OMITTED] TR18JY97.163

    (b) The number of method CVs produced for a reporting 
organization will equal the number of different method designations 
having more than one primary monitor employed by the organization 
during the quarter. (When exactly one monitor of a specified 
designation is used by a reporting organization, it will be 
collocated with an FRM sampler.)
    5.5.2.6 Precision for Each Method Designation Employed by Each 
Reporting Organization- Annual Basis (CVk). For each 
method designation k used by the reporting organization, the 
quarterly estimated coefficients of variation, CVk,q, are 
pooled using Equation 25, where nk,q is the number of 
collocated primary monitors for the designated method during the qth 
quarter and also the number of degrees of freedom associated with 
the quarter's precision estimate for the method designation, 
CVk,q, as follows:

Equation 25
[GRAPHIC] [TIFF OMITTED] TR18JY97.164

    5.5.3 Collocated Samplers, Where the Duplicate Sampler is an FRM 
Device. At low concentrations, agreement between the measurements of 
collocated samplers may be relatively poor. For this reason, 
collocated measurement pairs are selected for use in the precision 
calculations only when both measurements are above the following 
limits: PM2.5: 6 g/m3. These 
duplicate sampler results are used to assess measurement system 
bias. Quarterly bias estimates are calculated by EPA for each 
primary sampler and for each method designation employed by each 
reporting organization. Annual precision estimates are calculated by 
EPA for each primary monitor, for each method designation employed 
by each reporting organization, and nationally for each method 
designation.
    5.5.3.1 Accuracy for a Single Check (d'i). The 
percentage difference, d'i, for each check is calculated 
by EPA using Equation 26, where Xi represents the 
concentration produced from the FRM sampler taken as the true value 
and Yi represents concentration reported for the primary 
sampler, as follows:

Equation 26
[GRAPHIC] [TIFF OMITTED] TR18JY97.165

    5.5.3.2 Bias of a Single Sampler - Quarterly Basis 
(D'j,q).
    (a) For particulate sampler j, the average of the individual 
percentage differences during the quarter q is calculated by EPA 
using Equation 27, where nj,q is the number of checks 
made for sampler j during the calendar quarter, as follows:

Equation 27
[GRAPHIC] [TIFF OMITTED] TR18JY97.166

    (b) The standard deviation, s'j,q, of sampler j's 
percentage differences for quarter q is calculated using Equation 
28, as follows:

Equation 28
[GRAPHIC] [TIFF OMITTED] TR18JY97.167

    (c) The 95 Percent Confidence Limits for the single sampler's 
bias are calculated using Equations 29 and 30 where 
t0.975,df is the 0.975 quantile of Student's t 
distribution with df = nj,q-1 degrees of freedom, as 
follows:

Equation 29
[GRAPHIC] [TIFF OMITTED] TR18JY97.168

Equation 30
[GRAPHIC] [TIFF OMITTED] TR18JY97.169

    5.5.3.3 Bias of a Single Sampler - Annual Basis 
(D'j).
    (a) For particulate sampler j, the mean bias for the year is 
derived from the quarterly bias estimates, D'j,q, using 
Equation 31, where the variables are as defined for Equations 27 and 
28, as follows:

Equation 31
[GRAPHIC] [TIFF OMITTED] TR18JY97.170

    (b) The standard error of the above estimate, sej' is 
calculated using Equation 32, as follows:

Equation 32
[GRAPHIC] [TIFF OMITTED] TR18JY97.171

    (c) The 95 Percent Confidence Limits for the single sampler's 
bias are calculated using Equations 33 and 34, where 
t0.975,df is the 0.975 quantile of Student's t 
distribution with 
df=(nj,1+nj,2+nj,3+nj,4-
4) degrees of freedom, as follows:

Equation 33
[GRAPHIC] [TIFF OMITTED] TR18JY97.172

Equation 34
[GRAPHIC] [TIFF OMITTED] TR18JY97.173

    5.5.3.4 Bias for a Single Reporting Organization (D') - Annual 
Basis. The reporting organizations mean bias is calculated using 
Equation 35, where variables are as defined in Equations 31 and 32, 
as follows:

Equation 35
[GRAPHIC] [TIFF OMITTED] TR18JY97.174

    5.5.4 FRM Audits. FRM Audits are performed once per quarter for 
selected samplers. The reporting organization reports concentration 
data from the primary sampler. Calculations for FRM Audits are 
similar to those for collocated samplers having FRM samplers as 
duplicates. The calculations differ because only one check is 
performed per quarter.
    5.5.4.1 Accuracy for a Single Sampler, Quarterly Basis 
(di). The percentage difference, di, for each 
check is calculated using Equation 26, where Xi 
represents the concentration produced from the FRM sampler and 
Yi represents the concentration reported for the primary 
sampler. For quarter q, the bias estimate for sampler j is denoted 
Dj,q.
    5.5.4.2 Bias of a Single Sampler - Annual Basis 
(D'j). For particulate sampler j, the mean bias for the 
year is derived from the quarterly bias estimates, Dj,q, 
using Equation 31, where nj,q equals 1 because one FRM 
audit is performed per quarter.
    5.5.4.3. Bias for a Single Reporting Organization - Annual Basis 
(D'). The reporting organizations mean bias is calculated using 
Equation 35, where variables are as defined in Equations 31 and 32.
References in Appendix A of Part 58
    (1) Rhodes, R.C. Guideline on the Meaning and Use of Precision 
and Accuracy Data Required by 40 CFR part 58, Appendices A and B. 
EPA-600/4-83/023. U.S. Environmental Protection Agency, Research 
Triangle Park, NC 27711, June, 1983.
    (2) American National Standard--Specifications and Guidelines 
for Quality

[[Page 38842]]

Systems for Environmental Data Collection and Environmental 
Technology Programs. ANSI/ASQC E4-1994. January 1995. Available from 
American Society for Quality Control, 611 East Wisconsin Avenue, 
Milwaukee, WI 53202.
    (3) EPA Requirements for Quality Management Plans. EPA QA/R-2. 
August 1994. Available from U.S. Environmental Protection Agency, 
ORD Publications Office, Center for Environmental Research 
Information (CERI), 26 W. Martin Luther King Drive, Cincinnati, OH 
45268.
    (4) EPA Requirements for Quality Assurance Project Plans for 
Environmental Data Operations. EPA QA/R-5. August 1994. Available 
from U.S. Environmental Protection Agency, ORD Publications Office, 
Center for Environmental Research Information (CERI), 26 W. Martin 
Luther King Drive, Cincinnati, OH 45268.
    (5) Guidance for the Data Quality Objectives Process. EPA QA/G-
4. September 1994. Available from U.S. Environmental Protection 
Agency, ORD Publications Office, Center for Environmental Research 
Information (CERI), 26 W. Martin Luther King Drive, Cincinnati, OH 
45268.
    (6) Quality Assurance Handbook for Air Pollution Measurement 
Systems, Volume 1--A Field Guide to Environmental Quality Assurance. 
EPA-600/R-94/038a. April 1994. Available from U.S. Environmental 
Protection Agency, ORD Publications Office, Center for Environmental 
Research Information (CERI), 26 W. Martin Luther King Drive, 
Cincinnati, OH 45268.
    (7) Quality Assurance Handbook for Air Pollution Measurement 
Systems, Volume II--Ambient Air Specific Methods EPA-600/R-94/038b. 
Available from U.S. Environmental Protection Agency, ORD 
Publications Office, Center for Environmental Research Information 
(CERI), 26 W. Martin Luther King Drive, Cincinnati, OH 45268.
    (7a) Copies of section 2.12 of the Quality Assurance Handbook 
for Air Pollution Measurement Systems, are available from Department 
E (MD-77B), U.S. EPA, Research Triangle Park, NC 27711.
    (8) List of Designated Reference and Equivalent Methods. 
Available from U.S. Environmental Protection Agency, National 
Exposure Research Laboratory, Quality Assurance Branch, MD-77B, 
Research Triangle Park, NC 27711.
    (9) Technical Assistance Document for Sampling and Analysis of 
Ozone Precursors. Atmospheric Research and Exposure Assessment 
Laboratory, U.S. Environmental Protection Agency, Research Triangle 
Park, NC 27711. EPA 600/8-91-215. October 1991.
    (10) EPA Traceability Protocol for Assay and Certification of 
Gaseous Calibration Standards. EPA-600/R-93/224. September 1993. 
Available from U.S. Environmental Protection Agency, ORD 
Publications Office, Center for Environmental Research Information 
(CERI), 26 W. Martin Luther King Drive, Cincinnati, OH 45268.
    (11) Paur, R.J. and F.F. McElroy. Technical Assistance Document 
for the Calibration of Ambient Ozone Monitors. EPA-600/4-79-057. 
U.S. Environmental Protection Agency, Research Triangle Park, NC 
27711, September, 1979.
    (12) McElroy, F.F. Transfer Standards for the Calibration of 
Ambient Air Monitoring Analyzers for Ozone. EPA-600/4-79-056. U.S. 
Environmental Protection Agency, Research Triangle Park, NC 27711, 
September, 1979.
    (13) Musick, D.R. The Ambient Air Precision and Accuracy 
Program: 1995 Annual Report. EPA-454/R97001. U.S. Environmental 
Protection Agency, Research Triangle Park, NC 27711, February 1997.
    (14) Papp, M.L., J,B., Elkins, D.R., Musick and M.J., Messner, 
Data Quality Objectives for the PM2.5. Monitoring Data, 
U.S. Environmental Protection Agency, Research Triangle Park, NC 
27711. In preparation.
    (15) Photochemical Assessment Monitoring Stations Implementation 
Manual. EPA-454/B-93-051, U.S. Environmental Protection Agency, 
Research Triangle Park, NC 27711, March 1994.

Tables to Appendix A of Part 58

                                Table A-1.--Minimum Data Assessment Requirements                                
----------------------------------------------------------------------------------------------------------------
                                                                                                  Parameters    
             Method                Assessment Method       Coverage        Minimum Frequency       Reported     
----------------------------------------------------------------------------------------------------------------
Precision:                                                                                                      
    Automated Methods for SO2,    Response check at   Each analyzer       Once per 2 weeks    Actual            
     NO2, O3, and CO               concentration                                               concentration \2\
                                   between .08 and                                             and measured     
                                   .10 ppm (8 & 10                                             concentration \3\
                                   ppm for CO) \2\                                                              
                                                                                                                
    Manual Methods: All methods   Collocated          1 site for 1-5      Once every six      Particle mass     
     except PM2.5                  samplers            sites               days                concentration    
                                                      2 sites for 6-20                         indicated by     
                                                       sites                                   sampler and by   
                                                      3 sites >20 sites                        collocated       
                                                       (sites with                             sampler          
                                                       highest conc.)                                           
Accuracy:                                                                                                       
    Automated Methods for SO2,    Response check at   1. Each analyzer    1. Once per year    Actual            
     NO2, O3, and CO              .03-.08 ppm1,2      2. 25% of           2. Each calendar     concentration \2\
                                  .15-.20 ppm1,2       analyzers (at       quarter             and measured     
                                  .35-.45 ppm1,2       least 1)                                (indicated)      
                                  80-.90 ppm1,2 (if                                            concentration \3\
                                   applicable)                                                 for each level   
                                                                                                                
    Manual Methods for SO2, and   Check of            Analytical system   Each day samples    Actual            
     NO2                           analytical                              are analyzed, at    concentration and
                                   procedure with                          least twice per     measured         
                                   audit standard                          quarter             (indicated)      
                                   solutions                                                   concentration for
                                                                                               each audit       
                                                                                               solution         
                                                                                                                
    TSP, PM10                     Check of sampler    1. Each sampler     1. Once per year    Actual flow rate  
                                   flow rate          2. 25% of samplers  2. Each calendar     and flow rate    
                                                       (at least 1)        quarter             indicated by the 
                                                                                               sampler          
                                                                                                                
    Lead                          1. Check of sample  1. Each sampler     1. Include with     1. Same as for TSP
                                   flow rate as for                        TSP                                  
                                   TSP                                                                          
                                  2. Check of         2. Analytical       2. Each quarter     2. Actual         
                                   analytical system   system                                  concentration and
                                   with Pb audit                                               measured         
                                   strips                                                      (indicated)      
                                                                                               concentration of 
                                                                                               audit samples    
                                                                                               (g Pb/  
                                                                                               strip)           
PM2.5                                                                                                           

[[Page 38843]]

                                                                                                                
    Manual and Automated Methods- Collocated          25% of SLAMS        Once every six      1. Particle mass  
     Precision.                    samplers            (monitors with      days                concentration    
                                                       Conc affecting                          indicated by     
                                                       NAAQS violation                         sampler and by   
                                                       status)                                 collocated       
                                                                                               sampler          
                                                                                              2. 24-hour value  
                                                                                               for automated    
                                                                                               methods          
    Manual and Automated Methods- 1. Check of         25% of SLAMS        1. Minimum of       1. Actual flow    
     Accuracy and Bias             sampler flow rate   (monitors with      every calendar      rate and flow    
                                                       Conc affecting      quarter, 4 checks   rate indicated by
                                                       NAAQS violation     per year            sampler          
                                                       status)                                                  
                                  2. Audit with                           2. Minimum 4        2. Particle mass  
                                   reference method                        measurements per    concentration    
                                                                           year                indicated by     
                                                                                               sampler and by   
                                                                                               audit reference  
                                                                                               sampler          
----------------------------------------------------------------------------------------------------------------
\1\ Concentration times 100 for CO.                                                                             
\2\ Effective concentration for open path analyzers.                                                            
\3\ Corrected concentration, if applicable, for open path analyzers.                                            



  Table A-2.--Summary of PM2.5 Collocation and Audits Procedures As an Example of a Typical Reporting Organization Needing 43 Monitors, Having Procured 
                                                      FRMs and Three Other Equivalent Method Types                                                      
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                               # of Collocated      # of Independent FRM
         Method Designation            Total # of Monitors     Total # Collocated     # of Collocated FRMs  Monitors of Same Type          Audits       
--------------------------------------------------------------------------------------------------------------------------------------------------------
FRM                                            25                       6                      6                     n/a                     6          
Type A                                         10                       3                      2                      1                      3          
Type C                                          2                       1                      1                      0                      1          
Type D                                          6                       2                      1                      1                      2          
--------------------------------------------------------------------------------------------------------------------------------------------------------

    m. Appendix C is amended by revising section 2.2 and adding 
sections 2.2.1 and 2.2.2, adding sections 2.4 through 2.5, revising 
section 2.7.1, and adding section 2.9 and references 4 through 6 to 
section 6.0 to read as follows:
Appendix C--Ambient Air Quality Monitoring Methodology
    *    *    *    *    *
    2.2 Substitute PM10 samplers.
    2.2.1 For purposes of showing compliance with the NAAQS for 
particulate matter, a high volume TSP sampler described in 40 CFR 
part 50, Appendix B, may be used in a SLAMS in lieu of a 
PM10 monitor as long as the ambient concentrations of 
particles measured by the TSP sampler are below the PM10 
NAAQS. If the TSP sampler measures a single value that is higher 
than the PM10 24-hour standard, or if the annual average 
of its measurements is greater than the PM10 annual 
standard, the TSP sampler operating as a substitute PM10 
sampler must be replaced with a PM10 monitor. For a TSP 
measurement above the 24-hour standard, the TSP sampler should be 
replaced with a PM10 monitor before the end of the 
calendar quarter following the quarter in which the high 
concentration occurred. For a TSP annual average above the annual 
standard, the PM10 monitor should be operating by June 30 
of the year following the exceedance.
    2.2.2 In order to maintain historical continuity of ambient 
particulate matter trends and patterns for PM10 NAMS that 
were previously TSP NAMS, the TSP high volume sampler must be 
operated concurrently with the PM10 monitor for a one-
year period beginning with the PM10 NAMS start-up date. 
The operating schedule for the TSP sampler must be at least once 
every 6 days regardless of the PM10 sampling frequency.
    *    *    *    *    *
    2.4 Approval of non-designated PM2.5 methods operated 
at specific individual sites. A method for PM2.5 that has 
not been designated as a reference or equivalent method as defined 
in Sec. 50.1 of this chapter may be approved for use for purposes of 
section 2.1 of this Appendix at a particular SLAMS under the 
following stipulations.
    2.4.1 The method must be demonstrated to meet the comparability 
requirements (except as provided in this section 2.4.1) set forth in 
Sec. 53.34 of this chapter in each of the four seasons at the site 
at which it is intended to be used. For purposes of this section 
2.4.1, the requirements of Sec. 53.34 of this chapter shall apply 
except as follows:
    2.4.1.1 The method shall be tested at the site at which it is 
intended to be used, and there shall be no requirement for tests at 
any other test site.
    2.4.1.2 For purposes of this section 2.4, the seasons shall be 
defined as follows: Spring shall be the months of March, April, and 
May; summer shall be the months of June, July, and August; fall 
shall be the months of September, October, and November; and winter 
shall be the months of December, January, and February; when 
alternate seasons are approved by the Administrator.
    2.4.1.3 No PM10 samplers shall be required for the 
test, as determination of the PM2.5/PM10 ratio 
at the test site shall not be required.
    2.4.1.4 The specifications given in Table C-4 of part 53 of this 
chapter for Class I methods shall apply, except that there shall be 
no requirement for any minimum number of sample sets with Rj greater 
than 40 g/m3 for 24-hour samples or greater than 
15 g/m3 average concentration collected over a 
48-hour period.
    2.4.2 The monitoring agency wishing to use the method must 
develop and implement appropriate quality assurance procedures for 
the method.
    2.4.3 The monitoring agency wishing to use the method must 
develop and implement appropriate procedures for assessing and 
reporting the precision and accuracy of the method comparable to the 
procedures set forth in Appendix A of this part for designated 
reference and equivalent methods.
    2.4.4 The assessment of network operating precision using 
collocated measurements with reference method ``audit'' samplers 
required under section 3 of Appendix A of this part shall be carried 
out semi-annually rather than annually (i.e., monthly audits with 
assessment determinations each 6 months).
    2.4.5 Requests for approval under this section 2.4 must meet the 
general submittal requirements of sections 2.7.1 and 2.7.2.1 of this 
Appendix and must include the requirements in sections 2.4.5.1 
through 2.4.5.7 of this Appendix.
    2.4.5.1 A clear and unique description of the site at which the 
method or sampler will be used and tested, and a description of the 
nature or character of the site and the particulate matter that is 
expected to occur there.
    2.4.5.2 A detailed description of the method and the nature of 
the sampler or analyzer upon which it is based.

[[Page 38844]]

    2.4.5.3 A brief statement of the reason or rationale for 
requesting the approval.
    2.4.5.4 A detailed description of the quality assurance 
procedures that have been developed and that will be implemented for 
the method.
    2.4.5.5 A detailed description of the procedures for assessing 
the precision and accuracy of the method that will be implemented 
for reporting to AIRS.
    2.4.5.6 Test results from the comparability tests as required in 
section 2.4.1 through 2.4.1.4 of this Appendix.
    2.4.5.7 Such further supplemental information as may be 
necessary or helpful to support the required statements and test 
results.
    2.4.6 Within 120 days after receiving a request for approval of 
the use of a method at a particular site under this section 2.4 and 
such further information as may be requested for purposes of the 
decision, the Administrator will approve or disapprove the method by 
letter to the person or agency requesting such approval.
    2.5 Approval of non-designated methods under Sec. 58.13(f). An 
automated (continuous) method for PM2.5 that is not 
designated as either a reference or equivalent method as defined in 
Sec. 50.1 of this chapter may be approved under Sec. 58.13(f) for 
use at a SLAMS for the limited purposes of Sec. 58.13(f). Such an 
analyzer that is approved for use at a SLAMS under Sec.  58.13(f), 
identified as correlated acceptable continuous (CAC) monitors, shall 
not be considered a reference or equivalent method as defined in 
Sec. 50.1 of this chapter by virtue of its approval for use under 
Sec. 58.13(f), and the PM2.5 monitoring data obtained 
from such a monitor shall not be otherwise used for purposes of part 
50 of this chapter.
    *    *    *    *    *
    2.7.1 Requests for approval under sections 2.4, 2.6.2, or 2.8 of 
this Appendix must be submitted to: Director, National Exposure 
Assessment Laboratory, Department E, (MD-77B), U.S. Environmental 
Protection Agency, Research Triangle Park, North Carolina 27711.
    *    *    *    *    *
    2.9 Use of IMPROVE Samplers at a SLAMS. ``IMPROVE'' samplers may 
be used in SLAMS for monitoring of regional background and regional 
transport concentrations of fine particulate matter. The IMPROVE 
samplers were developed for use in the Interagency Monitoring of 
Protected Visual Environments (IMPROVE) network to characterize all 
of the major components and many trace constituents of the 
particulate matter that impair visibility in Federal Class I Areas. 
These samplers are routinely operated at about 70 locations in the 
United States. IMPROVE samplers consist of four sampling modules 
that are used to collect twice weekly 24-hour duration simultaneous 
samples. Modules A, B, and C collect PM2.5 on three 
different filter substrates that are compatible with a variety of 
analytical techniques, and module D collects a PM10 
sample. PM2.5 mass and elemental concentrations are 
determined by analysis of the 25mm diameter stretched Teflon filters 
from module A. More complete descriptions of the IMPROVE samplers 
and the data they collect are available elsewhere (References 4, 5, 
and 6 of this Appendix).
    *    *    *    *    *
6.0 References.
    *    *    *    *    *
    (4) Eldred, R.A., Cahill, T.A., Wilkenson, L.K., et al., 
Measurements of fine particles and their chemical components in the 
IMPROVE/NPS networks, in Transactions of the International Specialty 
Conference on Visibility and Fine Particles, Air and Waste 
Management Association: Pittsburgh, PA, 1990; pp 187-196.
    (5) Sisler, J.F., Huffman, D., and Latimer, D.A.; Spatial and 
temporal patterns and the chemical composition of the haze in the 
United States: An analysis of data from the IMPROVE network, 1988-
1991, ISSN No. 0737-5253-26, National Park Service, Ft. Collins, CO, 
1993.
    (6) Eldred, R.A., Cahill, T.A., Pitchford, M., and Malm, W.C.; 
IMPROVE--a new remote area particulate monitoring system for 
visibility studies, Proceedings of the 81st Annual Meeting of the 
Air Pollution Control Association, Dallas, Paper 88-54.3, 1988.
    n. Appendix D is amended by revising in the table of contents the 
entries for 2.8, 3.7, 4., and 5. and adding an entry for 6., by 
revising the first three paragraphs and Table 1 of section 1., revising 
the second paragraph in section 2. and adding a new paragraph to the 
end of the section before section 2.1, revising section 2.8 and adding 
sections 2.8.0.1 through 2.8.2.3, revising the third and fifth 
paragraphs in section 3., revising section 3.7 and adding sections 
3.7.1 through 3.7.7.4, revising the sixth paragraph in section 4.2 and 
redesignating Figures 1 and 2 as Figures 5 and 6 respectively, and 
revising the redesignated figures, revising footnote 3 of Table 2 of 
section 4.4, revising section 5. and reference 18 in section 6. to read 
as follows:
Appendix D--Network Design for State and Local Air Monitoring Stations 
(SLAMS), National Air Monitoring Stations (NAMS), and Photochemical 
Assessment Monitoring Stations (PAMS)
    *    *    *    *    *
    2.8 Particulate Matter Design Criteria for SLAMS
    *    *    *    *    *
    3.7 Particulate Matter Design Criteria for NAMS
    4. Network Design for Photochemical Assessment Monitoring 
Stations (PAMS)
    5. Summary
    6. References
1. SLAMS Monitoring Objectives and Spatial Scales.
    The purpose of this Appendix is to describe monitoring 
objectives and general criteria to be applied in establishing the 
State and Local Air Monitoring Stations (SLAMS) networks and for 
choosing general locations for new monitoring stations. It also 
describes criteria for determining the number and location of 
National Air Monitoring Stations (NAMS), Photochemical Assessment 
Monitoring Stations (PAMS), and core Stations for PM2.5. 
These criteria will also be used by EPA in evaluating the adequacy 
of the SLAMS/NAMS/PAMS and core PM2.5 networks.
    The network of stations that comprise SLAMS should be designed 
to meet a minimum of six basic monitoring objectives. These basic 
monitoring objectives are:
    (1) To determine highest concentrations expected to occur in the 
area covered by the network.
    (2) To determine representative concentrations in areas of high 
population density.
    (3) To determine the impact on ambient pollution levels of 
significant sources or source categories.
    (4) To determine general background concentration levels.
    (5) To determine the extent of Regional pollutant transport 
among populated areas; and in support of secondary standards.
    (6) To determine the welfare-related impacts in more rural and 
remote areas (such as visibility impairment and effects on 
vegetation).
    It should be noted that this Appendix contains no criteria for 
determining the total number of stations in SLAMS networks, except 
that a minimum number of lead SLAMS and PM2.5 are 
prescribed and the minimal network introduced in Sec. 58.20 is 
explained. The optimum size of a particular SLAMS network involves 
trade offs among data needs and available resources that EPA 
believes can best be resolved during the network design process.
    *    *    *    *    *

     Table 1.--Relationship Among Monitoring Objectives and Scale of    
                           Representativeness                           
------------------------------------------------------------------------
           Monitoring Objective               Appropriate Siting Scales 
------------------------------------------------------------------------
Highest concentration.....................  Micro, Middle, neighborhood 
                                             (sometimes urban1)         
Population................................  Neighborhood, urban         
Source impact.............................  Micro, middle, neighborhood 
General/background........................  Neighborhood, urban,        
                                             regional                   
Regional transport........................  Urban/regional              
Welfare-related impacts...................  Urban/regional              
------------------------------------------------------------------------
1 Urban denotes a geographic scale applicable to both cities and rural  
  areas                                                                 

    *    *    *    *    *
2. SLAMS Network Design Procedures.
    *    *    *    *    *
    The discussion of scales in sections 2.3 through 2.8 of this 
Appendix does not include all of the possible scales for each 
pollutant. The scales that are discussed are those that are felt to 
be most pertinent for SLAMS network design.
    *    *    *    *    *
    Information such as emissions density, housing density, 
climatological data, geographic information, traffic counts, and the 
results of modeling will be useful in designing regulatory networks. 
Air pollution control agencies have shown the value of

[[Page 38845]]

screening studies, such as intensive studies conducted with portable 
samplers, in designing networks. In many cases, in selecting sites 
for core PM2.5 or carbon monoxide SLAMS, and for defining 
the boundaries of PM2.5 optional community monitoring 
zones, air pollution control agencies will benefit from using such 
studies to evaluate the spatial distribution of pollutants.
    *    *    *    *    *
    2.8 Particulate Matter Design Criteria for SLAMS.
    As with other pollutants measured in the SLAMS network, the 
first step in designing the particulate matter network is to collect 
the necessary background information. Various studies in References 
11, 12, 13, 14, 15, and 16 of section 6 of this Appendix have 
documented the major source categories of particulate matter and 
their contribution to ambient levels in various locations throughout 
the country.
    2.8.0.1 Sources of background information would be regional and 
traffic maps, and aerial photographs showing topography, 
settlements, major industries and highways. These maps and 
photographs would be used to identify areas of the type that are of 
concern to the particular monitoring objective. After potentially 
suitable monitoring areas for particulate matter have been 
identified on a map, modeling may be used to provide an estimate of 
particulate matter concentrations throughout the area of interest. 
After completing the first step, existing particulate matter 
stations should be evaluated to determine their potential as 
candidates for SLAMS designation. Stations meeting one or more of 
the six basic monitoring objectives described in section 1 of this 
Appendix must be classified into one of the five scales of 
representativeness (micro, middle, neighborhood, urban and regional) 
if the stations are to become SLAMS. In siting and classifying 
particulate matter stations, the procedures in references 17 and 18 
of section 6 of this Appendix should be used.
    2.8.0.2 The most important spatial scales to effectively 
characterize the emissions of particulate matter from both mobile 
and stationary sources are the middle scales for PM10 and 
neighborhood scales for both PM10 and PM2.5. 
For purposes of establishing monitoring stations to represent large 
homogenous areas other than the above scales of representativeness 
and to characterize regional transport, urban or regional scale 
stations would also be needed. Most PM2.5 monitoring in 
urban areas should be representative of a neighborhood scale.
    2.8.0.3 Microscale--This scale would typify areas such as 
downtown street canyons and traffic corridors where the general 
public would be exposed to maximum concentrations from mobile 
sources. In some circumstances, the microscale is appropriate for 
particulate stations; core SLAMS on the microscale should, however, 
be limited to urban sites that are representative of long-term human 
exposure and of many such microenvironments in the area. In general, 
microscale particulate matter sites should be located near inhabited 
buildings or locations where the general public can be expected to 
be exposed to the concentration measured. Emissions from stationary 
sources such as primary and secondary smelters, power plants, and 
other large industrial processes may, under certain plume 
conditions, likewise result in high ground level concentrations at 
the microscale. In the latter case, the microscale would represent 
an area impacted by the plume with dimensions extending up to 
approximately 100 meters. Data collected at microscale stations 
provide information for evaluating and developing hot spot control 
measures. Unless these sites are indicative of population-oriented 
monitoring, they may be more appropriately classified as SPMs.
    2.8.0.4 Middle Scale--Much of the measurement of short-term 
public exposure to coarse fraction particles (PM10) is on 
this scale and on the neighborhood scale; for fine particulate, much 
of the measurement is on the neighborhood scale. People moving 
through downtown areas, or living near major roadways, encounter 
particles that would be adequately characterized by measurements of 
this spatial scale. Thus, measurements of this type would be 
appropriate for the evaluation of possible short-term exposure 
public health effects of particulate matter pollution. In many 
situations, monitoring sites that are representative of micro-scale 
or middle-scale impacts are not unique and are representative of 
many similar situations. This can occur along traffic corridors or 
other locations in a residential district. In this case, one 
location is representative of a neighborhood of small scale sites 
and is appropriate for evaluation of long-term or chronic effects. 
This scale also includes the characteristic concentrations for other 
areas with dimensions of a few hundred meters such as the parking 
lot and feeder streets associated with shopping centers, stadia, and 
office buildings. In the case of PM10, unpaved or seldom 
swept parking lots associated with these sources could be an 
important source in addition to the vehicular emissions themselves.
    2.8.0.5 Neighborhood Scale--Measurements in this category would 
represent conditions throughout some reasonably homogeneous urban 
subregion with dimensions of a few kilometers and of generally more 
regular shape than the middle scale. Homogeneity refers to the 
particulate matter concentrations, as well as the land use and land 
surface characteristics. Much of the PM2.5 exposures are 
expected to be associated with this scale of measurement. In some 
cases, a location carefully chosen to provide neighborhood scale 
data would represent not only the immediate neighborhood but also 
neighborhoods of the same type in other parts of the city. Stations 
of this kind provide good information about trends and compliance 
with standards because they often represent conditions in areas 
where people commonly live and work for periods comparable to those 
specified in the NAAQS. In general, most PM2.5 monitoring 
in urban areas should have this scale. A PM2.5 monitoring 
location is assumed to be representative of a neighborhood scale 
unless the monitor is adjacent to a recognized PM2.5 
emissions source or is otherwise demonstrated to be representative 
of a smaller spatial scale by an intensive monitoring study. This 
category also may include industrial and commercial neighborhoods 
especially in districts of diverse land use where residences are 
interspersed.
    2.8.0.6 Neighborhood scale data could provide valuable 
information for developing, testing, and revising models that 
describe the larger-scale concentration patterns, especially those 
models relying on spatially smoothed emission fields for inputs. The 
neighborhood scale measurements could also be used for neighborhood 
comparisons within or between cities. This is the most likely scale 
of measurements to meet the needs of planners.
    2.8.0.7 Urban Scale--This class of measurement would be made to 
characterize the particulate matter concentration over an entire 
metropolitan or rural area ranging in size from 4 to 50 km. Such 
measurements would be useful for assessing trends in area-wide air 
quality, and hence, the effectiveness of large scale air pollution 
control strategies. Core PM2.5 SLAMS may have this scale.
    2.8.0.8 Regional Scale--These measurements would characterize 
conditions over areas with dimensions of as much as hundreds of 
kilometers. As noted earlier, using representative conditions for an 
area implies some degree of homogeneity in that area. For this 
reason, regional scale measurements would be most applicable to 
sparsely populated areas with reasonably uniform ground cover. Data 
characteristics of this scale would provide information about larger 
scale processes of particulate matter emissions, losses and 
transport. Especially in the case of PM2.5, transport 
contributes to particulate concentrations and may affect multiple 
urban and State entities with large populations such as in the 
Eastern United States. Development of effective pollution control 
strategies requires an understanding at regional geographical scales 
of the emission sources and atmospheric processes that are 
responsible for elevated PM2.5 levels and may also be 
associated with elevated ozone and regional haze.
    2.8.1 Specific Design Criteria for PM2.5.
    2.8.1.1 Monitoring Planning Areas.
    Monitoring planning areas (MPAs) shall be used to conform to the 
community-oriented monitoring approach used for the PM2.5 
NAAQS given in part 50 of this chapter. MPAs are required to 
correspond to all metropolitan statistical areas (MSAs) with 
population greater than 200,000, and all other areas determined to 
be in violation of the PM2.5 NAAQS.1 MPAs for 
other designated parts of the State are optional. All MPAs shall be 
defined on the basis of existing, delineated mapping data such as 
State boundaries, county boundaries, zip codes, census blocks, or 
census block groups.
---------------------------------------------------------------------------

    1The boundaries of MPAs do not have to necessarily correspond to 
those of MSAs and existing intra or interstate air pollution 
planning districts may be utilized.
---------------------------------------------------------------------------

    2.8.1.2 PM2.5 Monitoring Sites within the State's PM 
Monitoring Network Description.
    2.8.1.2.1 The minimum required number, type of monitoring sites, 
and sampling

[[Page 38846]]

requirements for PM2.5 are based on monitoring planning 
areas described in the PM monitoring network description and 
proposed by the State in accordance with Sec. 58.20.
    2.8.1.2.2 Comparisons to the PM2.5 NAAQS may be based 
on data from SPMs in addition to SLAMS (including NAMS, core SLAMS 
and collocated PM2.5 sites at PAMS), that meet the 
requirements of Sec. 58.13 and Appendices A, C and E of this part, 
that are included in the PM monitoring network description. For 
comparison to the annual NAAQS, the monitors should be neighborhood 
scale community-oriented locations. Special purpose monitors that 
meet part 58 requirements will be exempt from NAAQS comparisons with 
the PM2.5 NAAQS for the first 2 calendar years of their 
operation to encourage PM2.5 monitoring initially. After 
this time, however, any SPM that records a violation of the 
PM2.5 NAAQS must be seriously considered as a potential 
SLAMS site during the annual SLAMS network review in accordance with 
Sec. 58.25. If such SPMs are not established as a SLAMS, the agency 
must document in its annual report the technical basis for excluding 
it as a SLAMS.
    2.8.1.2.3 The health-effects data base that served as the basis 
for selecting the new PM2.5 standards relied on a spatial 
average approach that reflects average community-oriented area-wide 
PM exposure levels. Under this approach, the most effective way to 
reduce total population risk is by lowering the annual distributions 
of ambient 24-hour PM2.5 concentrations, as opposed to 
controlling peak 24-hour concentrations on individual days. The 
annual standard selected by EPA will generally be the controlling 
standard for lowering both short- and long-term PM2.5 
concentrations on an area-wide basis and will achieve this result. 
In order to be consistent with this rationale, therefore, 
PM2.5 data collected from SLAMS and special purpose 
monitors that are representative, not of area-wide but rather, of 
relatively unique population-oriented microscale, or localized hot 
spot, or unique population-oriented middle-scale impact sites are 
only eligible for comparison only to the 24-hour PM2.5 
NAAQS. However, in instances where certain population-oriented 
micro- or middle-scale PM2.5 monitoring sites are 
determined by the EPA Regional Administrator to collectively 
identify a larger region of localized high ambient PM2.5 
concentrations, data from these population-oriented sites would be 
eligible for comparison to the annual NAAQS.
    2.8.1.2.4 Within each MPA, the responsible air pollution control 
agency shall install core SLAMS, other required SLAMS and as many 
PM2.5 stations judged necessary to satisfy the SLAMS 
requirements and monitoring objectives of this Appendix.
    2.8.1.3 Core Monitoring Stations for PM2.5.
    Core monitoring stations or sites are a subset of the SLAMS 
network for PM2.5 that are sited to represent community-
wide air quality. These core sites include sites to be collocated at 
PAMS.
    2.8.1.3.1 Within each monitoring planning area, the responsible 
air pollution control agency shall install the following core 
PM2.5 SLAMS:
    (a) At least two core PM2.5 SLAMS per MSA with 
population greater than 500,000 sampling everyday, unless exempted 
by the Regional Administrator, including at least one station in a 
population-oriented area of expected maximum concentration and at 
least one station in an area of poor air quality and at least one 
additional core monitor collocated at a PAMS site if the MPA is also 
a PAMS area2.
---------------------------------------------------------------------------

    2The core monitor to be collocated at a PAMS site shall not be 
considered a part of the PAMS as described in section 4 of this 
Appendix, but shall instead be considered to be a component of the 
particular MPA PM2.5 network.
---------------------------------------------------------------------------

    (b) At least one core PM2.5 SLAMS per MSA with 
population greater than 200,000 and less than or equal to 500,000 
sampling every third day.
    (c) Additional core PM2.5 SLAMS per MSA with 
population greater than 1 million, sampling every third day, as 
specified in the following table:

   Table 1.--Required Number of Core SLAMS According to MSA Population  
------------------------------------------------------------------------
                                            Minimum Required No. of Core
              MSA Population                           Sites1           
------------------------------------------------------------------------
>1 M                                        3                           
------------------------------------------------------------------------
>2 M                                        4                           
------------------------------------------------------------------------
>4 M                                        6                           
------------------------------------------------------------------------
>6 M                                        8                           
------------------------------------------------------------------------
>8 M                                        10                          
------------------------------------------------------------------------
1Core SLAMS at PAMS are in addition to these numbers.                   

    2.8.1.3.2 The site situated in the area of expected maximum 
concentration is analogous to NAMS ``category a.'' 3 This 
will henceforth be termed a category a core SLAMS site. The site 
located in the area of poor air quality with high population density 
or representative of maximum population impact is analogous to NAMS, 
``category b.'' This second site will be called a category b core 
SLAMS site.
---------------------------------------------------------------------------

    3The measured maximum concentrations at core population-oriented 
sites should be consistent with the averaging time of the NAAQS. 
Therefore, sites only with high concentrations for shorter averaging 
times (say 1-hour) should not be category ``a'' core SLAMS monitors.
---------------------------------------------------------------------------

    2.8.1.3.3 Those MPAs that are substantially impacted by several 
different and geographically disjoint local sources of fine 
particulate should have separate core sites to monitor each 
influencing source region.
    2.8.1.3.4 Within each monitoring planning area, one or more 
required core SLAMS may be exempted by the Regional Administrator. 
This may be appropriate in areas where the highest concentration is 
expected to occur at the same location as the area of maximum or 
sensitive population impact, or areas with low concentrations (e.g., 
highest concentrations are less than 80 percent of the NAAQS). When 
only one core monitor for PM2.5 is included in a MPA or 
optional CMZ, however, a ``category a'' core site is strongly 
preferred to determine community-oriented PM2.5 
concentrations in areas of high average PM2.5 
concentration.
    2.8.1.3.5 More than the minimum number of core SLAMS should be 
deployed as necessary in all MPAs. Except for the core SLAMS 
described in section 2.8.1.3.1 of this Appendix, the additional core 
SLAMS must only comply with the minimum sampling frequency for SLAMS 
specified in Sec. 58.13(e).
    2.8.1.3.6 A subset of the core PM2.5 SLAMS shall be 
designated NAMS as discussed in section 3.7 of this Appendix. The 
selection of core monitoring sites in relation to MPAs and CMZs is 
discussed further in section 2.8.3 of this Appendix.
    2.8.1.3.7 Core monitoring sites shall represent neighborhood or 
larger spatial scales. A monitor that is established in the ambient 
air that is in or near a populated area, and meets appropriate 40 
CFR part 58 criteria (i.e., meets the requirements of Sec. 58.13 and 
Sec. 58.14, Appendices A, C, and E of this part) can be presumed to 
be representative of at least a neighborhood scale, is eligible to 
be called a core site and shall produce data that are eligible for 
comparison to both the 24-hour and annual PM2.5 NAAQS. If 
the site is adjacent to a dominating local source or can be shown to 
have average 24-hour concentrations representative of a smaller 
spatial scale, then the site would only be compared to the 24-hour 
PM2.5 NAAQS.
    2.8.1.3.8 Continuous fine particulate monitoring at core SLAMS. 
At least one continuous fine particulate analyzer (e.g., beta 
attenuation analyzer; tapered-element, oscillating microbalance 
(TEOM); transmissometer; nephelometer; or other acceptable 
continuous fine particulate monitor) shall be located at a core 
monitoring PM2.5 site in each metropolitan area with a 
population greater than 1 million. These analyzers shall be used to 
provide improved temporal resolution to better understand the 
processes and causes of elevated PM2.5 concentrations and 
to facilitate public reporting of PM2.5 air quality and 
will be in accordance with appropriate methodologies and QA/QC 
procedures approved by the Regional Administrator.
    2.8.1.4 Other PM2.5 SLAMS Locations.
    In addition to the required core sites described in section 
2.8.1.3 of this Appendix, the State shall also install and operate 
on an every third day sampling schedule at least one SLAMS to 
monitor for regional background and at least one SLAMS to monitor 
regional transport. These monitoring stations may be at a community-
oriented site and their requirement may be satisfied by a 
corresponding SLAMS monitor in an area having similar air quality in 
another State. The State shall also be required to establish 
additional SLAMS sites based on the total population outside the 
MSA(s) associated with monitoring planning areas that contain 
required core SLAMS. There shall be one such additional SLAMS for 
each 200,000 people. The minimum number of SLAMS may be deployed 
anywhere in the State to satisfy the SLAMS monitoring objectives 
including monitoring of small scale impacts which may not be 
community-oriented or for regional transport as described in section 
1

[[Page 38847]]

of this Appendix. Other SLAMS may also be established and are 
encouraged in a State PM2.5 network.
    2.8.1.5 Additional PM2.5 Analysis Requirements.
    (a) Within 1 year after September 16, 1997, chemical speciation 
will be required at approximately 25 PM2.5 core sites 
collocated at PAMS sites (1 type 2 site per PAMS area) and at 
approximately 25 other core sites for a total of approximately 50 
sites. The selection of these sites will be performed by the 
Administrator in consultation with the Regional Administrator and 
the States. Chemical speciation is encouraged at additional sites. 
At a minimum, chemical speciation to be conducted will include 
analysis for elements, selected anions and cations, and carbon. 
Samples for required speciation will be collected using appropriate 
monitoring methods and sampling schedule in accordance with 
procedures approved by the Administrator.
    (b) Air pollution control agencies shall archive 
PM2.5 filters from all other SLAMS sites for a minimum of 
one year after collection. These filters shall be made available for 
supplemental analyses at the request of EPA or to provide 
information to State and local agencies on the composition for 
PM2.5. The filters shall be archived in accordance with 
procedures approved by the Administrator.
    2.8.1.6 Community Monitoring Zones.
    2.8.1.6.1 The CMZs describe areas within which two or more core 
monitors may be averaged for comparison with the annual 
PM2.5 NAAQS. This averaging approach as specified in 40 
CFR part 50, Appendix N, is directly related to epidemiological 
studies used as the basis for the PM2.5 NAAQS. A CMZ 
should characterize an area of relatively similar annual average air 
quality (i.e., the average concentrations at individual sites shall 
not exceed the spatial average by more than 20 percent) and exhibit 
similar day to day variability (e.g., the monitoring sites should 
not have low correlations, say less than 0.6). Moreover, the entire 
CMZ should principally be affected by the same major emission 
sources of PM2.5 .
    2.8.1.6.2 Each monitoring planning area may have at least one 
CMZ, that may or may not cover the entire MPA. In metropolitan 
statistical areas (MSAs) for which MPAs are required, the CMZs may 
completely cover the entire MSA. When more than one CMZ is described 
within an MPA, CMZs shall not overlap in their geographical 
coverage. All areas in the ambient air may become a CMZ.
    2.8.1.6.3. As PM2.5 networks are first established, 
core sites would be used individually for making comparisons to the 
annual PM2.5 NAAQS. As these networks evolve, individual 
monitors may not be adequate by themselves to characterize the 
annual average community wide air quality. This is especially true 
for areas with sharp gradients in annual average air quality. 
Therefore, CMZs with multiple core SLAMS or other eligible sites as 
described in accordance with section 2.8.1.2 to this Appendix, may 
be established for the purposes of providing improved estimates of 
community wide air quality and for making comparisons to the annual 
NAAQS. This CMZ approach is subject to the constraints of section 
2.8.1.6.1 to this Appendix.
    2.8.1.6.4 The spatial representativeness of individual 
monitoring sites should be considered in the design of the network 
and in establishing the boundaries of CMZs. Communities within the 
MPA with the highest PM2.5 concentrations must have a 
high priority for PM2.5 monitoring. Until a sufficient 
number of monitoring stations or CMZs are established, however, the 
monitored air quality in all parts of the MPA may not be precisely 
known. It would be desirable, however, to design the placement of 
monitors so that those portions of the MPAs without monitors could 
be characterized as having average concentrations less than the 
monitored portions of the network.
    2.8.1.7 Selection of Monitoring Locations Within MPAs or CMZs.
    2.8.1.7.1 Figure 1 of this Appendix illustrates a hypothetical 
monitoring planning area and shows the location of monitors in 
relation to population and areas of poor air quality. Figure 2 of 
this Appendix shows the same hypothetical MPA as Figure 1 of this 
Appendix and illustrates potential community monitoring zones and 
the location of core monitoring sites within them. Figure 3 of this 
Appendix illustrates which sites within the CMZs of the same MPA may 
be used for comparison to the PM2.5 NAAQS.
    2.8.1.7.2 In Figure 1 of this Appendix, a hypothetical 
monitoring planning area is shown representing a typical Eastern US 
urban areas. The ellipses represent zones with relatively high 
population and poor air quality, respectively. Concentration 
isopleths are also depicted. The highest population density is 
indicated by the urban icons, while the area of worst air quality is 
presumed to be near the industrial symbols. The monitoring area 
should have at least one core monitor to represent community wide 
air quality in each sub-area affected by different emission sources. 
Each monitoring planning area with population greater than 500,000 
is required to have at least two core population-oriented monitors 
that will sample everyday (with PAMS areas requiring three) and may 
have as many other core SLAMS, other SLAMS, and SPMs as necessary. 
All SLAMS should generally be population-oriented, while the SPMs 
can focus more on other monitoring objectives, e.g., identifying 
source impacts and the area boundaries with maximum concentration. 
Ca denotes ``category a'' core SLAMS site (community-
oriented site in area of expected maximum concentration); it is 
shown within the populated area and closest to the area with highest 
concentration. Cb denotes a ``category b'' core SLAMS 
site (area of poor air quality with high population density or 
representative of maximum population impact); it is shown in the 
area of poor air quality, closest to highest population density. S 
denotes other SLAMS sites (monitoring for any objective: Max 
concentration, population exposure, source-oriented, background, or 
regional transport or in support of secondary NAAQS). P denotes a 
Special Purpose Monitor (a specialized monitor that, for example, 
may use a non-reference sampler). Finally, note that all SPMs would 
be subject to the 2-year moratorium against data comparison to the 
NAAQS for the first 2 complete calendar years of its operation.
    2.8.1.7.3 A Monitoring Planning Area may have one or more 
community monitoring zones (CMZ) for aggregation of data from 
eligible SLAMS and SPM sites for comparison to the annual NAAQS. The 
planning area has large gradients of average air quality and, as 
shown in Figure 2 may be assigned three CMZs: An industrial zone, a 
downtown central business district (CBD), and a residential area. 
(If there is not a large difference between downtown concentrations 
and other residential areas, a separate CBD zone would not be 
appropriate).

[[Page 38848]]

[GRAPHIC] [TIFF OMITTED] TR18JY97.175


    2.8.1.7.4 Figure 3 of this Appendix illustrates how CMZs and 
PM2.5 monitors might be located in a hypothetical MPA 
typical of a Western State. Western States with more localized 
sources of PM and larger geographic area could require a different 
mix

[[Page 38849]]

of SLAMS and SPM monitors and may need more total monitors. As the 
networks are deployed, the available monitors may not be sufficient 
to completely represent all geographic portions of the Monitoring 
Planning Area. Due to the distribution of pollution and population 
and because of the number and spatial representativeness of 
monitors, the MPAs and CMZs may not cover the entire State.
[GRAPHIC] [TIFF OMITTED] TR18JY97.176

    2.8.1.7.5 Figure 4 of this Appendix shows how the MPAs, CMZs, 
and PM2.5 monitors might be distributed within a 
hypothetical State. Areas of the State included within MPAs are 
shown within heavy solid lines. Two MPAs are illustrated. Areas in 
the State outside the MPAs will also include monitors, but this 
monitoring coverage may be limited. This portion of the State may 
also be represented by CMZs (shown by areas enclosed within dotted 
lines). The monitors that are intended for comparison to the NAAQS 
are indicated by X. Furthermore, eligible monitors within a CMZ 
could be averaged for comparison to the annual NAAQS or examined 
individually for comparison to both NAAQS. Both within the MPAs and 
in the remainder of the State, some special study monitors might not 
satisfy applicable 40 CFR part 58 requirements and will not be 
eligible for comparison to the NAAQS.

[[Page 38850]]

[GRAPHIC] [TIFF OMITTED] TR18JY97.177


    2.8.2 Substitute PM Monitoring Sites.
    2.8.2.1 Section 2.2 of Appendix C of this part describes 
conditions under which TSP samplers can be used as substitutes for 
PM10. This provision is intended to be used when 
PM10 concentrations are expected to be very low and 
substitute TSP samplers can be used to satisfy the minimum number of 
PM10 samplers needed for an adequate PM10 
network.
    2.8.2.2 If data produced by substitute PM samplers exceed the 
concentration levels described in Appendix C of this part, then the 
need for this sampler to be converted to a PM10 or 
PM2.5 sampler, shall be considered in the PM monitoring 
network review. If the State does not believe that a PM10 
or PM2.5 sampler should be sited, the State shall submit 
documentation to EPA as part of its annual PM report to justify this 
decision. If a PM site is not designated as a substitute site in the 
PM monitoring network description, then high concentrations at this 
site would not necessarily cause this site to become a 
PM2.5 or PM10 site, whichever is indicated.
    2.8.2.3 Consistent with Sec. 58.1, combinations of SLAMS 
PM10 or PM2.5 monitors and other monitors may 
occupy the same structure without any mutual effect on the 
regulatory definition of the monitors.
3. Network Design for National Air Monitoring Stations (NAMS).
    *    *    *    *    *
    Category (a): Stations located in area(s) of expected maximum 
concentrations, generally microscale for CO, microscale or middle 
scale for Pb, middle scale or neighborhood scale for population-
oriented particulate matter, urban or regional scale for Regional 
transport PM2.5, neighborhood scale for SO2, and NO2, and 
urban scale for O3.
    *    *    *    *    *
    For each MSA where NAMS are required, both categories of 
monitoring stations must be established. In the case of 
SO2 if only one NAMS is needed, then category (a) must be 
used. The analysis and interpretation of data from NAMS should 
consider the distinction between these types of stations as 
appropriate.
    *    *    *    *    *
    3.7 Particulate Matter Design Criteria for NAMS.
    3.7.1 Table 4 indicates the approximate number of permanent 
stations required in MSAs to characterize national and regional 
PM10 air quality trends and geographical patterns. The 
number of PM10 stations in areas where MSA populations 
exceed 1,000,000 must be in the range from 2 to 10 stations, while 
in low population urban areas, no more than two stations are 
required. A range of monitoring stations is specified in Table 4 
because sources of pollutants and local control efforts can vary 
from one part of the country to another and therefore, some 
flexibility is allowed in selecting the actual number of stations in 
any one locale.
    3.7.2 Through promulgation of the NAAQS for PM2.5, 
the number of PM10 SLAMS is expected to decrease, but 
requirements to maintain PM10 NAMS remain in effect. The 
PM10 NAMS are retained to provide trends data, to support 
national assessments and decisions, and in some cases to continue 
demonstration that a NAAQS for PM10 is maintained as a 
requirement under a State Implementation Plan.
    3.7.3 The PM2.5 NAMS shall be a subset of the core 
PM2.5 SLAMS and other SLAMS intended to monitor for 
regional transport. The PM2.5 NAMS are planned as long-
term monitoring stations concentrated in metropolitan areas. A 
target range of 200 to 300 stations shall be designated nationwide. 
The largest metropolitan areas (those with a population greater than 
approximately one million) shall have at least one PM2.5 
NAMS stations.
    3.7.4 The number of total PM2.5 NAMS per Region will 
be based on recommendations of the EPA Regional Offices, in concert 
with

[[Page 38851]]

their State and local agencies, in accordance with the network 
design goals described in sections 3.7.5 through 3.7.7 of this 
Appendix. The selected stations should represent the range of 
conditions occurring in the Regions and will consider factors such 
as total number or type of sources, ambient concentrations of 
particulate matter, and regional transport.
    3.7.5 The approach for PM2.5 NAMS is intended to give 
State and local agencies maximum flexibility while apportioning a 
limited national network. By advancing a range of monitors per 
Region, EPA intends to balance the national network with respect to 
geographic area and population. Table 5 presents the target number 
of PM2.5 NAMS per Region to meet the national goal of 200 
to 300 stations. These numbers consider a variety of factors such as 
Regional differences in metropolitan population, population density, 
land area, sources of particulate emissions, and the numbers of 
PM10 NAMS.
    3.7.6 States will be required to establish approximately 50 NAMS 
sites for routine chemical speciation of PM2.5. These 
sites will include those collocated at approximately 25 PAMS sites 
and approximately 25 other core SLAMS sites to be selected by the 
Administrator. After 5 years of data collection, the Administrator 
may exempt some sites from collecting speciated data. The number of 
NAMS sites at which speciation will be performed each year and the 
number of samples per year will be determined by the Administrator.
    3.7.7 Since emissions associated with the operation of motor 
vehicles contribute to urban area particulate matter levels, 
consideration of the impact of these sources must be included in the 
design of the NAMS network, particularly in MSAs greater than 
500,000 population. In certain urban areas particulate emissions 
from motor vehicle diesel exhaust currently is or is expected to be 
a significant source of particulate matter ambient levels. The 
actual number of NAMS and their locations must be determined by EPA 
Regional Offices and the State agencies, subject to the approval of 
the Administrator as required by Sec. 58.32. The Administrator's 
approval is necessary to ensure that individual stations conform to 
the NAMS selection criteria and that the network as a whole is 
sufficient in terms of number and location for purposes of national 
analyses.

                             Table 4.--PM10 National Air Monitoring Station Criteria                            
                                    [Approximate Number of Stations per MSA]1                                   
----------------------------------------------------------------------------------------------------------------
                                                                       High           Medium            Low     
                       Population Category                        Concentration2  Concentration3  Concentration4
----------------------------------------------------------------------------------------------------------------
>1,000,000......................................................       6-10                4-8           2-4    
500,000-1,000,000...............................................        4-8                2-4           1-2    
250,000-500,000.................................................        3-4                1-2           0-1    
100,000-250,000.................................................        1-2                0-1             0    
----------------------------------------------------------------------------------------------------------------
1 Selection of urban areas and actual number of stations per area will be jointly determined by EPA and the     
  State agency.                                                                                                 
2 High concentration areas are those for which ambient PM10 data show ambient concentrations exceeding either   
  PM10 NAAQS by 20 percent or more.                                                                             
3 Medium concentration areas are those for which ambient PM10 data show ambient concentrations exceeding 80     
  percent of the PM10 NAAQS.                                                                                    
4 Low concentration areas are those for which ambient PM10 data show ambient concentrations less than 80 percent
  of the PM10 NAAQS.                                                                                            

    3.7.7.1 Selection of urban areas and actual number of stations 
per area will be jointly determined by EPA and the State agency.
    3.7.7.2 High concentration areas are those for which: Ambient 
PM10 data show ambient concentrations exceeding either 
PM10 NAAQS by 20 percent or more.
    3.7.7.3 Medium concentration areas are those for which: Ambient 
PM10 data show ambient concentrations exceeding either 80 
percent of the PM10 NAAQS.
    3.7.7.4 Low concentration areas are those for which: Ambient 
PM10 data show ambient concentrations less than 80 
percent of the PM10 NAAQS.

           Table 5.--Goals for Number of PM2.5 NAMS by Region           
------------------------------------------------------------------------
                                                           Percent of   
            EPA Region                Number of NAMS     National Total 
-------------------------------------------\1\--------------------------
1.................................  15 to 20           6 to 8           
2.................................  20 to 30           8 to 12          
3.................................  20 to 25           8 to 10          
4.................................  35 to 50           14 to 20         
5.................................  35 to 50           14 to 20         
6.................................  25 to 35           10 to 14         
7.................................  10 to 15           4 to 6           
8.................................  10 to 15           4 to 6           
9.................................  25 to 40           10 to 16         
10................................  10 to 15           4 to 6           
                                   -------------------------------------
    Total.........................  205-295            100              
------------------------------------------------------------------------
\1\ Each region will have one to three NAMS having the monitoring of    
  regional transport as a primary objective.                            

    *    *    *    *    *
    4.2 PAMS Monitoring Objectives.
    *    *    *    *    *
    States choosing to submit an individual network description for 
each affected nonattainment area, irrespective of its proximity to 
other affected areas, must fulfill the requirements for isolated 
areas as described in section 4 of this Appendix, as an example, and 
illustrated by Figure 5. States containing areas which experience 
significant impact from long-range transport or are proximate to 
other nonattainment areas (even in other States) should collectively 
submit a network description which contains alternative sites to 
those that would be required for an isolated area. Such a submittal 
should, as a guide, be based on the example provided in Figure 6, 
but must include a demonstration that the design satisfies the 
monitoring data uses and fulfills the PAMS monitoring objectives 
described in sections 4.1 and 4.2 of this Appendix.

[[Page 38852]]

[GRAPHIC] [TIFF OMITTED] TR18JY97.178



[[Page 38853]]

[GRAPHIC] [TIFF OMITTED] TR18JY97.179



[[Page 38854]]

    *    *    *    *    *
    4.4 Minimum Monitoring Network Requirements.
    *    *    *    *    *
    Table 2 * * *

    3See Figure 5.
    *    *    *    *    *
5. Summary.
    Table 6 of this Appendix shows by pollutant, all of the spatial 
scales that are applicable for SLAMS and the required spatial scales 
for NAMS. There may also be some situations, as discussed later in 
Appendix E of this part, where additional scales may be allowed for 
NAMS purposes.

                   Table 6.--Summary of Spatial Scales for SLAMS and Required Scales for NAMS                   
----------------------------------------------------------------------------------------------------------------
                                                          Scales Applicable for SLAMS                           
        Spatial Scale        -----------------------------------------------------------------------------------
                                  SO2         CO          O3          NO2         Pb         PM10        PM2.5  
----------------------------------------------------------------------------------------------------------------
Micro.......................                                                        
Middle......................                                   
Neighborhood................                                   
Urban.......................                                          
Regional....................                                                 
                                                                                                                
                                                                                                                
(6)Scales Required for NAMS                                                                                     
                                                                                                                
Micro.......................                                                      1 
Middle......................                                                             1 
Neighborhood................                                   
Urban.......................                                                             2 
Regional....................                                                                          2  
----------------------------------------------------------------------------------------------------------------
\1\ Only permitted if representative of many such micro-scale environments in a residential district (for middle
  scale, at least two).                                                                                         
\2\ Either urban or regional scale for regional transport sites.                                                

6. References.
    *    *    *    *    *
    18. Watson et al. Guidance for Network Design and Optimum Site 
Exposure for PM2.5 and PM10. Prepared for U.S. 
Environmental Protection Agency, Research Triangle Park, NC.
    o. Appendix E is amended by revising the entry for 8. in the table 
of contents, by revising the heading to section 8., adding a sentence 
at the end of the first paragraph of section 8.1, and in section 8.3 
removing the term ``PM10'' wherever it appears and adding in 
its place ``PM'' to read as follows:
Appendix E--Probe and Monitoring Path Siting Criteria for Ambient Air 
Quality Monitoring
    *    *    *    *    *
    8. Particulate Matter (PM10 and PM2.5)
    *    *    *    *    *
8. Particulate Matter (PM10 and PM2.5).
    8.1 Vertical Placement * * * Although microscale or middle scale 
stations are not the preferred spatial scale for PM2.5 
sites, there are situations where such sites are representative of 
several locations within an area where large segments of the 
population may live or work (e.g., central business district of 
Metropolitan area). In these cases, the sampler inlet for such 
microscale PM2.5 stations must also be 2-7 meters above 
ground level.
    *    *    *    *    *
    p. Appendix F is amended by revising in the table of contents the 
entry for 2.7.3 and adding a new entry for 2.7.4, by redesignating 
section 2.7.3 as section 2.7.4 and adding a new section 2.7.3 to read 
as follows:
Appendix F--Annual SLAMS Air Quality Information
    *    *    *    *    *
    2.7.3 Annual Summary Statistics

    2.7.4 Episode and Other Unscheduled Sampling Data
    *    *    *    *    *
    2.7.3 Annual Summary Statistics. Annual arithmetic mean 
(g/m3) as specified in 40 CFR part 50, Appendix 
N. All daily PM-fine values above the level of the 24-hour PM-fine 
NAAQS and dates of occurrence. Sampling schedule used such as once 
every 6 days, everyday, etc. Number of 24-hour average 
concentrations in ranges:

------------------------------------------------------------------------
                                                              Number of 
                           Range                                Values  
------------------------------------------------------------------------
0 to 15 (g/m\3\)..................................             
16 to 30...................................................             
31 to 50...................................................             
51 to 70...................................................             
71 to 90...................................................             
91 to 110..................................................             
Greater than 110...........................................             
------------------------------------------------------------------------

[FR Doc. 97-18579 Filed 7-17-97; 8:45 am]
BILLING CODE 6560-50-F